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201. Menthol Mouth Rinsing and Cycling Performance in Females Under Heat Stress

Author

Scott G. Thomas, Erica H. Gavel, Heather M. Logan-Sprenger, Joshua Good, and Ira Jacobs

Subjects
medicine.medical_specialty, Hot Temperature, Mouthwashes, Physical Therapy, Sports Therapy and Rehabilitation, Athletic Performance, Placebo, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Time trial, Heart Rate, Internal medicine, Heart rate, Humans, Medicine, Orthopedics and Sports Medicine, Exercise, Hand Strength, business.industry, 030229 sport sciences, Thermoregulation, Confidence interval, Bicycling, Menthol, chemistry, Sprint, Cardiology, Female, Cycling, business, Heat-Shock Response, 030217 neurology & neurosurgery
Abstract

Purpose: The effects of menthol (MEN) mouth rinse (MR) on performance, physiological, and perceptual variables in female cyclists during a 30-km independent time trial (ITT) were tested. Methods: The participants (n = 9) cycled for 30 km in hot conditions (30°C [0.6°C], 70% [1%] relative humidity, 12 [1] km/h wind speed) on 2 test occasions: with a placebo MR and with MEN MR. Handgrip and a 5-second sprint were measured before, following the first MR, and after the ITT. Ratings of perceived exertion Borg 6 to 20, thermal sensation, and thermal pleasantness were recorded every 5 km. Core temperature and heart rate were recorded throughout. Results: The ITT performance significantly improved with MEN MR by 2.3% (2.7%) relative to the placebo (62.6 [5.7] vs 64.0 [4.9] min P = .034; d = 0.85; 95% confidence interval, 0.14 to 2.8 min). The average power output was significantly higher in the MEN trial (P = .031; d = 0.87; 95% confidence interval, 0.9 to 15.0 W). No significant interaction of time and MR for handgrip (P = .581, η2 = .04) or sprint was observed (P = .365, η2 = .103). Core temperature, heart rate, ratings of perceived exertion, and thermal sensation did not significantly differ between trials at set distances (P > .05). Pleasantness significantly differed between the placebo and MEN only at 5 km, with no differences at other TT distances. Conclusion: These results suggest that a nonthermal cooling agent can improve 30-km ITT performance in female cyclists, although the improved performance with MEN MR is not due to altered thermal perception.

Published
2021
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206. Zirconium-Catalyzed Hydroalumination of C═O Bonds: Site-Selective De-O-acetylation of Peracetylated Compounds and Mechanistic Insights

Author

Romain M. Q. Renard, Thomas Lecourt, Vincent Gandon, Thibaut Courant, Marine Gavel, and Antoine Joosten

Subjects
Zirconium, 010405 organic chemistry, Hydride, Organic Chemistry, chemistry.chemical_element, 010402 general chemistry, 01 natural sciences, Medicinal chemistry, 0104 chemical sciences, Catalysis, chemistry.chemical_compound, chemistry, Catalytic cycle, Acetylation, Site selective, Stoichiometry, Zirconocene dichloride
Abstract

An unprecedented hydroalumination of C ═ O bonds catalyzed by zirconocene dichloride is reported herein and applied to the site-selective deprotection of peracetylated functional substrates. A mixed metal hydride, with 1:1 zirconium/aluminum stoichiometry, is also shown to be the reductive species. A catalytic cycle is finally proposed for this transformation with no precedent in the field of zirconium catalysis.

Published
2021
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208. Gaia Data Release 3: Summary of the content and survey properties

Author

Gaia Collaboration, Vallenari, A., Brown, A. G. A., Prusti, T., de Bruijne, J. H. J., Arenou, F., Babusiaux, C., Biermann, M., Creevey, O. L., Ducourant, C., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U. L., Lindegren, L., Luri, X., Mignard, F., Panem, C., Pourbaix, D., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Bastian, U., Drimmel, R., Jansen, F., Katz, D., Lattanzi, M. G., van Leeuwen, F., Bakker, J., Cacciari, C., Castañeda, J., De Angeli, F., Fabricius, C., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Mowlavi, N., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Roux, W., Seabroke, G. M., Sordoørcit, R., Thévenin, F., Gracia-Abril, G., Portell, J., Teyssier, D., Altmann, M., Andrae, R., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Damerdji, Y., Davidson, M., de Teodoro, P., Campos, M. Nuñez, Delchambre, L., Dell'Oro, A., Esquej, P., Fernández-Hernández, J., Fraile, E., Garabato, D., García-Lario, P., Gosset, E., Haigron, R., Halbwachs, J. -L., Hambly, N. C., Harrison, D. L., Hernández, J., Hestroffer, D., Hodgkin, S. T., Holl, B., Janßen, K., de Fombelle, G. Jevardat, Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Sarro, L. M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Aramburu, A. Abreu, Aerts, C., Aguado, J. J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M. A., Alves, J., Anders, F., Anderson, R. I., Varela, E. Anglada, Antoja, T., Baines, D., Baker, S. G., Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bartolomé, S., Bassilana, J. -L., Bauchet, N., Becciani, U., Bellazzini, M., Berihuete, A., Bernet, M., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Blazere, A., Boch, T., Bombrun, A., Bossini, D., Bouquillon, S., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Casamiquela, L., Castellani, M., Castro-Ginard, A., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W. J., Cornez, T., Cowell, S., Crifo, F., Cropper, M., Crosta, M., Crowley, C., Dafonte, C., Dapergolas, A., David, M., David, P., de Laverny, P., De Luise, F., De March, R., De Ridder, J., de Souza, R., de Torres, A., del Peloso, E. F., del Pozo, E., Delbo, M., Delgado, A., Delisle, J. -B., Demouchy, C., Dharmawardena, T. E., Di Matteo, P., Diakite, S., Diener, C., Distefano, E., Dolding, C., Edvardsson, B., Enke, H., Fabre, C., Fabrizio, M., Faigler, S., Fedorets, G., Fernique, P., Fienga, A., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., Garcia-Gutierrez, A., Garcia-Reinaldos, M., García-Torres, M., Garofalo, A., Gavel, A., Gavras, P., Gerlach, E., Geyer, R., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., González-Vidal, J. J., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L. P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Sarmiento, M. H., Hidalgo, S. L., Hilger, T., Hładczuk, N., Hobbs, D., Holland, G., Huckle, H. E., Jardine, K., Jasniewicz, G., Piccolo, A. Jean-Antoine, Jiménez-Arranz, Ó., Jorissen, A., Campillo, J. Juaristi, Julbe, F., Karbevska, L., Kervella, P., Khanna, S., Kontizas, M., Kordopatis, G., Korn, A. J., Kóspál, Á, Kostrzewa-Rutkowska, Z., Kruszyńska, K., Kun, M., Laizeau, P., Lambert, S., Lanza, A. F., Lasne, Y., Campion, J. -F. Le, Lebreton, Y., Lebzelter, T., Leccia, S., Leclerc, N., Lecoeur-Taibi, I., Liao, S., Licata, E. L., Lindstrøm, H. E. P., Lister, T. A., Livanou, E., Lobel, A., Lorca, A., Loup, C., Pardo, P. Madrero, Romeo, A. Magdaleno, Managau, S., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Marcos, J., Santos, M. M. S. Marcos, Pina, D. Marín, Marinoni, S., Marocco, F., Marshall, D. J., Polo, L. Martin, Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., McMillan, P. J., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Noval, L., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J. O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, L., Panahi, A., Payne-Wardenaar, S., Esteller, X. Peñalosa, Penttilä, A., Pichon, B., Piersimoni, A. M., Pineau, F. -X., Plachy, E., Plum, G., Poggio, E., Prša, A., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Raiteri, C. M., Rambaux, N., Ramos, P., Ramos-Lerate, M., Fiorentin, P. Re, Regibo, S., Richards, P. J., Diaz, C. Rios, Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, A. C., Robin, C., Roelens, M., Rogues, H. R. O., Rohrbasser, L., Romero-Gómez, M., Rowell, N., Royer, F., Mieres, D. Ruz, Rybicki, K. A., Sadowski, G., Núñez, A. Sáez, Sellés, A. Sagristà, Sahlmann, J., Salguero, E., Samaras, N., Gimenez, V. Sanchez, Sanna, N., Santoveña, R., Sarasso, M., Schultheis, M., Sciacca, E., Segol, M., Segovia, J. C., Ségransan, D., Semeux, D., Shahaf, S., Siddiqui, H. I., Siebert, A., Siltala, L., Silvelo, A., Slezak, E., Slezak, I., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spagna, A., Spina, L., Spoto, F., Steele, I. A., Steidelmüller, H., Stephenson, C. A., Süveges, M., Surdej, J., Szabados, L., Szegedi-Elek, E., Taris, F., Taylo, M. B., Teixeira, R., Tolomei, L., Tonello, N., Torra, F., Torra, J., Elipe, G. Torralba, Trabucchi, M., Tsounis, A. T., Turon, C., Ulla, A., Unger, N., Vaillant, M. V., van Dillen, E., van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, L., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., Zucker, S., Zwitter, T., INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), University of Manchester, European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), 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), 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 Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Geneva Observatory, Université de Genève = University of Geneva (UNIGE), Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), Technische Universität Dresden = Dresden University of Technology (TU Dresden), Centre National d'Études Spatiales [Toulouse] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), Institut de Physique de Rennes (IPR), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Space and Planetary Science, Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the third data release of the European Space Agency's Gaia mission, GDR3. The GDR3 catalogue is the outcome of the processing of raw data collected with the Gaia instruments during the first 34 months of the mission by the Gaia Data Processing and Analysis Consortium. The GDR3 catalogue contains the same source list, celestial positions, proper motions, parallaxes, and broad band photometry in the G, G$_{BP}$, and G$_{RP}$ pass-bands already present in the Early Third Data Release. GDR3 introduces an impressive wealth of new data products. More than 33 million objects in the ranges $G_{rvs} < 14$ and $3100, Comment: 23 pages, 2 figures

