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A comprehensive quantification of global nitrous oxide sources and sinks 期刊论文
Nature, 2020
作者:  Hanqin Tian;  Rongting Xu;  Josep G. Canadell;  Rona L. Thompson;  Wilfried Winiwarter;  Parvadha Suntharalingam;  Eric A. Davidson;  Philippe Ciais;  Robert B. Jackson;  Greet Janssens-Maenhout;  Michael J. Prather;  Pierre Regnier;  Naiqing Pan;  Shufen Pan;  Glen P. Peters;  Hao Shi;  Francesco N. Tubiello;  ;  nke Zaehle;  Feng Zhou;  Almut Arneth;  Gianna Battaglia;  Sarah Berthet;  Laurent Bopp;  Alexander F. Bouwman;  Erik T. Buitenhuis;  Jinfeng Chang;  Martyn P. Chipperfield;  Shree R. S. Dangal;  Edward Dlugokencky;  James W. Elkins;  Bradley D. Eyre;  Bojie Fu;  Bradley Hall;  Akihiko Ito;  Fortunat Joos;  Paul B. Krummel;  Angela Landolfi;  Goulven G. Laruelle;  Ronny Lauerwald;  Wei Li;  Sebastian Lienert;  Taylor Maavara;  Michael MacLeod;  Dylan B. Millet;  Stefan Olin;  Prabir K. Patra;  Ronald G. Prinn;  Peter A. Raymond;  Daniel J. Ruiz;  Guido R. van der Werf;  Nicolas Vuichard;  Junjie Wang;  Ray F. Weiss;  Kelley C. Wells;  Chris Wilson;  Jia Yang;  Yuanzhi Yao
收藏  |  浏览/下载:25/0  |  提交时间:2020/10/12
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:19/0  |  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.


  
Asteroid impact, not volcanism, caused the end-Cretaceous dinosaur extinction 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (29) : 17084-17093
作者:  Chiarenza, Alfio Alessandro;  Farnsworth, Alexander;  Mannion, Philip D.;  Lunt, Daniel J.;  Valdes, Paul J.;  Morgan, Joanna, V;  Allison, Peter A.
收藏  |  浏览/下载:17/0  |  提交时间:2020/07/06
Dinosauria  extinction  end-Cretaceous  Chicxulub  Deccan  
Evaluation of Southern Ocean cloud in the HadGEM3 general circulation model and MERRA-2 reanalysis using ship-based observations 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (11) : 6607-6630
作者:  Kuma, Peter;  Mcdonald, Adrian J.;  Morgenstern, Olaf;  Alexander, Simon P.;  Cassano, John J.;  Garrett, Sally;  Halla, Jamie;  Hartery, Sean;  Harvey, Mike J.;  Parsons, Simon;  Plank, Graeme;  Varma, Vidya;  Williams, Jonny
收藏  |  浏览/下载:9/0  |  提交时间:2020/06/09
The diurnal characteristics of PM-bound ROS and its influencing factors at urban ambient and roadside environments 期刊论文
Atmospheric Research, 2020
作者:  Nirmal Kumar Gali, Stevanovic Svetlana, Peter Brimblecombe, Reece Alexander Brown, ... Ning Zhi
收藏  |  浏览/下载:1/0  |  提交时间:2020/05/20
A metabolic pathway for bile acid dehydroxylation by the gut microbiome 期刊论文
NATURE, 2020
作者:  Zhong, Miao;  Tran, Kevin;  Min, Yimeng;  Wang, Chuanhao;  Wang, Ziyun;  Dinh, Cao-Thang;  De Luna, Phil;  Yu, Zongqian;  Rasouli, Armin Sedighian;  Brodersen, Peter;  Sun, Song;  Voznyy, Oleksandr;  Tan, Chih-Shan;  Askerka, Mikhail;  Che, Fanglin;  Liu, Min;  Seifitokaldani, Ali;  Pang, Yuanjie;  Lo, Shen-Chuan;  Ip, Alexander;  Ulissi, Zachary;  Sargent, Edward H.
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/03

The biosynthetic pathway that produces the secondary bile acids DCA and LCA in human gut microbes has been fully characterized, engineered into another bacterial host, and used to confer DCA production in germ-free mice-an important proof-of-principle for the engineering of gut microbial pathways.


