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

Author

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., Orazi, V. D, Dougados, C., Doute, 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., Kenworthy, M., Kervella, P., Kral, Q., Kuhn, J., Lagadec, E., Laibe, G., Langlois, M., Lagrange, A. -M., Launhardt, R., Leboulleux, L., Coroller, H. Le, Causi, G. Li, Loupias, M., Maire, A. L., Marleau, G., Martinache, F., Martinez, P., Mary, D., Mattioli, M., Mazoyer, J., Meheut, H., Menard, F., Mesa, D., Meunier, N., Miguel, Y., Milli, J., Min, M., Molliere, P., Mordasini, C., Moretto, G., Mugnier, L., Arena, G. Muro, Nardetto, N., Diaye, M. N, 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, A., and Zurlo, A.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Solar and Stellar 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., Comment: White paper submitted to ESO on Feb. 20th, 2020

Published
2020

3. Resolved astrometric orbits of ten O-type binaries

Author

Bouquin, J. -B. Le, Sana, H., Gosset, E., De Becker, M., Duvert, G., Absil, O., Anthonioz, F., Berger, J. -P., Ertel, S., Grellmann, R., Guieu, S., Kervella, P., Rabus, M., and Willson, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Our long term aim is to derive model-independent stellar masses and distances for long period massive binaries by combining apparent astrometric orbit with double-lined radial velocity amplitudes (SB2). We follow-up ten O+O binaries with AMBER, PIONIER and GRAVITY at the VLTI. Here, we report about 130 astrometric observations over the last 7 years. We combine this dataset with distance estimates to compute the total mass of the systems. We also compute preliminary individual component masses for the five systems with available SB2 radial velocities. Nine over the ten binaries have their three dimensional orbit well constrained. Four of them are known colliding wind, non-thermal radio emitters, and thus constitute valuable targets for future high angular resolution radio imaging. Two binaries break the correlation between period and eccentricity tentatively observed in previous studies. It suggests either that massive star formation produce a wide range of systems, or that several binary formation mechanisms are at play. Finally, we found that the use of existing SB2 radial velocity amplitudes can lead to unrealistic masses and distances. If not understood, the biases in radial velocity amplitudes will represent an intrinsic limitation for estimating dynamical masses from SB2+interferometry or SB2+Gaia. Nevertheless, our results can be combined with future Gaia astrometry to measure the dynamical masses and distances of the individual components with an accuracy of 5 to 15\%, completely independently of the radial velocities., Comment: Accepted in A&A; Astrometric positions available in CDS; revised version after language edition

Published
2016
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4. Search for substellar-mass companions and asymmetries in their parent discs

Author

Willson, M., Kraus, S., Kluska, J., Monnier, J. D., Ireland, M., Aarnio, A., Sitko, M. L., Calvet, N., Espaillat, C., and Wilner, D. J.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Transitional discs are a class of circumstellar discs around young stars with extensive clearing of dusty material within their inner regions on 10s of au scales. One of the primary candidates for this kind of clearing is the formation of planet(s) within the disc that then accrete or clear their immediate area as they migrate through the disc. Our sample included eight transitional discs. Using the Keck/NIRC2 instrument we utilised the Sparse Aperture Masking (SAM) interferometry technique to search for asymmetries indicative of ongoing planet formation. We searched for close-in companions using both model fitting and interferometric image reconstruction techniques. Using simulated data, we derived diagnostics that helped us to distinguish between point sources and extended asymmetric disc emission. In addition, we investigated the degeneracy between the contrast and separation that appear for marginally resolved companions. We found FP Tau to contain a previously unseen disc wall, and DM Tau, LkHa 330, and TW Hya to contain an asymmetric signal indicative of point source-like emission. We placed upper limits on the contrast of a companion in RXJ1842.9-3532 and V2246 Oph. We ruled the asymmetry signal in RXJ1615.3-3255 and V2062 Oph to be false positives. In the cases where our data indicated a potential companion we computed estimates for the value of $M_c \dot M_c$ and found values in the range of $10^{-5} - 10^{-3} M^2_J yr^{-1}$. We found significant asymmetries in four targets. Of these, three were consistent with companions. We resolved a previously unseen gap in the disc of FP Tau extending inwards from approximately 10 au., Comment: 14 pages, 12 figures, A&A, accepted

Published
2016
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5. A new blue whale song-type described for the Arabian Sea and Western Indian Ocean

Author

Cerchio, S, Willson, A, Leroy, EC, Muirhead, C, Al Harthi, S, Baldwin, R, Cholewiak, D, Collins, T, Minton, G, Rasoloarijao, T, Rogers, TL, and Sarrouf Willson, M

