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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:17/0  |  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.


  
Reply to: "Impact of marine processes on flow dynamics of northern Antarctic Peninsula outlet glaciers" by Rott et al. 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Tuckett, Peter A.;  Ely, Jeremy C.;  Sole, Andrew J.;  Livingstone, Stephen J.;  Davison, Benjamin J.;  van Wessem, J. Melchior
收藏  |  浏览/下载:12/0  |  提交时间:2020/06/16
Nitrogen and phosphorus constrain the CO2 fertilization of global plant biomass (vol 21, pg 561, 2020) 期刊论文
NATURE CLIMATE CHANGE, 2020, 10 (7) : 696-697
作者:  Terrer, Cesar;  Jackson, Robert B.;  Prentice, I. Colin;  Keenan, Trevor F.;  Kaiser, Christina;  Vicca, Sara;  Fisher, Joshua B.;  Reich, Peter B.;  Stocker, Benjamin D.;  Hungate, Bruce A.;  Penuelas, Josep;  McCallum, Ian;  Soudzilovskaia, Nadejda A.;  Cernusak, Lucas A.;  Talhelm, Alan F.;  Van Sundert, Kevin;  Piao, Shilong;  Newton, Paul C. D.;  Hovenden, Mark J.;  Blumenthal, Dana M.;  Liu, Yi Y.;  Mueller, Christoph;  Winter, Klaus;  Field, Christopher B.;  Viechtbauer, Wolfgang;  Van Lissa, Caspar J.;  Hoosbeek, Marcel R.;  Watanabe, Makoto;  Koike, Takayoshi;  Leshyk, Victor O.;  Polley, H. Wayne;  Franklin, Oskar
收藏  |  浏览/下载:31/0  |  提交时间:2020/06/01
Increasing contribution of peatlands to boreal evapotranspiration in a warming climate 期刊论文
NATURE CLIMATE CHANGE, 2020, 10 (6) : 555-+
作者:  Helbig, Manuel;  Waddington, James Michael;  Alekseychik, Pavel;  Amiro, Brian D.;  Aurela, Mika;  Barr, Alan G.;  Black, T. Andrew;  Blanken, Peter D.;  Carey, Sean K.;  Chen, Jiquan;  Chi, Jinshu;  Desai, Ankur R.;  Dunn, Allison;  Euskirchen, Eugenie S.;  Flanagan, Lawrence B.;  Forbrich, Inke;  Friborg, Thomas;  Grelle, Achim;  Harder, Silvie;  Heliasz, Michal;  Humphreys, Elyn R.;  Ikawa, Hiroki;  Isabelle, Pierre-Erik;  Iwata, Hiroki;  Jassal, Rachhpal;  Korkiakoski, Mika;  Kurbatova, Juliya;  Kutzbach, Lars;  Lindroth, Anders;  Lofvenius, Mikaell Ottosson;  Lohila, Annalea;  Mammarella, Ivan;  Marsh, Philip;  Maximov, Trofim;  Melton, Joe R.;  Moore, Paul A.;  Nadeau, Daniel F.;  Nicholls, Erin M.;  Nilsson, Mats B.;  Ohta, Takeshi;  Peichl, Matthias;  Petrone, Richard M.;  Petrov, Roman;  Prokushkin, Anatoly;  Quinton, William L.;  Reed, David E.;  Roulet, Nigel T.;  Runkle, Benjamin R. K.;  Sonnentag, Oliver;  Strachan, Ian B.;  Taillardat, Pierre;  Tuittila, Eeva-Stiina;  Tuovinen, Juha-Pekka;  Turner, Jessica;  Ueyama, Masahito;  Varlagin, Andrej;  Wilmking, Martin;  Wofsy, Steven C.;  Zyrianov, Vyacheslav
收藏  |  浏览/下载:14/0  |  提交时间:2020/05/13
Characterization of organic aerosol across the global remote troposphere: a comparison of ATom measurements and global chemistry models 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (8) : 4607-4635
作者:  Hodzic, Alma;  Campuzano-Jost, Pedro;  Bian, Huisheng;  Chin, Mian;  Colarco, Peter R.;  Day, Douglas A.;  Froyd, Karl D.;  Heinold, Bernd;  Jo, Duseong S.;  Katich, Joseph M.;  Kodros, John K.;  Nault, Benjamin A.;  Pierce, Jeffrey R.;  Ray, Eric;  Schacht, Jacob;  Schill, Gregory P.;  Schroder, Jason C.;  Schwarz, Joshua P.;  Sueper, Donna T.;  Tegen, Ina;  Tilmes, Simone;  Tsigaridis, Kostas;  Yu, Pengfei;  Jimenez, Jose L.
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/02
Simulation of organic aerosol formation during the CalNex study: updated mobile emissions and secondary organic aerosol parameterization for intermediate-volatility organic compounds 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (7) : 4313-4332
作者:  Lu, Quanyang;  Murphy, Benjamin N.;  Qin, Momei;  Adams, Peter;  Zhao, Yunliang;  Pye, Havala O. T.;  Efstathiou, Christos;  Allen, Chris;  Robinson, Allen L.
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/02
Pharmacologic fibroblast reprogramming into photoreceptors restores vision 期刊论文
NATURE, 2020, 581 (7806) : 83-+
作者:  Jiang, Mingkai;  Medlyn, Belinda E.;  Drake, John E.;  Duursma, Remko A.;  Anderson, Ian C.;  Barton, Craig V. M.;  Boer, Matthias M.;  Carrillo, Yolima;  Castaneda-Gomez, Laura;  Collins, Luke;  Crous, Kristine Y.;  De Kauwe, Martin G.;  dos Santos, Bruna M.;  Emmerson, Kathryn M.;  Facey, Sarah L.;  Gherlenda, Andrew N.;  Gimeno, Teresa E.;  Hasegawa, Shun;  Johnson, Scott N.;  Kannaste, Astrid;  Macdonald, Catriona A.;  Mahmud, Kashif;  Moore, Ben D.;  Nazaries, Loic;  Neilson, Elizabeth H. J.;  Nielsen, Uffe N.;  Niinemets, Ulo;  Noh, Nam Jin;  Ochoa-Hueso, Raul;  Pathare, Varsha S.;  Pendall, Elise;  Pihlblad, Johanna;  Pineiro, Juan;  Powell, Jeff R.;  Power, Sally A.;  Reich, Peter B.;  Renchon, Alexandre A.;  Riegler, Markus;  Rinnan, Riikka;  Rymer, Paul D.;  Salomon, Roberto L.;  Singh, Brajesh K.;  Smith, Benjamin;  Tjoelker, Mark G.;  Walker, Jennifer K. M.;  Wujeska-Klause, Agnieszka;  Yang, Jinyan;  Zaehle, Soenke;  Ellsworth, David S.
收藏  |  浏览/下载:45/0  |  提交时间:2020/07/03

