Search

Your search keyword '"N'diaye M"' showing total 1,193 results
Start Over "N'diaye M" Language english

Refine your results

more »

more »

more »

more »

more »

more »
1,193 results on '"N'diaye M"'

1. Detecting life outside our solar system with a large high-contrast-imaging mission

Author

Snellen, Ignas A. G., Snik, F., Kenworthy, M., Albrecht, S., Anglada-Escudé, G., Baraffe, I., Baudoz, P., Benz, W., Beuzit, J.-L., Biller, B., Birkby, J. L., Boccaletti, A., van Boekel, R., de Boer, J., Brogi, Matteo, Buchhave, L., Carone, L., Claire, M., Claudi, R., Demory, B.-O., Désert, J.-M., Desidera, S., Gaudi, B. S., Gratton, R., Gillon, M., Grenfell, J. L., Guyon, O., Henning, T., Hinkley, S., Huby, E., Janson, M., Helling, C., Heng, K., Kasper, M., Keller, C. U., Krause, O., Kreidberg, L., Madhusudhan, N., Lagrange, A.-M., Launhardt, R., Lenton, T. M., Lopez-Puertas, M., Maire, A.-L., Mayne, N., Meadows, V., Mennesson, B., Micela, G., Miguel, Y., Milli, J., Min, M., de Mooij, E., Mouillet, D., N’Diaye, M., D’Orazi, V., Palle, E., Pagano, I., Piotto, G., Queloz, D., Rauer, H., Ribas, I., Ruane, G., Selsis, F., Sozzetti, A., Stam, D., Stark, C.C., Vigan, A., and de Visser, Pieter

Published
2022
Full Text
View/download PDF

2. Author Correction: Imaging low-mass planets within the habitable zone of α Centauri

Author

Wagner, K., Boehle, A., Pathak, P., Kasper, M., Arsenault, R., Jakob, G., Käufl, U., Leveratto, S., Maire, A.-L., Pantin, E., Siebenmorgen, R., Zins, G., Absil, O., Ageorges, N., Apai, D., Carlotti, A., Choquet, É., Delacroix, C., Dohlen, K., Duhoux, P., Forsberg, P., Fuenteseca, E., Gutruf, S., Guyon, O., Huby, E., Kampf, D., Karlsson, M., Kervella, P., Kirchbauer, J.-P., Klupar, P., Kolb, J., Mawet, D., N’Diaye, M., de Xivry, G. Orban, Quanz, S. P., Reutlinger, A., Ruane, G., Riquelme, M., Soenke, C., Sterzik, M., Vigan, A., and de Zeeuw, T.

Published
2021
Full Text
View/download PDF

3. Imaging low-mass planets within the habitable zone of α Centauri

Author

Wagner, K., Boehle, A., Pathak, P., Kasper, M., Arsenault, R., Jakob, G., Käufl, U., Leveratto, S., Maire, A.-L., Pantin, E., Siebenmorgen, R., Zins, G., Absil, O., Ageorges, N., Apai, D., Carlotti, A., Choquet, É., Delacroix, C., Dohlen, K., Duhoux, P., Forsberg, P., Fuenteseca, E., Gutruf, S., Guyon, O., Huby, E., Kampf, D., Karlsson, M., Kervella, P., Kirchbauer, J.-P., Klupar, P., Kolb, J., Mawet, D., N’Diaye, M., Orban de Xivry, G., Quanz, S. P., Reutlinger, A., Ruane, G., Riquelme, M., Soenke, C., Sterzik, M., Vigan, A., and de Zeeuw, T.

Published
2021
Full Text
View/download PDF

4. Obesogenic diet induces sex-specific alterations of contextual fear memory and associated hippocampal activity in mice.

Author

N'Diaye M, Ducourneau EG, Bakoyiannis I, Potier M, Lafenetre P, and Ferreira G

Subjects
Animals, Male, Female, Mice, Prefrontal Cortex metabolism, Fear physiology, Hippocampus metabolism, Diet, High-Fat adverse effects, Obesity metabolism, Obesity psychology, Obesity physiopathology, Sex Characteristics, Memory physiology, Mice, Inbred C57BL
Abstract

In addition to metabolic and cardiovascular disorders, obesity is associated with cognitive deficits in humans and animal models. We have previously shown that obesogenic high-fat and sugar diet intake during adolescence (adoHFSD) impairs hippocampus (HPC)-dependent memory in rodents. These results were obtained in males only and it remains to evaluate whether adoHFSD has similar effect in females. Therefore, here, we investigated the effects of adoHFSD consumption on HPC-dependent contextual fear memory and associated brain activation in male and female mice. Exposure to adoHFSD increased fat mass accumulation and glucose levels in both males and females but impaired contextual fear memory only in males. Compared with females, contextual fear conditioning induced higher neuronal activation in the dorsal and ventral HPC (CA1 and CA3 subfields) as well as in the medial prefrontal cortex in males. Also, adoHFSD-fed males showed enhanced c-Fos expression in the dorsal HPC, particularly in the dentate gyrus, and in the basolateral amygdala compared with the other groups. Finally, chemogenetic inactivation of the dorsal HPC rescued adoHFSD-induced memory deficits in males. Our results suggest that males are more vulnerable to the effects of adoHFSD on HPC-dependent aversive memory than females, due to overactivation of the dorsal HPC., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Published
2024
Full Text
View/download PDF

6. Heimdallr, Baldr, and Solarstein: designing the next generation of VLTI instruments in the Asgard suite.

Author

Taras AK, Robertson JG, Allouche F, Courtney-Barrer B, Carter J, Crous F, Cvetojevic N, Ireland M, Lagarde S, Martinache F, McGinness G, N'Diaye M, Robbe-Dubois S, and Tuthill P

Abstract

High angular resolution imaging is an increasingly important capability in contemporary astrophysics. Of particular relevance to emerging fields such as the characterization of exoplanetary systems, imaging at the required spatial scales and contrast levels results in forbidding challenges in the correction of atmospheric phase errors, which in turn drives demanding requirements for precise wavefront sensing. Asgard is the next-generation instrument suite at the European Southern Observatory's Very Large Telescope Interferometer (VLTI), targeting advances in sensitivity, spectral resolution, and nulling interferometry. In this paper, we describe the requirements and designs of three core modules: Heimdallr, a beam combiner for fringe tracking, low order wavefront correction, and visibility science; Baldr, a Zernike wavefront sensor to correct high order atmospheric aberrations; and Solarstein, an alignment and calibration unit. In addition, we draw generalizable insights for designing such system and discuss integration plans.

Published
2024
Full Text
View/download PDF

7. Obesogenic diet induces circuit-specific memory deficits in mice.

Author

Bakoyiannis I, Ducourneau EG, N'diaye M, Fermigier A, Ducroix-Crepy C, Bosch-Bouju C, Coutureau E, Trifilieff P, and Ferreira G

Subjects
Male, Animals, Mice, Hippocampus, Anxiety, Memory Disorders etiology, Diet, High-Fat adverse effects, Obesity etiology
Abstract

Obesity is associated with neurocognitive dysfunction, including memory deficits. This is particularly worrisome when obesity occurs during adolescence, a maturational period for brain structures critical for cognition. In rodent models, we recently reported that memory impairments induced by obesogenic high-fat diet (HFD) intake during the periadolescent period can be reversed by chemogenetic manipulation of the ventral hippocampus (vHPC). Here, we used an intersectional viral approach in HFD-fed male mice to chemogenetically inactivate specific vHPC efferent pathways to nucleus accumbens (NAc) or medial prefrontal cortex (mPFC) during memory tasks. We first demonstrated that HFD enhanced activation of both pathways after training and that our chemogenetic approach was effective in normalizing this activation. Inactivation of the vHPC-NAc pathway rescued HFD-induced deficits in recognition but not location memory. Conversely, inactivation of the vHPC-mPFC pathway restored location but not recognition memory impairments produced by HFD. Either pathway manipulation did not affect exploration or anxiety-like behaviour. These findings suggest that HFD intake throughout adolescence impairs different types of memory through overactivation of specific hippocampal efferent pathways and that targeting these overactive pathways has therapeutic potential., Competing Interests: IB, ED, MN, AF, CD, CB, EC, PT, GF No competing interests declared, (© 2024, Bakoyiannis, Ducourneau et al.)

Published
2024
Full Text
View/download PDF

8. ANDES, the high resolution spectrograph for the ELT:science case, baseline design and path to construction

Author

Marconi, Alessandro, Abreu, M., Adibekyan, V., Alberti, V., Albrecht, S., Alcaniz, J., Aliverti, M., Allende Prieto, C., Alvarado Gómez, J., Amado, P., Amate, M., Andersen, M., Artigau, E., Baker, C., Baldini, V., Balestra, A., Barnes, S., Baron, F., Barros, S., Bauer, S., Beaulieu, M., Bellido-Tirado, O., Benneke, B., Bensby, T., Bergin, E., Biazzo, K., Bik, A., Birkby, J., Blind, N., Boisse, I., Bolmont, E., Bonaglia, M., Bonfils, X., Borsa, F., Brandeker, A., Brandner, W., Broeg, C., Brogi, M., Brousseau, D., Brucalassi, A., Brynnel, J., Buchhave, L., Buscher, D., Cabral, A., Calderone, G., Calvo-Ortega, R., Canto Martins, B., Cantalloube, F., Carbonaro, L., Chauvin, G., Chazelas, B., Cheffot, A.-L., Cheng, Y., Chiavassa, A., Christensen, L., Cirami, R., Cook, N., Cooke, R., Coretti, I., Covino, S., Cowan, N., Cresci, G., Cristiani, S., Cunha Parro, V., Cupani, G., d'Odorico, V., de Castro Leão, I., de Cia, A., de Medeiros, J., Debras, F., Debus, M., Demangeon, O., Dessauges-Zavadsky, M., Di Marcantonio, P., Dionies, F., Doyon, R., Dunn, J., Ehrenreich, D., Faria, J., Feruglio, C., Fisher, M., Fontana, A., Fumagalli, M., Fusco, Thierry, Fynbo, J., Gabella, O., Gaessler, W., Gallo, E., Gao, X., Genolet, L., Genoni, M., Giacobbe, P., Giro, E., Gonçalves, R., Gonzalez, O., González Hernández, J., Gracia Témich, F., Haehnelt, M., Haniff, C., Hatzes, A., Helled, R., Hoeijmakers, H.J., Huke, P., Järvinen, S., Järvinen, A., Kaminski, A., Korn, A., Kouach, D., Kowzan, Grzegorz, Kreidberg, L., Landoni, M., Lanotte, A., Lavail, A., Li, J., Liske, J., Lovis, C., Lucatello, S., Lunney, D., Macintosh, M., Madhusudhan, N., Magrini, L., Maiolino, R., Malo, L., Man, A., Marquart, T., Marques, E., Martins, A., Martins, C., Maslowski, P., Mason, C., Mason, E., Mccracken, R., Mergo, P., Micela, G., Mitchell, T., Mollière, P., Monteiro, M., Montgomery, D., Mordasini, C., Morin, J., Mucciarelli, A., Murphy, M., N'Diaye, M., Neichel, B., Niedzielski, A., Niemczura, E., Nortmann, L., Noterdaeme, P., Nunes, N., Oggioni, L., Oliva, E., Önel, H., Origlia, L., Östlin, G., Palle, E., Papaderos, P., Pariani, G., Peñate Castro, J., Pepe, F., Perreault Levasseur, L., Petit, P., Pino, L., Piqueras, J., Pollo, A., Poppenhaeger, K., Quirrenbach, A., Rauscher, E., Rebolo, R., Redaelli, E., Reffert, S., Reid, D., Reiners, A., Richter, P., Riva, M., Rivoire, S., Rodríguez-López, C., Roederer, I., Romano, D., Rousseau, Sylvain, Rowe, J., Salvadori, S., Santos, N., Santos Diaz, P., Sanz-Forcada, J., Sarajlic, Mirsad, Sauvage, Jean-François, Schäfer, S., Schiavon, R., Schmidt, T., Selmi, C., Sivanandam, S., Sordet, M., Sordo, R., Sortino, F., Sosnowska, D., Sousa, S., Stempels, E., Strassmeier, K., Suárez Mascareño, A., Sulich, A., Sun, X., Tanvir, N.R., Tenegi-Sanginés, F., Thibault, S., Thompson, S., Tozzi, A., Turbet, M., Vallée, P., Varas, R., Venn, K., Véran, J.-P., Verma, A., Viel, M., Wade, G., Waring, C., Weber, M., Weder, J., Wehbe, B., Weingrill, J., Woche, M., Xompero, M., Zackrisson, E., Zanutta, A., Zapatero Osorio, M., Zechmeister, M., Zimara, J., Evans, Christopher J., Bryant, Julia J., Motohara, Kentaro, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, DOTA, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, Laboratoire Univers et Particules de Montpellier (LUPM), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA [Salon], ONERA, Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Agenzia Spaziale Italiana, Fundação para a Ciência e a Tecnologia (Portugal), European Commission, Swedish Research Council, Australian Research Council, European Research Council, and National Science Foundation (US)

Subjects
[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Diffraction limited IFU, fundamental physics, Extremely large telescope, fundamental physic, physics and evolution of galaxies, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], extremely large telescopes, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], physics and evolution of stars, Fibre-fed spcetrograh, Sandage effect, exoplanets, High resolution spectroscopy, infrared spectrographs, stars and planets formation, Variation of physics fundamental constants, ground-based instruments, cosmology, Fundamental physics, Exoplanet atmospheres, Echelle spectrograph, high resolution spectrographs
Abstract