Subjects
Zoology, QL1-991, Botany, QK1-989
Abstract

Blue whales Balaenoptera musculus in the Indian Ocean (IO) are currently thought to represent 2 or 3 subspecies (B. m. intermedia, B. m. brevicauda, B. m. indica), and believed to be structured into 4 populations, each with a diagnostic song-type. Here we describe a previously unreported song-type that implies the probable existence of a population that has been undetected or conflated with another population. The novel song-type was recorded off Oman in the northern IO/Arabian Sea, off the western Chagos Archipelago in the equatorial central IO, and off Madagascar in the southwestern IO. As this is the only blue whale song that has been identified in the western Arabian Sea, we label it the ‘Northwest Indian Ocean’ song-type to distinguish it from other regional song-types. Spatiotemporal variation suggested a distribution west of 70°E, with potential affinity for the northern IO/Arabian Sea, and only minor presence in the southwestern IO. Timing of presence off Oman suggested that intensive illegal Soviet whaling that took 1294 blue whales in the 1960s likely targeted this population, as opposed to the more widely distributed ‘Sri Lanka’ acoustic population as previously assumed. Based upon geographic distribution and potential aseasonal reproduction found in the Soviet catch data, we suggest that if there is a northern IO subspecies (B. m. indica), it is likely this population. Moreover, the potentially restricted range, intensive historic whaling, and the fact that the song-type has been previously undetected, suggests a small population that is in critical need of status assessment and conservation action.

Published
2020
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9. GraphCast: Learning skillful medium-range global weather forecasting

Author

Battaglia, P. and Willson, M.

Abstract

We present our recent paper “GraphCast: Learning skillful medium-range global weather forecasting” (https://arxiv.org/abs/2212.12794). GraphCast is a machine-learning (ML) based weather simulator, trained from the ERA5 reanalysis archive, which can make forecasts, at 6-hour time intervals, of five surface variables and six atmospheric variables (37 vertical pressure levels), on a 0.25-degree grid (~25 km at the equator). GraphCast can generate a 10-day forecasts (35 gigabytes of data) in under 60 seconds, while outperforming ECMWF's deterministic operational forecasting system, HRES, on 90.0% of the 2760 variable and lead time combinations we evaluated, as well as all other ML baselines. These results represent a key step forward in complementing and improving weather modeling with ML, opening new opportunities for fast, accurate forecasting. In this talk we will go into the details of the model architecture, as well as providing a detailed evaluation against HRES., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Published
2023
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10. Impact of water vapor seeing on mid-infrared high-contrast imaging at ELT scale

Author

Absil, O., Delacroix, C., Orban de Xivry, G., Pathak, P., Willson, M., Berio, P., Boekel, R. van, Matter, A., Defrère, D., Burtscher, L.H., Woillez, J., Brandl, B.R., Schreiber, L., Schmidt, D., Vernet, E., Schreiber, L, Schmidt, D, Vernet, E, Schreiber, L., Schmidt, D., and Vernet, E.

Subjects
Technology, Science & Technology, FOS: Physical sciences, mid-infrared instrumentation, Optics, Astronomy & Astrophysics, water vapor seeing, wavefront control, high-contrast imaging, Physical Sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Instruments & Instrumentation, atmospheric effects
Abstract

The high-speed variability of the local water vapor content in the Earth atmosphere is a significant contributor to ground-based wavefront quality throughout the infrared domain. Unlike dry air, water vapor is highly chromatic, especially in the mid-infrared. This means that adaptive optics correction in the visible or near-infrared domain does not necessarily ensure a high wavefront quality at longer wavelengths. Here, we use literature measurements of water vapor seeing, and more recent infrared interferometric data from the Very Large Telescope Interferometer (VLTI), to evaluate the wavefront quality that will be delivered to the METIS mid-infrared camera and spectrograph for the Extremely Large Telescope (ELT), operating from 3 to 13 {\mu}m, after single-conjugate adaptive optics correction in the near-infrared. We discuss how the additional wavefront error due to water vapor seeing is expected to dominate the wavefront quality budget at N band (8-13 {\mu}m), and therefore to drive the performance of mid-infrared high-contrast imaging modes at ELT scale. Then we present how the METIS team is planning to mitigate the effect of water vapor seeing using focal-plane wavefront sensing techniques, and show with end-to-end simulations by how much the high-contrast imaging performance can be improved., Comment: 13 pages, paper presented at SPIE Astronomical Telescopes + Instrumentation 2022

Published
2022

13. 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

14. Can right ventricular speckle tracking imaging be used in arrhytmogenic cardiomyopathy screening? A study of healthy paediatric athletes with and without echocardiographic modified task force criteria

Author

Dorobantu, D, primary, Riding, N, additional, Mcclean, G, additional, Adamuz, C, additional, Ryding, D, additional, Perry, D, additional, Mcnally, S, additional, Stuart, AG, additional, Oxborough, DL, additional, Willson, M, additional, Williams, CA, additional, and Pieles, GE, additional

Published
2021
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15. Visual Health Assessment and Evaluation of Anthropogenic Threats to Arabian Sea Humpback Whales in Oman.

Author

MINTON, G., VAN BRESSEM, M. F., WILLSON, A., COLLINS, T., AL HARTHI, S., WILLSON, M. SARROUF, BALDWIN, R., LESLIE, M., and VAN WAEREBEEK, K.