Published
2022
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211. Echoes of an Empire: Mortality in the Former Soviet Union Since the Mid-1990s

Author

Gavel, Julia, Cutler, David, and Boycko, Maxim

Subjects
Mathematics, Economics
Abstract

The collapse of the Soviet Union in 1991 initiated a period of significant socio-economic transformation across its former republics, fundamentally altering the landscape of public health and mortality. This thesis explores the complex interplay of economic, healthcare, behavioral, and psychosocial factors in- fluencing mortality rates in the former Soviet Union from the mid-1990s through 2019. Utilizing linear regression models, it assesses the impact of these factors across fifteen former Soviet countries, with a detailed case study on Kyrgyzstan, highlighting the nuanced nature of mortality trends in the region. The study reveals that economic indicators alone do not account for the observed mortality trends within the former Soviet Union from the mid-1990s through the 2010s contrary to expectations. Rather, it is the shifts in risk behaviors, with a particular emphasis on alcohol consumption, that correlate most significantly with mortality rates across the region (with an R-squared value of 0.32 and strong graphical correlation for mortality by alcohol consumption). This finding highlights the limited impact of economic growth, healthcare system reforms, and psychosocial outlook on mortality trends, all of which failed to show graphical and in the absence of targeted interventions addressing risk behaviors. By examining the variance in mortality trends across the region, this thesis provides insight into the broader socio-political dynamics influencing public health outcomes post-Soviet dissolution.

Published
2024

212. GPI Spectra of HR8799 C, D, and E in H-K Bands with KLIP Forward Modeling

Author

Greenbaum, Alexandra Z, Pueyo, Laurent, Ruffio, Jean-Baptiste, Wang, Jason J, De Rosa, Robert J, Aguilar, Jonathan, Rameau, Julien, Barman, Travis, Marois, Christian, Marley, Mark S, Konopacky, Quinn, Rajan, Abhijith, Macintosh, Bruce, Bailey, Vanessa P, Bauman, Brian, Bulger, Joanna, Burrows, Adam S, Cardwell, Andrew, Chilcote, Jeffrey, Cotten, Tara, Dillon, Daren, Doyon, Rene, Duchene, Gaspard, Dunn, Jennifer, Erikson, Darren, Fitzgerald, Michael P, Follette, Katherine B, Gavel, Donald, Goodsell, Stephen J, Graham, James R, Hartung, Markus, Hibon, Pascale, Hung, Li-Wei, Ingraham, Patrick, Kalas, Paul, Larkin, James E, Maire, Jerome, Marchis, Franck, McBride, James, Metchev, Stanimir, Millar-Blanchaer, Maxwell A, Morzinski, Katie M, Nielsen, Eric L, Norton, Andrew, Oppenheimer, Rebecca, Palmer, David, Patience, Jennifer, Perrin, Marshall, Poyneer, Lisa, Rantakyro, Fredrik T, Sadakuni, Naru, Saddlemyer, Leslie, Savransky, Dmitry, Schneider, Adam C, Serio, Andrew, Sivaramakrishnan, Anand, Song, Inseok, Soummer, Remi, Thomas, Sandrine, Wallace, J. Kent, Ward-Duong, Kimberly, Wiktorowicz, Sloane, and Wolff, Schuyler

Subjects
Astronomy
Abstract

We demonstrate KLIP forward modeling spectral extraction on Gemini Planet Imager coronagraphic data of HR8799, using PyKLIP. We report new and re-reduced spectrophotometry of HR8799 c, d, and e from H-K bands. We discuss a strategy for choosing optimal KLIP PSF subtraction parameters by injecting fake sources and recovering them over a range of parameters. The K1/K2 spectra for planets c and d are similar to previously published results from the same dataset. We also present a K band spectrum of HR8799e for the first time and show that our H-band spectra agree well with previously published spectra from the VLT/SPHERE instrument. We compare planets c, d, and e with M, L, and T-type field objects. All objects are consistent with low gravity mid-to-late L dwarfs, however, a lack of standard spectra for low gravity late L-type objects lead to poor fit for gravity. We place our results in context of atmospheric models presented in previous publications and discuss differences in the spectra of the three planets.

Published
2018

214. Distributed intrusion detection scheme using dual-axis dimensionality reduction for Internet of things (IoT)

Author

Shashank Gavel, Ajay Singh Raghuvanshi, and Sudarshan Tiwari

Subjects
Scheme (programming language), business.industry, Network packet, Computer science, Dimensionality reduction, Real-time computing, Intrusion detection system, Kalman filter, Theoretical Computer Science, Hardware and Architecture, Internet of Things, business, computer, Software, Information Systems, computer.programming_language
Abstract

The immense growth in the cyber world has given birth to various types of cybercrimes in the Internet of things (IoT). Cybercrimes have breached the multiple levels of cybersecurity that is one of the major issues in the IoT networks. Due to the rise in IoT applications, both devices and services are prone to security attacks and intrusions. The intrusion breaches the data packet extracted from different nodes deployed in the IoT network. Most of the intrusive attacks are very near variants of previously marked cyberattacks containing many repetitive data and features. And to detect the intrusion, the data packet needs to be analyzed. This article presents a novel scheme, i.e., dual-axis dimensionality reduction, that utilizes Kalman filter and salp swarm algorithm (coded as KF-SSA) for analyzing and minimizing the data packet. The proposed data reduction scheme is utilized with KELM-based multiclass classifier to efficiently detect intrusion in the IoT network (KF-SSA with KELM). The proposed method’s overall results are evaluated using standard intrusion detection datasets, i.e., NSL-KDD, KYOTO 2006+ (2015), CICIDS2017, and CICIDS2018 (AWS). The result from the proposed data reduction technique obtains highly reduced data, i.e., 70.% for NSL-KDD and 86.43% for CICIDS2017. The analyzed result shows high detection accuracy of 99.9% for NSL-KDD and 95.68% for CICIDS2017 with decreased computational time.

Published
2021
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215. Optimum Pellet Basicity Desirable for Blast Furnace Operation

Author

Ashish Agrawal, Srinivas Dwarapudi, Indrajit Paul, Mahaboob Basha Shaik, and Dharm Jeet Gavel

Subjects
0209 industrial biotechnology, Blast furnace, Materials science, Mechanical Engineering, digestive, oral, and skin physiology, Metallurgy, Metals and Alloys, Pellets, 02 engineering and technology, Raw material, Geotechnical Engineering and Engineering Geology, Dissociation (chemistry), Permeability (earth sciences), 020303 mechanical engineering & transports, 020901 industrial engineering & automation, 0203 mechanical engineering, Pellet, Materials Chemistry, medicine, Swelling, medicine.symptom
Abstract

The stability of blast furnace process depends upon the quality of raw materials charged into the furnace. Among iron-bearing materials, pellets are an important feed material for the blast furnace operation. However, pellets exhibit swelling inside the blast furnace due to the high temperature inside the furnace, which causes dissociation of pellets and if swelling index is not controlled properly, it gets crumbled into fragments. This results in the deterioration of the gas permeability due to the void blockage. Therefore, it is important to characterize pellets prior to its utilisation in the blast furnace. In the present study, the effect of increase in basicity on the physicochemical properties of pellets is investigated and an attempt is made to derive an optimum pellet basicity for desired properties in the blast furnace operation.

Published
2021
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216. Awareness Regarding COVID-19 Among Health Care Workers in a Tribal District of Chhattisgarh, India

Author

Nag S, Tiwari A, Gavel S, and Noor S

Subjects
Aging, Coronavirus disease 2019 (COVID-19), business.industry, General Health Professions, Health care, Medicine, Dentistry (miscellaneous), business, Socioeconomics, Health Professions (miscellaneous), Biochemistry, Genetics and Molecular Biology (miscellaneous), General Dentistry, General Biochemistry, Genetics and Molecular Biology
Published
2021
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219. Neptune Long-Lived Atmospheric Features in 2013 - 2015 from Small (28-cm) to Large (10-m) Telescopes

Author

Hueso, R, de Pater, I, Simon, A, Sanchez-Lavega, A, Delcroix, M, Wong, M. H, Tollefson, J. W, Baranec, C, de Kleer, K, Luszcz-Cook, S. H, Orton, G. S, Hammel, H. B, Gomez-Forrellad, J. M, Ordonez-Etxeberria, I, Sromovsky, L, Fry, P, Colas, F, Rojas, J. F, Perez-Hoyos, S, Gorczynski, P, Guarro, J, Kivits, W, Miles, P, Millika, D, Nicholas, P, Sussenbach, J, Wesley, A, Sayanagi, K, Ammons, S. M, Gates, E. L, Gavel, D, Garcia, E. Victor, Law, N. M, Mendikoa, I, and Riddle, R

Subjects
Lunar And Planetary Science And Exploration
Abstract

Since 2013, observations of Neptune with small telescopes (28-50 cm) have resulted in several detections of long-lived bright atmospheric features that have also been observed by large telescopes such as Keck II or Hubble. The combination of both types of images allows the study of the long-term evolution of major cloud systems in the planet. In 2013 and 2014 two bright features were present on the planet at southern mid-latitudes. These may have merged in late 2014, possibly leading to the formation of a single bright feature observed during 2015 at the same latitude. This cloud system was first observed in January 2015 and nearly continuously from July to December 2015 in observations with telescopes in the 2-10-m class and in images from amateur astronomers. These images show the bright spot as a compact feature at −40.1 +/- 1.6 deg planetographic latitude well resolved from a nearby bright zonal band that extended from −42 deg to −20 deg. The size of this system depends on wavelength and varies from a longitudinal extension of 8000 +/- 900 km and latitudinal extension of 6500 +/- 900 km in Keck II images in H and Ks bands to 5100 +/- 1400 km in longitude and 4500 +/- 1400 km in latitude in HST images in 657 nm. Over July to September 2015 the structure drifted westward in longitude at a rate of 24.48 +/- 0.03 deg/day or −94 +/- 3 m/s. This is about 30 m/s slower than the zonal winds measured at the time of the Voyager 2 flyby. Tracking its motion from July to November 2015 suggests a longitudinal oscillation of 16 deg in amplitude with a 90-day period, typical of dark spots on Neptune and similar to the Great Red Spot oscillation in Jupiter. The limited time covered by high-resolution observations only covers one full oscillation and other interpretations of the changing motions could be possible. HST images in September 2015 show the presence of a dark spot at short wavelengths located in the southern flank (planetographic latitude −47.0 deg) of the bright compact cloud observed throughout 2015. The drift rate of the bright cloud and dark spot translates to a zonal speed of −87.0 +/- 2.0 m/s, which matches the Voyager 2 zonal speeds at the latitude of the dark spot. Identification of a few other features in 2015 enabled the extraction of some limited wind information over this period. This work demonstrates the need of frequently monitoring Neptune to understand its atmospheric dynamics and shows excellent opportunities for professional and amateur collaborations.