Ground-based and airborne instrumentation for astronomy IX (2022), Montreal, JUL 17-22, 2022.--Proceedings of SPIE - The International Society for Optical Engineering vol. 12184 Article number 1218424.-- Complete list of authors: Marconi, A.; Abreu, M.; Adibekyan, V.; Alberti, V.; Albrecht, S.; Alcaniz, J.; Aliverti, M.; Allende Prieto, C.; Gomez, J. D. Alvarado; Amado, P. J.; Amate, M.; Andersen, M. I.; Artigau, E.; Baker, C.; Baldini, V.; Balestra, A.; Barnes, S. A.; Baron, F.; Barros, S. C. C.; Bauer, S. M.; Beaulieu, M.; Bellido-Tirado, O.; Benneke, B.; Bensby, T.; Bergin, E. A.; Biazzo, K.; Bik, A.; Birkby, J. L.; Blind, N.; Boisse, I.; Bolmont, E.; Bonaglia, M.; Bonfils, X.; Borsa, F.; Brandeker, A.; Brandner, W.; Broeg, C. H.; Brogi, M.; Brousseau, D.; Brucalassi, A.; Brynnel, J.; Buchhave, L. A.; Buscher, D. F.; Cabral, A.; Calderone, G.; Calvo-Ortega, R.; Cantalloube, F.; Canto Martins, B. L.; Carbonaro, L.; Chauvin, G.; Chazelas, B.; Cheffot, A. -L.; Cheng, Y. S.; Chiavassa, A.; Christensen, L.; Cirami, R.; Cook, N. J.; Cooke, R. J.; Coretti, I.; Covino, S.; Cowan, N.; Cresci, G.; Cristiani, S.; Cunha Parro, V.; Cupani, G.; D'Odorico, V.; de Castro Leao, I.; De Cia, A.; De Medeiros, J. R.; Debras, F.; Debus, M.; Demangeon, O.; Dessauges-Zavadsky, M.; Di Marcantonio, P.; Dionies, F.; Doyon, R.; Dunn, J.; Ehrenreich, D.; Faria, J. P.; Feruglio, C.; Fisher, M.; Fontana, A.; Fumagalli, M.; Fusco, T.; Fynbo, J.; Gabella, O.; Gaessler, W.; Gallo, E.; Gao, X.; Genolet, L.; Genoni, M.; Giacobbe, P.; Giro, E.; Goncalves, R. S.; Gonzalez, O. A.; Gonzalez Hernandez, J. I.; Gracia Temich, F.; Haehnelt, M. G.; Haniff, C.; Hatzes, A.; Helled, R.; Hoeijmakers, H. J.; Huke, P.; Jaervinen, A. S.; Jaervinen, S. P.; Kaminski, A.; Korn, A. J.; Kouach, D.; Kowzan, G.; Kreidberg, L.; Landoni, M.; Lanotte, A.; Lavail, A.; Li, J.; Liske, J.; Lovis, C.; Lucatello, S.; Lunney, D.; MacIntosh, M. J.; Madhusudhan, N.; Magrini, L.; Maiolino, R.; Malo, L.; Man, A. W. S.; Marquart, T.; Marques, E. L.; Martins, C. J. A. P.; Martins, A. M.; Maslowski, P.; Mason, E.; Mason, C. A.; McCracken, R. A.; Mergo, P.; Micela, G.; Mitchell, T.; Molliere, P.; Monteiro, M. A.; Montgomery, D.; Mordasini, C.; Morin, J.; Mucciarelli, A.; Murphy, M. T.; N'Diaye, M.; Neichel, B.; Niedzielski, A. T.; Niemczura, E.; Nortmann, L.; Noterdaeme, P.; Nunes, N. J.; Oggioni, L.; Oliva, E.; Onel, H.; Origlia, L.; Ostlin, G.; Palle, E.; Papaderos, P.; Pariani, G.; Penate Castro, J.; Pepe, F.; Levasseur, L. Perreault; Petit, P.; Pino, L.; Piqueras, J.; Pollo, A.; Poppenhaeger, K.; Quirrenbach, A.; Rauscher, E.; Rebolo, R.; Redaelli, E. M. A.; Reffert, S.; Reid, D. T.; Reiners, A.; Richter, P.; Riva, M.; Rivoire, S.; Rodriguez-Lopez, C.; Roederer, I. U.; Romano, D.; Rousseau, S.; Rowe, J.; Salvadori, S.; Sanna, N.; Santos, N. C.; Diaz, P. Santos; Sanz-Forcada, J.; Sarajlic, M.; Sauvage, J. -F.; Schaefer, S.; Schiavon, R. P.; Schmidt, T. M.; Selmi, C.; Sivanandam, S.; Sordet, M.; Sordo, R.; Sortino, F.; Sosnowska, D.; Sousa, S. G.; Stempels, E.; Strassmeier, K. G.; Suarez Mascareno, A.; Sulich, A.; Sun, X.; Tanvir, N. R.; Tenegi-Sangines, F.; Thibault, S.; Thompson, S. J.; Tozzi, A.; Turbet, M.; Vallee, P.; Varas, R.; Venn, K. A.; Veran, J. -P.; Verma, A.; Viel, M.; Wade, G.; Waring, C.; Weber, M.; Weder, J.; Wehbe, B.; Weingrill, J.; Woche, M.; Xompero, M.; Zackrisson, E.; Zanutta, A.; Zapatero Osorio, M. R.; Zechmeister, M.; Zimara, J., The first generation of ELT instruments includes an optical-infrared high resolution spectrograph, indicated as ELT-HIRES and recently christened ANDES (ArmazoNes high Dispersion Echelle Spectrograph). ANDES consists of three fibre-fed spectrographs (UBV, RIZ, YJH) providing a spectral resolution of similar to 100,000 with a minimum simultaneous wavelength coverage of 0.4-1.8 mu m with the goal of extending it to 0.35-2.4 mu m with the addition of a K band spectrograph. It operates both in seeing- and diffraction-limited conditions and the fibre-feeding allows several, interchangeable observing modes including a single conjugated adaptive optics module and a small diffraction-limited integral field unit in the NIR. Its modularity will ensure that ANDES can be placed entirely on the ELT Nasmyth platform, if enough mass and volume is available, or partly in the Coude room. ANDES has a wide range of groundbreaking science cases spanning nearly all areas of research in astrophysics and even fundamental physics. Among the top science cases there are the detection of biosignatures from exoplanet atmospheres, finding the fingerprints of the first generation of stars, tests on the stability of Nature's fundamental couplings, and the direct detection of the cosmic acceleration. The ANDES project is carried forward by a large international consortium, composed of 35 Institutes from 13 countries, forming a team of more than 200 scientists and engineers which represent the majority of the scientific and technical expertise in the field among ESO member states., The Italian effort for ANDES is supported by the Italian National Institute for Astrophysics (INAF). The Portuguese participation is supported by FCT -Fundacao para a Ciencia e a Tecnologia through national funds and by FEDER through COMPETE2020 -Programa Operacional Competitividade e Internacionalizacao by these grants: UID/FIS/04434/2019, UIDB/04434/2020 & UIDP/04434/2020; POCI-01-0145-FEDER-032113 & PTDC/FIS-AST/32113/2017. Swedish participation in the ANDES project is made possible through the national Swedish ELT Instrumentation Consortium (SELTIC), suppored by the Swedish Research Council (VR). CJM acknowledges FCT and POCH/FSE (EC) support through Investigador FCT Contract 2021.01214.CEECIND/CP1658/CT0001. JLB acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under grant agreement No 805445. MTM acknowledges the support of the Australian Research Council through Future Fellowship grant FT180100194 SS acknowledges funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program under grant agreement No 804240. TMS acknowledgment the support from the SNF synergia grant CRSII5-193689 (BLUVES), With funding from the Spanish government through the Severo Ochoa Centre of Excellence accreditation SEV-2017-0709

Published
2022
Full Text
View/download PDF

9. Low-order wavefront control using a Zernike sensor through Lyot coronagraphs for exoplanet imaging: II. Concurrent operation with stroke minimization.

Author

Pourcelot, R., Por, E. H., N'Diaye, M., Benard, H., Brady, G., Canas, L., Carbillet, M., Dohlen, K., Laginja, I., Lugten, J., Noss, J., Perrin, M. D., Petrone, P., Pueyo, L., Redmond, S. F., Sahoo, A., Vigan, A., Will, S. D., and Soummer, R.

Subjects
WAVEFRONT sensors, CORONAGRAPHS, SPACE telescopes, PLANETARY observations, SPECTRAL imaging, EXTRASOLAR planets
Abstract

Context. Wavefront sensing and control (WFSC) will play a key role in improving the stability of future large segmented space telescopes while relaxing the thermo-mechanical constraints on the observatory structure. Coupled with a coronagraph to reject the light of an observed bright star, WFSC enables the generation and stabilisation of a dark hole (DH) in the star image to perform planet observations. Aims. While WFSC traditionally relies on a single wavefront sensor (WFS) input to measure wavefront errors, the next generation of instruments will require several WFSs to address aberrations with different sets of spatial and temporal frequency contents. The multiple measurements produced in such a way will then have to be combined and converted to commands for deformable mirrors to modify the wavefront subsequently. Methods. We asynchronously operate a loop controlling the high-order modes digging a DH and a control loop that uses the rejected light by a Lyot coronagraph with a Zernike wavefront sensor to stabilize the low-order aberrations. Using the HiCAT testbed with a segmented telescope aperture, we implement concurrent operations and quantify the expected cross-talk between the two controllers. We then present experiments that alternate high-order and low-order control loops to identify and estimate their respective contributions. Results. We show an efficient combination of the high-order and low-order control loops, keeping a DH contrast better than 5 × 10-8 over a 30 min experiment and stability improvement by a factor of 1.5. In particular, we show a contrast gain of 1.5 at separations close to the DH inner working angle, thanks to the low-order controller contribution. Conclusions. Concurrently digging a DH and using the light rejected by a Lyot coronagraph to stabilize the wavefront is a promising path towards exoplanet imaging and spectroscopy with future large space observatories. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

10. Translational utility of experimental autoimmune encephalomyelitis: recent developments

Author

Guerreiro-Cacais AO, Laaksonen H, Flytzani S, N’diaye M, Olsson T, and Jagodic M

Subjects
Pathology, RB1-214, Therapeutics. Pharmacology, RM1-950
Abstract

Andre Ortlieb Guerreiro-Cacais, Hannes Laaksonen, Sevasti Flytzani, Marie N'diaye, Tomas Olsson, Maja Jagodic Neuroimmunology Unit, Department of Clinical Neuroscience, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden Abstract: Multiple sclerosis (MS) is a complex autoimmune condition with firmly established genetic and environmental components. Genome-wide association studies (GWAS) have revealed a large number of genetic polymorphisms in the vicinity of, and within, genes that associate to disease. However, the significance of these single-nucleotide polymorphisms in disease and possible mechanisms of action remain, with a few exceptions, to be established. While the animal model for MS, experimental autoimmune encephalomyelitis (EAE), has been instrumental in understanding immunity in general and mechanisms of MS disease in particular, much of the translational information gathered from the model in terms of treatment development (glatiramer acetate and natalizumab) has been extensively summarized. In this review, we would thus like to cover the work done in EAE from a GWAS perspective, highlighting the research that has addressed the role of different GWAS genes and their pathways in EAE pathogenesis. Understanding the contribution of these pathways to disease might allow for the stratification of disease subphenotypes in patients and in turn open the possibility for new and individualized treatment approaches in the future. Keywords: autoimmunity, multiple sclerosis, risk genes, EAE, knockouts, pathways

Published
2015

11. Correction to: Imported falciparum malaria in adults: host- and parasite-related factors associated with severity. The French prospective multicenter PALUREA cohort study

Author

Bruneel, Fabrice, Tubach, Florence, Mira, Jean-Paul, Houze, Sandrine, Gibot, Sebastien, Huisse, Marie-Genevieve, Megarbane, Bruno, Choquet, Christophe, Corne, Philippe, Peytel, Eric, Villers, Daniel, Camus, Christophe, Bouchaud, Olivier, Caumes, Eric, Girard, Pierre-Marie, Simon, Fabrice, Kalloumeh, Antoine, Roy, Carine, Durand, Remy, Le Bras, Jacques, Matheron, Sophie, Wolff, Michel, Mourvillier, B., Aubron, C., Bouadma, L., Regnier, B., d’Ortenzio, E., Matra, R., Bouvet, E., Tourret, J., Dorchies, J., Males, S., Rioux, C., Flicoteaux, R., Yeni, P., Spingler, F., Kargougou, E., Casalino, E., Ollivier, V., Grandchamp, B., Miri, Y., Fresnoy, E., Grelon, F., Asfar, P., Kouatchet, A., Mercat, A., Joly-Guillou, M. L., Kempf, M., Eveillard, M., Daoudal, P., Royer, A., Runge, I., Mathonnet, A., Boulain, T., Bret, L., Hocqueloux, L., Segalin, J. M., Mille, C., Niang, M., Prazuck, T., Fortin, M., Schortgen, F., Brun Buisson, C., Botterel, F., Bretagne, S., Leroy, O., Georges, H., Meybeck, A., Guery, B., Patoz, P., Dhennain, C., Chakarian, D., Azougagh, K., Bonmarchand, G., Abboud, P., Favennec, L., Lemeland, J. F., Petrognani, R., Nau, A., Puidupin, A., Carpentier, J. P., Garnotel, E., Moalic, J. L., Tual, L., Amathieu, R., Dhonneur, G., N’Diaye, M., Jeantils, V., Chassaignon, C., Guillerm, A. L., Riche, D., Javaud, N., Pevirieri, F., Benkel, J., Luis, D., Bon, M. C., Lenoir, G., Bernot, B., Collignon, A., Bemba, D., Poilane, I., Trouillet, J. L., Luyt, C. E., Mirabel, M., Chastre, J., Hochedez, P., Perignon, A., Thellier, M., Danis, M., Faussart, A., Nafziger, J., Gastinne, H., Pichon, N., Ajzenberg, D., Darde, M. L., Jacobs, F., Brivet, F., Veyradier, A., Marfaing-Koka, A., Timsit, J. F., Hammer, L., Maubon, D., Pelloux, H., Pene, F., Charpentier, J., Marque, S., Rousseau, C., Guezennec, P., Troche, G., Bedos, J. P., Eloy, O., Palette, C., Therby, A., Monnier, S., Greder-Bellan, A., Cougot, P., Kuteifan, K., Mootien, Y., Guiot, P., Delarbre, J. M., Kiefer, M. H., Page, B., Vieillard Baron, A., Dunand, J., Loubieres, Y., Ricome, J. L., Peltier, J. Y., Giudicelli, Y., Pelletier, C., Rousseau, J. M., Imbert, P., Rapp, C., Mechai, F., Barruet, R., Debord, T., Pilo, J. E., Cavallo, J. D., Angles, O., Genestal, M., Bretonnière, C., Nicolet, L., Jalin, L., Talarmin, J. P., Grossi, O., Raffi, F., Gay-Andrieu, F., Bompoil, T., Gros, A., Le Tulzo, Y., Revest, M., Fily, F., Chapplain, J. M., Tattevin, P., Michelet, C., Chevrier, S., Guigen, C., Baud, F., Launay, J. M., Gourmel, C., Derouin, F., de Miranda, S., Thiery, G., Legriel, S., Azoulay, E., Schlemmer, B., Colin de Verdieres, N., Lagrange-Xelot, M., Gallien, S., De Castro, N., Pavie, J., Lafaurie, M., Molina, J. M., Sarfati, C., Derouin, F., Jonquet, P., Schved, J. F., Biron, C., Bret, C., Klouche, K., Beraud, P., Cristol, J. P., Gruson, D., Herpe, B., Delacre, M., Castaing, Y., Fialon, P., Vincendeau, P., Vincent, F., Karoubi, P., Cohen, Y., Cordel, H., Prendki, V., Cailhol, J., Abgrall, S., Gros, H., Fantinato, C., Cymbalista, F., Senghor, Y., Memain, N., Thuong, M., Adrie, C., Darques, L., Moret, G., Fraisse, F., Godineau, N., Chaplain, C., Prevel, M., Mary, R. J., Plantefeve, G., Bleichner, G., Mentec, H., Leturdu, F., Hyvernat, H., Bernardin, G., Delaunay, P., Marty, P., Baudel, J. L., Maury, E., Offenstadt, G., Meynard, J. L., Pacanowski, J., Ouazene, Z., Bollens, D., Meyohas, M. C., Fonquerine, L., Belkadi, G., Magne, D., Roux, P., Rusel, L., Ricard, J. D., Dreyfuss, D., Mortier, E., Vinceneux, P., Bloch, M., Galeazzi, G., Charbonneau, P., Duhamel, C., Leclercq, R., Delassus, J. L., Malbec, D., Lusina, D., Broutier, H., Charlier, C., Lanternier, F., Coignard, H., Lortholary, O., Bougnoux, M. E., Consigny, P. H., Simons de Fanti, A., Leguern, A. S., Massin, F., and The PALUREA Study Group

