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A remnant planetary core in the hot-Neptune desert 期刊论文
NATURE, 2020, 583 (7814) : 39-+
作者:  David J. Armstrong;  Thé;  o A. Lopez;  Vardan Adibekyan;  Richard A. Booth;  Edward M. Bryant;  Karen A. Collins;  Magali Deleuil;  Alexandre Emsenhuber;  Chelsea X. Huang;  George W. King;  Jorge Lillo-Box;  Jack J. Lissauer;  Elisabeth Matthews;  Olivier Mousis;  Louise D. Nielsen;  Hugh Osborn;  Jon Otegi;  Nuno C. Santos;  ;  rgio G. Sousa;  Keivan G. Stassun;  Dimitri Veras;  Carl Ziegler;  Jack S. Acton;  Jose M. Almenara;  David R. Anderson;  David Barrado;  Susana C. C. Barros;  Daniel Bayliss;  Claudia Belardi;  Francois Bouchy;  ;  sar Briceñ;  o;  Matteo Brogi;  David J. A. Brown;  Matthew R. Burleigh;  Sarah L. Casewell;  Alexander Chaushev;  David R. Ciardi;  Kevin I. Collins;  Knicole D. Coló;  n;  Benjamin F. Cooke;  Ian J. M. Crossfield;  Rodrigo F. Dí;  az;  Elisa Delgado Mena;  Olivier D. S. Demangeon;  Caroline Dorn;  Xavier Dumusque;  Philipp Eigmü;  ller;  Michael Fausnaugh;  Pedro Figueira;  Tianjun Gan;  Siddharth Gandhi;  Samuel Gill;  Erica J. Gonzales;  Michael R. Goad;  Maximilian N. Gü;  nther;  Ravit Helled;  Saeed Hojjatpanah;  Steve B. Howell;  James Jackman;  James S. Jenkins;  Jon M. Jenkins;  Eric L. N. Jensen;  Grant M. Kennedy;  David W. Latham;  Nicholas Law;  Monika Lendl;  Michael Lozovsky;  Andrew W. Mann;  Maximiliano Moyano;  James McCormac;  Farzana Meru;  Christoph Mordasini;  Ares Osborn;  Don Pollacco;  Didier Queloz;  Liam Raynard;  George R. Ricker;  Pamela Rowden;  Alexandre Santerne;  Joshua E. Schlieder;  Sara Seager;  Lizhou Sha;  Thiam-Guan Tan;  Rosanna H. Tilbrook;  Eric Ting;  Sté;  phane Udry;  Roland Vanderspek;  Christopher A. Watson;  Richard G. West;  Paul A. Wilson;  Joshua N. Winn;  Peter Wheatley;  Jesus Noel Villasenor;  Jose I. Vines;  Zhuchang Zhan
收藏  |  浏览/下载:20/0  |  提交时间:2020/07/06

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune '  desert'  (1,2)(a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b(3), which is thought to have an unusually massive core, and recent discoveries such as LTT9779b(4)and NGTS-4b(5), on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune'  s but an anomalously large mass of39.1-2.6+2.7Earth masses and a density of5.2-0.8+0.7grams per cubic centimetre, similar to Earth'  s. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than3.9-0.9+0.8 per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation(6). Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.


Observations of TOI-849b reveal a radius smaller than Neptune'  s but a large mass of about 40 Earth masses, indicating that the planet is the remnant core of a gas giant.