Published
2017
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221. Gaia Data Release 3: Analysis of the Gaia BP/RP spectra using the General Stellar Parameterizer from Photometry

Author

Andrae, R., Fouesneau, M., Sordo, R., Bailer-Jones, C. A. L., Dharmawardena, T. E., Rybizki, J., De Angeli, F., Lindstrøm, H. E. P., Marshall, D. J., Drimmel, R., Korn, A. J., Soubiran, C., Brouillet, N., Casamiquela, L., Rix, H. -W., Aramburu, A. Abreu, Álvarez, M. A., Bakker, J., Bellas-Velidis, I., Bijaoui, A., Brugaletta, E., Burlacu, A., Carballo, R., Chaoul, L., Chiavassa, A., Contursi, G., Cooper, W. J., Creevey, O. L., Dafonte, C., Dapergolas, A., de Laverny, P., Delchambre, L., Demouchy, C., Edvardsson, B., Frémat, Y., Garabato, D., García-Lario, P., García-Torres, M., Gavel, A., Gomez, A., González-Santamaría, I., Hatzidimitriou, D., Heiter, U., Piccolo, A. Jean-Antoine, Kontizas, M., Kordopatis, G., Lanzafame, A. C., Lebreton, Y., Licata, E. L., Livanou, E., Lobel, A., Lorca, A., Romeo, A. Magdaleno, Manteiga, M., Marocco, F., Mary, N., Nicolas, C., Ordenovic, C., Pailler, F., Palicio, P. A., Pallas-Quintela, L., Panem, C., Pichon, B., Poggio, E., Recio-Blanco, A., Riclet, F., Robin, C., Santoveña, R., Sarro, L. M., Schultheis, M. S., Segol, M., Silvelo, A., Slezak, I., Smart, R. L., Süveges, M., Thévenin, F., Elipe, G. Torralba, Ulla, A., Utrilla, E., Vallenari, A., van Dillen, E., Zhao, H., Zorec, J., Max Planck Institute for Astronomy (MPIA), Max-Planck Institute for Astronomy, Konigstuhl 17, D-69117, Heidelberg, Germany, INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Astronomie (MPIA), Institute of Astronomy, University of Cambridge (IoA), Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), 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), Istituto Nazionale di Astrofisica, Torino, Italy, Department of Astronomy and Space Physics [Uppsala], Uppsala University, Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), M2A 2018, Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), UNIVERSITY OF HULL IECS GBR, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Conservation Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen, The Netherlands, National Observatory of Athens (NOA), Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), 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'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), Institut de Physique de Rennes (IPR), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
stars: fundamental parameters -methods: data analysis, Astrophysics - Solar and Stellar Astrophysics, surveys, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, statistical, Solar and Stellar Astrophysics (astro-ph.SR), catalogs, stars: fundamental parameters -methods: data analysis statistical surveys catalogs
Abstract

We present the General Stellar Parameterizer from Photometry (GSP-Phot), which is part of the astrophysical parameters inference system (Apsis). GSP-Phot is designed to produce a homogeneous catalogue of parameters for hundreds of millions of single non-variable stars based on their astrometry, photometry, and low-resolution BP/RP spectra. These parameters are effective temperature, surface gravity, metallicity, absolute $M_G$ magnitude, radius, distance, and extinction for each star. GSP-Phot uses a Bayesian forward-modelling approach to simultaneously fit the BP/RP spectrum, parallax, and apparent $G$ magnitude. A major design feature of GSP-Phot is the use of the apparent flux levels of BP/RP spectra to derive, in combination with isochrone models, tight observational constraints on radii and distances. We carefully validate the uncertainty estimates by exploiting repeat Gaia observations of the same source. The data release includes GSP-Phot results for 471 million sources with $G20$), mostly within 2kpc. Metallicity estimates exhibit substantial biases compared to literature values and are only useful at a qualitative level. However, we provide an empirical calibration of our metallicity estimates that largely removes these biases. Extinctions $A_0$ and $A_{\rm BP}$ show typical differences from reference values of 0.07-0.09 mag. MCMC samples of the parameters are also available for 95% of the sources. GSP-Phot provides a homogeneous catalogue of stellar parameters, distances, and extinctions that can be used for various purposes, such as sample selections (OB stars, red giants, solar analogues etc.)., 23 pages, 19 figures

Published
2022
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222. Gaia Data Release 3: Chemical cartography of the Milky Way

Author

Collaboration, Gaia, Recio-Blanco, A., Kordopatis, G., de Laverny, P., Palicio, P. A., Spagna, A., Spina, L., Katz, D., Re Fiorentin, P., Poggio, E., Mcmillan, P. J., Vallenari, A., Lattanzi, M. G., Seabroke, G. M., Casamiquela, L., Bragaglia, A., Antoja, T., Bailer-Jones, C. A. L., Andrae, R., Fouesneau, M., Cropper, M., Cantat-Gaudin, T., Heiter, U., Bijaoui, A., Brown, A. G. A., Prusti, T., de Bruijne, J. H. J., Arenou, F., Babusiaux, C., Biermann, M., Creevey, O. L., Ducourant, C., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U. L., Lindegren, L., Luri, X., Mignard, F., Panem, C., Pourbaix, D., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N. A., Bastian, U., Drimmel, R., Jansen, F., van Leeuwen, F., Bakker, J., Cacciari, C., Castañeda, J., De Angeli, F., Fabricius, C., Frémat, Y., Galluccio, L., Guerrier, A., Masana, E., Messineo, R., Mowlavi, N., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Roux, W., Sordo, R., Thévenin, F., Gracia-Abril, G., Portell, J., Teyssier, D., Altmann, M., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Damerdji, Y., Davidson, M., de Teodoro, P., Nuñez Campos, M., Delchambre, L., Dell'Oro, A., Esquej, P., Fernández-Hernández, J., Fraile, E., Garabato, D., García-Lario, P., Gosset, E., Haigron, R., Halbwachs, J. -L., Hambly, N. C., Harrison, D. L., Hernández, J., Hestroffer, D., Hodgkin, S. T., Holl, B., Janßen, K., Jevardat de Fombelle, G., Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Sarro, L. M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Abreu Aramburu, A., Aerts, C., Aguado, J. J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M. A., Alves, J., Anders, F., Anderson, R. I., Anglada Varela, E., Baines, D., Baker, S. G., Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bartolomé, S., Bassilana, J. -L., Bauchet, N., Becciani, U., Bellazzini, M., Berihuete, A., Bernet, M., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Boch, T., Bombrun, A., Bossini, D., Bouquillon, S., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Castellani, M., Castro-Ginard, A., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W. J., Cornez, T., Cowell, S., Crifo, F., Crosta, M., Crowley, C., Dafonte, C., Dapergolas, A., David, P., De Luise, F., De March, R., De Ridder, J., de Souza, R., de Torres, A., del Peloso, E. F., del Pozo, E., Delbo, M., Delgado, A., Delisle, J. -B., Demouchy, C., Dharmawardena, T. E., Di Matteo, P., Diakite, S., Diener, C., Distefano, E., Dolding, C., Edvardsson, B., Enke, H., Fabre, C., Fabrizio, M., Faigler, S., Fedorets, G., Fernique, P., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., Garcia-Gutierrez, A., Garcia-Reinaldos, M., García-Torres, M., Garofalo, A., Gavel, A., Gavras, P., Gerlach, E., Geyer, R., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., González-Vidal, J. J., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L. P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Sarmiento, M. H., Hidalgo, S. L., Hładczuk, N., Hobbs, D., Holland, G., Huckle, H. E., Jardine, K., Jasniewicz, G., Jean-Antoine Piccolo, A., Jiménez-Arranz, Ó., Juaristi Campillo, J., Julbe, F., Karbevska, L., Kervella, P., Khanna, S., Korn, A. J., Kóspál, Á, Kostrzewa-Rutkowska, Z., Kruszyńska, K., Kun, M., Laizeau, P., Lambert, S., Lanza, A. F., Lasne, Y., Le Campion, J. -F., Lebreton, Y., Lebzelter, T., Leccia, S., Leclerc, N., Lecoeur-Taibi, I., Liao, S., Licata, E. L., Lindstrøm, H. E. P., Lister, T. A., Livanou, E., Lobel, A., Lorca, A., Loup, C., Madrero Pardo, P., Magdaleno Romeo, A., Managau, S., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Marcos, J., Marcos Santos, M. M. S., Marín Pina, D., Marinoni, S., Marocco, F., Marshall, D. J., Polo, L. Martin, Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Noval, L., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J. O., Pagani, C., Pagano, I., Palaversa, L., Pallas-Quintela, L., Panahi, A., Payne-Wardenaar, S., Peñalosa Esteller, X., Penttilä, A., Pichon, B., Piersimoni, A. M., Pineau, F. -X., Plachy, E., Plum, G., Prša, A., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Raiteri, C. M., Ramos, P., Ramos-Lerate, M., Regibo, S., Richards, P. J., Rios Diaz, C., Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, A. C., Robin, C., Roelens, M., Rogues, H. R. O., Rohrbasser, L., Romero-Gómez, M., Rowell, N., Royer, F., Ruz Mieres, D., Rybicki, K. A., Sadowski, G., Sáez Núñez, A., Sagristà Sellés, A., Sahlmann, J., Salguero, E., Samaras, N., Sanchez Gimenez, V., Sanna, N., Santoveña, R., Sarasso, M., Schultheis, M., Sciacca, E., Segol, M., Segovia, J. C., Ségransan, D., Semeux, D., Shahaf, S., Siddiqui, H. I., Siebert, A., Siltala, L., Silvelo, A., Slezak, E., Slezak, I., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spoto, F., Steele, I. A., Steidelmüller, H., Stephenson, C. A., Süveges, M., Surdej, J., Szabados, L., Szegedi-Elek, E., Taris, F., Taylor, M. B., Teixeira, R., Tolomei, L., Tonello, N., Torra, F., Torra, J., Torralba Elipe, G., Trabucchi, M., Tsounis, A. T., Turon, C., Ulla, A., Unger, N., Vaillant, M. V., van Dillen, E., van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, Ł., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., Zucker, S., Zwitter, T., 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), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Monash University [Clayton], Galaxies, Etoiles, Physique, Instrumentation (GEPI), 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), Department of Chemistry [UCL, London], University College of London [London] (UCL), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Mullard Space Science Laboratory (MSSL), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Alma Mater Studiorum Università di Bologna [Bologna] (UNIBO), Institut de Ciencies del Cosmos (ICCUB), Universitat de Barcelona (UB), Max Planck Institute for Astronomy (MPIA), Max-Planck Institute for Astronomy, Konigstuhl 17, D-69117, Heidelberg, Germany, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), Institut de Physique de Rennes (IPR), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Astrophysics and Astronomy, Cosmology and Nongalactic Astrophysics (astro-ph.CO), astro-ph.SR, Astronomy, astro-ph.GA, Galaxy: abundances Stars: abundances Galaxy: evolution Galaxy: kinematics and dynamics open clusters and associations Galaxy:structure Galaxy: disc Galaxy: halo, open clusters and associations, Galaxy: disc, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, evolution [Galaxy], halo [Galaxy], Astrophysics::Solar and Stellar Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Earth and Planetary Astrophysics (astro-ph.EP), High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Galaxy: evolution, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Stars: abundances, abundances [Galaxy], Astronomy and Astrophysics, kinematics and dynamics [Galaxy], Astrophysics - Astrophysics of Galaxies, Galaxy: halo, abundances [stars], Galaxy:structure, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), astro-ph.EP, astro-ph.CO, Galaxy: abundances, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, disk [Galaxy], Galaxy: kinematics and dynamics, astro-ph.IM, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