Published
2017
Full Text
View/download PDF

12. Optimisation de l'utilisation des ressources communes dans le bassin arachidier du Sénégal : évaluation ex ante de plans et d'alternatives de gestion durable

Author

Sanogo, D., N'Diaye, M., Badji, M., and Beye, SA.

Subjects
Sylvopastoral system, resources management, local communities, community participation, Senegal, Biotechnology, TP248.13-248.65, Environmental sciences, GE1-350
Abstract

Optimizing the use of common resources in the groundnut basin of Senegal: An ex-ante evaluation of plans and alternatives for sustainable management. The preservation of inter village forestry and pastoral spaces (ESPIVs) is an endogenous initiative, introduced by local communities in the groundnut basin of Senegal, to meet the combined effects of climate change and resource degradation. Located outside crop-growing areas, these community reserves are a source of fodder for livestock and for local transhumance, and they provide additional income for rural populations. The preservation of these ESPIVs is supported by management tools such as the Simple Management Plan (PSG) and the Development and Management Plan (PAG). In some cases, the economic impact of these plans on poverty reduction at the community level is very noticeable. But in other cases, the expectations of the communities are not being met. This article is an ex-ante evaluation of the projected management plans of two ESPIVs in the groundnut basin of Senegal. The results show that simpler management options involving reduced areas would make only a small contribution to local development, even when consolidated with various incitative measures. Management options involving interventions in the infrastructure of vast areas with a high forest-product potential would have a positive impact on the economic surplus of the members of those communities, hence reinforcing possibilities for local development. However, this approach is controversial and simpler management options therefore need to be re-assessed. These simpler options would involve alternatives for revenue generation, such as taxation for access to common land resources by transhumant livestock and the marketing of non-ligneous forest products. This study shows the limits of PSG compared to PAG and proposes alternatives for improved approaches to managing ESPIVs. Thus, the study provides decision-makers with possible negotiating tracks in a situation requiring the sustainable management of common resources within a context of decentralization.

Published
2014

13. MedRes

Author

Gratton, R., Keller, C.U., Diolaiti, E., Baruffolo, A., Bonnefoy, M., D'Orazi, V., Langlois, M., Loupias, M., N'Diaye, M., Pantin, E., Stadler, E., Wildi, F., Beuzit, J.-L., Boccaletti, A., Chauvin, G., Desidera, S., Mouillet, D., Bianco, A., Cascone, E., Cortecchia, F., De Caprio, V., De Rosa, A., Desgrange, C., Frangiamore, M., Landman, R., Lombini, M., Malaguti, G., Mesa, D., Milli, J., Morgante, G., Pichon, T., Schiavone, F., Schreiber, L., Terenzi, L., Zanutta, A., Evans, C.J., Bryant, J.J., Mohohara, K., Evans, C.J., Bryant, J.J., and Mohohara, K.

Published
2022

14. Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor: IV. Temporal stability of non-common path aberrations in VLT/SPHERE.

Author

Vigan, A., Dohlen, K., N'Diaye, M., Cantalloube, F., Girard, J. H., Milli, J., Sauvage, J.-F., Wahhaj, Z., Zins, G., Beuzit, J.-L., Caillat, A., Costille, A., Le Merrer, J., Mouillet, D., and Tourenq, S.

Subjects
SPECKLE interference, ADAPTIVE optics, WAVEFRONT sensors, IMAGE reconstruction, CALIBRATION, DETECTORS
Abstract

Coronagraphic imaging of exoplanets and circumstellar environments using ground-based instruments on large telescopes is intrinsically limited by speckles induced by uncorrected aberrations. These aberrations originate from the imperfect correction of the atmosphere by an extreme adaptive optics system; from static optical defects; or from small opto-mechanical variations due to changes in temperature, pressure, or gravity vector. More than the speckles themselves, the performance of high-contrast imagers is ultimately limited by their temporal stability, since most post-processing techniques rely on difference of images acquired at different points in time. Identifying the origin of the aberrations and the timescales involved is therefore crucial to understanding the fundamental limits of dedicated high-contrast instruments. In previous works we demonstrated the use of a Zernike wavefront sensor called ZELDA for sensing non-common path aberrations (NCPA) in the VLT/SPHERE instrument. We now use ZELDA to investigate the stability of the instrumental aberrations using five long sequences of measurements obtained at high cadence on the internal calibration source. Our study reveals two regimes of decorrelation of the NCPA. The first, with a characteristic timescale of a few seconds and an amplitude of a few nanometers, is induced by a fast internal turbulence within the enclosure. The second is a slow quasi-linear decorrelation on the order of a few 10−3 nmrms s−1 that acts on timescales from minutes to hours. We use coronagraphic image reconstruction to demonstrate that these two NCPA contributions have a measurable impact on differences of images, and that the fast internal turbulence is a dominating term over to the slow linear decorrelation. We also use dedicated sequences where the derotator and atmospheric dispersion compensators emulate a real observation to demonstrate the importance of performing observations symmetric around the meridian, which minimizes speckle decorrelation, and therefore maximizes the sensitivity to point sources in difference of images. [ABSTRACT FROM AUTHOR]

Published
2022
Full Text
View/download PDF

15. Missed Debris Disks of the HST Archive: an Insight of the ALICE Project

Author

Choquet, Elodie, Soummer, R, Perrin, M, Pueyo, L, Hagan, B, Gofas-Salas, E, Chen, C, Golimowski, D, Debes, J, Hines, D.C, Sivaramakrishnan, A, Stark, C, Moro-Martin, A, Wolff, S, Mazoyer, J, N'Diaye, M, Ygouf, M, Greenbaum, A, and Ren, B

Subjects
Lunar And Planetary Science And Exploration, Optics
Published
2016

17. Cored dark-matter profiles in z≃1 star forming galaxies

Author

Bouché, N.F., Bera, S., Krajnović, D., Emsellem, E., Mercier, W., Schaye, J., Epinat, B., Richard, J., Zoutendijk, S.L., Abril-Melgarejo, V., Brinchmann, J., Bacon, R., Contini, T., Boogaard, L., Wisotzki, L., Maseda, M., Steinmetz, M., Siebert, A., Baillié, K., Lagarde, N., Malzac, J., Marquette, J-., N'Diaye, M, Venot, O., and Lagadec E.

Subjects
Galaxies: high-redshift, Galaxies: kinematics and dynamics, Methods, Data analysis, Galaxies: evolution
Published
2021

18. SPHERE+: Imaging young Jupiters down to the snowline

Author

Augereau, J. -C., Baudino, J. -L., Beuzit, J. -L., Bouret, J. -C., Desert, J. -M., Delisle, J. -B., Orazi, V. D, Gonzalez, J. -F., Lagrange, A. -M., Coroller, H. Le, Arena, G. Muro, Diaye, M. N, Sauvage, J. -F., Schmid, H. -M., Boccaletti, A., Chauvin, G., Mouillet, D., Absil, O., Allard, F., Antoniucci, S., Augereau, J.-C, Barge, P., Baruffolo, A., Baudino, J.-L, Baudoz, P., Beaulieu, M., Benisty, M., Beuzit, J.-L, Bianco, A., Biller, B., Bonavita, B., Bonnefoy, M., Bos, S., Bouret, J.-C, Brandner, W., Buchschache, N., Carry, B., Cantalloube, F., Cascone, E., Carlotti, A., Charnay, B., Chiavassa, A., Choquet, E., Clenet, Y., Crida, A., De Boer, J., De Caprio, V., Desidera, S., Desert, J.-M, Delisle, J.-B, Delorme, P., Dohlen, K., Doelman, D., Dominik, C., D'orazi, V, Dougados, C., Douté, S., Fedele, D., Feldt, M., Ferreira, F., Fontanive, C., Fusco, T., Galicher, R., Garufi, A., Gendron, E., Ghedina, A., Ginski, C., Gonzalez, J.-F, Gratadour, D., Gratton, R., Guillot, T., Haffert, S., Hagelberg, J., Henning, T., Huby, E., Janson, M., Kamp, I., Keller, C. U., Kenworthy, M., Kervella, P., Kral, Q., Kuhn, J., Lagadec, E., Laibe, G., Langlois, M., Lagrange, A.-M, Launhardt, R., Leboulleux, L., Le Coroller, H, Causi, G. Li, Loupias, M., Maire, A. L., Marleau, G., Martinache, F., Martinez, P., Mary, D., Mattioli, M., Mazoyer, J., Meheut, H., Ménard, F., Mesa, D., Meunier, N., Miguel, Y., Milli, J., Min, M., Molliere, P., Mordasini, C., Moretto, G., Mugnier, L., Muro Arena, G, Nardetto, N., N'Diaye, M, Nesvadba, N., Pedichini, F., Pinilla, P., Por, E., Potier, A., Quanz, S., Rameau, J., Roelfsema, R., Rouan, D., Rigliaco, E., Salasnich, B., Samland, M., Sauvage, J.-F, Schmid, H.-M, Segransan, D., Snellen, I., Snik, F., Soulez, F., Stadler, E., Stam, D., Tallon, M., Thebault, P., Thiebaut, E., Tschudi, C., Udry, S., van Holstein, R., Vernazza, P, Vidal, F., Vigan, A., Waters, R., Wildi, F., Willson, M., Zanutta, A., Zavagno, Annie, Zurlo, A., Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Cte d’Azur, 96 Boulevard de l’Observatoire, Nice, 06300, France, Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Département de Recherche sur la Fusion Contrôlée (DRFC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Department of Biochemistry and Molecular Biology, Mayo Clinic, Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), DOTA, ONERA, Université Paris Saclay [Châtillon], ONERA-Université Paris-Saclay, Université Côte d'Azur (UCA), University of Arizona, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institute of Astronomy [ETH Zürich], Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), NOVA Optical Infrared Instrumentation Group, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève = University of Geneva (UNIGE), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), Croissance et propriétés de systèmes hybrides en couches minces (INSP-E8), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Unité de recherche d'Économie et Sociologie Rurales (ESR), Institut National de la Recherche Agronomique (INRA), INAF - Osservatorio Astronomico di Roma (OAR), Universität Greifswald - University of Greifswald, European Southern Observatory [Santiago] (ESO), Immunopathologie et chimie thérapeutique (ICT), Institut de biologie moléculaire et cellulaire (IBMC), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute for Astronomy [Edinburgh] (IfA), University of Edinburgh, INAF - Osservatorio Astronomico di Capodimonte (OAC), Hôpital Cochin [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astrofisico di Arcetri (OAA), DOTA, ONERA, Université Paris Saclay [Palaiseau], Department of Astronomy, Stockholm University, Kapteyn Astronomical Institute [Groningen], University of Groningen [Groningen], Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Sterrewacht Leiden, Astrophysique Relativiste Théories Expériences Métrologie Instrumentation Signaux (ARTEMIS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), and Universiteit Leiden

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

SPHERE (Beuzit et al,. 2019) has now been in operation at the VLT for more than 5 years, demonstrating a high level of performance. SPHERE has produced outstanding results using a variety of operating modes, primarily in the field of direct imaging of exoplanetary systems, focusing on exoplanets as point sources and circumstellar disks as extended objects. The achievements obtained thus far with SPHERE (~200 refereed publications) in different areas (exoplanets, disks, solar system, stellar physics...) have motivated a large consortium to propose an even more ambitious set of science cases, and its corresponding technical implementation in the form of an upgrade. The SPHERE+ project capitalizes on the expertise and lessons learned from SPHERE to push high contrast imaging performance to its limits on the VLT 8m-telescope. The scientific program of SPHERE+ described in this document will open a new and compelling scientific window for the upcoming decade in strong synergy with ground-based facilities (VLT/I, ELT, ALMA, and SKA) and space missions (Gaia, JWST, PLATO and WFIRST). While SPHERE has sampled the outer parts of planetary systems beyond a few tens of AU, SPHERE+ will dig into the inner regions around stars to reveal and characterize by mean of spectroscopy the giant planet population down to the snow line. Building on SPHERE's scientific heritage and resounding success, SPHERE+ will be a dedicated survey instrument which will strengthen the leadership of ESO and the European community in the very competitive field of direct imaging of exoplanetary systems. With enhanced capabilities, it will enable an even broader diversity of science cases including the study of the solar system, the birth and death of stars and the exploration of the inner regions of active galactic nuclei., White paper submitted to ESO on Feb. 20th, 2020

Published
2020

20. MICADO, the ELT first-light imager

Author

Matteo, P.D., Creevey, O., Crida, A., Kordopatis, G., Malzas, J., Marquette, J.-B., N'Diaye, M., Venot, O., and Astronomy

Subjects
ELT, observing modes, MCAO, MICADO, SCAO, science cases
Abstract

The MICADO instrument is the first light imager of the European ELT. It will work in the near-infrared (0.8-2.4 μm), over a large field (up to 50") and high sensitivity (similar to JWST). MICADO will benefit from two modes of adaptive optics correction: a MCAO correction, uniform on the field of MICADO and developed by the MAORY consortium, and a classic correction of the SCAO type, with high performance in the direction of the star guide and developed under the responsibility of the MICADO consortium. In a phased approach of the integration of adaptive optics to the ELT, MICADO will first be operational in SCAO mode. Offering four observing modes (imaging mode, astrometry, long-slit spectroscopy with R̃20000 and high contrast imaging), MICADO aims to scan a wide range of scientific objectives: small bodies and planets of the solar system, exoplanets and exo-disks, stellar populations in distant galaxies, black holes and the center of our galaxy, evolution and dynamics of galaxies.