Photoreceptor loss is the final common endpoint in most retinopathies that lead to irreversible blindness, and there are no effective treatments to restore vision(1,2). Chemical reprogramming of fibroblasts offers an opportunity to reverse vision loss  however, the generation of sensory neuronal subtypes such as photoreceptors remains a challenge. Here we report that the administration of a set of five small molecules can chemically induce the transformation of fibroblasts into rod photoreceptor-like cells. The transplantation of these chemically induced photoreceptor-like cells (CiPCs) into the subretinal space of rod degeneration mice (homozygous for rd1, also known as Pde6b) leads to partial restoration of the pupil reflex and visual function. We show that mitonuclear communication is a key determining factor for the reprogramming of fibroblasts into CiPCs. Specifically, treatment with these five compounds leads to the translocation of AXIN2 to the mitochondria, which results in the production of reactive oxygen species, the activation of NF-kappa B and the upregulation of Ascl1. We anticipate that CiPCs could have therapeutic potential for restoring vision.


A set of five small molecules can induce the transformation of fibroblasts into rod photoreceptor-like cells, which can partially restore pupil reflex and visual function when transplanted into a rod degeneration mouse model.


  
Ambient air quality in the Kathmandu Valley, Nepal, during the pre-monsoon: concentrations and sources of particulate matter and trace gases 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (5) : 2927-2951
作者:  Islam, Md Robiul;  Jayarathne, Thilina;  Simpson, Isobel J.;  Werden, Benjamin;  Maben, John;  Gilbert, Ashley;  Praveen, Puppala S.;  Adhikari, Sagar;  Panday, Arnico K.;  Rupakheti, Maheswar;  Blake, Donald R.;  Yokelson, Robert J.;  DeCarlo, Peter F.;  Keene, William C.;  Stone, Elizabeth A.
收藏  |  浏览/下载:13/0  |  提交时间:2020/07/02
Asynchronous carbon sink saturation in African and Amazonian tropical forests 期刊论文
NATURE, 2020, 579 (7797) : 80-+
作者:  Wannes Hubau;  Simon L. Lewis;  Oliver L. Phillips;  Kofi Affum-Baffoe;  Hans Beeckman;  Aida Cuní;  -Sanchez;  Armandu K. Daniels;  Corneille E. N. Ewango;  Sophie Fauset;  Jacques M. Mukinzi;  Douglas Sheil;  Bonaventure Sonké;  Martin J. P. Sullivan;  Terry C. H. Sunderland;  Hermann Taedoumg;  Sean C. Thomas;  Lee J. T. White;  Katharine A. Abernethy;  Stephen Adu-Bredu;  Christian A. Amani;  Timothy R. Baker;  Lindsay F. Banin;  Fidè;  le Baya;  Serge K. Begne;  Amy C. Bennett;  Fabrice Benedet;  Robert Bitariho;  Yannick E. Bocko;  Pascal Boeckx;  Patrick Boundja;  Roel J. W. Brienen;  Terry Brncic;  Eric Chezeaux;  George B. Chuyong;  Connie J. Clark;  Murray Collins;  James A. Comiskey;  David A. Coomes;  Greta C. Dargie;  Thales de Haulleville;  Marie Noel Djuikouo Kamdem;  Jean-Louis Doucet;  Adriane Esquivel-Muelbert;  Ted R. Feldpausch;  Alusine Fofanah;  Ernest G. Foli;  Martin Gilpin;  Emanuel Gloor;  Christelle Gonmadje;  Sylvie Gourlet-Fleury;  Jefferson S. Hall;  Alan C. Hamilton;  David J. Harris;  Terese B. Hart;  Mireille B. N. Hockemba;  Annette Hladik;  Suspense A. Ifo;  Kathryn J. Jeffery;  Tommaso Jucker;  Emmanuel Kasongo Yakusu;  Elizabeth Kearsley;  David Kenfack;  Alexander Koch;  Miguel E. Leal;  Aurora Levesley;  Jeremy A. Lindsell;  Janvier Lisingo;  Gabriela Lopez-Gonzalez;  Jon C. Lovett;  Jean-Remy Makana;  Yadvinder Malhi;  Andrew R. Marshall;  Jim Martin;  Emanuel H. Martin;  Faustin M. Mbayu;  Vincent P. Medjibe;  Vianet Mihindou;  Edward T. A. Mitchard;  Sam Moore;  Pantaleo K. T. Munishi;  Natacha Nssi Bengone;  Lucas Ojo;  Fidè;  le Evouna Ondo;  Kelvin S.