  
International evaluation of an AI system for breast cancer screening 期刊论文
NATURE, 2020, 577 (7788) : 89-+
作者:  McKinney, Scott Mayer;  Sieniek, Marcin;  Godbole, Varun;  Godwin, Jonathan;  Antropova, Natasha;  Ashrafian, Hutan;  Back, Trevor;  Chesus, Mary;  Corrado, Greg C.;  Darzi, Ara;  Etemadi, Mozziyar;  Garcia-Vicente, Florencia;  Gilbert, Fiona J.;  Halling-Brown, Mark;  Hassabis, Demis;  Jansen, Sunny;  Karthikesalingam, Alan;  Kelly, Christopher J.;  King, Dominic;  Ledsam, Joseph R.;  Melnick, David;  Mostofi, Hormuz;  Peng, Lily;  Reicher, Joshua Jay;  Romera-Paredes, Bernardino;  Sidebottom, Richard;  Suleyman, Mustafa;  Tse, Daniel;  Young, Kenneth C.;  De Fauw, Jeffrey;  Shetty, Shravya
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03

Screening mammography aims to identify breast cancer at earlier stages of the disease, when treatment can be more successful(1). Despite the existence of screening programmes worldwide, the interpretation of mammograms is affected by high rates of false positives and false negatives(2). Here we present an artificial intelligence (AI) system that is capable of surpassing human experts in breast cancer prediction. To assess its performance in the clinical setting, we curated a large representative dataset from the UK and a large enriched dataset from the USA. We show an absolute reduction of 5.7% and 1.2% (USA and UK) in false positives and 9.4% and 2.7% in false negatives. We provide evidence of the ability of the system to generalize from the UK to the USA. In an independent study of six radiologists, the AI system outperformed all of the human readers: the area under the receiver operating characteristic curve (AUC-ROC) for the AI system was greater than the AUC-ROC for the average radiologist by an absolute margin of 11.5%. We ran a simulation in which the AI system participated in the double-reading process that is used in the UK, and found that the AI system maintained non-inferior performance and reduced the workload of the second reader by 88%. This robust assessment of the AI system paves the way for clinical trials to improve the accuracy and efficiency of breast cancer screening.


  
Monumental architecture at Aguada Fenix and the rise of Maya civilization 期刊论文
NATURE, 2020
作者:  Bedding, Timothy R.;  Murphy, Simon J.;  Hey, Daniel R.;  Huber, Daniel;  Li, Tanda;  Smalley, Barry;  Stello, Dennis;  White, Timothy R.;  Ball, Warrick H.;  Chaplin, William J.;  Colman, Isabel L.;  Fuller, Jim;  Gaidos, Eric;  Harbeck, Daniel R.;  Hermes, J. J.;  Holdsworth, Daniel L.;  Li, Gang;  Li, Yaguang;  Mann, Andrew W.;  Reese, Daniel R.;  Sekaran, Sanjay;  Yu, Jie;  Antoci, Victoria;  Bergmann, Christoph;  Brown, Timothy M.;  Howard, Andrew W.;  Ireland, Michael J.;  Isaacson, Howard;  Jenkins, Jon M.;  Kjeldsen, Hans;  McCully, Curtis;  Rabus, Markus;  Rains, Adam D.;  Ricker, George R.;  Tinney, Christopher G.;  Vanderspek, Roland K.
收藏  |  浏览/下载:30/0  |  提交时间:2020/07/03

Archaeologists have traditionally thought that the development of Maya civilization was gradual, assuming that small villages began to emerge during the Middle Preclassic period (1000-350 bc  dates are calibrated throughout) along with the use of ceramics and the adoption of sedentism(1). Recent finds of early ceremonial complexes are beginning to challenge this model. Here we describe an airborne lidar survey and excavations of the previously unknown site of Aguada Fenix (Tabasco, Mexico) with an artificial plateau, which measures 1,400 m in length and 10 to 15 m in height and has 9 causeways radiating out from it. We dated this construction to between 1000 and 800 bc using a Bayesian analysis of radiocarbon dates. To our knowledge, this is the oldest monumental construction ever found in the Maya area and the largest in the entire pre-Hispanic history of the region. Although the site exhibits some similarities to the earlier Olmec centre of San Lorenzo, the community of Aguada Fenix probably did not have marked social inequality comparable to that of San Lorenzo. Aguada Fenix and other ceremonial complexes of the same period suggest the importance of communal work in the initial development of Maya civilization.


Lidar survey of the Maya lowlands uncovers the monumental site of Aguada Fenix, which dates to around 1000-800 bc and points to the role of communal construction in the development of Maya civilization.


  
Global airborne sampling reveals a previously unobserved dimethyl sulfide oxidation mechanism in the marine atmosphere 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (9) : 4505-4510
作者:  Veres, Patrick R.;  Neuman, J. Andrew;  Bertram, Timothy H.;  Assaf, Emmanuel;  Wolfe, Glenn M.;  Williamson, Christina J.;  Weinzierl, Bernadett;  Tilmes, Simone;  Thompson, Chelsea R.;  Thames, Alexander B.;  Schroder, Jason C.;  Saiz-Lopez, Alfonso;  Rollins, Andrew W.;  Roberts, James M.;  Price, Derek;  Peischl, Jeff;  Nault, Benjamin A.;  Moller, Kristian H.;  Miller, David O.;  Meinardi, Simone;  Li, Qinyi;  Lamarque, Jean-Francois;  Kupc, Agnieszka;  Kjaergaard, Henrik G.;  Kinnison, Douglas;  Jimenez, Jose L.;  Jernigan, Christopher M.;  Hornbrook, Rebecca S.;  Hills, Alan;  Dollner, Maximilian;  Day, Douglas A.;  Cuevas, Carlos A.;  Campuzano-Jost, Pedro;  Burkholder, James;  Bui, T. Paul;  Brune, William H.;  Brown, Steven S.;  Brock, Charles A.;  Bourgeois, Ilann;  Blake, Donald R.;  Apel, Eric C.;  Ryerson, Thomas B.