Published
2019

21. High-fidelity Imaging of the Inner AU Mic Debris Disk: Evidence of Differential Wind Sculpting?

Author

Molaverdikhani, K., Trifonov, T., Mollière, P., Frankel, N., Messina, S., Biller, B. A., Roux, A., Damasso, M., Del Sordo, F., Brandner, W., Kervella, P., Mugnier, L., Romero, C., Sozzetti, A., Antichi, J., Huby, E., N’Diaye, M., Kitzmann, D., Tang, Y. W., Habart, E., Beck, T. L., Potier, A., Singh, G., Di Folco, E., Péricaud, J., Dutrey, A., Chapillon, E., Guilloteau, S., Piétu, V., Pawellek, N., Brown, S., Buey, T., Moeller-Nilsson, O., Stolker, T., Hunziker, S., Abe, L., Avenhaus, H., Baruffolo, A., Bazzon, A., Costille, A., Daban, J.-B., Downing, M., Engler, N., Gisler, D., Hubin, N., Puget, P., Quanz, S. P., Roelfsema, R., Salasnich, B., Siebenmorgen, R., Suarez, M., Szulágyi, J., Thalmann, Ch., Pohl, A., Fantinel, D., Maurel, D., Origné, A., Petit, C., Rigal, F., Girard, J. H., Mouillet, D., Dohlen, K., Snik, F., Keller, C. U., Ginski, C., Stam, D. M., Wahhaj, Z., Kasper, M., Schmid, H. M., Perret, D., Dominik, C., Turatto, M., Beuzit, J.-L., Keppler, M., Rodet, L., Charnay, B., Bae, J., De Boer, J., Müller, A., Pairet, B., Antoniucci, S., Brown Sevilla, S., Cascone, E., Claudi, R. U., Lagadec, E., Martinez, P., Meunier, N., Petrus, S., Pinte, C., Rochat, S., Sauvage, J.-F., Peretti, S., Ségransan, D., Lavie, B., Baudino, J.-L., Janson, M., Heng, Kevin, Udry, S., Daemgen, S., Le Coroller, H., Samland, M., Carbillet, M., Carle, M., Hugot, E., Magnard, Y., Moulin, T., Pavlov, A., Pragt, J., Rabou, P., Rousset, G., Sevin, A., Soenke, C., Stadler, E., Weber, L., Wildi, F., Bhowmik, T., Thébault, P., Kral, Q., Mazoyer, J., van Holstein, R. G., Baudoz, P., Galicher, R., Olofsson, J., Pantin, E., Perrot, C., Mesa, D., Langlois, M., Garufi, A., Gratton, R., Desidera, S., D'Orazi, V., Flasseur, O., Barbieri, M., Benisty, M., Henning, Th., Ligi, R., Sissa, E., Vigan, A., Zurlo, A., Bonnefoy, M., Cantalloube, F., Chauvin, G., Cheetham, A. C., De Caprio, V., Delorme, P., Feldt, M., Fusco, T., Gluck, L., Hagelberg, J., Lazzoni, C., Madec, F., Maire, A.-L., Ménard, F., Meyer, M. R., Ramos, J., Rickman, E. L., Rouan, D., Schmidt, T., van der Plas, G., D’Orazi, V., De Caprio, V, Van der Plas, G, Wisniewski, John P., Kowalski, Adam F., Davenport, James R. A., Schneider, Glenn, Grady, Carol A., Hebb, Leslie, Lawson, Kellen D., Augereau, Jean-Charles, Boccaletti, A., Brown, Alexander, Debes, John H., Gaspar, Andras, Henning, Thomas K., Hines, Dean C., Kuchner, Marc J., Lagrange, Anne-Marie, Milli, Julien, Sezestre, Elie, Stark, Christopher C., Thalmann, Christian, Wisniewski, John, Kowalski, Adam, Davenport, James, Grady, Carol, Lawson, Kellen, Debes, John, Henning, Thomas, Hines, Dean, Kuchner, Marc, Stark, Christopher, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
planets and satellites: detection, 010504 meteorology & atmospheric sciences, planets and satellites: dynamical evolution and stability, stars: individual: HD 117214, stars: individual: AB Aur, techniques: image processing, Astrophysics, M dwarf stars, 01 natural sciences, stars: individual: HD 19467, accretion, Debris disks, Astrophysics::Solar and Stellar Astrophysics, infrared: planetary systems, 010303 astronomy & astrophysics, instrumentation: spectrographs, Physics, Earth and Planetary Astrophysics (astro-ph.EP), planets and satellites: atmospheres, [PHYS]Physics [physics], planet-disk interactions, accretion disks, stars: individual: HD 32297, protoplanetary disks, stars: individual: Proxima, Exoplanet, Astrophysics - Solar and Stellar Astrophysics, binaries: general, techniques: imaging spectroscopy, techniques: interferometric, stars individual: HIP 65875, planets and satellites: individual: Proxima c, Astrophysics::Earth and Planetary Astrophysics, methods: observational, radio lines: stars, binaries: spectroscopic, brown dwarfs, (stars:) planetary systems, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Brown dwarf, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, stars: pre-main sequence, instrumentation: adaptive optics, planets and satellites: terrestrial planets, stars: individual: PDS70, instrumentation: high angular resolution, 0103 physical sciences, planetary systems, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Debris disk, polarization, HD 163296, Stellar rotation, Starspot, techniques: high angular resolution, Astronomy and Astrophysics, Planetary system, methods: data analysis, binaries: visual, Starspots, techniques: polarimetric, Polar wind, Space and Planetary Science, Circumstellar disks, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Heliosphere, Astrophysics - Earth and Planetary Astrophysics
Abstract

The Astrophysical Journal Letters, 883 (1), ISSN:1967-2014, ISSN:2041-8213

Published
2019
Full Text
View/download PDF

22. Recovering saturated images for high dynamic kernel-phase analysis

Author

Laugier, R., Martinache, F., Ceau, A., Mary, D., N'diaye, Mamadou, Beuzit, J. -L., N’Diaye, M., Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France., Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Joseph Louis LAGRANGE (LAGRANGE), Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)

Subjects
[PHYS]Physics [physics], [SDU]Sciences of the Universe [physics]
Abstract

International audience; Kernel-phase observables extracted from mid- to high-Strehl images are proving to be a powerful tool to probe within a few angular resolution elements of point sources. The attainable contrast is however limited by the dynamic range of the imaging sensors. The Fourier interpretation of images with pixels exposed beyond the saturation has so far been avoided. We show that in cases where the image is dominated by the light of a point source, we can use an interpolation to reconstruct the otherwise lost pixels with an accuracy sufficient to enable the extraction of kernel-phases from the patched image. We demonstrate the usability of our method by applying it to archive images of the Gl 494AB system, taken with the Hubble Space Telescope in 1997. Using this new data point along with other resolved observations and radial velocity measurements, we produce improved constraints on the orbital parameters of the system, and consequently the masses of its components.

Published
2019
Full Text
View/download PDF

23. Atmospheric characterization of terrestrial exoplanets in the mid-infrared: biosignatures, habitability & diversity

Author

Quanz, S.P., Absil, O., Angerhausen, D., Benz, W., Bonfils, X., Berger, J.-P., Brogi, M., Cabrera, J., Danchi, W.C., Defrère, D., Dishoeck, E.F. van, Ehrenreich, D., Ertel, S., Fortney, J., Gaudi, S., Girard, J., Glauser, A., Grenfell, J.L., Ireland, M., Janson, M., Kammerer, J., Kitzmann, D., Kraus, S., Krause, O., Labadie, L., Lacour, S., Lichtenberg, T., Line, M., Linz, H., Loicq, J., Mennesson, B., Meyer, M.R., Miguel, Y., Monnier, J., N'Diaye, M., Pallé, E., Queloz, D., Rauer, H., Ribas, I., Rugheimer, S., Selsis, F., Serabyn, G., Snellen, I.A.G., Sozzetti, A., Stapelfeldt, K.R., Triaud, A., Udry, S., and Wyatt, M.

Abstract

Exoplanet science is one of the most thriving fields of modern astrophysics. A major goal is the atmospheric characterization of dozens of small, terrestrial exoplanets in order to search for signatures in their atmospheres that indicate biological activity, assess their ability to provide conditions for life as we know it, and investigate their expected atmospheric diversity. None of the currently adopted projects or missions, from ground or in space, can address these goals. In this White Paper we argue that a large space-based mission designed to detect and investigate thermal emission spectra of terrestrial exoplanets in the MIR wavelength range provides unique scientific potential to address these goals and surpasses the capabilities of other approaches. While NASA might be focusing on large missions that aim to detect terrestrial planets in reflected light, ESA has the opportunity to take leadership and spearhead the development of a large MIR exoplanet mission within the scope of the "Voyage 2050" long-term plan establishing Europe at the forefront of exoplanet science for decades to come. Given the ambitious science goals of such a mission, additional international partners might be interested in participating and contributing to a roadmap that, in the long run, leads to a successful implementation. A new, dedicated development program funded by ESA to help reduce development and implementation cost and further push some of the required key technologies would be a first important step in this direction. Ultimately, a large MIR exoplanet imaging mission will be needed to help answer one of mankind's most fundamental questions: "How unique is our Earth?"

Published
2019

24. ESA Voyage 2050 White Paper: Detecting life outside our solar system with a large high-contrast-imaging mission

Author

Snellen, I.A.G., Albrecht, S., Anglada-Escude, G., Baraffe, I., Baudoz, P., Benz, W., Beuzit, J.-L., Biller, B., Birkby, J., Boccaletti, A., Boekel, R. van, Boer, J. de, Brogi, M., Buchhave, L., Carone, L., Claire, M., Claudi, R., Demory, B.-O., Desert, J.-M., Desidera, S., Gaudi, S., Gratton, R., Gillon, M., Grenfell, J.L., Guyon, O., Henning, T., Hinkley, S., Ruby, E., Janson, M., Helling, C., Heng, K., Kasper, M., Keller, C.U., Kenworthy, M.A., Krause, O., Kreidberg, L., Madhusudhan, N., Lagrange, A.-M., Launhardt, R., Lenton, T., Lopez-Puertas, M., Maire, A.-L., Mayne, N., Meadows, V., Mennesson, B., Micela, G., Miguel, Y., Milli, J., Min, M., Mooij, E. de, Mouillet, D., N'Diaye, M., D'Orazi, V., Palle, E., Pagano, I., Piotto, G., Queloz, D., Rauer, H., Ribas, I., Ruane, G., Selsis, F., Snik, F., Sozzetti, A., Stam, D., Stark, C., Vigan, A., and Visser, P. de

Abstract

In this white paper, we recommend the European Space Agency plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as currently under study by NASA. Such a mission will be needed to characterize a sizable sample of temperate Earth-like planets in the habitable zones of nearby Sun-like stars and to search for extraterrestrial biological activity. We provide an overview of relevant European expertise, and advocate ESA to start a technology development program towards detecting life outside the Solar system.

Published
2019

25. Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor: III. On-sky validation in VLT/SPHERE.

Author

Vigan, A., N'Diaye, M., Dohlen, K., Sauvage, J.-F., Milli, J., Zins, G., Petit, C., Wahhaj, Z., Cantalloube, F., Caillat, A., Costille, A., Le Merrer, J., Carlotti, A., Beuzit, J.-L., and Mouillet, D.