Subjects
KILLER whale, ENDANGERED species, GILLNETTING, DISEASE prevalence, WHALES, HUMPBACK whale
Abstract

The sub-population of humpback whales inhabiting the Arabian Sea is a small and genetically distinct population that remains in low latitudes year-round. Designated as Endangered on the IUCN Red list of Threatened Species, the sub-population faces a number of threats throughout its range, including entanglement in fishing gear, ship strikes, disease and habitat degradation. Research conducted primarily off the coast of Sultanate of Oman over the past 20 years has contributed to understanding the population's distribution, abundance, and conservation status. However, information on the population's health and specific threats is limited. This study examines all available images of Arabian Sea humpback whales obtained between 2000 and 2018 for evidence of disease, predation, epizoites, ectoparasites, and human-induced scars and wounds. Tattoo skin disease-like lesions were detected in 41% of 93 whales, with a roughly equal distribution between males and females. Prevalence of the disease was significantly higher in 2012-2018 (51.7%) than in 2000-2011 (27.6%). Killer whale tooth rakes were detected on the ventral surface of the tail flukes of 12% (95% CI 4.5-18%) of 77 individuals. Roughly two thirds (66.6%: 95% CI 52-80%) of the 42 individuals represented by good quality photographs of the caudal peduncle region at the fluke insertion bore scarring patterns consistent with entanglement in fishing gear. At least two individuals showed severe injuries or deformations likely caused by interactions with fishing gear. Six individuals had injuries consistent with vessel strikes. Documented entanglement events from Oman and Pakistan involved large-mesh nylon gillnets, known to be used extensively throughout the Arabian Sea. These findings indicate an urgent need to design effective measures for the management and mitigation of threats, and to continue monitoring Arabian Sea humpback whales, with an emphasis on methods that allow continued and expanded assessment of health, body condition, and anthropogenic interactions. [ABSTRACT FROM AUTHOR]

Published
2022
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18. Modern tin mining and processing at Melaleuca, Port Davey, Tasmania

Author

Willson M. and Willson M.

Abstract

In 1935, cassiterite was discovered on the Melaleuca plain and the deposits were exploited by a succession of small-scale operations. In 1941, the lease was purchased by Charles King who worked the deposit alone until 1945 when he was joined by his son Deny King. In the summer of 1973, Peter and Barbara Willson and their young family sailed into Port Davey for a holiday and returned to Hobart having purchased part of the King lease and other leases in the area. As a qualified mining engineer, Peter and Barbara used modern alluvial mining, processing and smelting techniques to produce tin from the peat soils of Melaleuca. Peter started mining at Melaleuca in 1974 with just a pan, pick, shovel and wheelbarrow. The mining operation was gradually expanded with purchases of heavy machinery: a backhoe, excavator and dump trucks. At Melaleuca, cassiterite is found in the gravel sands that lie between bedrock and the overlying peat topsoil. Strip mining proved to be the most economic and practical method of winning the cassiterite-bearing coarse gravel sands. The processing plant used a gravity circuit to separate the cassiterite from the gravel sands and was designed and built entirely by Peter. He also designed and built his first smelter, a blast furnace in 1992 and constructed the reverberatory furnace in 1997. The smelter product still contained some impurities. To improve the quality of the product, two separate refining processes were undertaken. The mine workings encompass a large part of the Melaleuca plain but only a small percentage is still visible from the ground or air due to diligent rehabilitation. In 2011, Peter and Barbara agreed to relinquish the majority of their mining leases to the Tasmanian Wilderness World Heritage Area., In 1935, cassiterite was discovered on the Melaleuca plain and the deposits were exploited by a succession of small-scale operations. In 1941, the lease was purchased by Charles King who worked the deposit alone until 1945 when he was joined by his son Deny King. In the summer of 1973, Peter and Barbara Willson and their young family sailed into Port Davey for a holiday and returned to Hobart having purchased part of the King lease and other leases in the area. As a qualified mining engineer, Peter and Barbara used modern alluvial mining, processing and smelting techniques to produce tin from the peat soils of Melaleuca. Peter started mining at Melaleuca in 1974 with just a pan, pick, shovel and wheelbarrow. The mining operation was gradually expanded with purchases of heavy machinery: a backhoe, excavator and dump trucks. At Melaleuca, cassiterite is found in the gravel sands that lie between bedrock and the overlying peat topsoil. Strip mining proved to be the most economic and practical method of winning the cassiterite-bearing coarse gravel sands. The processing plant used a gravity circuit to separate the cassiterite from the gravel sands and was designed and built entirely by Peter. He also designed and built his first smelter, a blast furnace in 1992 and constructed the reverberatory furnace in 1997. The smelter product still contained some impurities. To improve the quality of the product, two separate refining processes were undertaken. The mine workings encompass a large part of the Melaleuca plain but only a small percentage is still visible from the ground or air due to diligent rehabilitation. In 2011, Peter and Barbara agreed to relinquish the majority of their mining leases to the Tasmanian Wilderness World Heritage Area.

Published
2019

21. Framing the women’s AFL: Contested spaces and emerging narratives of hope and opportunity for women in sport

Author

Willson, M., Tye, M., Gorman, S., Ely-Harper, K., Creagh, R., Leaver, T., Magladry, M., Efthimiou, O., Willson, M., Tye, M., Gorman, S., Ely-Harper, K., Creagh, R., Leaver, T., Magladry, M., and Efthimiou, O.