收藏  |  浏览/下载:23/0  |  提交时间:2020/05/13
dimethyl sulfide  marine sulfur  autoxidation  marine aerosols  aerosol sulfate  
The Influence of Lifting Condensation Level on Low-Level Outflow and Rotation in Simulated Supercell Thunderstorms 期刊论文
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2019, 76 (5) : 1349-1372
作者:  Brown, Matthew;  Nowotarski, Christopher J.
收藏  |  浏览/下载:9/0  |  提交时间:2019/11/26
Dynamics  Severe storms  Supercells  Thermodynamics  Numerical analysis  modeling  
Empowering Latina scientists 期刊论文
SCIENCE, 2019, 363 (6429) : 825-826
作者:  Bernal, Ximena E.;  Rojas, Bibiana;  Pinto-E, Maria Alejandra;  Mendoza-Henao, Angela M.;  Herrera-Montes, Adriana;  Isabel Herrera-Montes, Maria;  Caceres Franco, Andrea del Pilar;  Ceron-Souza, Ivania;  Paz, Andrea;  Vergara, Daniela;  Barragan Contreras, Leidy Alejandra;  Salazar, Camilo;  Bohorquez Alonso, Martha Lucia;  Guarnizo, Carlos E.;  Sanchez, Adriana;  Olaya-Castro, Alexandra;  Urbina-Cardona, Nicolas;  Guayasamin, Juan M.;  Uy, Floria Mora-Kepfer;  Feris, Faride Lamadrid;  Franco-Orozco, Barbara;  Munoz, Martha M.;  Patricia Rincon-Diaz, Martha;  Sanchez Herrera, Melissa;  Betancourth-Cundar, Mileidy;  Tarvin, Rebecca D.;  Marquez, Roberto;  Lopez-Aguirre, Camilo;  Ron, Santiago R.;  Ramirez, Santiago;  Paez-Vacas, Monica;  Gaitan-Espitia, Juan Diego;  Navarrete-Mendez, Maria J.;  Vianna, Juliana A.;  Varela-Jaramillo, Andrea;  Sanchez-Martinez, Paola M.;  Caminer Rodriguez, Marcel Adrian;  Garcia-Robledo, Carlos;  Kuprewicz, Erin K.;  Gomez-Bahamon, Valentina;  Chacon-Vargas, Katherine;  Trillo, Alex;  Ramirez Castaneda, Valeria;  Buenaventura, Eliana;  Carolina Monmany-Garzia, A.;  Carolina Carnaval, Ana;  Dick, Christopher W.;  Jose Andrade-Nunez, Maria;  Carvajal Castro, Juan David;  Marcela Pinto, Diana;  Camargo-Sanabria, Angela A.;  Lips, Karen R.;  Motta-Gonzalez, Diana;  Canedo, Clarissa;  Melissa Diaz, Jhandra;  Navarro-Suarez, Adriana M.;  Corredor, Karen;  Roa-Varon, Adela;  Flechas, Sandra V.;  Andres Martinez-Lanfranco, Juan;  Chiarioni Thome, Maria Tereza;  Caldwell, Michael S.;  Ballestas, Onil;  Mejia M, Carolina;  Chaverri, Gloriana;  Rossi, Alejandra;  Bonaccorso, Elisa;  Pimiento, Catalina;  Guerrero, Rafael F.;  Warkentin, Karen M.;  Montoya-Pachongo, Carolina;  Alvarez, Silvia J.;  Gonzalez-Duran, Gustavo;  Anganoy-Criollo, Marvin;  Martinez-Habibe, Maria Cristina;  Ramirez, Juan P.;  Burrowes, Patricia;  Catenazzi, Alessandro;  Riveros, Andre J.;  Targino, Mariane;  Velez, Alejandro;  Vargas, Oscar M.;  Zapata, Felipe;  Waltrick, Camilla Spengler;  Ceron, Karoline;  Segovia Salcedo, Claudia;  Silva-Velasco, Martha;  Ochoa-Herrera, Valeria;  Medina, Iliana;  Narins, Peter M.;  Alves Saccol, Suelen da Silva;  de Castro Godinho, Marcela Brasil;  Velasquez Escobar, Beatriz Eugenia;  Velasco, Julian A.;  Lomascolo, Silvia;  Hoke, Kim;  Zeidemann, Vivian;  Almeida-Santos, Patricia;  