Gaia DR3 opens a new era of all-sky spectral analysis of stellar populations thanks to the nearly 5.6 million stars observed by the RVS and parametrised by the GSP-spec module. The all-sky Gaia chemical cartography allows a powerful and precise chemo-dynamical view of the Milky Way with unprecedented spatial coverage and statistical robustness. First, it reveals the strong vertical symmetry of the Galaxy and the flared structure of the disc. Second, the observed kinematic disturbances of the disc -- seen as phase space correlations -- and kinematic or orbital substructures are associated with chemical patterns that favour stars with enhanced metallicities and lower [alpha/Fe] abundance ratios compared to the median values in the radial distributions. This is detected both for young objects that trace the spiral arms and older populations. Several alpha, iron-peak elements and at least one heavy element trace the thin and thick disc properties in the solar cylinder. Third, young disc stars show a recent chemical impoverishment in several elements. Fourth, the largest chemo-dynamical sample of open clusters analysed so far shows a steepening of the radial metallicity gradient with age, which is also observed in the young field population. Finally, the Gaia chemical data have the required coverage and precision to unveil galaxy accretion debris and heated disc stars on halo orbits through their [alpha/Fe] ratio, and to allow the study of the chemo-dynamical properties of globular clusters. Gaia DR3 chemo-dynamical diagnostics open new horizons before the era of ground-based wide-field spectroscopic surveys. They unveil a complex Milky Way that is the outcome of an eventful evolution, shaping it to the present day (abridged)., Astronomy and Astrophysics (accepted, in press)

Published
2022
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223. Gaia Data Release 3: Stellar multiplicity, a teaser for the hidden treasure

Author

Gaia Collaboration, Arenou, F., Babusiaux, C., Barstow, M. A., Faigler, S., Jorissen, A., Kervella, P., Mazeh, T., Mowlavi, N., Panuzzo, P., Sahlmann, J., Shahaf, S., Sozzetti, A., Bauchet, N., Damerdji, Y., Gavras, P., Giacobbe, P., Gosset, E., Halbwachs, J. -L., Holl, B., Lattanzi, M. G., Leclerc, N., Morel, T., Pourbaix, D., Fiorentin, P. Re, Sadowski, G., Ségransan, D., Siopis, C., Teyssier, D., Zwitter, T., Planquart, L., Brown, A. G. A., Vallenari, A., Prusti, T., de Bruijne, J. H. J., Biermann, M., Creevey, O. L., Ducourant, C., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Klioner, S. A., Lammers, U. L., Lindegren, L., Luri, X., Mignard, F., Panem, C., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Bastian, U., Drimmel, R., Jansen, F., Katz, D., van Leeuwen, F., Bakker, J., Cacciari, C., Castañeda, J., De Angeli, F., Fabricius, C., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Nicolas, C., Nienartowicz, K., Pailler, F., Riclet, F., Roux, W., Seabroke, G. M., Sordo, R., Thévenin, F., Gracia-Abril, G., Portell, J., Altmann, M., Andrae, R., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Davidson, M., de Teodoro, P., Campos, M. Nuñez, Delchambre, L., Dell'Oro, A., Esquej, P., Fernández-Hernández, J., Fraile, E., Garabato, D., García-Lario, P., Haigron, R., Hambly, N. C., Harrison, D. L., Hernández, J., Hestroffer, D., Hodgkin, S. T., Janßen, K., de Fombelle, G. Jevardat, Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Sarro, L. M., Smith, M., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Aramburu, A. Abreu, Aerts, C., Aguado, J. J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M. A., Alves, J., Anders, F., Anderson, R. I., Varela, E. Anglada, Antoja, T., Baines, D., Baker, S. G., Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Bartolomé, S., Bassilana, J. -L., Becciani, U., Bellazzini, M., Berihuete, A., Bernet, M., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Blazere, A., Boch, T., Bombrun, A., Bossini, D., Bouquillon, S., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Casamiquela, L., Castellani, M., Castro-Ginard, A., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W. J., Cornez, T., Cowell, S., Crifo, F., Cropper, M., Crosta, M., Crowley, C., Dafonte, C., Dapergolas, A., David, P., de Laverny, P., De Luise, F., De March, R., De Ridder, J., de Souza, R., de Torres, A., del Peloso, E. F., del Pozo, E., Delbo, M., Delgado, A., Delisle, J. -B., Demouchy, C., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Enke, H., Fabre, C., Fabrizio, M., Fedorets, G., Fernique, P., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., Garcia-Gutierrez, A., Garcia-Reinaldos, M., García-Torres, M., Garofalo, A., Gavel, A., Gerlach, E., Geyer, R., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gomez, A., González-Núñez, J., González-Santamaría, I., González-Vidal, J. J., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L. P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Sarmiento, M. H., Hidalgo, S. L., Hładczuk, N., Hobbs, D., Holland, G., Huckle, H. E., Jardine, K., Jasniewicz, G., Piccolo, A. Jean-Antoine, Jiménez-Arranz, Ó., Campillo, J. Juaristi, Julbe, F., Karbevska, L., Khanna, S., Kordopatis, G., Korn, A. J., Kóspál, Á, Kostrzewa-Rutkowska, Z., Kruszyńska, K., Kun, M., Laizeau, P., Lambert, S., Lanza, A. F., Lasne, Y., Campion, J. -F. Le, Lebreton, Y., Lebzelter, T., Leccia, S., Lecoeur-Taibi, I., Liao, S., Licata, E. L., Lindstrøm, H. E. P., Lister, T. A., Livanou, E., Lobel, A., Lorca, A., Loup, C., Pardo, P. Madrero, Romeo, A. Magdaleno, Managau, S., Mann, R. G., Manteiga, M., Marchant, J. M., Marconi, M., Marcos, J., Santos, M. M. S. Marcos, Pina, D. Marín, Marinoni, S., Marocco, F., Marshall, D. J., Polo, L. Martin, Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., McMillan, P. J., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morris, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Noval, L., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J. O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, L., Panahi, A., Payne-Wardenaar, S., Esteller, X. Peñalosa, Penttilä, A., Pichon, B., Piersimoni, A. M., Pineau, F. -X., Plachy, E., Plum, G., Poggio, E., Prša, A., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Raiteri, C. M., Ramos, P., Ramos-Lerate, M., Regibo, S., Richards, P. J., Diaz, C. Rios, Ripepi, V., Riva, A., Rix, H. -W., Rixon, G., Robichon, N., Robin, A. C., Robin, C., Roelens, M., Rogues, H. R. O., Rohrbasser, L., Romero-Gómez, M., Rowell, N., Royer, F., Mieres, D. Ruz, Rybicki, K. A., Núñez, A. Sáez, Sellés, A. Sagristà, Salguero, E., Samaras, N., Gimenez, V. Sanchez, Sanna, N., Santoveña, R., Sarasso, M., Schultheis, M. S., Sciacca, E., Segol, M., Segovia, J. C., Semeux, D., Siddiqui, H. I., Siebert, A., Siltala, L., Silvelo, A., Slezak, E., Slezak, I., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spagna, A., Spina, L., Spoto, F., Steele, I. A., Steidelmüller, H., Stephenson, C. A., Süveges, M., Surdej, J., Szabados, L., Szegedi-Elek, E., Taris, F., Taylor, M. B., Teixeira, R., Tolomei, L., Tonello, N., Torra, F., Torra, J., Elipe, G. Torralba, Trabucchi, M., Tsounis, A. T., Turon, C., Ulla, A., Unger, N., Vaillant, M. V., van Dillen, E., van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, Ł., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., Zucker, S., Galaxies, Etoiles, Physique, Instrumentation (GEPI), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), 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), Department of Physics and Astronomy [Leicester], University of Leicester, School of Physics and Astronomy [Tel Aviv] (TAU), Raymond and Beverly Sackler Faculty of Exact Sciences [Tel Aviv] (TAU), Tel Aviv University (TAU)-Tel Aviv University (TAU), Institut d'Astronomie et d'Astrophysique [Bruxelles] (IAA), Université libre de Bruxelles (ULB), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Astronomie Astrophysique et Géophysique (CRAAG), Institut d'Astrophysique et de Géophysique [Liège], Université de Liège, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Heckscher-Klinikum, 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, and 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)