Abstract

This article explores historical, contemporary and emerging sites of contestation within sports, with a particular focus on women’s Australian Rules football in Australia. Sport played out on the field, in the media, popular culture, governance and legal arenas are positioned in this article as contested public spaces. The increasing presence of women in these spaces is seen as a shift towards a more socially just sporting space. With an emphasis on the contemporary sporting landscape and the historical commencement of the national women’s Australian Football League Women (AFLW) competition in February 2017, the evolution of this sport as a contested space can be understood as it relates to narratives of hope and opportunity for women. With overwhelming public feeling that the first AFLW season was a success, it is time to pause and consider what this development means for elite women’s sport, and women in contemporary Australian society more broadly.

Published
2017

22. Resolved astrometric orbits of ten O-type binaries

Author

Le Bouquin, J. -B., Sana, H., Gosset, E., De Becker, M., Duvert, G., Absil, O., Anthonioz, F., Berger, J. -P., Ertel, S., Grellmann, R., Guieu, S., Kervella, P., Rabus, M., Willson, M., Le Bouquin, J. -B., Sana, H., Gosset, E., De Becker, M., Duvert, G., Absil, O., Anthonioz, F., Berger, J. -P., Ertel, S., Grellmann, R., Guieu, S., Kervella, P., Rabus, M., and Willson, M.

Abstract

Aims. Our long-term aim is to derive model-independent stellar masses and distances for long period massive binaries by combining apparent astrometric orbit with double-lined radial velocity amplitudes (SB2). Methods. We followed-up ten O+O binaries with AMBER, PIONIER and GRAVITY at the VLTI. Here, we report on 130 astrometric observations over the last seven years. We combined this dataset with distance estimates to compute the total mass of the systems. We also computed preliminary individual component masses for the five systems with available SB2 radial velocities. Results. Nine of the ten binaries have their three-dimensional orbit well constrained. Four of them are known to be colliding wind, non-thermal radio emitters, and thus constitute valuable targets for future high angular resolution radio imaging. Two binaries break the correlation between period and eccentricity tentatively observed in previous studies. This suggests either that massive star formation produces a wide range of systems, or that several binary formation mechanisms are at play. Finally, we found that the use of existing SB2 radial velocity amplitudes can lead to unrealistic masses and distances. Conclusions. If not understood, the biases in radial velocity amplitudes will represent an intrinsic limitation for estimating dynamical masses from SB2+ interferometry or SB2+ Gaia. Nevertheless, our results can be combined with future Gaia astrometry to measure the dynamical masses and distances of the individual components with an accuracy of 5 to 15%, completely independently of the radial velocities.

Published
2017

23. Don't give up on it: Smoking cessation

Author

Willson M, Kohnstam Dt, and Wilson M

Subjects
medicine.medical_specialty, Order (business), medicine.medical_treatment, Intervention (counseling), medicine, Smoking cessation, General Medicine, Psychiatry, Psychology, Learning unit
Abstract

The aim of this Learning Unit is to give you the facts about smoking in order to enhance your assessment of your clients' health risks and the benefits they are likely to gain from stopping smoking, and to target intervention appropriately to help them stop.

Published
2016

24. Characterizing patient-oriented tools that could be packaged with guidelines to promote self-management and guideline adoption: a meta-review

Author

Vernooij, RWM, Willson, M, and Gagliardi, AR

Subjects
Implementation, Patient engagement, Self-management, Systematic review, Clinical practice guidelines
Abstract

Background: Self-management is an important component of care for patients or consumers (henceforth termed patients) with chronic conditions. Research shows that patients view guidelines as potential sources of self-management support. However, few guidelines provide such support. The primary purpose of this study was to characterize effective types of self-management interventions that could be packaged as resources in (i.e., appendices) or with guidelines (i.e., accompanying products). Methods: We conducted a meta-review of systematic reviews that evaluated self-management interventions. MEDLINE, EMBASE, and the Cochrane Library were searched from 2005 to 2014 for English language systematic reviews. Data were extracted on study characteristics, intervention (content, delivery, duration, personnel, single or multifaceted), and outcomes. Interventions were characterized by the type of component for different domains (inform, activate, collaborate). Summary statistics were used to report the characteristics, frequency, and impact of the types of self-management components. A Measurement Tool to Assess Systematic Reviews (AMSTAR) was used to assess the methodological quality of included reviews. Results: Seventy-seven studies were included (14 low, 44 moderate, 18 high risk of bias). Reviews addressed numerous clinical topics, most frequently diabetes (23, 30 %). Fifty-four focused on single (38 educational, 16 self-directed) and 21 on multifaceted interventions. Support for collaboration with providers was the least frequently used form of self-management. Most conditions featured multiple types of self-management components. The most frequently occurring type of self-management component across all studies was lifestyle advice (72 %), followed by psychological strategies (69 %), and information about the condition (49 %). In most reviews, the intervention both informed and activated patients (57, 76 %). Among the reviews that achieved positive results, 83 % of interventions involved activation alone, 94 % in combination with information, and 95 % in combination with information and collaboration. No trends in the characteristics and impact of self-management by condition were observed. Conclusions: This study revealed numerous opportunities for enhancing guidelines with resources for both patients and providers to support self-management. This includes single resources that provide information and/or prompt activation. Further research is needed to more firmly establish the statistical association between the characteristics of self-management support and outcomes; and to and optimize the design of self-management resources that are included in or with guidelines, in particular, resources that prompt collaboration with providers.