-H. Peh;  Georgia C. Pickavance;  Axel Dalberg Poulsen;  John R. Poulsen;  Lan Qie;  Jan Reitsma;  Francesco Rovero;  Michael D. Swaine;  Joey Talbot;  James Taplin;  David M. Taylor;  Duncan W. Thomas;  Benjamin Toirambe;  John Tshibamba Mukendi;  Darlington Tuagben;  Peter M. Umunay;  Geertje M. F. van der Heijden;  Hans Verbeeck;  Jason Vleminckx;  Simon Willcock;  Hannsjö;  rg Wö;  ll;  John T. Woods;  Lise Zemagho
收藏  |  浏览/下载:23/0  |  提交时间:2020/05/13

Structurally intact tropical forests sequestered about half of the global terrestrial carbon uptake over the 1990s and early 2000s, removing about 15 per cent of anthropogenic carbon dioxide emissions(1-3). Climate-driven vegetation models typically predict that this tropical forest '  carbon sink'  will continue for decades(4,5). Here we assess trends in the carbon sink using 244 structurally intact African tropical forests spanning 11 countries, compare them with 321 published plots from Amazonia and investigate the underlying drivers of the trends. The carbon sink in live aboveground biomass in intact African tropical forests has been stable for the three decades to 2015, at 0.66 tonnes of carbon per hectare per year (95 per cent confidence interval 0.53-0.79), in contrast to the long-term decline in Amazonian forests(6). Therefore the carbon sink responses of Earth'  s two largest expanses of tropical forest have diverged. The difference is largely driven by carbon losses from tree mortality, with no detectable multi-decadal trend in Africa and a long-term increase in Amazonia. Both continents show increasing tree growth, consistent with the expected net effect of rising atmospheric carbon dioxide and air temperature(7-9). Despite the past stability of the African carbon sink, our most intensively monitored plots suggest a post-2010 increase in carbon losses, delayed compared to Amazonia, indicating asynchronous carbon sink saturation on the two continents. A statistical model including carbon dioxide, temperature, drought and forest dynamics accounts for the observed trends and indicates a long-term future decline in the African sink, whereas the Amazonian sink continues to weaken rapidly. Overall, the uptake of carbon into Earth'  s intact tropical forests peaked in the 1990s. Given that the global terrestrial carbon sink is increasing in size, independent observations indicating greater recent carbon uptake into the Northern Hemisphere landmass(10) reinforce our conclusion that the intact tropical forest carbon sink has already peaked. This saturation and ongoing decline of the tropical forest carbon sink has consequences for policies intended to stabilize Earth'  s climate.


  
Water scarcity and fish imperilment driven by beef production 期刊论文
NATURE SUSTAINABILITY, 2020, 3 (4) : 319-328
作者:  Richter, Brian D.;  Bartak, Dominique;  Caldwell, Peter;  Davis, Kyle Frankel;  Debaere, Peter;  Hoekstra, Arjen Y.;  Li, Tianshu;  Marston, Landon;  McManamay, Ryan;  Mekonnen, Mesfin M.;  Ruddell, Benjamin L.;  Rushforth, Richard R.;  Troy, Tara J.
收藏  |  浏览/下载:12/0  |  提交时间:2020/05/13