Subjects
Astrophysics - Solar and Stellar Astrophysics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract

The Gaia DR3 Catalogue contains for the first time about eight hundred thousand solutions with either orbital elements or trend parameters for astrometric, spectroscopic and eclipsing binaries, and combinations of them. This paper aims to illustrate the huge potential of this large non-single star catalogue. Using the orbital solutions together with models of the binaries, a catalogue of tens of thousands of stellar masses, or lower limits, partly together with consistent flux ratios, has been built. Properties concerning the completeness of the binary catalogues are discussed, statistical features of the orbital elements are explained and a comparison with other catalogues is performed. Illustrative applications are proposed for binaries across the H-R diagram. The binarity is studied in the RGB/AGB and a search for genuine SB1 among long-period variables is performed. The discovery of new EL CVn systems illustrates the potential of combining variability and binarity catalogues. Potential compact object companions are presented, mainly white dwarf companions or double degenerates, but one candidate neutron star is also presented. Towards the bottom of the main sequence, the orbits of previously-suspected binary ultracool dwarfs are determined and new candidate binaries are discovered. The long awaited contribution of Gaia to the analysis of the substellar regime shows the brown dwarf desert around solar-type stars using true, rather than minimum, masses, and provides new important constraints on the occurrence rates of substellar companions to M dwarfs. Several dozen new exoplanets are proposed, including two with validated orbital solutions and one super-Jupiter orbiting a white dwarf, all being candidates requiring confirmation. Beside binarity, higher order multiple systems are also found., Comment: 60 pages, 60 figures. Accepted for publication in Astronomy & Astrophysics (2022-06-09). The catalogue of binary masses is available for download from the ESA Gaia DR3 Archive and will be available from the CDS/VizieR service

Published
2022
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224. Characterizing the Thermal Demands and Mobility Performance During International Wheelchair Rugby Competition

Author

Erica H, Gavel, Melissa A, Lacroix, Vicky L, Goosey-Tolfrey, and Heather M, Logan-Sprenger

Subjects
General Earth and Planetary Sciences, General Environmental Science
Abstract

ObjectiveTo determine the thermoregulatory responses and mobility performance of wheelchair rugby (WCR) players during international competition.MethodsEleven male National Team WCR players volunteered for the study. Testing occurred during a four game series against international competition (temp 24.7 ± 0.7°C, relative humidity 50.1 ± 3.6%), with movement time (MT) and gastrointestinal temperature (Tgi) recorded continuously.ResultsThe mean maximal Tgi was 38.6 ± 0.6°C (37.9–39.7) and did not significantly differ among Low-Class, Mid-Class, and High-Class athletes (p > 0.05). Moreover, there was a strong and significant relationship between minutes (min) played per quarter of the game and change in Tgi (r = 0.36, p = 0.01). Athletes moved a total of 27:43 ± 9:40 min:seconds (s), spent a total of 15:02 ± 8.23 min:s in Zone 1 (53.5%), 8:19 ± 3:20 min:s in Zone 2 (31.7%), and 5:59 ± 1:51 min:s in Zone 3 (21.3%). There were no differences among classification in total movement time (p = 0.169) or for speed in Zone 1, Zone 2, or Zone 3 (p > 0.05). The relationship between peak forward speed and total movement time was strong (p = 0.021, r = 0.68).ConclusionThis study demonstrated that the time spent in absolute movement zones is not classification dependent, the change in core temperature is related to movement time per quarter. Furthermore, peak speeds obtained on-court were linked to overall movement time which suggests athletes should warm-up before going on court.

Published
2022
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225. Line contact ring magnetorheological finishing process for precision polishing of optics

Author

Prabhat Kumar Baghel, Khushwant Singh Gavel, Gufran Sayeed Khan, and Raj Kumar

Subjects
Electrical and Electronic Engineering, Engineering (miscellaneous), Atomic and Molecular Physics, and Optics
Abstract

A line contact ring magnetorheological finishing (RMRF) process is conceptualized and developed for the finishing of precision optical surfaces. This tool is analogous to the cup wheel tool widely used in the optical industry for forming and fine grinding but semi-rigid in nature, thus removing high irregularities preferentially. This paper presents detailed simulations of the development of the new, to the best of our knowledge, RMRF tool and its experimental use and suitability in the polishing process. The line contact interaction between the workpiece and magnetorheological fluid present in the annular region is responsible for the finishing mechanism. The material removal rate and influence function of the RMRF process were calculated, which is essential and used for corrective polishing. The volumetric material removal rate was 0.0010406 m m 3 / min with surface roughness of 5.94 nm; however, it can be increased with optimization of machine parameters such as gap, tool rotation, current, etc. Using this RMRF process, a polishing experiment was done over an NBK-7 glass workpiece of 40 mm aperture having 70 mm radius of curvature. Surface roughness improved down to 7 nm from 28.5 nm, and figure error improved down to 295 nm from 849 nm after four cycles of polishing. This investigation demonstrates the suitability of the RMRF process for precision polishing technology for glass optics.

Published
2022

227. Unraveling the low-frequency triggered electromagnetic signatures in potentized homeopathic medicine

Author

Hari N. Bhargaw, Nisanth Nambison, Manoj Gupta, Mohit Sharma, Avanish Srivast, Prabhat Baghel, Meraj Ahmed, Mahendra Jadhav, and Khushwant Gavel

Subjects
Mechanics of Materials, Mechanical Engineering, General Materials Science, Condensed Matter Physics
Abstract

In the present work, a novel experimental tool was developed to precisely measure the potency levels in various homeopathic medicines, under various excitation frequencies. Electromagnetic responses (output voltages) are detected from the homeopathic medicines in different potencies. These unique electromagnetic responses were captured using an electromagnetic coil at 300 Hz and 4.8 kHz for each potency level developed in-house. Different potencies of Homeopathic medicine Ferrum Metallicum (FM-1X to FM-6X), prepared with α‑lactose monohydrate as its base, exhibited significant and distinct electromagnetic signals. At high excitation frequency, the output signal voltage from high homeopathic potencies had a better resolution compared to the signal obtained at lower frequency. The electromagnetic signal of various homeopathic medicines was also measured, and a distinct output voltage corresponding to each potency level was detected. Our experimental results confirmed that each homeopathic medicine has characteristic electromagnetic signals under excitation/resonance frequency. The results not only provide scientific evidence to easily classify the homeopathic medicine potency but, also helps to understand the science behind the curative action in terms of photon emission of homeopathic medicines.

Published
2023
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228. Bedrock geologic map of the Western Tanacross area, Tanacross Quadrangle, Alaska.

Author

Wypych, Alicja, Naibert, T. J., Newberry, R.-J., Twelker, Evan, Gavel, M. M., Wildland, A. D., Szumigala, D. J., Regan, S. P., Avirett, D. F., Barrera, M. L., Bernard, C. M., Blackwell, N. J. S., Fessenden, S. N., Harvey, D. A., Hubbard, A. K., Masterman, S. S., Muller, I. P., Turner, M. M., and Wyatt, W. C.