The gut microbiota synthesize hundreds of molecules, many of which influence host physiology. Among the most abundant metabolites are the secondary bile acids deoxycholic acid (DCA) and lithocholic acid (LCA), which accumulate at concentrations of around 500 mu M and are known to block the growth ofClostridium difficile(1), promote hepatocellular carcinoma(2)and modulate host metabolism via the G-protein-coupled receptor TGR5 (ref.(3)). More broadly, DCA, LCA and their derivatives are major components of the recirculating pool of bile acids(4)  the size and composition of this pool are a target of therapies for primary biliary cholangitis and nonalcoholic steatohepatitis. Nonetheless, despite the clear impact of DCA and LCA on host physiology, an incomplete knowledge of their biosynthetic genes and a lack of genetic tools to enable modification of their native microbial producers limit our ability to modulate secondary bile acid levels in the host. Here we complete the pathway to DCA and LCA by assigning and characterizing enzymes for each of the steps in its reductive arm, revealing a strategy in which the A-B rings of the steroid core are transiently converted into an electron acceptor for two reductive steps carried out by Fe-S flavoenzymes. Using anaerobic in vitro reconstitution, we establish that a set of six enzymes is necessary and sufficient for the eight-step conversion of cholic acid to DCA. We then engineer the pathway intoClostridium sporogenes, conferring production of DCA and LCA on a nonproducing commensal and demonstrating that a microbiome-derived pathway can be expressed and controlled heterologously. These data establish a complete pathway to two central components of the bile acid pool.


  
Rapid reconstruction of SARS-CoV-2 using a synthetic genomics platform 期刊论文
NATURE, 2020
作者:  Touat, Mehdi;  Li, Yvonne Y.;  Boynton, Adam N.;  Spurr, Liam F.;  Iorgulescu, J. Bryan;  Bohrson, Craig L.;  Cortes-Ciriano, Isidro;  Birzu, Cristina;  Geduldig, Jack E.;  Pelton, Kristine;  Lim-Fat, Mary Jane;  Pal, Sangita;  Ferrer-Luna, Ruben;  Ramkissoon, Shakti H.;  Dubois, Frank;  Bellamy, Charlotte;  Currimjee, Naomi;  Bonardi, Juliana;  Qian Kenin;  Ho, Patricia;  Malinowski, Seth;  Taquet, Leon;  Jones, Robert E.;  Shetty, Aniket;  Chow, Kin-Hoe;  Sharaf, Radwa;  Pavlick, Dean;  Albacker, Lee A.;  Younan, Nadia;  Baldini, Capucine;  Verreault, Maite;  Giry, Marine;  Guillerm, Erell;  Ammari, Samy;  Beuvon, Frederic;  Mokhtari, Karima;  Alentorn, Agusti;  Dehais, Caroline;  Houillier, Caroline;  Laigle-Donadey, Florence;  Psimaras, Dimitri;  Lee, Eudocia Q.;  Nayak, Lakshmi;  McFaline-Figueroa, J. Ricardo;  Carpentier, Alexandre;  Cornu, Philippe;  Capelle, Laurent;  Mathon, Bertrand;  Barnholtz-Sloan, Jill S.;  Chakravarti, Arnab;  Bi, Wenya Linda;  Chiocca, E. Antonio;  Fehnel, Katie Pricola;  Alexandrescu, Sanda;  Chi, Susan N.;  Haas-Kogan, Daphne;  Batchelor, Tracy T.;  Frampton, Garrett M.;  Alexander, Brian M.;  Huang, Raymond Y.;  Ligon, Azra H.;  Coulet, Florence;  Delattre, Jean-Yves;  Hoang-Xuan, Khe;  Meredith, David M.;  Santagata, Sandro;  Duval, Alex;  Sanson, Marc;  Cherniack, Andrew D.;  Wen, Patrick Y.;  Reardon, David A.;  Marabelle, Aurelien;  Park, Peter J.;  Idbaih, Ahmed;  Beroukhim, Rameen;  Bandopadhayay, Pratiti;  Bielle, Franck;  Ligon, Keith L.
收藏  |  浏览/下载:11/0  |  提交时间:2020/07/03

Reverse genetics has been an indispensable tool to gain insights into viral pathogenesis and vaccine development. The genomes of large RNA viruses, such as those from coronaviruses, are cumbersome to clone and manipulate inEscherichia coliowing to the size and occasional instability of the genome(1-3). Therefore, an alternative rapid and robust reverse-genetics platform for RNA viruses would benefit the research community. Here we show the full functionality of a yeast-based synthetic genomics platform to genetically reconstruct diverse RNA viruses, including members of theCoronaviridae,FlaviviridaeandPneumoviridaefamilies. Viral subgenomic fragments were generated using viral isolates, cloned viral DNA, clinical samples or synthetic DNA, and these fragments were then reassembled in one step inSaccharomyces cerevisiaeusing transformation-associated recombination cloning to maintain the genome as a yeast artificial chromosome. T7 RNA polymerase was then used to generate infectious RNA to rescue viable virus. Using this platform, we were able to engineer and generate chemically synthesized clones of the virus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)(4), which has caused the recent pandemic of coronavirus disease (COVID-19), in only a week after receipt of the synthetic DNA fragments. The technical advance that we describe here facilitates rapid responses to emerging viruses as it enables the real-time generation and functional characterization of evolving RNA virus variants during an outbreak.