Paola Ferraro, Daiana;  Araujo-Vieira, Katyuscia;  da Rocha, Sabine Borges;  Torres, Maria Fernanda;  Daniel Cadena, Carlos;  Collevatti, Rosane Garcia;  Vasconcellos, Mariana Mira;  Recart, Wilnelia;  Mitchell Aide, T.;  Bacon, Christine;  Jeckel, Adriana Moriguchi;  Diele-Viegas, Luisa Maria;  Calijorne Lourenco, Ana Carolina;  Santos, Danusy Lopes;  Rieder Cholak, Luiza;  Mendes, Roberta Graboski;  Silva, Fernanda Magalhaes;  Guedes, Thais;  Lopez-Perilla, Yeny R.;  Fusinatto, Luciana Ardenghi;  Terra, Juliana de Souza;  Rodriguez Brenes, Sofia;  Narvaez, Andrea E.;  Zina, Juliana;  Calderon-Espinosa, Martha L.;  Pardo-Diaz, Carolina;  Abadie, Michelle;  Maldonado-Chaparro, Adriana;  Cespedes Arias, Laura N.;  Montesinos, Rachel;  Fenker, Jessica;  Brunes, Tuliana Oliveira;  Ferreira Lantyer Silva, Amanda Santiago;  Vallejos, Johana Goyes;  Costa Rodrigues, Ana Paula V.;  Friol, Natalia Rizzo;  Herrera-Alvarez, Santiago;  de Souza, Eletra;  Araujo, Olivia G. S.;  Citeli, Nathalie Q. K.;  Ruggeri, Joice;  Fierro-Calderon, Eliana;  Acevedo-Charry, Orlando;  Barato, Paola;  Campos-Cerqueira, Marconi;  Mazzini, Flavia;  Beltran, Ivan;  Alejandra Meneses-Giorgi, Maria;  Jerez, Adriana;  Clavijo, Andrea P.;  Neira Jimenez, Carolina;  Dantas, Gisele P. M.;  Nascimento, Luciana Barreto;  Caballero, Susana J.;  Henao Sepulveda, A. Carolina;  Wolff, Marta;  Barnabe, Paula Cristina;  Quinones-Lebron, Shakira G.;  Bressan, Raissa Fries;  Gomez-Montoya, Nataly;  Gomez, Camila;  Colon-Pineiro, Zuania;  Esquivel Dobles, Carolina;  Bloch, Natasha;  Stynoski, Jennifer L.;  Arango, Daniel;  Marisol Gonzalez, Tania;  Luque Moreno, Francisco;  Taylor, Ryan;  Lawrence, J. P.;  Briscoe, Adriana Darielle Mejia;  Ortiz-Barrientos, Daniel;  Elena Salerno, Patricia;  Restrepo, Silvia;  Pasukonis, Andrius;  Damasceno, Roberta Pacheco;  Cecilia Dalton, Maria;  Proehl, Heike;  Valdez-Ward, Evelyn;  Andrea Rodriguez, Sabrina;  Marquez Garcia, Marcela;  Bianca Bonaparte, Eugenia;  Molina Escobar, Jorge Alberto;  Brown, Jason L.;  Yeager, Justin;  Kikuchi, David;  Ringler, Max;  Duran, Linda Hernandez;  Schulte, Lisa M.;  Vaira, Marcos;  Pereyra, Laura;  Astudillo Bravo, Diana;  Jose Salica, Maria;  Varga, Sandra;  Eguren, Antonieta;  Grattarola, Florencia;  Bernal, Moises A.;  Soledad Gaston, Maria;  Ortega Chinchilla, Jesus Eduardo;  Burdfield-Steel, Emily;  Valencia, Lina M.;  Ringler, Eva;  Rada, Marco;  Melendez-Ackerman, Elvia;  Botero, Carlos A.;  Estrada-Villegas, Sergio;  Orizaola, German;  Pinto, Brendan J.;  Gonzalez-Bellido, Paloma;  Hunter, Kimberly L.;  Rueda Solano, Luis Alberto;  Gordon, Swanne;  Guerra, Monica A.;  Jose Albo, Maria;  Vega-Frutis, Rocio;  Blundo, Cecilia;  Castaneda-Gomez, Laura;  Donnelly, Maureen A.;  Escobar, Betsabe D. Castro;  Isabel Moreno, Maria;  Crawford, Andrew J.;  Jiggins, Chris D.;  Roessler, Daniela C.;  Bravo Valencia, Laura;  Sarmiento, Carolina;  