Published
2016

25. Characterizing patient-oriented tools that could be packaged with guidelines to promote self-management and guideline adoption: A meta-review

Author

Vernooij, R.W.M., Willson, M., Gagliardi, A.R., Armstrong, M., Brouwers, M., Bussières, A., Fleuren, M., Gali, K., Huckson, S., Jones, S., Lewis, S.Z., James, R., Marshall, C., and Mazza, D.

Subjects
Life, Health, CH - Child Health, Implementation, Patient engagement, Self-management, Systematic review, ELSS - Earth, Life and Social Sciences, Healthy for Life, Clinical practice guidelines, Healthy Living
Abstract

Background: Self-management is an important component of care for patients or consumers (henceforth termed patients) with chronic conditions. Research shows that patients view guidelines as potential sources of self-management support. However, few guidelines provide such support. The primary purpose of this study was to characterize effective types of self-management interventions that could be packaged as resources in (i.e., appendices) or with guidelines (i.e., accompanying products). Methods: We conducted a meta-review of systematic reviews that evaluated self-management interventions. MEDLINE, EMBASE, and the Cochrane Library were searched from 2005 to 2014 for English language systematic reviews. Data were extracted on study characteristics, intervention (content, delivery, duration, personnel, single or multifaceted), and outcomes. Interventions were characterized by the type of component for different domains (inform, activate, collaborate). Summary statistics were used to report the characteristics, frequency, and impact of the types of self-management components. A Measurement Tool to Assess Systematic Reviews (AMSTAR) was used to assess the methodological quality of included reviews. Results: Seventy-seven studies were i6ncluded (14 low, 44 moderate, 18 high risk of bias). Reviews addressed numerous clinical topics, most frequently diabetes (23, 30 %). Fifty-four focused on single (38 educational, 16 self-directed) and 21 on multifaceted interventions. Support for collaboration with providers was the least frequently used form of self-management. Most conditions featured multiple types of self-management components. The most frequently occurring type of self-management component across all studies was lifestyle advice (72 %), followed by psychological strategies (69 %), and information about the condition (49 %). In most reviews, the intervention both informed and activated patients (57, 76 %). Among the reviews that achieved positive results, 83 % of interventions involved activation alone, 94 % in combination with information, and 95 % in combination with information and collaboration. No trends in the characteristics and impact of self-management by condition were observed. Conclusions: This study revealed numerous opportunities for enhancing guidelines with resources for both patients and providers to support self-management. This includes single resources that provide information and/or prompt activation. Further research is needed to more firmly establish the statistical association between the characteristics of self-management support and outcomes; and to and optimize the design of self-management resources that are included in or with guidelines, in particular, resources that prompt collaboration with providers. © 2016 Vernooij et al.

Published
2016

26. Resolved astrometric orbits of ten O-type binaries

Author

Le Bouquin, J.-B., primary, Sana, H., additional, Gosset, E., additional, De Becker, M., additional, Duvert, G., additional, Absil, O., additional, Anthonioz, F., additional, Berger, J.-P., additional, Ertel, S., additional, Grellmann, R., additional, Guieu, S., additional, Kervella, P., additional, Rabus, M., additional, and Willson, M., additional

Published
2017
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27. Observational calibration of the projection factor of Cepheids

Author

Belkacem, K., Marques, J., Goupil, M., Sonoi, T., Ouazzani, R., Dupret, M., Mathis, S., Mosser, B., Grosjean, M., Benisty, M., Juhasz, A., Boccaletti, A., Avenhaus, H., Milli, J., Thalmann, C., Dominik, C., Pinilla, P., Buenzli, E., Pohl, A., Beuzit, J.-L., Birnstiel, T., De Boer, J., Bonnefoy, M., Chauvin, G., Christiaens, V., Garufi, A., Grady, C., Henning, T., Huélamo, N., Isella, A., Langlois, M., Menard, F., Mouillet, D., Olofsson, J., Pantin, E., Pinte, C., Pueyo, L., Breitfelder, J., Kervella, P., Mérand, A., Gallenne, A., Szabados, L., Anderson, R., Willson, M., Le Bouquin, J.-B., Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'automatique et de génie des procédés (LAGEP), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Supérieure Chimie Physique Électronique de Lyon-Centre National de la Recherche Scientifique (CNRS), 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, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Space Sciences, Technologies and Astrophysics Research Institute (STAR), Université de Liège, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), 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), Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Institute of Astronomy [ETH Zürich], Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Ludwig-Maximilians-Universität München (LMU), Cardiovasculaire, métabolisme, diabétologie et nutrition (CarMeN), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Hospices Civils de Lyon (HCL), Departamento de Astronomía, Universidad de Chile, Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), INAF - Osservatorio Astrofisico di Arcetri (OAA), Istituto Nazionale di Astrofisica (INAF), 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), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), 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), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, School of Physics, University of Exeter, Space Telescope Science Institute (STSci), Laboratoire Franco-Chilien d'Astronomie (LFCA), Universidad de Concepción [Chile]-Pontificia Universidad Católica de Chile (UC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Universidad de Chile, Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Hospices Civils de Lyon (HCL)-Institut National de la Santé et de la Recherche Médicale (INSERM), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), and 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)

Subjects
[PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015

28. Plasma sprayed Nd-Fe-B permanent magnets

Author

Willson, M., Bauser, S., and Liu, S.