Subjects
ADAPTIVE optics, WAVEFRONT sensors, ANGULAR distance, IMAGE reconstruction, LIGHT sources, FACTORIALS
Abstract

Second-generation exoplanet imagers using extreme adaptive optics (ExAO) and coronagraphy have demonstrated their great potential for studying close circumstellar environments and for detecting new companions and helping to understand their physical properties. However, at very small angular separation, their performance in contrast is limited by several factors: diffraction by the complex telescope pupil (central obscuration and spiders) not perfectly canceled by the coronagraph, residual dynamic wavefront errors, chromatic wavefront errors, and wavefront errors resulting from noncommon path aberrations (NCPAs). These latter are differential aberrations between the visible wavefront sensing path of the ExAO system and the near-infrared science path in which the coronagraph is located. In a previous work, we demonstrated the use of a Zernike wavefront sensor called ZELDA for sensing NCPAs in the VLT/SPHERE exoplanet imager and their compensation with the high-order deformable mirror of the instrument. These early tests on the internal light source led to encouraging results for the attenuation of the quasi-static speckles at very small separation. In the present work, we move to the next step with the on-sky validation of NCPA compensation with ZELDA. With an improved procedure for the compensation of NCPAs, we start by reproducing previous results on the internal source. We show that the amount of aberration integrated between 1 and 15 cycles/pupil (c/p) is decreased by a factor of approximately five, which translates into a gain in raw contrast of between 2 and 3 at separations below 300 mas. On sky, we demonstrate that NCPA compensation works in closed loop, leading to an attenuation of the amount of aberration by a factor of approximately two. However, we identify a loss of sensitivity for the sensor that is only partly explained by the difference in Strehl ratio between the internal and on-sky measurements. Our simulations show that the impact of ExAO residuals on ZELDA measurements is negligible for integration times beyond a few tenths of a second. Coronagraphic imaging on sky is improved in raw contrast by a factor of 2.5 at most in the ExAO-corrected region. We use coronagraphic image reconstruction based on a detailed model of the instrument to demonstrate that both internal and on-sky raw contrasts can be precisely explained, and we establish that the observed performance after NCPA compensation is no longer limited by an improper compensation for aberration but by the current apodized-pupil Lyot coronagraph design. We finally conclude that a coronagraph upgrade combined to a proper NCPA compensation scheme could easily bring a gain in raw contrast of a factor of two to three below 200 mas. [ABSTRACT FROM AUTHOR]

Published
2019
Full Text
View/download PDF

27. Fine cophasing of segmented aperture telescopes with ZELDA, a Zernike wavefront sensor in the diffraction-limited regime

Author

N'diaye, Mamadou, Janin-Potiron, P., N’Diaye, M., Martinez, P., Vigan, A., Dohlen, K., Carbillet, M., Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), European Project: 683029 ,KERNEL, Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France., Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015 - 2019) (COMUE UCA), and Université Nice Sophia Antipolis (... - 2019) (UNS)

Subjects
[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Aperture, Zernike polynomials, ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION, FOS: Physical sciences, Astrophysics, 01 natural sciences, 010309 optics, symbols.namesake, Optics, High angular resolution, 0103 physical sciences, Piston (optics), Adaptive optics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), ComputingMilieux_MISCELLANEOUS, Physics, Wavefront, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Wavefront sensor, Cophasing, Tilt (optics), Space and Planetary Science, [SDU]Sciences of the Universe [physics], Computer Science::Computer Vision and Pattern Recognition, symbols, business, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract

Segmented aperture telescopes require an alignment procedure with successive steps from coarse alignment to monitoring process in order to provide very high optical quality images for stringent science operations such as exoplanet imaging. The final step, referred to as fine phasing, calls for a high sensitivity wavefront sensing and control system in a diffraction-limited regime to achieve segment alignment with nanometric accuracy. In this context, Zernike wavefront sensors represent promising options for such a calibration. A concept called the Zernike unit for segment phasing (ZEUS) was previously developed for ground-based applications to operate under seeing-limited images. Such a concept is, however, not suitable for fine cophasing with diffraction-limited images. We revisit ZELDA, a Zernike sensor that was developed for the measurement of residual aberrations in exoplanet direct imagers, to measure segment piston, tip, and tilt in the diffraction-limited regime. We introduce a novel analysis scheme of the sensor signal that relies on piston, tip, and tilt estimators for each segment, and provide probabilistic insights to predict the success of a closed-loop correction as a function of the initial wavefront error. The sensor unambiguously and simultaneously retrieves segment piston and tip-tilt misalignment. Our scheme allows for correction of these errors in closed-loop operation down to nearly zero residuals in a few iterations. This sensor also shows low sensitivity to misalignment of its parts and high ability for operation with a relatively bright natural guide star. Our cophasing sensor relies on existing mask technologies that make the concept already available for segmented apertures in future space missions., 11 pages, 10 figures. Accepted for publication in A&A - sec. 13

Published
2017
Full Text
View/download PDF

29. ZELDA, a Zernike wavefront sensor for the fine measurement of quasi-static aberrations in coronagraphic systems: concept studies and results with VLT/SPHERE

Author

N'Diaye, M., Vigan, Arthur, Dohlen, K., Sauvage, J.-F., Caillat, A., Costille, A., Girard, J. H. V., Beuzit, J.-L., Fusco, T., Blanchard, P., Le merrer, J., Le Mignant, D., Madec, F., Moreaux, G., Mouillet, D., Puget, P., Zins, G., Marchetti, Enrico, Close, Laird, Véran, Jean-Pierre, Space Telescope Science Institute (STSci), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Chimie, Ingénierie Moléculaire et Matériaux d'Angers (CIMMA), Université d'Angers (UA)-Centre National de la Recherche Scientifique (CNRS), NRC Herzberg Institute of Astrophysics, and National Research Council of Canada (NRC)

Subjects
Physics, Wavefront, Zernike polynomials, business.industry, Brown dwarf, Astrophysics::Instrumentation and Methods for Astrophysics, Wavefront sensor, 01 natural sciences, Exoplanet, Deformable mirror, 010309 optics, symbols.namesake, Optics, Planet, 0103 physical sciences, symbols, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, Adaptive optics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract

International audience; The high-contrast imaging instruments VLT/SPHERE and GPI have been routinely observing gas giant planets, brown dwarfs, and debris disks around nearby stars since 2013-2014. In these facilities, low-wind effects or differential aberrations between the extreme Adaptive Optics sensing path and the science path represent critical limitations for the observation of exoplanets orbiting their host star with a contrast ratio larger than 106 at small separations. To circumvent this problem, we proposed ZELDA, a Zernike wavefront sensor to measure these quasistatic aberrations at a nanometric level. A prototype was installed on VLT/SPHERE during its integration in Chile. We recently performed measurements on an internal source with ZELDA in the presence of Zernike or Fourier modes introduced with the deformable mirror of the instrument. In this communication, we present the results of our experiment and report on the contrast gain obtained with a first ZELDA-based wavefront correction. We finally discuss the suitability of such a solution for a possible upgrade of VLT/SPHERE and for its use with future E-ELT instruments or space missions with high-contrast capabilities (e.g. WFIRST-AFTA, HDST).

Published
2016
Full Text
View/download PDF

30. Stop-less Lyot coronagraph for exoplanet characterization: first on-sky validation in VLT/SPHERE

Author

Vigan, Arthur, N'Diaye, M., Dohlen, K., Beuzit, J.-L., Costille, A., Caillat, A., Baruffolo, A., Blanchard, P., Carle, M., Ferrari, M., Fusco, T., Gluck, L., Hugot, E., Jaquet, M., Langlois, M., Le Mignant, D., Llored, M., Madec, F., Mouillet, D., Origné, A., Puget, P., Salasnich, B., Sauvage, J.-F., Navarro, Ramon, Burge, James, Sauvage, F., Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Space Telescope Science Institute (STSci), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Chimie, Ingénierie Moléculaire et Matériaux d'Angers (CIMMA), Université d'Angers (UA)-Centre National de la Recherche Scientifique (CNRS), Caratterizzazione e Sviluppo di Materiali per la Fotonica e l'Optoelecttronica (CSMFO), CNR Istituto di Fotonica e Nanotecnologie [Trento] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR)-Consiglio Nazionale delle Ricerche [Roma] (CNR), Netherlands Institute for Radio Astronomy (ASTRON), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)-National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie, Ingénierie Moléculaire et Matériaux d'Angers (CIMMA), Centre National de la Recherche Scientifique (CNRS)-Université d'Angers (UA), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), ITA, USA, and FRA

Subjects
Physics, Lyot stop, business.industry, media_common.quotation_subject, Phase (waves), 01 natural sciences, Exoplanet, law.invention, 010309 optics, Speckle pattern, Optics, Apodization, law, Sky, 0103 physical sciences, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Coronagraph, Long-slit spectroscopy, media_common
Abstract

International audience; The VLT/SPHERE instrument includes a unique long-slit spectroscopy (LSS) mode coupled with Lyot coronagraphy dedicated to the spectral characterization of directly imaged giant exoplanets. The performance of this mode is limited by its non-optimal coronagraph, but in a previous work we demonstrated that it could be significantly improved at small inner-working angles using the stop-less Lyot coronagraph (SLLC). A prototype of the SLLC was installed in VLT/SPHERE in 2014 during the reintegration of the instrument in Paranal, and it was extensively tested in 2015 to characterize its performance. The performance is tested in both imaging and spectroscopy using data acquired on the internal source of SPHERE. In imaging, we obtain a raw contrast gain of a factor 10 at 0.3" with the SLLC. We also demonstrate that no Lyot stop is required to reach the full performance, which validates the SLLC concept. Comparison with a realistic simulation model shows that we are currently limited by the internal phase aberrations of SPHERE. In spectroscopy, we obtain a gain of 1 mag in a limited range of angular separations. Simulations show that although the main limitation comes from phase errors, the performance in the non-SLLC case is very close to the ultimate limit of the LSS mode. We present the very first on-sky data with the SLLC, which appear extremely promising for the future scientific exploitation of an apodized LSS mode in SPHERE. Finally, we explore a new possibility for the speckle subtraction in the LSS mode that could significantly improve the data analysis with respect to methods based on spectral differences.

Published
2016
Full Text
View/download PDF

31. SAXO, the SPHERE extreme AO system: on-sky final performance and future improvements

Author

Fusco, T., Sauvage, J.-F., Mouillet, D., Costille, A., Petit, C., Beuzit, J.-L., Dohlen, K., Milli, J., Girard, J., Kasper, M., Vigan, Arthur, Suarez, M., Soenke, C., Downing, M., N'Diaye, M., Baudoz, P., Sevin, A., Baruffolo, A., Schmid, H.-M., Salasnich, B., Hugot, E., Hubin, N., Marchetti, Enrico, Close, Laird, Véran, Jean-Pierre, Schmid, M., Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'Astrophysique de Grenoble (LAOG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Southern Observatory (ESO), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM), ESO, Physics Department [Garching], Technical University of Munich (TUM)-Technical University of Munich (TUM), Space Telescope Science Institute (STSci), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Anthropologie Moléculaire et Imagerie de Synthèse (AMIS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), NRC Herzberg Institute of Astrophysics, National Research Council of Canada (NRC), ITA, USA, FRA, DEU, CHE, Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM)-Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées

Subjects
High Contrast Imaging, media_common.quotation_subject, Polarimetry, 01 natural sciences, 7. Clean energy, law.invention, 010309 optics, Telescope, Optics, law, 0103 physical sciences, Adaptive optics, 010303 astronomy & astrophysics, Coronagraph, Instrumentation: Adaptive Optics, media_common, Wavefront, Scientific instrument, Physics, business.industry, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Exoplanet, 13. Climate action, Sky, Astrophysics::Earth and Planetary Astrophysics, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience; The SPHERE (Spectro-Polarimetric High-contrast Exoplanet Research) instrument aims at detecting extremely faint sources (giant extrasolar planets) in the vicinity of bright stars1. Such a challenging goal requires the use of a very-high-order performance Adaptive Optics [AO] system feeding the scientific instruments with a quasi-perfect flat wave front corrected from all the atmospheric turbulence and internal defects. This AO system, called SAXO (Sphere Ao for eXoplanet Observation) is the heart of the instrument, a heart beating 1200 time per second and providing unprecedented image quality for a large ground based telescope at optical/near infrared wavelength. We will present the latest results obtained on-sky, demonstrating its exceptional performance (in terms of correction quality, stability and robustness) and tremendous potentiality for high contrast imaging and more specifically for exoplanet discovery.

Published
2016
Full Text
View/download PDF

32. Characterisation of a turbulent module for the MITHIC high-contrast imaging testbed

Author

Vigan, Arthur, Postnikova, M., Caillat, A., Sauvage, J.-F., Dohlen, K., El Hadi, K., Fusco, T., Lamb, M., N'Diaye, M., Marchetti, Enrico, Close, Laird, Véran, Jean-Pierre, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Space Telescope Science Institute (STSci), NRC Herzberg Institute of Astrophysics, and National Research Council of Canada (NRC)

Subjects
Wavefront, Continuous phase modulation, business.industry, Zernike polynomials, Computer science, Testbed, Phase (waves), Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, 01 natural sciences, 010309 optics, symbols.namesake, Optics, 0103 physical sciences, symbols, Segmentation, business, Astrophysics - Instrumentation and Methods for Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

Future high-contrast imagers on ground-based extremely large telescopes will have to deal with the segmentation of the primary mirrors. Residual phase errors coming from the phase steps at the edges of the segments will have to be minimized in order to reach the highest possible wavefront correction and thus the best contrast performance. To study these effects, we have developed the MITHIC high-contrast testbed, which is designed to test various strategies for wavefront sensing, including the Zernike sensor for Extremely accurate measurements of Low-level Differential Aberrations (ZELDA) and COronagraphic Focal-plane wave-Front Estimation for Exoplanet detection (COFFEE). We recently equipped the bench with a new atmospheric turbulence simulation module that offers both static phase patterns representing segmented primary mirrors and continuous phase strips representing atmospheric turbulence filtered by an AO or an XAO system. We present a characterisation of the module using different instruments and wavefront sensors, and the first coronagraphic measurements obtained on MITHIC., Comment: Presented at SPIE Astronomical Instrumentation + Telescope 2016

Published
2016
Full Text
View/download PDF

33. A 12-year follow-up of intestinal schistosomiasis in pre-school-aged children in Assoni Village, Eastern Senegal.

Author

N'Diaye M, Keita BF, Danfakha F, Keita F, Keita G, Senghor CS, Diop B, Diawara L, Bessin F, Vernet C, Barbier D, Dewavrin P, and Klotz F

Subjects
Child, Child, Preschool, Follow-Up Studies, Humans, Infant, Praziquantel therapeutic use, Prevalence, Senegal epidemiology, Schistosomiasis drug therapy, Schistosomiasis epidemiology, Schistosomiasis prevention & control, Schistosomiasis mansoni drug therapy, Schistosomiasis mansoni epidemiology, Schistosomiasis mansoni prevention & control
Abstract

Background: To monitor the prevalence of schistosomiasis in school-aged children (SAC), the National Bilharzia Control Program (PNLB) was set up by the Senegalese authorities; however, geographically isolated Bedik ethnic groups that did not benefit from this program were found to be heavily infected with Schistosoma mansoni. This observation led us to implement a new schistosomiasis control program in 2008 under the aegis of the non-governmental organization "Le Kaïcedrat" and in partnership with the PNLB/WHO to monitor the prevalence of schistosomiasis in this area. In the village of Assoni, where 100% of SAC were infected, analysis of the stools of pre-school-aged children (PSAC) showed that they were massively infected, so we decided to focus our program on them., Methods: From 2008 to 2020, we (i) monitored the prevalence of S. mansoni in PSAC in Assoni using double-stool smear preparation, (ii) treated the infected PSAC with a standard dose of praziquantel 40 mg/kg, (iii) ran educational campaigns each year in the village, and (iv) built latrines to improve sanitation and reduce schistosomiasis transmission. Linear regression was used to examine the trend in the annual schistosomiasis prevalence and a two-sided of Chi-squared test was used to compare prevalence between the different age groups of PSAC., Results: We observed an extremely high prevalence of schistosomiasis (78%) in PSAC before implementation of the program in 2008. Contamination occurred in very young children, as 64.3% of children under 2 years old were infected. Moreover, prevalence increased with age and reached 96.8% in children 4 to < 6 years old. Our annual interventions in Assoni Village raised awareness among villagers that water bodies were areas of significant infestation, allowed the building of 88 latrines and led to a decrease in prevalence in PSAC as only 11% of these children were infected in 2020., Conclusion: Our study allowed Assoni to be the first village in Senegal to treat PSAC since 2014, but only on an individual basis. It also shows that schistosomiasis is difficult to eradicate and that multi-sectorial actions are required to keep its prevalence at a low level.