Munoz, Karen A.;  Galeano, Sandra P.;  del Rosario Castaneda, Maria;  Caro Cardenas, Cindy Jeanet;  Zalamea, Paul-Camilo;  Arias, Monica;  Zank, Caroline;  Suarez-Mayorga, Angela M.;  Colombo, Patrick;  Cuervo, Andres M.;  Coriolano, Iara Reinaldo;  de Melo, Lilian Sayuri Ouchi;  Buitrago Cardona, Alexandra;  Elias, Marianne;  Gonzalez, Mabel;  Maria Aldana, Ana;  Gubert, Carolina;  Luis Parra, Juan;  Contador, Tamara;  Coelho, Lorena;  Trillo, Mariana;  Bordin, Kauane;  Zulian, Viviane;  Moreno Arias, Rafael;  Loretto, Matthias-Claudio;  Alejandra Medina, Claudia;  Lyra, Mariana L.;  Pulido-Santacruz, Paola;  Rosser, Neil;  Waldron, Talia;  Moreno Duran, Carmen Helena;  Pizano, Camila;  Hoedl, Walter;  Fratani, Jessica;  Duport Bru, Ana Sofia;  Grosso, Jimena;  Vera Candioti, Florencia;  Adarve Rengifo, Isabel
收藏  |  浏览/下载:24/0  |  提交时间:2019/11/27
Southeast Atmosphere Studies: learning from model-observation syntheses 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2018, 18 (4) : 2615-2651
作者:  Mao, Jingqiu;  Carlton, Annmarie;  Cohen, Ronald C.;  Brune, William H.;  Brown, Steven S.;  Wolfe, Glenn M.;  Jimenez, Jose L.;  Pye, Havala O. T.;  Ng, Nga Lee;  Xu, Lu;  McNeill, V. Faye;  Tsigaridis, Kostas;  McDonald, Brian C.;  Warneke, Carsten;  Guenther, Alex;  Alvarado, Matthew J.;  de Gouw, Joost;  Mickley, Loretta J.;  Leibensperger, Eric M.;  Mathur, Rohit;  Nolte, Christopher G.;  Portmann, Robert W.;  Unger, Nadine;  Tosca, Mika;  Horowitz, Larry W.
收藏  |  浏览/下载:6/0  |  提交时间:2019/04/09
Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2017, 17 (18)
作者:  Baier, Bianca C.;  Brune, William H.;  Miller, David O.;  Blake, Donald;  Long, Russell;  Wisthaler, Armin;  Cantrell, Christopher;  Fried, Alan;  Heikes, Brian;  Brown, Steven;  McDuffie, Erin;  Flocke, Frank;  Apel, Eric;  Kaser, Lisa;  Weinheimer, Andrew
收藏  |  浏览/下载:9/0  |  提交时间:2019/04/09
Glyoxal yield from isoprene oxidation and relation to formaldehyde: chemical mechanism, constraints from SENEX aircraft observations, and interpretation of OMI satellite data 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2017, 17 (14)
作者:  Miller, Christopher Chan;  Jacob, Daniel J.;  Marais, Eloise A.;  Yu, Karen;  Travis, Katherine R.;  Kim, Patrick S.;  Fisher, Jenny A.;  Zhu, Lei;  Wolfe, Glenn M.;  Hanisco, Thomas F.;  Keutsch, Frank N.;  Kaiser, Jennifer;  Min, Kyung-Eun;  Brown, Steven S.;  Washenfelder, Rebecca A.;  Abad, Gonzalo Gonzalez;  Chance, Kelly
收藏  |  浏览/下载:13/0  |  提交时间:2019/04/09
Interaction between top-down and bottom-up control in marine food webs 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2017, 114 (8) : 1952-1957
作者:  Lynam, Christopher Philip;  Llope, Marcos;  Moellmann, Christian;  Helaoutet, Pierre;  Bayliss-Brown, Georgia Anne;  Stenseth, Nils C.
收藏  |  浏览/下载:12/0  |  提交时间:2019/11/27
trophic control  ecosystem modeling  marine food web functioning  wasp-waist  regime shifts