Subjects
Plasma physics -- Research, Boron -- Magnetic properties, Iron compounds -- Magnetic properties, Neodymium -- Magnetic properties, Physics
Abstract

The direct deposition of the Nd-Fe-B magnet materials into complex shapes by eliminating the extensive cutting and shaping fabrication steps that are typical for a magnetic device is demonstrated. The controlled atmosphere plasma spray (CAPS) process can be used as an alternate method for synthesizing high performance nanocrystalline and nanocomposite Nd-Fe-B magnets as the products of plasma spray were bulk materials and magnetocrystalline anisotropy was developed during plasma spray.

Published
2003

29. Home ranges and movements of Egyptian Vultures Neophron percnopterus in relation to rubbish dumps in Oman and the Horn of Africa.

Author

McGrady, M. J., Karelus, D. L., Rayaleh, H. A., Willson, M. Sarrouf, Meyburg, B. U., Oli, M. K., and Bildstein, K.

Abstract

Capsule: Non-breeding Egyptian Vultures Neophron percnopterus tracked in Oman and the Horn of Africa ranged over large areas and made regular use of anthropogenic sources of food. Tracking data provide evidence that vultures monitor the availability of food within their home ranges. Aims: To study home range and movement patterns of non-breeding Egyptian Vultures. Methods: Five non-breeding Egyptian Vultures were tracked using Global Positioning System technology. Home range sizes were estimated using data only from vultures tracked for more than 11 months, and movements described. Analyses sought to determine whether patterns in movement were related to the location of rubbish dump sites and landfills. Results: Home range sizes of non-breeding Egyptian Vultures (95% kernel density estimator), ranged from 4238 to 7323 km². The average 3-hourly step length ranged from 3106.51 ± 173.16 m (mean ± se; median: 143.72 m; interquartile range, IQR: 2237.41 m) to 6519.46 ± 224.93 m (median: 2131.40 m; IQR: 7098.73 m). Egyptian Vulture activities centred on a few large rubbish dump sites that likely provided perpetually abundant food, but they frequently left those sites and visited other dumps. Conclusions: In line with what is known about Egyptian Vulture ecology, tracked birds ranged over large areas and made use of anthropogenic sources of food. Given the perpetual abundance of food at large rubbish dumps and in the presence of other scavengers feeding at them, there seemed little motivation for Egyptian Vultures to move away from them, unless it was to monitor food resources at other places within their home ranges. This movement behaviour likely reflects the potential benefit to vultures of knowledge about food availability in the wider environment, despite food being abundant at the site at which they are currently located. [ABSTRACT FROM AUTHOR]

Published
2018
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31. Introduction to Microlithography

Author

L. F. THOMPSON, C. G. WILLSON, M. J. BOWDEN, L. F. THOMPSON, L. F. THOMPSON, M. J. BOWDEN, C. Grant Willson, L. F. THOMPSON, M. J. BOWDEN, J. A. MUCHA, D. W. HESS, B. J. Lin and L. F. THOMPSON, C. G. WILLSON, M. J. BOWDEN, L. F. THOMPSON, L. F. THOMPSON, M. J. BOWDEN, C. Grant Willson, L. F. THOMPSON, M. J. BOWDEN, J. A. MUCHA, D. W. HESS, B. J. Lin

Published
1983

33. Modified berberine and protoberberines from Enantia chlorantha as potential inhibitors of Trypanosoma brucei

Author

Nyasse B, Nkwengoua Tchouboun Zondegoumba Ernestine, Sondengam B, Denier C, and Willson M

Subjects
Phosphoglycerate Kinase, Plants, Medicinal, Berberine, Phosphofructokinases, Berberine Alkaloids, Trypanosoma brucei brucei, Animals, Glyceraldehyde-3-Phosphate Dehydrogenases, Indicators and Reagents, Enzyme Inhibitors, Trypanocidal Agents, Plant Epidermis
Abstract

Phytochemical study of the stem bark of Enantia chlorantha resulted in the isolation of two protoberberines 1 and 2. These alkaloids as well as commercially available berberine were modified chemically and tested in vitro against Typanosoma brucei proliferation as well as on three targeted glycolytic enzymes. The inhibitory activities observed were in the range of 20 microM (ED50 values).

Published
2002

34. Evolution of syncarpy in angiosperms: theoretical and phylogenetic analyses of the effects of carpel fusion on offspring quantity and quality

Author

Armbruster, Scott, Debevec, E., and Willson, M.

Subjects
Biology
Abstract

The repeated evolution of fused carpels (syncarpy) is one of the dominant features of angiosperm macroevolution. We present results of new phylogenetic and theoretical analyses to assess the frequency and nature of transitions to syncarpy, and the possible advantages of syncarpy over apocarpy under a variety of ecological conditions. Using a recent molecular estimate of angiosperm phylogeny, we ascertained that a minimum of 17 independent evolutionary transitions from apocarpy to syncarpy have occurred; about three-quarters of these transitions allowed pollen tubes to cross between carpels and fertilize ovules that would otherwise be left unfertilized. Most of these transitions also intensified competition between pollen, potentially enhancing offspring fitness. The high proportion of evolutionary transitions promoting pollen competition and pollen-tube access to all carpels supports the hypothesis that the main advantage of syncarpy is in increasing offspring quality and quantity. The potential advantages of syncarpy were more thoroughly evaluated by analytical and simulation studies. These showed that the advantage of syncarpy over apocarpy involving increased offspring-quantity held under conditions of marginal pollination and declined with increasing pollination. The offspring-quality advantage persisted over a wider range of conditions, including under quite high pollination rates.