Published
2021
Full Text
View/download PDF

34. Calibration of the island effect: Experimental validation of closed-loop focal plane wavefront control on Subaru/SCExAO.

Author

N’Diaye, M., Martinache, F., Jovanovic, N., Lozi, J., Guyon, O., Norris, B., Ceau, A., and Mary, D.

Abstract

Context. Island effect (IE) aberrations are induced by differential pistons, tips, and tilts between neighboring pupil segments on ground-based telescopes, which severely limit the observations of circumstellar environments on the recently deployed exoplanet imagers (e.g., VLT/SPHERE, Gemini/GPI, Subaru/SCExAO) during the best observing conditions. Caused by air temperature gradients at the level of the telescope spiders, these aberrations were recently diagnosed with success on VLT/SPHERE, but so far no complete calibration has been performed to overcome this issue. Aims. We propose closed-loop focal plane wavefront control based on the asymmetric Fourier pupil wavefront sensor (APF-WFS) to calibrate these aberrations and improve the image quality of exoplanet high-contrast instruments in the presence of the IE. Methods. Assuming the archetypal four-quadrant aperture geometry in 8 m class telescopes, we describe these aberrations as a sum of the independent modes of piston, tip, and tilt that are distributed in each quadrant of the telescope pupil. We calibrate these modes with the APF-WFS before introducing our wavefront control for closed-loop operation. We perform numerical simulations and then experimental tests on a real system using Subaru/SCExAO to validate our control loop in the laboratory and on-sky. Results. Closed-loop operation with the APF-WFS enables the compensation for the IE in simulations and in the laboratory for the small aberration regime. Based on a calibration in the near infrared, we observe an improvement of the image quality in the visible range on the SCExAO/VAMPIRES module with a relative increase in the image Strehl ratio of 37%. Conclusions. Our first IE calibration paves the way for maximizing the science operations of the current exoplanet imagers. Such an approach and its results prove also very promising in light of the Extremely Large Telescopes (ELTs) and the presence of similar artifacts with their complex aperture geometry. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

35. Fine cophasing of segmented aperture telescopes with ZELDA, a Zernike wavefront sensor in the diffraction-limited regime.

Author

Janin-Potiron, P., N’Diaye, M., Martinez, P., Vigan, A., Dohlen, K., and Carbillet, M.

Abstract

Context. Segmented aperture telescopes require an alignment procedure with successive steps from coarse alignment to monitoring process in order to provide very high optical quality images for stringent science operations such as exoplanet imaging. The final step, referred to as fine phasing, calls for a high sensitivity wavefront sensing and control system in a diffraction-limited regime to achieve segment alignment with nanometric accuracy. In this context, Zernike wavefront sensors represent promising options for such a calibration. A concept called the Zernike unit for segment phasing (ZEUS) was previously developed for ground-based applications to operate under seeing-limited images. Such a concept is, however, not suitable for fine cophasing with diffraction-limited images. Aims. We revisit ZELDA, a Zernike sensor that was developed for the measurement of residual aberrations in exoplanet direct imagers, to measure segment piston, tip, and tilt in the diffraction-limited regime. Methods. We introduce a novel analysis scheme of the sensor signal that relies on piston, tip, and tilt estimators for each segment, and provide probabilistic insights to predict the success of a closed-loop correction as a function of the initial wavefront error. Results. The sensor unambiguously and simultaneously retrieves segment piston and tip-tilt misalignment. Our scheme allows for correction of these errors in closed-loop operation down to nearly zero residuals in a few iterations. This sensor also shows low sensitivity to misalignment of its parts and high ability for operation with a relatively bright natural guide star. Conclusions. Our cophasing sensor relies on existing mask technologies that make the concept already available for segmented apertures in future space missions. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

36. Integrated care pathways for airway diseases (AIRWAYS-ICPs)

Author

Bousquet, Jean, Addis, A., Adcock, I. M., Agache, I., Agusti, A., Alonso, A., Annesi-Maesano, I., Anto, Josep M., Bachert, C., Baena-Cagnani, C. E., Bai, C., Baigenzhin, A. K., Barbara, Cristina, Barnes, P. J., Bateman, E. D., Beck, L., Bedbrook, Anna, Bel, E. H., Benezet, O., Bennoor, K. S., Benson, M., Bernabeu-Wittel, M., Bewick, M., Bindslev-Jensen, C., Blain, Hubert, Blasi, F., Bonini, M., Bonini, S., Boulet, L. P., Bourdin, Arnaud, Bourret, Rodolphe, Brightling, C. E., Briggs, A. H., Brozek, J. L., Buhl, R., Bush, A., Caimmi, D. P., Calderon, M. A., Calverley, P. M., Camargos, P. A. M., Camuzat, Thierry, Canonica, G. W., Carlsen, K. H., Casale, T. B., Cazzola, M., A.M, Cepeda Sarabia, Cesario, A., Chen, Y. Z., Chkhartishvili, E., Chavannes, Niels H., Chiron, R., Chuchalin, Alexander G., Chung, K. F., Cox, L., Crooks, George, Cruz, A. A., Custovic, Adnan, Dahl, R., Dahlen, S. E., Blay, F. De, Dedeu, Antoni, Deleanu, D., Demoly, Pascal, Devillier, P., Didier, A., Dinh-Xuan, A. T., Djukanovic, R., Dokic, D., Douagui, H. B., Dubakiene, R., Eglin, S., Elliot, F., Emuzyte, R., Fabbri, Leonardo M., Fink-Wagner, A., Fletcher, M., Fokkens, W. J., Fonseca, J. A., Franco, A., Frith, P., Furber, A., Gaga, M., Garces, J., Garcia-Aymerich, Judith, Gamkrelidze, A., Diaz, S. González, Gouzi, Fares, Guzmán, M. A., Haahtela, T., Harrison, D., Hayot, M., Heaney, L. G., Heinrich, J., Hellings, P. W., Hooper, J., Humbert, M., Hyland, M. E., Iaccarino, G., Jakovenko, D., Jardim, J. R., Jeandel, Claude, Jenkins, C., Johnston, S. L., Jonquet, Olivier, Joos, G., Jung, K. S., Kalayci, O., Karunanithi, S., Keil, T., Khaltaev, N., Kolek, V., Kowalski, M. L., Kull, I., Kuna, P., Kvedariene, V., Le, Tuyen D., Carlsen, K. C. Lodrup, Louis, R., MacNee, W., Mair, A., Majer, I., Manning, P. J., Keenoy, E. De Manuel, Masjedi, M. R., Melén, E., Gomes, Elisabete Melo, Menzies-Gow, A., Mercier, G., Mercier, Jacques, Michel, J. P., Miculinic, N., Mihaltan, F., Milenkovic, B., Molimard, M., Momas, I., Montilla-Santana, A., Almeida, M. Morais, Morgan, M., N'Diaye, M., Nafti, S., Nekam, K., Neou, A., Nicod, L., O'Hehir, R. E., Ohta, K., Paggiaro, P. L., Palkonen, S., Palmer, S., Papadopoulos, N. G., Papi, A., Passalacqua, G., Pavord, I., Pigearias, B., Plavec, D., Postma, D. S., Price, D., Rabe, K. F., Radier-Pontal, F., Redon, Josep, Rennard, S., Roberts, J., Robine, J. M., Roca, J., Roche, N., Rodenas, F., Roggeri, A., Rolland, C., Rosado-Pinto, J., Ryan, D., Samolinski, B., Sanchez-Borges, M., Schunemann, H. J., Sheikh, A., Shields, K. M., Siafakas, N., Sibille, Y., Similowski, T., Small, I., Sola-Morales, O., Sooronbaev, T., Stelmach, R., Sterk, P. J., Stiris, T., Sud, P., Tellier, V., To, T., Todo-Bom, A., Triggiani, M., Valenta, R., Valero, A. L., Valiulis, A., Valovirta, E., Ganse, E. Van, Vandenplas, O., Vasankari, T., Vestbo, J., Vezzani, G., Viegi, Giovanni, Visier, L., Vogelmeier, C., Vontetsianos, T., Wagstaff, R., Wahn, U., Wallaert, B., Whalley, B., Wickman, M., Williams, D. M., Wilson, N., Yawn, B. P., Yiallouros, Panayiotis K., Yorgancioglu, A., Yusuf, O. M., Zar, H. J., Zhong, N., Zidarn, M., Zuberbier, T., Bousquet, J., Addis, A., Adcock, I., Agache, I., Agusti, A., Alonso, A., Annesi-Maesano, I., Anto, J. M., Bachert, C., Baena-Cagnani, C. E., Bai, C., Baigenzhin, A., Barbara, C., Barnes, P. J., Bateman, E. D., Beck, L., Bedbrook, A., Bel, E. H., Benezet, O., Bennoor, K. S., Benson, M., Bernabeu-Wittel, M., Bewick, M., Bindslev-Jensen, C., Blain, H., Blasi, F., Bonini, M., Bonini, S., Boulet, L. P., Bourdin, A., Bourret, R., Bousquet, P. J., Brightling, C. E., Briggs, A., Brozek, J., Buhl, R., Bush, A., Caimmi, D., Calderon, M., Calverley, P., Camargos, P. A., Camuzat, T., Canonica, G. W., Carlsen, K. H., Casale, T. B., Cazzola, M., Cepeda Sarabia, A. M., Cesario, A., Chen, Y. Z., Chkhartishvili, E., Chavannes, N. H., Chiron, R., Chuchalin, A., Chung, K. F., Cox, L., Crooks, G., Crooks, M. G., Cruz, A. A., Custovic, A., Dahl, R., Dahlen, S. E., De Blay, F., Dedeu, T., Deleanu, D., Demoly, P., Devillier, P., Didier, A., Dinh-Xuan, A. T., Djukanovic, R., Dokic, D., Douagui, H., Dubakiene, R., Eglin, S., Elliot, F., Emuzyte, R., Fabbri, L., Fink Wagner, A., Fletcher, M., Fokkens, W. J., Fonseca, J., Franco, A., Frith, P., Furber, A., Gaga, M., Garces, J., Garcia-Aymerich, J., Gamkrelidze, A., Gonzales-Diaz, S., Gouzi, F., Guzman, M. A., Haahtela, T., Harrison, D., Hayot, M., Heaney, L. G., Heinrich, J., Hellings, P. W., Hooper, J., Humbert, M., Hyland, M., Iaccarino, G., Jakovenko, D., Jardim, J. R., Jeandel, C., Jenkins, C., Johnston, S. L., Jonquet, O., Joos, G., Jung, K. S., Kalayci, O., Karunanithi, S., Keil, T., Khaltaev, N., Kolek, V., Kowalski, M. L., Kull, I., Kuna, P., Kvedariene, V., Le, L. T., Lodrup Carlsen, K. C., Louis, R., Macnee, W., Mair, A., Majer, I., Manning, P., De Manuel Keenoy, E., Masjedi, M. R., Melen, E., Melo-Gomes, E., Menzies-Gow, A., Mercier, G., Mercier, J., Michel, J. P., Miculinic, N., Mihaltan, F., Milenkovic, B., Molimard, M., Momas, I., Montilla-Santana, A., Morais-Almeida, M., Morgan, M., N'Diaye, M., Nafti, S., Nekam, K., Neou, A., Nicod, L., O'Hehir, R., Ohta, K., Paggiaro, P., Palkonen, S., Palmer, S., Papadopoulos, N. G., Papi, A., Passalacqua, G., Pavord, I., Pigearias, B., Plavec, D., Postma, D. S., Price, D., Rabe, K. F., Radier Ponta, F., Redon, J., Rennard, S., Roberts, J., Robine, J. M., Roca, J., Roche, N., Rodenas, F., Roggeri, A., Rolland, C., Rosado-Pinto, J., Ryan, D., Samolinski, B., Sanchez-Borges, M., Schunemann, H. J., Sheikh, A., Shields, M., Siafakas, N., Sibille, Y., Similowski, T., Small, I., Sola-Morales, O., Sooronbaev, T., Stelmach, R., Sterk, P. J., Stiris, T., Sud, P., Tellier, V., To, T., Todo-Bom, A., Triggiani, M., Valenta, R., Valero, A. L., Valiulis, A., Valovirta, E., Van Ganse, E., Vandenplas, O., Vasankari, T., Vestbo, J., Vezzani, G., Viegi, G., Visier, L., Vogelmeier, C., Vontetsianos, T., Wagstaff, R., Wahn, U., Wallaert, B., Whalley, B., Wickman, M., Williams, D. M., Wilson, N., Yawn, B. P., Yiallouros, P. K., Yorgancioglu, A., Yusuf, O. M., Zar, H. J., Zhong, N., Zidarn, M., Zuberbier, T., Département pneumologie et addictologie [Montpellier], Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Hôpital Arnaud de Villeneuve, Department of Allergy and Clinical Immunology, Faculty of Medicine-Transylvania University, Applied Tumor Virology, German Cancer Research Center - Deutsches Krebsforschungszentrum [Heidelberg] (DKFZ), Ghent University Hospital, Laboratoire d'ingénierie osteo-articulaire et dentaire (LIOAD), Université de Nantes (UN)-IFR26-Institut National de la Santé et de la Recherche Médicale (INSERM), Contre les MAladies Chroniques pour un VIeillissement Actif en Languedoc-Roussillon (MACVIA-LR), Université Montpellier 1 (UM1)-Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre Hospitalier Universitaire de Nîmes (CHU Nîmes)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-European Innovation Partnership on Active and Healthy Ageing Reference Site (EIP on AHA), Commission Européenne-Commission Européenne-Organisation Mondiale de la Santé / World Health Organization Office (OMS / WHO), Academic Medical Center - Academisch Medisch Centrum [Amsterdam] (AMC), University of Amsterdam [Amsterdam] (UvA), iQ4U consultants Ltd, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier), Department of Pathophysiology and Transplantation, Università degli Studi di Milano = University of Milan (UNIMI), Istituto di Geoscienze e Georisorse, Pavia, Institute of Neurobiology and Molecular Medicine, CNR, Rome, Italy and Department of Medicine-University of Naples Federico II = Università degli studi di Napoli Federico II, Physiologie & médecine expérimentale du Cœur et des Muscles [U 1046] (PhyMedExp), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Infection, Immunity and Inflammation, Royal Brompton Hospital, Région Languedoc-Roussillon-Midi-Pyrénées, Service de physiologie et explorations fonctionelles [CHU Cochin], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Cochin [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), University Hospital Southampton, Vilnius University [Vilnius], IMIM-Hospital del Mar, Generalitat de Catalunya, Helsingin yliopisto = Helsingfors universitet = University of Helsinki, University Hospitals Leuven [Leuven], University of Edinburgh, Pneumology Department, Marius Nasta Institute of Pneumology, Department of Prevention of Environmental Hazards and Allergology, Medical University of Warsaw - Poland-Faculté de Pharmacie de Paris, Monash University [Melbourne], Allergy and Respiratory Diseases, Università degli studi di Genova = University of Genoa (UniGe), Mécanismes moléculaires dans les démences neurodégénératives (MMDN), Université Montpellier 2 - Sciences et Techniques (UM2)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Neurophysiologie Respiratoire Expérimentale et Clinique, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Santé et de la Recherche Médicale (INSERM), AcademicMedical Center, Oslo University Hospital [Oslo], University of Coimbra [Portugal] (UC), Division of Clinical Immunology and Allergy, University of Naples Federico II = Università degli studi di Napoli Federico II, University of Turku, Evaluation et modélisation des effets thérapeutiques, Département biostatistiques et modélisation pour la santé et l'environnement [LBBE], Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire de Biométrie et Biologie Evolutive - UMR 5558 (LBBE), Université de Lyon-Université de Lyon-Institut National de Recherche en Informatique et en Automatique (Inria)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), Consiglio nazionale delle ricerche, Instituto di fisiologia clinica, Charité - UniversitätsMedizin = Charité - University Hospital [Berlin], Service de Pneumologie et Immuno-Allergologie [CHU LIlle], Pole Cardio-vasculaire et pulmonaire [CHU Lille], Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille)-Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), University Hospital of Cologne [Cologne], Çocuk Sağlığı ve Hastalıkları, AII - Amsterdam institute for Infection and Immunity, Pulmonology, Ear, Nose and Throat, Centre Hospitalier Régional Universitaire [Montpellier] (CHRU Montpellier)-Université Montpellier 1 (UM1)-Centre Hospitalier Universitaire de Nîmes (CHU Nîmes)-European Innovation Partnership on Active and Healthy Ageing Reference Site (EIP on AHA), Commission Européenne-Commission Européenne-Organisation Mondiale de la Santé / World Health Organization Office (OMS / WHO)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Montpellier (UM), University of Milan, CNR, Rome, Italy and Department of Medicine-University of Naples Federico II, Université de Montpellier (UM)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of Helsinki, University of Genoa (UNIGE), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Università degli studi di Napoli Federico II, Groningen Research Institute for Asthma and COPD (GRIAC), Yiallouros, Panayiotis K. [0000-0002-8339-9285], Custovic, Adnan [0000-0001-5218-7071], and Γιάλλουρος, Παναγιώτης