Subjects
GEOLOGICAL surveys, BEDROCK, TRONDHJEMITE, TRACHYTE, TONALITE, DIORITE
Published
2024
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233. Variability studies in Brinjal (Solanum melongena L.) in Chhattisgarh plains

Author

Sabeena Fatima Ansari, Nandan Mehta, Sajid Ansari and J. P. Gavel

Subjects
Brinjal, variability, Plant culture, SB1-1110
Abstract

Mean performance and genetic variability parameters were estimated in 7 parents and twenty one hybrids of brinjal derivedfrom seven diallel cross combinations to identify suitable parents and F1s for brinjal cultivation.. The study revealed that highlysignificant differences were observed for most of the traits. Mean performance showed that IBWL recorded highest fruit yield of1004 g per plant followed by PPC (974g), GL (931g), MK (918g) and PPR (872g) whereas, in F1, PPC x PPR registered a fruityield of 1347 g per plant followed by WBPF x PPR (1317 g), IBWL x PPR (1293g), IBWL x PPC, PPL x PPR (1287g), WBPFx PPC (1282g), IBWL x WBPF and PPL x PPC (1274g). The moderate estimates of Genotypic coefficient of variation (GCV)and Phenotypic coefficient of variation (PCV) were observed for number of fruits per cluster, average fruit weight, total numberof fruits per plant, fruit length. Maximum Genotypic coefficient of variation (GCV) & Phenotypic coefficient of variation (PCV)were observed for number of flowers per inflorescence, number of fruits per picking and fruit girth, indicating that selection canbe predicted to improve the brinjal genotypes for these characters. The highest estimates of heritability coupled with high geneticadvance estimated for the average fruit weight and number of fruits per plant showed effectiveness of simple selection forimprovement of these characters

Published
2011

234. Laboratory demonstration of optimal identification and control of tip-tilt systems

Author

Sengupta, Aditya R, Schmidt, Dirk1, Schreiber, Laura, Vernet, Elise, Sengupta, Aditya R, Gerard, Benjamin L, Dillon, Daren, van Kooten, Maaike, Gavel, Donald, Jensen-Clem, Rebecca, Sengupta, Aditya R, Schmidt, Dirk1, Schreiber, Laura, Vernet, Elise, Sengupta, Aditya R, Gerard, Benjamin L, Dillon, Daren, van Kooten, Maaike, Gavel, Donald, and Jensen-Clem, Rebecca

Published
2022

235. Estimating $\left[ \alpha / \text{Fe} \right]$ from Gaia low-resolution BP/RP spectra using the ExtraTrees algorithm

Author

Gavel, Alvin, Andrae, René, Fouesneau, Morgan, Korn, Andreas J., Sordo, Rosanna, Gavel, Alvin, Andrae, René, Fouesneau, Morgan, Korn, Andreas J., and Sordo, Rosanna

Abstract

Gaia Data Release 3 will contain more than a billion sources with positions, parallaxes, and proper motions. In addition, for hundreds of millions of stars, it will include low-resolution blue photometer (BP) and red photometer (RP) spectra. Obtained by dispersing light with prisms, these spectra have resolutions that are too low to allow us to measure individual spectral lines and bands. However, the combined BP/RP spectra can be used to estimate some stellar properties such as $T_{\text{eff}}$, $\log{g}$, and $\left[ \text{M} / \text{H} \right]$. We investigate the feasibility of using the ExtraTrees algorithm to estimate the alpha element to iron abundance ratio $\left[ \alpha / \text{H} \right]$ from low-resolution BP/RP spectra. To infer $\left[ \alpha / \text{H} \right]$ from the spectra, we created regression models trained on two samples: a set of synthetic spectra and a set of observed spectra from stars that have known $\left[ \alpha / \text{H} \right]$ since they have been observed using HERMES. We applied each model to the other sample and to a larger observed sample to assess the performance of the models. In addition, we used our models to analyse stars from the Gaia-Enceladus structure. We find that models using the ExtraTrees algorithm can be used to estimate $\left[ \alpha / \text{H} \right]$ from low-resolution BP/RP spectra of cool stars. However, they do this by exploiting correlations between $\left[ \alpha / \text{H} \right]$ and other parameters, rather than the causal effect of $\left[ \alpha / \text{H} \right]$ on the spectrum. Hence, they are unlikely to be useful in studies that attempt to distinguish stars that only differ in $\left[ \alpha / \text{H} \right]$., Comment: 12 pages, 23 figures

Published
2022
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236. Gaia Early Data Release 3 The celestial reference frame (Gaia-CRF3)

Author

Klioner, S. A., Heiter, Ulrike, Gavel, Alvin, Korn, Andreas, Zwitter, T., Klioner, S. A., Heiter, Ulrike, Gavel, Alvin, Korn, Andreas, and Zwitter, T.

Abstract

Context. Gaia-CRF3 is the celestial reference frame for positions and proper motions in the third release of data from the Gaia mission, Gaia DR3 (and for the early third release, Gaia EDR3, which contains identical astrometric results). The reference frame is defined by the positions and proper motions at epoch 2016.0 for a specific set of extragalactic sources in the (E)DR3 catalogue. Aims. We describe the construction of Gaia-CRF3 and its properties in terms of the distributions in magnitude, colour, and astrometric quality. Methods. Compact extragalactic sources in Gaia DR3 were identified by positional cross-matching with 17 external catalogues of quasi-stellar objects (QSO) and active galactic nuclei (AGN), followed by astrometric filtering designed to remove stellar contaminants. Selecting a clean sample was favoured over including a higher number of extragalactic sources. For the final sample, the random and systematic errors in the proper motions are analysed, as well as the radio-optical offsets in position for sources in the third realisation of the International Celestial Reference Frame (ICRF3). Results. Gaia-CRF3 comprises about 1.6 million QSO-like sources, of which 1 2 million have five-parameter astrometric solutions in Gaia DR3 and 0.4 million have six-parameter solutions. The sources span the magnitude range G = 13-21 with a peak density at 20.6 mag, at which the typical positional uncertainty is about 1 mas. The proper motions show systematic errors on the level of 12 mu as yr(-1) on angular scales greater than 15 deg. For the 3142 optical counterparts of ICRF3 sources in the S/X frequency bands, the median offset from the radio positions is about 0.5 mas, but it exceeds 4 mas in either coordinate for 127 sources. We outline the future of Gaia-CRF in the next Gaia data releases. Appendices give further details on the external catalogues used, how to extract information about the Gaia-CRF3 sources, potential (Galactic) confusion sources, and the e, For complete list of authors see http://dx.doi.org/10.1051/0004-6361/202243483

Published
2022
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237. On Improving Piano Technique : Experiences reducing tension and discomfort applied to the Etudes Op. 10 by Frédéric Chopin

Author

Gavel, Leo and Gavel, Leo

Abstract

The purpose of this thesis is to document what the author has experienced and learned in his search for answers to the question “how do I play piano without discomfort or pain?”. In this thesis, the question is specifically investigated through the author’s experiences trying to retrain a playing technique riddled with severe tension into one with enough comfort and ease to enable him to play the Etudes Op. 10 by Frédéric Chopin according to his musical wishes. First, an exploration of the existing piano technique literature to find information on what constitutes a “healthy” technique was conducted. Next, an extensive period of experimentation with the various ideas encountered followed, where a variety of issues with the author´s technique were identified, many setbacks were encountered, and some insights were gained. Finally, these ideas were applied on the author´s study of the Etudes until a take of the author playing through the set was recorded. The thesis ends with documenting the conclusions the author has made regarding piano technique based on this process, and finally with some reflections over the experience as a whole., Frédéric Chopin - Etudes, Op. 10Leo Gavel, piano