Published
2002

35. Consumption choice by bears feeding on salmon

Author

Gende, S. M., Quinn, T. P., and Willson, M. F.

Abstract

Consumption choice by brown (Ursus arctos) and black bears (U. americanus) feeding on salmon was recorded for over 20,000 bear-killed fish from 1994 to 1999 in Bristol Bay (sockeye salmon, Oncorhynchus nerka) and southeastern Alaska (pink, O. gorbuscha and chum salmon O. keta). These data revealed striking patterns of partial and selective consumption that varied with relative availability and attributes of the fish. As the availability of salmon decreased, bears consumed a larger proportion of each fish among both years and habitats. When availability was high (absolute number and density of salmon), bears consumed less biomass per captured fish, targeting energy-rich fish (those that had not spawned) or energy-rich body parts (eggs in females; brain in males). In contrast, individual fish were consumed to a much greater extent, regardless of sex or spawning status, in habitats or years of low salmon availability. The proportion of biomass consumed per fish was similar for males and females, when spawning status was statistically controlled, but bears targeted different body parts: the body flesh, brain and dorsal hump in males and the roe in females. Bears thus appeared to maximize energy intake by modifying the amount and body parts consumed, based on availability and attributes of spawning salmon.

Published
2001

36. Integrating ecology and environmental ethics: earth stewardship in the southern end of the America

Author

Rozzi, R., Armesto, J., Anderson, C., Massardo, F., Poole, A., Moses, K., Hargrove, E., Mansilla, A., Kennedy, J., Willson, M., Jax, Kurt, Jones, C., Callicott, J.B., Arroyo, M.K., Rozzi, R., Armesto, J., Anderson, C., Massardo, F., Poole, A., Moses, K., Hargrove, E., Mansilla, A., Kennedy, J., Willson, M., Jax, Kurt, Jones, C., Callicott, J.B., and Arroyo, M.K.

Abstract

The South American temperate and sub-Antarctic forests cover the longest latitudinal range in the Southern Hemisphere and include the world’s southernmost forests. However, until now, this unique biome has been absent from global ecosystem research and monitoring networks. Moreover, the latitudinal range of between 40 degrees (°) south (S) and 60° S constitutes a conspicuous gap in the International Long-Term Ecological Research (ILTER) and other international networks. We first identify 10 globally salient attributes of biological and cultural diversity in southwestern South America. We then present the nascent Chilean Long-Term Socio-Ecological Research (LTSER) network, which will incorporate a new biome into ILTER. Finally, we introduce the field environmental philosophy methodology, developed by the Chilean LTSER network to integrate ecological sciences and environmental ethics into graduate education and biocultural conservation. This approach broadens the prevailing economic spectrum of social dimensions considered by LTSER programs and helps foster bioculturally diverse forms of Earth stewardship.

Published
2012

37. Stratigraphy and structural geology of the Kalgoorlie greenstones: key criteria for gold exploration.

Author

Tripp G.I., Kalgoorlie '07, Kalgoorlie, Western Australia, Geoconferences (WA) Inc, 25-27 Sept. 2007, Cassidy K.F., Rogers J., Sircombe K., Willson M., Tripp G.I., Kalgoorlie '07, Kalgoorlie, Western Australia, Geoconferences (WA) Inc, 25-27 Sept. 2007, Cassidy K.F., Rogers J., Sircombe K., and Willson M.

Abstract

The results are presented of recent mapping and geochronology studies carried out in Kalgoorlie, Western Australia. A combination of geological and geochemical methods is applied to the models developed from stratigraphic mapping and 3D modelling. A base geochemical data layer is used, comprising a suite of about 35-40 elements including immobile trace and rare earth elements and Au, As and base metal analyses. Practical targeting methods include mapping the distribution of metals and assessing the various fluid types based on the element association in each area. The availability of an accurate map allows the geological influence on the chemistry to be normalised, and anomalous results highlighted. Analysis of drill chips is used to assess the chemistry and crystallinity of micas to determine temperature and pH gradients in alteration systems and to identify the zones of maximum fluid flow. Fingerprinting of major Au deposits in the Kalgoorlie district and further afield is a critical component of the process. These techniques, in combination with geology, have identified successful drill targets and allowed for rapid assessment of prospectivity., The results are presented of recent mapping and geochronology studies carried out in Kalgoorlie, Western Australia. A combination of geological and geochemical methods is applied to the models developed from stratigraphic mapping and 3D modelling. A base geochemical data layer is used, comprising a suite of about 35-40 elements including immobile trace and rare earth elements and Au, As and base metal analyses. Practical targeting methods include mapping the distribution of metals and assessing the various fluid types based on the element association in each area. The availability of an accurate map allows the geological influence on the chemistry to be normalised, and anomalous results highlighted. Analysis of drill chips is used to assess the chemistry and crystallinity of micas to determine temperature and pH gradients in alteration systems and to identify the zones of maximum fluid flow. Fingerprinting of major Au deposits in the Kalgoorlie district and further afield is a critical component of the process. These techniques, in combination with geology, have identified successful drill targets and allowed for rapid assessment of prospectivity.

