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Increased Dust Aerosols in the High Troposphere Over the Tibetan Plateau From 1990s to 2000s 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (13)
作者:  Feng, Xingya;  Mao, Rui;  Gong, Dao-Yi;  Zhao, Chun;  Wu, Chenglai;  Zhao, Chuanfeng;  Wu, Guangjian;  Lin, Zhaohui;  Liu, Xiaohong;  Wang, Kaicun;  Sun, Yijie
收藏  |  浏览/下载:12/0  |  提交时间:2020/08/18
the Tibetan Plateau  dust aerosols  middle east  ice core  CMIP 6  
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.


  
Extreme climate after massive eruption of Alaska's Okmok volcano in 43 BCE and effects on the late Roman Republic and Ptolemaic Kingdom 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (27) : 15443-15449
作者:  McConnell, Joseph R.;  Sigl, Michael;  Plunkett, Gill;  Burke, Andrea;  Kim, Woon Mi;  Raible, Christoph C.;  Wilson, Andrew, I;  Manning, Joseph G.;  Ludlow, Francis;  Chellman, Nathan J.;  Innes, Helen M.;  Yang, Zhen;  Larsen, Jessica F.;  Schaefer, Janet R.;  Kipfstuhl, Sepp;  Mojtabavi, Seyedhamidreza;  Wilhelms, Frank;  Opel, Thomas;  Meyer, Hanno;  Steffensen, Jorgen Peder
收藏  |  浏览/下载:17/0  |  提交时间:2020/06/29
ice core  volcano  Okmok  Rome  climate forcing  
Twentieth Century Black Carbon and Dust Deposition on South Cascade Glacier, Washington State, USA, as Reconstructed From a 158-m-Long Ice Core 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (11)
作者:  Kaspari, S. D.;  Pittenger, D.;  Jenk, T. M.;  Morgenstern, U.;  Schwikowski, M.;  Buenning, N.;  Stott, L.
收藏  |  浏览/下载:16/0  |  提交时间:2020/08/18
light absorbing particles  black carbon  dust  ice core  cascades  melt  
Limited Retreat of the Wilkes Basin Ice Sheet During the Last Interglacial 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (13)
作者:  Sutter, J.;  Eisen, O.;  Werner, M.;  Grosfeld, K.;  Kleiner, T.;  Fischer, H.
收藏  |  浏览/下载:7/0  |  提交时间:2020/06/01
Sea Level  Warmer Worlds  Antarctica  Last Interglacial  Paleoclimate  Ice core  
Unprecedented Surface Chlorophyll Blooms in the Southeastern Arabian Sea During an Extreme Negative Indian Ocean Dipole 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (13)
作者:  Thushara, V;  Vinayachandran, P. N.
收藏  |  浏览/下载:10/0  |  提交时间:2020/06/01
Indian Ocean Dipole  chlorophyll  southeastern Arabian Sea  cold-core eddy  Ekman pumping  remote forcings  
Where I work Maria Josefa Verdugo 期刊论文
NATURE, 2020, 580 (7801) : 158-158
作者:  Farquharson, Jamie I.;  Amelung, Falk
收藏  |  浏览/下载:6/0  |  提交时间:2020/07/03

Maria Josefa Verdugo ships into the bitter cold of far-northern waters to measure ice-core properties as part of a year-round climate project.


Maria Josefa Verdugo ships into the bitter cold of far-northern waters to measure ice-core properties as part of a year-round climate project.


  
Nuclear force probed at short distances 期刊论文
NATURE, 2020, 578 (7796) : 524-525
作者:  Shukla, Aditi;  Yen, Jenny;  Pagano, Daniel J.;  Dodso, Anne E.;  Fei, Yuhan;  Gorham, Josh;  Seidman, J. G.;  Wickens, Marvin;  Kennedy, Scott
收藏  |  浏览/下载:13/0  |  提交时间:2020/07/03

The dense soup of matter in the core of neutron stars is hard to model, but particle-accelerator experiments in which energetic electrons scatter off atomic nuclei could help to explore this high-density regime.


A test of effective nucleon-nucleon interactions at short separations.


  
Structure of the human metapneumovirus polymerase phosphoprotein complex 期刊论文
NATURE, 2020, 577 (7789) : 275-+
作者:  Pan, Junhua;  Qian, Xinlei;  Lattmann, Simon;  El Sahili, Abbas;  Yeo, Tiong Han;  Jia, Huan;  Cressey, Tessa;  Ludeke, Barbara;  Noton, Sarah;  Kalocsay, Marian;  Fearns, Rachel;  Lescar, Julien
收藏  |  浏览/下载:12/0  |  提交时间:2020/07/03

Respiratory syncytial virus (RSV) and human metapneumovirus (HMPV) cause severe respiratory diseases in infants and elderly adults(1). No vaccine or effective antiviral therapy currently exists to control RSV or HMPV infections. During viral genome replication and transcription, the tetrameric phosphoprotein P serves as a crucial adaptor between the ribonucleoprotein template and the L protein, which has RNA-dependent RNA polymerase (RdRp), GDP polyribonucleotidyltransferase and cap-specific methyltransferase activities(2,3). How P interacts with L and mediates the association with the free form of N and with the ribonucleoprotein is not clear for HMPV or other major human pathogens, including the viruses that cause measles, Ebola and rabies. Here we report a cryo-electron microscopy reconstruction that shows the ring-shaped structure of the polymerase and capping domains of HMPV-L bound to a tetramer of P. The connector and methyltransferase domains of L are mobile with respect to the core. The putative priming loop that is important for the initiation of RNA synthesis is fully retracted, which leaves space in the active-site cavity for RNA elongation. P interacts extensively with the N-terminal region of L, burying more than 4,016 angstrom(2) of the molecular surface area in the interface. Two of the four helices that form the coiled-coil tetramerization domain of P, and long C-terminal extensions projecting from these two helices, wrap around the L protein in a manner similar to tentacles. The structural versatility of the four P protomers-which are largely disordered in their free state-demonstrates an example of a '  folding-upon-partner-binding'  mechanism for carrying out P adaptor functions. The structure shows that P has the potential to modulate multiple functions of L and these results should accelerate the design of specific antiviral drugs.


  
Structure and mechanism of the mitochondrial Ca2+ uniporter holocomplex 期刊论文
NATURE, 2020
作者:  Kalaany, Nada Y.;  Sabatini, David M.
收藏  |  浏览/下载:21/0  |  提交时间:2020/07/03

Mitochondria take up Ca2+ through the mitochondrial calcium uniporter complex to regulate energy production, cytosolic Ca2+ signalling and cell death(1,2). In mammals, the uniporter complex (uniplex) contains four core components: the pore-forming MCU protein, the gatekeepers MICU1 and MICU2, and an auxiliary subunit, EMRE, essential for Ca2+ transport(3-8). To prevent detrimental Ca2+ overload, the activity of MCU must be tightly regulated by MICUs, which sense changes in cytosolic Ca2+ concentrations to switch MCU on and off(9,10). Here we report cryo-electron microscopic structures of the human mitochondrial calcium uniporter holocomplex in inhibited and Ca2+-activated states. These structures define the architecture of this multicomponent Ca2+-uptake machinery and reveal the gating mechanism by which MICUs control uniporter activity. Our work provides a framework for understanding regulated Ca2+ uptake in mitochondria, and could suggest ways of modulating uniporter activity to treat diseases related to mitochondrial Ca2+ overload.


Cryo-electron microscopy reveals the structures of the mitochondrial calcium uniporter holocomplex in low- and high-calcium conditions, showing the gating mechanism that underlies uniporter activation in response to intracellular calcium signals.