Published
2022

238. Gaia Early Data Release 3: The celestial reference frame (Gaia-CRF3)

Author

Klioner, Sergei, Lindegren, Lennart, Mignard, François, Hernández, J., Ramos-Lerate, M., Bastian, U., Biermann, M., Bombrun, A., Torres, A. de, Gerlach, E., Geyer, R., Hilger, T., Hobbs, D., Lammers, U. L., McMillan, P. J., Steidelmüller, H., Teyssier, D., Raiteri, C. M., Bartolomé, S., Bernet, M., Castañeda, J., Clotet, M., Davidson, M., Fabricius, C., Garralda Torres, N., González-Vidal, J. J., Portell, J., Rowell, N., Torra, F., Torra, J., Brown, A. G. A., Vallenari, A., Prusti1, T., de Bruijne, J. H. J., Arenou, F., Babusiaux, C., Creevey, O. L., Ducourant, C., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Luri, X., Panem, C., Pourbaix, D., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Drimmel, Ronald, Jansen, F., Katz, D., Lattanzi, M. G., van Leeuwen, F., Bakker, J., Cacciari, C., De Angeli, F., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Mowlavi, N., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Roux, W., Seabroke, G. M., Sordo, R., Thévenin, F., Gracia-Abril, G., Altmann, M., Andrae, R., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Damerdji, Y., de Teodoro, P., Núñez Campos, M., Delchambre, L., Dell’Oro, A., Esquej, P., Fernández-Hernández, J., Fraile, E., Garabato, D., García-Lario, P., Gosset, E., Haigron, R., Halbwachs, J.-L., Hambly, N. C., Harrison, D. L., Hestroffer, D., Hodgkin, S. T., Holl, B., Janßen, K., Jevardat de Fombelle, G., Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Sarro, L. M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Abreu Aramburu, A., Aerts, C., Aguado, J. J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M. A., Alves, J., Anderson, R. I., Anglada Varela, E., Antoja, T., Baines, D., Baker, Steven, Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bassilana, J.-L., Bauchet, N., Becciani, U., Bellazzini, M., Berihuete, A., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Boch, T., Bossini, D., Bouquillon, S., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Casamiquela, L., Castellani, M., Castro-Ginard, A., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W. J., Cornez, T., Cowell, S., Crifo, F., Cropper, M., Crosta, M., Crowley, C., Dafonte, Carlos, Dapergolas, A., David, P., Laverny, P. de, De Luise, F., De March, R., De Ridder, J., de Souza, R., Peloso, E. F. del, Pozo, E. del, Delbo, M., Delgado, A., Delisle, J.-B., Demouchy, C., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Enke, H., Fabre, C., Fabrizio, M., Faigler, S., Fedorets, G., Fernique, P., Fienga, A., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., García-Gutiérrez, A., García-Reinaldos, M., García-Torres, M., Garofalo, A., Gavel, A., Gavras, P., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gómez García, Ángel, González-Núñez, J., González Santamaría, I., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L. P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Sarmiento, M. H., Hidalgo, S. L., Hładczuk, N., Holland, G., Huckle, H. E., Jardine, K., Jasniewicz, G., Jean-Antoine Piccolo, A., Jiménez-Arranz, Ó., Juaristi Campillo, J., Julbe, F., Karbevska, L., Kervella, P., Khanna, S., Kordopatis, Georges, Korn, A. J., Kóspál, Á., Kostrzewa-Rutkowska, Z., Kruszynska, K., Kun, M., Laizeau, P., Lambert, S., Lanza, A. F., Lasne, Y., Le Campion, J.-F., Lebreton, Y., Lebzelter, T., Leccia, S., Leclerc, N., Lecoeur-Taibi, I., Liao, S., Licata, E. L., Lindstrøm, H. E. P., Lister, T. A., Livanou, E, Lobel, A., Lorca, A., Loup, C., Madrero Pardo, P., Magdaleno Romeo, A., Managau, S., Mann, R. G., Manteiga, Minia, Marchant, J. M., Marconi, M., Marcos, J., Marcos Santos, M. M. S., Marín Pina, D., Marinoni, S., Marocco, F., Marshall, D. J., Martin Polo, L., Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Noval, L., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J. O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, Lara, Panahi, A., Payne-Wardenaar, S., Peñalosa Esteller, X., Penttilä, A., Pichon, B., Piersimoni, A. M., Pineau, F.-X., Plachy, E., Plum, G., Poggio, E., Prš, A., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Rambaux, N., Ramos, P., Re Fiorentin, P., Regibo, S., Richards, P. J., Rios Diaz, C., Ripepi, V., Riva, A., Rix, H.-W., Rixon, G., Robichon, N., Robin, A. C., Robin, C., Roelens, M., Rogues, H. R. O., Rohrbasser, L., Romero-Gómez, M., Royer, F., Ruz Mieres, D., Rybicki, K. A., Sadowski, G., Sáez Núñez, A., Sagristà Sellés, A., Sahlmann, J., Salguero, E., Samaras, N., Sánchez Giménez, V., Sanna, N., Santoveña, Raúl, Sarasso, M., Schultheis, M., Sciacca, E., Segol, M., Segovia, J. C., Ségransan, D., Semeux, D., Shahaf, S., Siddiqui, H. I., Siebert, A., Siltala, L., Slezak, E., Slezak, I., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spagna, A., Spina, L., Spoto, F., Steele, I. A., Stephenson, C. A., Süveges, M., Surdej, J., Szabados, L., Szegedi-Elek, E., Taris, F., Taylor, M. B., Teixeira, R., Tolomei, L., Tonello, N., Torralba Elipe, Guillermo, Silvelo, Arturo, Trabucchi, M., Tsounis, A. T., Turon, C., Ulla, A., Unger, N., Vaillant, M. V., van Dillen, E., van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, L., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., Zucker, S., Zwitter, T., Klioner, Sergei, Lindegren, Lennart, Mignard, François, Hernández, J., Ramos-Lerate, M., Bastian, U., Biermann, M., Bombrun, A., Torres, A. de, Gerlach, E., Geyer, R., Hilger, T., Hobbs, D., Lammers, U. L., McMillan, P. J., Steidelmüller, H., Teyssier, D., Raiteri, C. M., Bartolomé, S., Bernet, M., Castañeda, J., Clotet, M., Davidson, M., Fabricius, C., Garralda Torres, N., González-Vidal, J. J., Portell, J., Rowell, N., Torra, F., Torra, J., Brown, A. G. A., Vallenari, A., Prusti1, T., de Bruijne, J. H. J., Arenou, F., Babusiaux, C., Creevey, O. L., Ducourant, C., Evans, D. W., Eyer, L., Guerra, R., Hutton, A., Jordi, C., Luri, X., Panem, C., Pourbaix, D., Randich, S., Sartoretti, P., Soubiran, C., Tanga, P., Walton, N. A., Bailer-Jones, C. A. L., Drimmel, Ronald, Jansen, F., Katz, D., Lattanzi, M. G., van Leeuwen, F., Bakker, J., Cacciari, C., De Angeli, F., Fouesneau, M., Frémat, Y., Galluccio, L., Guerrier, A., Heiter, U., Masana, E., Messineo, R., Mowlavi, N., Nicolas, C., Nienartowicz, K., Pailler, F., Panuzzo, P., Riclet, F., Roux, W., Seabroke, G. M., Sordo, R., Thévenin, F., Gracia-Abril, G., Altmann, M., Andrae, R., Audard, M., Bellas-Velidis, I., Benson, K., Berthier, J., Blomme, R., Burgess, P. W., Busonero, D., Busso, G., Cánovas, H., Carry, B., Cellino, A., Cheek, N., Clementini, G., Damerdji, Y., de Teodoro, P., Núñez Campos, M., Delchambre, L., Dell’Oro, A., Esquej, P., Fernández-Hernández, J., Fraile, E., Garabato, D., García-Lario, P., Gosset, E., Haigron, R., Halbwachs, J.-L., Hambly, N. C., Harrison, D. L., Hestroffer, D., Hodgkin, S. T., Holl, B., Janßen, K., Jevardat de Fombelle, G., Jordan, S., Krone-Martins, A., Lanzafame, A. C., Löffler, W., Marchal, O., Marrese, P. M., Moitinho, A., Muinonen, K., Osborne, P., Pancino, E., Pauwels, T., Recio-Blanco, A., Reylé, C., Riello, M., Rimoldini, L., Roegiers, T., Rybizki, J., Sarro, L. M., Siopis, C., Smith, M., Sozzetti, A., Utrilla, E., van Leeuwen, M., Abbas, U., Ábrahám, P., Abreu Aramburu, A., Aerts, C., Aguado, J. J., Ajaj, M., Aldea-Montero, F., Altavilla, G., Álvarez, M. A., Alves, J., Anderson, R. I., Anglada Varela, E., Antoja, T., Baines, D., Baker, Steven, Balaguer-Núñez, L., Balbinot, E., Balog, Z., Barache, C., Barbato, D., Barros, M., Barstow, M. A., Bassilana, J.-L., Bauchet, N., Becciani, U., Bellazzini, M., Berihuete, A., Bertone, S., Bianchi, L., Binnenfeld, A., Blanco-Cuaresma, S., Boch, T., Bossini, D., Bouquillon, S., Bragaglia, A., Bramante, L., Breedt, E., Bressan, A., Brouillet, N., Brugaletta, E., Bucciarelli, B., Burlacu, A., Butkevich, A. G., Buzzi, R., Caffau, E., Cancelliere, R., Cantat-Gaudin, T., Carballo, R., Carlucci, T., Carnerero, M. I., Carrasco, J. M., Casamiquela, L., Castellani, M., Castro-Ginard, A., Chaoul, L., Charlot, P., Chemin, L., Chiaramida, V., Chiavassa, A., Chornay, N., Comoretto, G., Contursi, G., Cooper, W. J., Cornez, T., Cowell, S., Crifo, F., Cropper, M., Crosta, M., Crowley, C., Dafonte, Carlos, Dapergolas, A., David, P., Laverny, P. de, De Luise, F., De March, R., De Ridder, J., de Souza, R., Peloso, E. F. del, Pozo, E. del, Delbo, M., Delgado, A., Delisle, J.-B., Demouchy, C., Dharmawardena, T. E., Diakite, S., Diener, C., Distefano, E., Dolding, C., Enke, H., Fabre, C., Fabrizio, M., Faigler, S., Fedorets, G., Fernique, P., Fienga, A., Figueras, F., Fournier, Y., Fouron, C., Fragkoudi, F., Gai, M., García-Gutiérrez, A., García-Reinaldos, M., García-Torres, M., Garofalo, A., Gavel, A., Gavras, P., Giacobbe, P., Gilmore, G., Girona, S., Giuffrida, G., Gomel, R., Gómez García, Ángel, González-Núñez, J., González Santamaría, I., Granvik, M., Guillout, P., Guiraud, J., Gutiérrez-Sánchez, R., Guy, L. P., Hatzidimitriou, D., Hauser, M., Haywood, M., Helmer, A., Helmi, A., Sarmiento, M. H., Hidalgo, S. L., Hładczuk, N., Holland, G., Huckle, H. E., Jardine, K., Jasniewicz, G., Jean-Antoine Piccolo, A., Jiménez-Arranz, Ó., Juaristi Campillo, J., Julbe, F., Karbevska, L., Kervella, P., Khanna, S., Kordopatis, Georges, Korn, A. J., Kóspál, Á., Kostrzewa-Rutkowska, Z., Kruszynska, K., Kun, M., Laizeau, P., Lambert, S., Lanza, A. F., Lasne, Y., Le Campion, J.-F., Lebreton, Y., Lebzelter, T., Leccia, S., Leclerc, N., Lecoeur-Taibi, I., Liao, S., Licata, E. L., Lindstrøm, H. E. P., Lister, T. A., Livanou, E, Lobel, A., Lorca, A., Loup, C., Madrero Pardo, P., Magdaleno Romeo, A., Managau, S., Mann, R. G., Manteiga, Minia, Marchant, J. M., Marconi, M., Marcos, J., Marcos Santos, M. M. S., Marín Pina, D., Marinoni, S., Marocco, F., Marshall, D. J., Martin Polo, L., Martín-Fleitas, J. M., Marton, G., Mary, N., Masip, A., Massari, D., Mastrobuono-Battisti, A., Mazeh, T., Messina, S., Michalik, D., Millar, N. R., Mints, A., Molina, D., Molinaro, R., Molnár, L., Monari, G., Monguió, M., Montegriffo, P., Montero, A., Mor, R., Mora, A., Morbidelli, R., Morel, T., Morris, D., Muraveva, T., Murphy, C. P., Musella, I., Nagy, Z., Noval, L., Ocaña, F., Ogden, A., Ordenovic, C., Osinde, J. O., Pagani, C., Pagano, I., Palaversa, L., Palicio, P. A., Pallas-Quintela, Lara, Panahi, A., Payne-Wardenaar, S., Peñalosa Esteller, X., Penttilä, A., Pichon, B., Piersimoni, A. M., Pineau, F.-X., Plachy, E., Plum, G., Poggio, E., Prš, A., Pulone, L., Racero, E., Ragaini, S., Rainer, M., Rambaux, N., Ramos, P., Re Fiorentin, P., Regibo, S., Richards, P. J., Rios Diaz, C., Ripepi, V., Riva, A., Rix, H.-W., Rixon, G., Robichon, N., Robin, A. C., Robin, C., Roelens, M., Rogues, H. R. O., Rohrbasser, L., Romero-Gómez, M., Royer, F., Ruz Mieres, D., Rybicki, K. A., Sadowski, G., Sáez Núñez, A., Sagristà Sellés, A., Sahlmann, J., Salguero, E., Samaras, N., Sánchez Giménez, V., Sanna, N., Santoveña, Raúl, Sarasso, M., Schultheis, M., Sciacca, E., Segol, M., Segovia, J. C., Ségransan, D., Semeux, D., Shahaf, S., Siddiqui, H. I., Siebert, A., Siltala, L., Slezak, E., Slezak, I., Smart, R. L., Snaith, O. N., Solano, E., Solitro, F., Souami, D., Souchay, J., Spagna, A., Spina, L., Spoto, F., Steele, I. A., Stephenson, C. A., Süveges, M., Surdej, J., Szabados, L., Szegedi-Elek, E., Taris, F., Taylor, M. B., Teixeira, R., Tolomei, L., Tonello, N., Torralba Elipe, Guillermo, Silvelo, Arturo, Trabucchi, M., Tsounis, A. T., Turon, C., Ulla, A., Unger, N., Vaillant, M. V., van Dillen, E., van Reeven, W., Vanel, O., Vecchiato, A., Viala, Y., Vicente, D., Voutsinas, S., Weiler, M., Wevers, T., Wyrzykowski, L., Yoldas, A., Yvard, P., Zhao, H., Zorec, J., Zucker, S., and Zwitter, T.