Published
2007

40. Glycolysis as a target for the design of new anti-trypanosome drugs.

Author

UCL - MD/BICL - Département de biochimie et de biologie cellulaire, Verlinde, C L, Hannaert, Véronique, Blonski, C., Willson, M., Périé, J J, Fothergill-Gilmore, L A, Opperdoes, Frederik, Gelb, M H, Hol, W G, Michels, Paulus, UCL - MD/BICL - Département de biochimie et de biologie cellulaire, Verlinde, C L, Hannaert, Véronique, Blonski, C., Willson, M., Périé, J J, Fothergill-Gilmore, L A, Opperdoes, Frederik, Gelb, M H, Hol, W G, and Michels, Paulus

Abstract

Glycolysis is perceived as a promising target for new drugs against parasitic trypanosomatid protozoa because this pathway plays an essential role in their ATP supply. Trypanosomatid glycolysis is unique in that it is compartmentalized, and many of its enzymes display unique structural and kinetic features. Structure- and catalytic mechanism-based approaches are applied to design compounds that inhibit the glycolytic enzymes of the parasites without affecting the corresponding proteins of the human host. For some trypanosomatid enzymes, potent and selective inhibitors have already been developed that affect only the growth of cultured trypanosomatids, and not mammalian cells.

Published
2001

45. Inhibition of the glycolytic enzymes in the trypanosome: an approach in the development of new leads in the therapy of parasitic diseases.

Author

UCL, Perié, J., Riviere-Alric, I, Blonski, C., Gefflaut, T., Lauth de Viguerie, N, Trinquier, M., Willson, M., Opperdoes, Frederik, Callens, M., UCL, Perié, J., Riviere-Alric, I, Blonski, C., Gefflaut, T., Lauth de Viguerie, N, Trinquier, M., Willson, M., Opperdoes, Frederik, and Callens, M.

Abstract

Glycolysis in the trypanosome represents an important target for the development of new therapeutic agents due to the fact that this metabolism is essential for the parasite, glucose being its sole source of energy. In addition, different features of this metabolism and those associated with glycolytic enzymes offer opportunities for the development of efficient and selective compounds. Examples are given in this work of inhibitors directed to the enzymes aldolase and glyceraldehyde-phosphate-dehydrogenase and also of molecules acting specifically on the clusters of basic amino-acids present at the surfaces of the glycolytic enzymes in the parasite.

Published
1993

46. Synthesis and activity of inhibitors highly specific for the glycolytic enzymes from Trypanosoma brucei.

Author

UCL, Willson, M., Callens, M., Kuntz, D A, Perié, J, Opperdoes, Frederik, UCL, Willson, M., Callens, M., Kuntz, D A, Perié, J, and Opperdoes, Frederik

Abstract

Most glycosomal enzymes of Trypanosoma brucei carry a relatively high number of positive charges. In at least 3 of the enzymes some of the charges unique to these enzymes are concentrated in 2 distinct areas on the enzymes' surface, about 4 nm apart [4] and these positively charged structural elements have been suggested to be the site of interaction with the trypanocidal drug Suramin. We have synthesized a series of symmetrical long chain molecules with negative charges or strong dipoles at each end. Several of these compounds inhibited the glycosomal enzymes more strongly than Suramin. They also exhibited a specificity for the trypanosome enzymes, when compared with homologous enzymes from other organisms. By varying the chain length of the active compounds, a 4-nm distance between the molecules' extremes proved optimal for inhibition. Tetra-substituted compounds were better than di-substituted. Modifications introduced at the two ends indicated that a planar orientation, with an amide bond linking a phenyl ring to the chain, is preferred. Inhibition kinetics for some of the enzymes indicated the existence of multi-site interactions with the inhibitors.

Published
1993

47. Inhibition of the Glycolytic-enzymes in the Trypanosome - An Approach in the Development of New Leads in the Therapy of Parasitic Diseases

Author

UCL - Autre, Perié, J., Rivierealric, I., Blonski, C., Gefflaut, T., Deviguerie, NL., Trinquier, M., Willson, M., Opperdoes, Frederik, Callens, M., 4th International Symposium on Molecular Aspects of Chemotherapy, UCL - Autre, Perié, J., Rivierealric, I., Blonski, C., Gefflaut, T., Deviguerie, NL., Trinquier, M., Willson, M., Opperdoes, Frederik, Callens, M., and 4th International Symposium on Molecular Aspects of Chemotherapy

Abstract

Glycolysis in the trypanosome represents an important target for the development of new therapeutic agents due to the fact that this metabolism is essential for the parasite, glucose being its sole source of energy. In addition, different features of this metabolism and those associated with glycolytic enzymes offer opportunities for the development of efficient and selective compounds. Examples are given in this work of inhibitors directed to the enzymes aldolase and glyceraldehyde-phosphate-dehydrogenase and also of molecules acting specifically on the clusters of basic amino-acids present at the surfaces of the glycolytic enzymes in the parasite.

Published
1993

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