A yeast-based synthetic genomics platform is used to reconstruct and characterize large RNA viruses from synthetic DNA fragments  this technique will facilitate the rapid analysis of RNA viruses, such as SARS-CoV-2, during an outbreak.


  
A plant genetic network for preventing dysbiosis in the phyllosphere 期刊论文
NATURE, 2020, 580 (7805) : 653-+
作者:  van den Brink, Susanne C.;  Alemany, Anna;  van Batenburg, Vincent;  Moris, Naomi;  Blotenburg, Marloes;  Vivie, Judith;  Baillie-Johnson, Peter;  Nichols, Jennifer;  Sonnen, Katharina F.;  Martinez Arias, Alfonso;  van Oudenaarden, Alexander
收藏  |  浏览/下载:59/0  |  提交时间:2020/07/03

Mutations in genes involved in immune signalling and vesicle trafficking cause defects in the leaf microbiome of Arabidopsis thaliana that result in damage to leaf tissues, suggesting mechanisms by which terrestrial plants control the level and diversity of endophytic phyllosphere microbiota.


The aboveground parts of terrestrial plants, collectively called the phyllosphere, have a key role in the global balance of atmospheric carbon dioxide and oxygen. The phyllosphere represents one of the most abundant habitats for microbiota colonization. Whether and how plants control phyllosphere microbiota to ensure plant health is not well understood. Here we show that the Arabidopsis quadruple mutant (min7 fls2 efr cerk1  hereafter, mfec)(1), simultaneously defective in pattern-triggered immunity and the MIN7 vesicle-trafficking pathway, or a constitutively activated cell death1 (cad1) mutant, carrying a S205F mutation in a membrane-attack-complex/perforin (MACPF)-domain protein, harbour altered endophytic phyllosphere microbiota and display leaf-tissue damage associated with dysbiosis. The Shannon diversity index and the relative abundance of Firmicutes were markedly reduced, whereas Proteobacteria were enriched in the mfec and cad1(S205F) mutants, bearing cross-kingdom resemblance to some aspects of the dysbiosis that occurs in human inflammatory bowel disease. Bacterial community transplantation experiments demonstrated a causal role of a properly assembled leaf bacterial community in phyllosphere health. Pattern-triggered immune signalling, MIN7 and CAD1 are found in major land plant lineages and are probably key components of a genetic network through which terrestrial plants control the level and nurture the diversity of endophytic phyllosphere microbiota for survival and health in a microorganism-rich environment.


  
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.


  
Performance-limiting nanoscale trap clusters at grain junctions in halide perovskites 期刊论文
NATURE, 2020, 580 (7803) : 360-+
作者:  van den Brink, Susanne C.;  Alemany, Anna;  van Batenburg, Vincent;  Moris, Naomi;  Blotenburg, Marloes;  Vivie, Judith;  Baillie-Johnson, Peter;  Nichols, Jennifer;  Sonnen, Katharina F.;  Arias, Alfonso;  van Oudenaarden, Alexander
收藏  |  浏览/下载:27/0  |  提交时间:2020/07/03

Halide perovskite materials have promising performance characteristics for low-cost optoelectronic applications. Photovoltaic devices fabricated from perovskite absorbers have reached power conversion efficiencies above 25 per cent in single-junction devices and 28 per cent in tandem devices(1,2). This strong performance (albeit below the practical limits of about 30 per cent and 35 per cent, respectively(3)) is surprising in thin films processed from solution at low-temperature, a method that generally produces abundant crystalline defects(4). Although point defects often induce only shallow electronic states in the perovskite bandgap that do not affect performance(5), perovskite devices still have many states deep within the bandgap that trap charge carriers and cause them to recombine non-radiatively. These deep trap states thus induce local variations in photoluminescence and limit the device performance(6). The origin and distribution of these trap states are unknown, but they have been associated with light-induced halide segregation in mixed-halide perovskite compositions(7) and with local strain(8), both of which make devices less stable(9). Here we use photoemission electron microscopy to image the trap distribution in state-of-the-art halide perovskite films. Instead of a relatively uniform distribution within regions of poor photoluminescence efficiency, we observe discrete, nanoscale trap clusters. By correlating microscopy measurements with scanning electron analytical techniques, we find that these trap clusters appear at the interfaces between crystallographically and compositionally distinct entities. Finally, by generating time-resolved photoemission sequences of the photo-excited carrier trapping process(10,11), we reveal a hole-trapping character with the kinetics limited by diffusion of holes to the local trap clusters. Our approach shows that managing structure and composition on the nanoscale will be essential for optimal performance of halide perovskite devices.