Abstract

[Abstract]: Context. Gaia-CRF3 is the celestial reference frame for positions and proper motions in the third release of data from the Gaia mission, Gaia DR3 (and for the early third release, Gaia EDR3, which contains identical astrometric results). The reference frame is defined by the positions and proper motions at epoch 2016.0 for a specific set of extragalactic sources in the (E)DR3 catalogue. Aims. We describe the construction of Gaia-CRF3 and its properties in terms of the distributions in magnitude, colour, and astrometric quality. Methods. Compact extragalactic sources in Gaia DR3 were identified by positional cross-matching with 17 external catalogues of quasi-stellar objects (QSO) and active galactic nuclei (AGN), followed by astrometric filtering designed to remove stellar contaminants. Selecting a clean sample was favoured over including a higher number of extragalactic sources. For the final sample, the random and systematic errors in the proper motions are analysed, as well as the radio-optical offsets in position for sources in the third realisation of the International Celestial Reference Frame (ICRF3). Results. Gaia-CRF3 comprises about 1.6 million QSO-like sources, of which 1.2 million have five-parameter astrometric solutions in Gaia DR3 and 0.4 million have six-parameter solutions. The sources span the magnitude range G = 13–21 with a peak density at 20.6 mag, at which the typical positional uncertainty is about 1 mas. The proper motions show systematic errors on the level of 12 µas yr–1 on angular scales greater than 15 deg. For the 3142 optical counterparts of ICRF3 sources in the S/X frequency bands, the median offset from the radio positions is about 0.5 mas, but it exceeds 4 mas in either coordinate for 127 sources. We outline the future of Gaia-CRF in the next Gaia data releases. Appendices give further details on the external catalogues used, how to extract information about the Gaia-CRF3 sources, potential (Galactic) confusion sources, a

Published
2022

239. Laboratory Demonstration of Optimal Identification and Control of Tip-Tilt Systems

Author

Sengupta, Aditya R., Gerard, Benjamin L., Dillon, Daren, van Kooten, Maaike, Gavel, Donald, Jensen-Clem, Rebecca, Sengupta, Aditya R., Gerard, Benjamin L., Dillon, Daren, van Kooten, Maaike, Gavel, Donald, and Jensen-Clem, Rebecca

Abstract

We present the results of testing optimal linear-quadratic-Gaussian (LQG) control for tip and tilt Zernike wavefront modes on the SEAL (Santa cruz Extreme AO Lab) testbed. The controller employs a physics model conditioned by the expected tip/tilt power spectrum and vibration peaks. The model builds on similar implementations, such as that of the Gemini Planet Imager, by considering the effects of loop delays and the response of the control hardware. Tests are being performed on SEAL using the Fast Atmospheric Self-coherent camera Technique (FAST), and being executed using a custom Python library to align optics, generate interaction matrices, and perform real-time control by combining controllers with simulated disturbance signals to be corrected. We have carried out open-loop data collection, characterizing the natural bench dynamics, and have shown a reduction in RMS wavefront error due to integrator control and LQG control., Comment: submitted to SPIE Astronomical Telescopes and Instrumentation 2022, paper number 12185-311

Published
2022
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240. FIELD STATION LOCATIONS AND MAGNETIC SUSCEPTIBILITY DATA FOR THE CHENA--POGO AND MOUNT HARPER PROJECTS, BIG DELTA AND CIRCLE QUADRANGLES, ALASKA, COLLECTED JUNE-SEPTEMBER 2023.

Author

Gavel, Michelle M., Twelker, Evan, Wypych, Alicja, Naibert, Travis J., Newberry, Rainer J., Szumigala, David J., Wildland, Alec D., Barrera, Michael L., Biegel, Jenna N., Harvey, David A., Ketcham, Richard A., Muller, Isabella P., and Reagan, Sean P.

Subjects
*MAGNETIC susceptibility, *GEOPHYSICAL surveys, *GEOLOGICAL mapping, *GEOLOGICAL maps, *LOCATION data
Abstract

During the 2023 field season, geologists from the Alaska Division of Geological & Geophysical Surveys conducted bedrock geologic mapping in the Big Delta and Circle quadrangles in Alaska. The project areas are of interest for potential mineral resource development, including gold and copper deposits. This report provides field station locations, rock descriptions, and magnetic susceptibility measurements. The data is available for download from the DGGS website. The project aims to produce accurate geologic maps to support mineral resource exploration in eastern Interior Alaska. [Extracted from the article]

Published
2023
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242. SUCCESS IN FIRST-GRADE READING

Author

DURRELL, DONALD D., NICHOLSON, ALICE, OLSON, ARTHUR V., GAVEL, SYLVIA R., and LINEHAN, ELEANOR B.

Published
2008

247. Effect of bridge wire material in electro-hydraulic forming of AA5754 sheet metal using experimental and finite element analysis

Author

Ayisha Ali, Meraj Ahmed, Manoj Soni, Surendra Kumar, Khushwant Singh Gavel, and Venkat Chilla

Abstract

High velocity forming techniques like electro-hydraulic forming are very advantageous over conventional forming for sheet metal forming application. The problems such as low formability, non-uniform strain distribution etc. in conventional quasi-static process can be tackled by electro-hydraulic forming (EHF). It is high strain rate process and exerts uniform pressure on the workpiece through shockwave/pulse propagating through liquid medium. In the process, energy is delivered to bridge wire connected between electrodes that is place inside cavity of dies. The pressure is generated inside liquid medium by vaporisation of the wire due to current pulse. The material of bridge wire/its diameter plays important role in generation of desired shockwave pressure and archiving better efficiency of the process. Present work investigates the effect of bridge wire material/its diameter on efficiency of the process by comparing formability of sheets by EHF process using wires of Al and Cu having three diameters (19, 21 and 24 gauge). FE simulation of the EHF process is also carried out using alternative process to simulate explosive forming process and the result have been correlated. It is found that the Al wire performs better when formability and strain distribution across samples are analysed as compared to corresponding Cu wires.

Published
2022
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250. Evaluation of a Peptide-Based Coassembled Nanofibrous and Thixotropic Hydrogel for Dermal Wound Healing

Author

Hamendra Singh Parmar, Pramod K. Gavel, Narendra Kumar, and Apurba K. Das

Subjects
chemistry.chemical_classification, Thixotropy, Dipeptide, integumentary system, Biochemistry (medical), technology, industry, and agriculture, Biomedical Engineering, Biomaterial, Peptide, General Chemistry, Biomaterials, chemistry.chemical_compound, chemistry, Wound healing, Biomedical engineering
Abstract

The development of a peptide-based coassembled thixotropic hydrogel is a promising biomaterial, which could be used for dermal wound healing application. Cyclodextrins are widely used as biocompatible cyclic oligosaccharides that have hydrophilic exterior and hydrophobic interior for the formation of functional biomaterials. The current work presents a paradigm of a coassembled hydrogel with suitable mechanical strength that exhibits in vivo wound healing efficacy. In this report, we have designed and synthesized an Amoc (9-anthracenemethoxycarbonyl)-capped dipeptide, which self-assembles into a tough and robust hydrogel owing to participation of various noncovalent interactions. The mechanical strength of the self-assembling peptide-based hydrogel is tuned by incorporation of equimolar β-cyclodextrin (CD), which leads to the formation of a coassembled hydrogel suitable for wound healing application. The coassembled hydrogel exhibits simple syringe injectability and is thixotropic in nature. The nanostructural morphology of the coassembled hydrogel reveals a highly cross-linked and entangled nanofibrillar network. Several spectroscopic data elucidate the presence of noncovalent interactions between CD and peptide, which could be the driving force for the formation of ordered nanostructures. The coassembled hydrogel shows potent antibacterial activity against Gram-positive pathogenic bacteria. In vitro biocompatibility of the coassembled hydrogel has been investigated with the human embryonic kidney (HEK293) and MCF-7 cell lines. Additionally, confocal laser scanning microscopic data show cellular uptake of the coassembled hydrogel with blue fluorescence. Moreover, the in vivo wound healing activity of the coassembled hydrogel has been investigated by the histopathology study. The biochemical parameters such as nitric oxide and collagen contents have been evaluated by Griess and hydroxy proline assays. All the results corroborate the wound healing efficacy of a nanofibrillar antibacterial coassembled hydrogel.

Published
2022

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