Subjects
Aging, Settore MED/10 - Malattie dell'Apparato Respiratorio, International Cooperation, Respiratory System, Medically Underserved Area, Comorbidity, Disease, Early intervention, Medical and Health Sciences, [SDV.MHEP.PSR]Life Sciences [q-bio]/Human health and pathology/Pulmonology and respiratory tract, Pulmonary Disease, Chronic Obstructive, 0302 clinical medicine, Disease control, Risk Factors, Chronic obstructive lung disease, Health care, 030212 general & internal medicine, Rhiniti, media_common, Rhinitis, Environmental exposure, Child health care, 3. Good health, ALLERGIC RHINITIS, Europe, CHRONIC RESPIRATORY-DISEASES, PERFORMANCE PROGRAM, Action plan, SIMULATION, Asthma, Decision Making, European Union, Guidelines as Topic, Humans, Pulmonary Disease, Chronic Obstructive, Quality of Life, Respiration Disorders, World Health Organization, SMOKING, Human, Pulmonary and Respiratory Medicine, medicine.medical_specialty, Chronic respiratory tract disease, DIAGNOSIS, OBSTRUCTIVE PULMONARY-DISEASE, 03 medical and health sciences, Quality of life (healthcare), EUROPEAN-UNION, medicine, MANAGEMENT, media_common.cataloged_instance, European union, Intensive care medicine, business.industry, Public health, Risk Factor, ta3121, Respiration Disorder, Integrated care, 030228 respiratory system, Physical therapy, Clinical Medicine, business, [SDV.MHEP]Life Sciences [q-bio]/Human health and pathology, SEVERE ASTHMA
Abstract

International audience; The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYS-ICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers).

Published
2014
Full Text
View/download PDF

37. Complications des otites moyennes chroniques

Author

Tall, A, Sylla, I, N'diaye, M, Diom, ES, Deguenonvo, R, Diallo, BK, N'diaye, IC, Diouf, R, and Diop, EM

Subjects
Otite moyenne chronique, Complications, Cholestéatome
Abstract

Objectif de l’étude : Rapporter la fréquence des complications des otites moyennes chroniques et présenter notre expérience dans leur prise en charge.Matériel et méthodes : Etude rétrospective concernant la période allant du 1er janvier 2000 au 31 décembre 2009. Les complications ont été réparties en 2 grands groupes : extracrâniennes et intracrâ-niennes.Résultats : 57 patients sur 350 reçus pour OMC ont présenté une complication, soit une fréquence de 18,38 %. Le cholestéatome était le plus grand pourvoyeur de ces complications (84,2%). Dix-neuf patients présentaient plus d’une complication, soit au total 76 cas. Les complications extracrâniennes ont été les plus fréquentes, 63 cas (83%), dominées par la mastoïdite extériorisée profuse (68,3%). Les complications intracrâniennes au nombre de 13 (17%) étaient dominées par la méningite purulente otogène (46,2%). La mastoïdectomie associée à une antibiothérapie à large spectre, occupait une place im-portante dans la prise en charge de ces complications. Elle a été réalisée chez 45 patients (79%). La mortalité a été estimée à 3,5% (2 cas de décès). Un drainage neurochirurgical a été effectué dans 4 cas (8,6 %).Conclusion : Cette étude se caractérise par un taux de complications d’OMC plus élevé que ceux rappor-tés dans la littérature, ainsi que par la prédominance des formes étendues et des associa-tions de complications chez un même patient.Mots clés : Otite moyenne chronique, Complications, Cholestéatome.The objective of this study : was to report the frequency and our experience of management of complications of chronic otitsmedia.Methods : We conducted a retrospective study covering 10 years period (from 1st January 2000 to 31 December 2009). Complications were divided into 2 groups: extracranial and intracranial.Results : Among 350 patients received for chronic otitis media, 57 presented complications, such as a rate of 18.38%. Cholesteatoma was the largest provider of these complications in order of 84.2%. Nineteen (19) patients had more than one complication. So, a total of 76 cases of complications were listed. Subperiostal mastoiditis was the most common findings, 68.3% of the extracranial complications. The intracranial complications, (17%), were domi-nated by otogenic purulent meningitis (46.2%). Radical mastoïdectomy with broad spectrum antibiotics occupied an important place in the management of these complications, performed in 45 patients (79%). Neurosurgical drainage was performed in 4 cases (8.6%). Mortality was estimated at 3.5% (2 deaths).Conclusion : COCM are characterized, in this study, by an elevated rate compared to that reported in the literature, the prevalence of extended forms and associations of complications in the same patient.Keys words : Chronic otitis media, Complications, Cholesteatoma.

Published
2015

39. Drug Repositioning of the α 1 -Adrenergic Receptor Antagonist Naftopidil: A Potential New Anti-Cancer Drug?

Author

Florent R, Poulain L, and N'Diaye M

Subjects
Humans, Male, Adrenergic alpha-1 Receptor Antagonists therapeutic use, Antineoplastic Agents therapeutic use, Drug Repositioning, Naphthalenes therapeutic use, Piperazines therapeutic use, Prostatic Hyperplasia drug therapy, Prostatic Hyperplasia metabolism, Prostatic Hyperplasia pathology, Prostatic Neoplasms drug therapy, Prostatic Neoplasms metabolism, Prostatic Neoplasms pathology
Abstract

Failure of conventional treatments is often observed in cancer management and this requires the development of alternative therapeutic strategies. However, new drug development is known to be a high-failure process because of the possibility of a lower efficacy than expected for the drug or appearance of non-manageable side effects. Another way to find alternative therapeutic drugs consists in identifying new applications for drugs already approved for a particular disease: a concept named "drug repurposing". In this context, several studies demonstrated the potential anti-tumour activity exerted by α1-adrenergic receptor antagonists and notably renewed interest for naftopidil as an anti-cancer drug. Naftopidil is used for benign prostatic hyperplasia management in Japan and a retrospective study brought out a reduced incidence of prostate cancer in patients that had been prescribed this drug. Further studies showed that naftopidil exerted anti-proliferative and cytotoxic effects on prostate cancer as well as several other cancer types in vitro, as well as ex vivo and in vivo. Moreover, naftopidil was demonstrated to modulate the expression of Bcl-2 family pro-apoptotic members which could be used to sensitise cancer cells to targeting therapies and to overcome resistance of cancer cells to apoptosis. For most of these anti-cancer effects, the molecular pathway is either not fully deciphered or shown to involve α1-adrenergic receptor-independent pathway, suggesting off target transduction signals. In order to improve its efficacy, naftopidil analogues were designed and shown to be effective in several studies. Thereby, naftopidil appears to display anti-cancer properties on different cancer types and could be considered as a candidate for drug repurposing although its anti-cancerous activities need to be studied more deeply in prospective randomized clinical trials.

Published
2020
Full Text
View/download PDF

40. Bim, Puma and Noxa upregulation by Naftopidil sensitizes ovarian cancer to the BH3-mimetic ABT-737 and the MEK inhibitor Trametinib.

Author

Florent R, Weiswald LB, Lambert B, Brotin E, Abeilard E, Louis MH, Babin G, Poulain L, and N'Diaye M

Subjects
Apoptosis Regulatory Proteins drug effects, Apoptosis Regulatory Proteins metabolism, Female, Humans, Mitogen-Activated Protein Kinase Kinases drug effects, Mitogen-Activated Protein Kinase Kinases metabolism, Up-Regulation drug effects, bcl-X Protein metabolism, Biphenyl Compounds pharmacology, Naphthalenes pharmacology, Nitrophenols pharmacology, Ovarian Neoplasms drug therapy, Piperazines pharmacology, Pyridones pharmacology, Pyrimidinones pharmacology, Sulfonamides pharmacology, bcl-X Protein drug effects
Abstract

Ovarian cancer represents the first cause of mortality from gynecologic malignancies due to frequent chemoresistance occurrence. Increasing the [BH3-only Bim, Puma, Noxa proapoptotic]/[Bcl-x L , Mcl-1 antiapoptotic] proteins ratio was proven to efficiently kill ovarian carcinoma cells and development of new molecules to imbalance Bcl-2 member equilibrium are strongly required. Drug repurposing constitutes an innovative approach to rapidly develop therapeutic strategies through exploitation of established drugs already approved for the treatment of noncancerous diseases. This strategy allowed a renewed interest for Naftopidil, an α 1 -adrenergic receptor antagonist commercialized in Japan for benign prostatic hyperplasia. Naftopidil was reported to decrease the incidence of prostate cancer and its derivative was described to increase BH3-only protein expression in some cancer models. Based on these arguments, we evaluated the effects of Naftopidil on ovarian carcinoma and showed that Naftopidil reduced cell growth and increased the expression of the BH3-only proteins Bim, Puma and Noxa. This effect was independent of α 1 -adrenergic receptors blocking and involved ATF4 or JNK pathway depending on cellular context. Finally, Naftopidil-induced BH3-only members sensitized our models to ABT-737 and Trametinib treatments, in vitro as well as ex vivo, in patient-derived organoid models.

