GSTDTAP

浏览/检索结果: 共5条,第1-5条 帮助

限定条件    
已选(0)清除 条数/页:   排序方式:
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.


  
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.


  
Kilauea lava fuels phytoplankton bloom in the North Pacific Ocean 期刊论文
SCIENCE, 2019, 365 (6457) : 1040-+
作者:  Wilson, Samuel T.;  Hawco, Nicholas J.;  Armbrust, E. Virginia;  Barone, Benedetto;  Bjorkman, Karin M.;  Boysen, Angela K.;  Burgos, Macarena;  Burrell, Timothy J.;  Casey, John R.;  DeLong, Edward F.;  Dugenne, Mathilde;  Dutkiewicz, Stephanie;  Dyhrman, Sonya T.;  Ferron, Sara;  Follows, Michael J.;  Foreman, Rhea K.;  Funkey, Carolina P.;  Harke, Matthew J.;  Henke, Britt A.;  Hill, Christopher N.;  Hynes, Annette M.;  Ingalls, Anitra E.;  Jahn, Oliver;  Kelly, Rachel L.;  Knapp, Angela N.;  Letelier, Ricardo M.;  Ribalet, Francois;  Shimabukuro, Eric M.;  Tabata, Ryan K. S.;  Turk-Kubo, Kendra A.;  White, Angelicque E.;  Zehr, Jonathan P.;  John, Seth;  Karl, David M.
收藏  |  浏览/下载:13/0  |  提交时间:2019/11/27
New NSF policy will stifle innovation 期刊论文
SCIENCE, 2018, 362 (6412) : 297-298
作者:  Alberts, Susan;  Anderson, Rindy;  Ballen, Cissy J.;  Barrick, Jeffrey E.;  Bordenstein, Seth;  Boyd, Sunny K.;  Bracken-Grissom, Heather;  Braun, Christopher B.;  Coppola, David M.;  Cox, Daniel N.;  Crandall, Keith A.;  Cronin, Thomas W.;  Demas, Gregory E.;  Derby, Charles D.;  Edwards, Scott V.;  Eisthen, Heather L.;  Foster, James A.;  Gilbert, Cole;  Halanych, Kenneth M.;  Herculano-Houzel, Suzana;  Hoekstra, Hopi;  Hof, Patrick R.;  Hoke, Kim L.;  Holekamp, Kay E.;  Jarvis, Erich;  Johnsen, Sonke;  Katz, Paul S.;  Kay, Leslie M.;  Kehoe, David M.;  Kelley, Darcy B.;  Kerr, Benjamin;  Ketterson, Ellen;  Kier, William M.;  Koehl, Mimi A. R.;  Last, Robert L.;  Lazazzera, Beth;  Lenski, Richard E.;  Losos, Jonathan B.;  Lutterschmidt, Deborah I.;  Lynch, Michael;  Mahon, Andrew R.;  Martindale, Mark Q.;  Martins, Emilia P.;  McClintock, James B.;  Mesce, Karen A.;  Mukhopadhyay, Suchetana;  Oakley, Todd H.;  Phelps, Steven M.;  Phillips, Richard P.;  Queller, David;  Renn, Suzy C. P.;  Rosvall, Kimberly;  Schweizer, Felix E.;  Shubin, Neil;  Silk, Joan;  Strassmann, Joan E.;  Strausfeld, Nicholas J.;  Strauss, Sharon Y.;  Striedter, Georg;  Swalla, Billie J.;  Tarrant, Ann;  Throop, Heather L.;  Turner, Paul E.;  Voss, S. Randal;  Wake, Marvalee H.;  Wares, John P.;  Webster, Mike;  White, Stephanie A.;  Wilczynski, Walter;  Wray, Greg A.;  Wright, Timothy F.
收藏  |  浏览/下载:20/0  |  提交时间:2019/11/27
Kilogram-scale prexasertib monolactate monohydrate synthesis under continuous-flow CGMP conditions 期刊论文
SCIENCE, 2017, 356 (6343) : 1144-1150
作者:  Cole, Kevin P.;  Groh, Jennifer McClary;  Johnson, Martin D.;  Burcham, Christopher L.;  Campbell, Bradley M.;  Diseroad, William D.;  Heller, Michael R.;  Howell, John R.;  Kallman, Neil J.;  Koenig, Thomas M.;  May, Scott A.;  Miller, Richard D.;  Mitchell, David;  Myers, David P.;  Myers, Steven S.;  Phillips, Joseph L.;  Polster, Christopher S.;  White, Timothy D.;  Cashman, Jim;  Hurley, Declan;  Moylan, Robert;  Sheehan, Paul;  Spencer, Richard D.;  Desmond, Kenneth;  Desmond, Paul;  Gowran, Olivia
收藏  |  浏览/下载:14/0  |  提交时间:2019/11/27