Published
2020
Full Text
View/download PDF

41. Stop-less Lyot coronagraph for exoplanet characterization: design, manufacturing, and tests of the apodizer

Author

Vigan, Arthur, N'Diaye, M., Dohlen, K., Navarro, Ramon, Cunningham, Colin, Barto, Allison, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Space Telescope Science Institute (STSci), and Netherlands Institute for Radio Astronomy (ASTRON)

Subjects
Physics, business.industry, Field of view, Orbital mechanics, Exoplanet, law.invention, Optics, Cardinal point, Apodization, law, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Coronagraph, Spectrograph, Long-slit spectroscopy
Abstract

International audience; Upcoming high-contrast imagers will all provide spectroscopic capabilities for the characterization of directly detected giant planets in wide orbits. While integral field spectroscopy (IFS) can provide both spatial and spectral information, it is usually limited in terms of field of view and resolution. The alternative is to use long slit spectroscopy coupled with coronagraphy (LSC), which can easily provide higher resolution and larger field of view. The SPHERE instrument for the VLT provides a LSC mode in its near-infrared imager and spectrograph, IRDIS. However, the fact that the occulting coronagraphic mask is merged in the focal plane with the slit reduces significantly its capacity to attenuate the diffraction, limiting the high-contrast capabilities of the instrument at close angular separations (0.3"-0.4"). To improve the diffraction suppression of the LSC in IRDIS, we recently proposed to use the stop-less Lyot coronagraph (SLLC) to build an apodized long slit coronagraph (ALSC), and we demonstrated that it improves notably the performance at small angular separation, allowing the spectral analysis of colder planets. The design of the SLLC apodizer has been optimized for an implementation in SPHERE/IRDIS, and it has recently been manufactured before being inserted into the instrument during reintegration of SPHERE in Paranal. In the current work, we present the final design of the SLLC apodizer, its specifications for the manufacturing step, and the first results obtained on SPHERE. We compare the results between the simple LSC and the new ALSC, and we draw the conclusions on the advantages and drawbacks of our design.

Published
2014
Full Text
View/download PDF

42. Right ventricle myxoma creating a partial obstruction of the pulmonary infundibulum: case report

Author

Ciss, A.G., Diarra, O., Dieng, P.A., Ba, P.S., Beye, S.A., N'diaye, A., Kane, O., Diop, I.B., and N'diaye, M.

Subjects
Myxoma -- Complications and side effects, Myxoma -- Case studies, Shortness of breath -- Risk factors, Shortness of breath -- Diagnosis, Shortness of breath -- Care and treatment, Shortness of breath -- Case studies, Echocardiography -- Usage, Health
Abstract

A 13-year old female was referred to hospital for severe dyspnoea (stage III NYHA), with an oedema of the face and the lower limbs. She was then steadily putting on weight and gained up to 5 kilogram's. The situation got worse and the patient referred to cardio vascular surgery. The interview indicated that there has never been a myxomatosis case in her family before. The physical examination revealed a worsening of the general health status and a clinical anaemia. However the pulse was regular, beating at 100 per minute; and the blood pressure was 100/60mmhg. There was no longer an oedema on the face, but the other bilateral pre-tibia oedema was still persistent and taking the gore. The examination also revealed a turgescence of the jugular veins and a hepatomegalia. The heart auscultation allowed a diagnosis of a pulmonary stenosis breath, which was not varying with the changes of postures. The patient did not present any neuro-endocrine clinical signs or any external skin problems. The chest cross section echocardiography revealed a cardiac tumour which implanted on the front lateral side of the right ventricle with an expansion into the pulmonary infundibulum. The patient was operated within 48 hours following her admission. The removal of the myxomatosis was achieved using technique of extra corporeal circulation (CEC). The heart was reached through a median sternotomy followed by a longitudinal right side atriotomy. The tricuspid valve was normal; the tumour was located across the tricuspid orifice. Time cross clamping was 15 minutes. The anatomy pathological examination showed a tumour myxomatosis-like tumour with two lobes measuring 4.2 x 2.3 centimeters. At its top there were zones and muscular tissue and hemorrhagic necrosis. The evolution was simple; the post operation scanning check ups were satisfactoryRight ventricle myxoma protruding into pulmonary artery is exceedingly rare. Obstruction of cardiac cavity is redoubtable complication of myxoma. We emphasize the importance of periodic follow up of young patient with echocardiography allowing early detection of recurrence., Introduction In cardiology tumours are very unusual and heart myxoma, which is generally a benign tumour, constitutes the most predominantly occurring cases. They actually represent 0.5 to 1 % of [...]

Published
2009

44. Integrated care pathways for airway diseases (AIRWAYS-ICPs)

Author

Bousquet, J. Addis, A. Adcock, I. Agache, I. Agusti, A. Alonso, A. Annesi-Maesano, I. Anto, J.M. Bachert, C. Baena-Cagnani, C.E. Bai, C. Baigenzhin, A. Barbara, C. Barnes, P.J. Bateman, E.D. Beck, L. Bedbrook, A. Bel, E.H. Benezet, O. Bennoor, K.S. Benson, M. Bernabeu-Wittel, M. Bewick, M. Bindslev-Jensen, C. Blain, H. Blasi, F. Bonini, M. Bonini, S. Boulet, L.P. Bourdin, A. Bourret, R. Bousquet, P.J. Brightling, C.E. Briggs, A. Brozek, J. Buhl, R. Bush, A. Caimmi, D. Calderon, M. Calverley, P. Camargos, P.A. Camuzat, T. Canonica, G.W. Carlsen, K.H. Casale, T.B. Cazzola, M. Cepeda Sarabia, A.M. Cesario, A. Chen, Y.Z. Chkhartishvili, E. Chavannes, N.H. Chiron, R. Chuchalin, A. Chung, K.F. Cox, L. Crooks, G. Crooks, M.G. Cruz, A.A. Custovic, A. Dahl, R. Dahlen, S.E. De Blay, F. Dedeu, T. Deleanu, D. Demoly, P. Devillier, P. Didier, A. Dinh-Xuan, A.T. Djukanovic, R. Dokic, D. Douagui, H. Dubakiene, R. Eglin, S. Elliot, F. Emuzyte, R. Fabbri, L. Fink Wagner, A. Fletcher, M. Fokkens, W.J. Fonseca, J. Franco, A. Frith, P. Furber, A. Gaga, M. Garcés, J. Garcia-Aymerich, J. Gamkrelidze, A. Gonzales-Diaz, S. Gouzi, F. Guzmán, M.A. Haahtela, T. Harrison, D. Hayot, M. Heaney, L.G. Heinrich, J. Hellings, P.W. Hooper, J. Humbert, M. Hyland, M. Iaccarino, G. Jakovenko, D. Jardim, J.R. Jeandel, C. Jenkins, C. Johnston, S.L. Jonquet, O. Joos, G. Jung, K.S. Kalayci, O. Karunanithi, S. Keil, T. Khaltaev, N. Kolek, V. Kowalski, M.L. Kull, I. Kuna, P. Kvedariene, V. Le, L.T. Lodrup Carlsen, K.C. Louis, R. MacNee, W. Mair, A. Majer, I. Manning, P. De Manuel Keenoy, E. Masjedi, M.R. Melen, E. Melo-Gomes, E. Menzies-Gow, A. Mercier, G. Mercier, J. Michel, J.P. Miculinic, N. Mihaltan, F. Milenkovic, B. Molimard, M. Momas, I. Montilla-Santana, A. Morais-Almeida, M. Morgan, M. N'Diaye, M. Nafti, S. Nekam, K. Neou, A. Nicod, L. O'Hehir, R. Ohta, K. Paggiaro, P. Palkonen, S. Palmer, S. Papadopoulos, N.G. Papi, A. Passalacqua, G. Pavord, I. Pigearias, B. Plavec, D. Postma, D.S. Price, D. Rabe, K.F. Radier Ponta, F. Redon, J. Rennard, S. Roberts, J. Robine, J.M. Roca, J. Roche, N. Rodenas, F. Roggeri, A. Rolland, C. Rosado-Pinto, J. Ryan, D. Samolinski, B. Sanchez-Borges, M. Schünemann, H.J. Sheikh, A. Shields, M. Siafakas, N. Sibille, Y. Similowski, T. Small, I. Sola-Morales, O. Sooronbaev, T. Stelmach, R. Sterk, P.J. Stiris, T. Sud, P. Tellier, V. To, T. Todo-Bom, A. Triggiani, M. Valenta, R. Valero, A.L. Valiulis, A. Valovirta, E. Van Ganse, E. Vandenplas, O. Vasankari, T. Vestbo, J. Vezzani, G. Viegi, G. Visier, L. Vogelmeier, C. Vontetsianos, T. Wagstaff, R. Wahn, U. Wallaert, B. Whalley, B. Wickman, M. Williams, D.M. Wilson, N. Yawn, B.P. Yiallouros, P.K. Yorgancioglu, A. Yusuf, O.M. Zar, H.J. Zhong, N. Zidarn, M. Zuberbier, T.

Abstract

The objective of Integrated Care Pathways for Airway Diseases (AIRWAYS-ICPs) is to launch a collaboration to develop multi-sectoral care pathways for chronic respiratory diseases in European countries and regions. AIRWAYS-ICPs has strategic relevance to the European Union Health Strategy and will add value to existing public health knowledge by: 1) proposing a common framework of care pathways for chronic respiratory diseases, which will facilitate comparability and trans-national initiatives; 2) informing cost-effective policy development, strengthening in particular those on smoking and environmental exposure; 3) aiding risk stratification in chronic disease patients, using a common strategy; 4) having a significant impact on the health of citizens in the short term (reduction of morbidity, improvement of education in children and of work in adults) and in the long-term (healthy ageing); 5) proposing a common simulation tool to assist physicians; and 6) ultimately reducing the healthcare burden (emergency visits, avoidable hospitalisations, disability and costs) while improving quality of life. In the longer term, the incidence of disease may be reduced by innovative prevention strategies. AIRWAYSICPs was initiated by Area 5 of the Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing. All stakeholders are involved (health and social care, patients, and policy makers).

Published
2014

45. Apodization in high-contrast long-slit spectroscopy

Author

N'diaye, Mamadou, Vigan, A., N’Diaye, M., Dohlen, K., Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), and Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2013
Full Text
View/download PDF

48. Stop-less Lyot coronagraph for exoplanet characterization

Author

Vigan, Arthur, N'Diaye, M., Dohlen, K., McLean, Ian, Ramsay, Suzanne, Takami, Hideki, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Space Telescope Science Institute (STSci)

Subjects
Diffraction, Physics, Lyot stop, business.industry, Astronomy, 01 natural sciences, Exoplanet, law.invention, 010309 optics, Speckle pattern, Optics, Apodization, law, Planet, 0103 physical sciences, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, Coronagraph, Long-slit spectroscopy
Abstract

International audience; The characterization of directly-imaged exoplanets at very small angular separations requires high-contrast spec-troscopic capabilities. For this purpose, the new generation of instruments dedicated to direct imaging of massive exoplanets at large orbital radii, such as VLT/SPHERE and Gemini/GPI, includes integral field spectroscopy (IFS) and/or long slit spectroscopy (LSS) coupled with coronography. LSS is particularly challenging since observations will be stronly limited by quasi-static speckles and diffraction residuals that need to be removed with a posteriori data analysis methods. It is therefore necessary to limit as much as possible the influence of diffraction in the data. In this work we compare the use of the classical Lyot coronagraph (CLC) and the stop- less Lyot coronagraph (SLLC) with LSS for the characterization of exoplanets. SLLC uses a grey apodization to suppress the diffraction above 4.53 λ/D and does not require the use of any Lyot stop, offering a convenient implementation. We show that this apodized long slit spectroscopy (ALSS) improves notably the performance at small angular separations (0.3"-0.4"), allowing the spectral analysis of colder planets.

Published
2012
Full Text
View/download PDF

49. Micro-Algues De La Mare Et Des Bassins D’arrosage a Port-Bouët (Abidjan, Côte D’ivoire)

Author

Djima, TI, N'diaye, M, Da, PK, and Saadou, M

Subjects
Micro-algues, eau douce, zone marécageuse, Port-Bouët, Côte d'Ivoire
Abstract

Les algues jouent un rôle important dans les chaines trophiques des écosystèmes aquatiques. L'étude a eu pour but, à la fois d'inventorier des peuplements algaux et de déterminer les paramètres physicochimiques du milieu influençant la répartition de ces algues en zone marécageuse à Port-Bouët (Abidjansud, Côte d'Ivoire). Des échantillons d'eau ont été prélevés, mensuellement au niveau de 5 stations, entre septembre 2004 et janvier 2005. L'analyse physico-chimique a montré que ces eaux ont eu des teneurs importantes en silice (SiO2), nutriments (NO3-, NO2-, NH4+, PO43-) et ont recelé d'importantes formes de microalgues. Au total, 105 espèces algales ont été identifiées. Celles-ci ont été réparties en 4 embranchements comme suit : 42, 39, 15 et 4 % Chlorophyta, Euglenophyta, Chrysophyta et de Cyanophyta, respectivement. L'analyse combinée des peuplements phytoplanctoniques, en relation avec les données physico-chimiques de chaque station, a permis d'obtenir 4 groupements phytoplanctoniques.Algae play an important role in trophic chains of aquatic systems. This survey aims to determine both algae community and the physico-chemical characteristics of the media of their distribution. Five water samples were collected monthly from stations located in the swampy areas of Port-Bouët (south of Abidjan, Côte d'Ivoire) between September 2004 and January 2005). The samples were analyzed for physico-chemical and biological characteristics. Results showed that the waters had high silicium (SiO2) and nutrient (NO3-, NO2-, NH4+, PO43-) contents, which resulted in significant algae population, with 105 individuals identified in these media. The taxa were divided into 4 groups as follows : 42, 39, 15 and 4 % of the Chlorophyta, Euglenophyta, Chrysophyta and Cyanophyta, respectively. Canonical Correspondence Analysis of the data revealed 4 main phytoplanktonic groups.Keywords: Micro algae, freshwater algae, swampy area, Port-Bouët, Côte d'Ivoire

Published
2012

50. Left Atrium Papillary Fibroelastomas: A Cause of Cerebral Emboli

Author

Ciss, A. G., Ba, P. S., Dieng, P. A., Azarnoush, K., Camilleri, L., Geoffroy, E., Innorta, A., Legault, B., Cosserant, B., de Riberolles, C., and N'diaye, M.

Subjects
Article Subject, cardiovascular system, cardiovascular diseases
Abstract

Papillary fibroelastomas are cardiac benign tumours. Among the benign cardiac tumor, papillary fibroelastomas are reported second after myxomas. Most often diagnosed incidentally, papillary fibroelastomas may embolize to cerebral circulation. Valvular locations are predominant; location in left atrium is rare. In this paper, we present a case of papillary fibroelastoma located in left atrium with symptoms of cerebral embolization. Transoesophageal echocardiography diagnosed a mobile mass. The patient was treated with surgical resection without further embolic complication.

Published
2012
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results