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Massive formation of early diagenetic dolomite in the Ediacaran ocean: Constraints on the "dolomite problem" 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (25) : 14005-14014
作者:  Chang, Biao;  Li, Chao;  Liu, Deng;  Foster, Ian;  Tripati, Aradhna;  Lloyd, Max K.;  Maradiaga, Ingrid;  Luo, Genming;  An, Zhihui;  She, Zhenbing;  Xie, Shucheng;  Tong, Jinnan;  Huang, Junhua;  Algeo, Thomas J.;  Lyons, Timothy W.;  Immenhauser, Adrian
收藏  |  浏览/下载：17/0  |  提交时间：2020/06/16
Doushantuo Formation  clumped isotope  early diagenesis  carbonate geochemistry  early oceans  
Revealing enigmatic mucus structures in the deep sea using DeepPIV 期刊论文
NATURE, 2020, 583 (7814) : 78-+
作者:  Nguyen, Ngoc Uyen Nhi;  Canseco, Diana C.;  Xiao, Feng;  Nakada, Yuji;  Li, Shujuan;  Lam, Nicholas T.;  Muralidhar, Shalini A.;  Savla, Jainy J.;  Hill, Joseph A.;  Le, Victor;  Zidan, Kareem A.;  El-Feky, Hamed W.;  Wang, Zhaoning;  Ahmed, Mahmoud Salama;  Hubbi, Maimon E.;  Menendez-Montes, Ivan
收藏  |  浏览/下载：13/0  |  提交时间：2020/06/09

Advanced deep-sea imaging tools yield insights into the structure and function of mucus filtration houses built by midwater giant larvaceans.


Many animals build complex structures to aid in their survival, but very few are built exclusively from materials that animals create (1,2). In the midwaters of the ocean, mucoid structures are readily secreted by numerous animals, and serve many vital functions(3,4). However, little is known about these mucoid structures owing to the challenges of observing them in the deep sea. Among these mucoid forms, the '  houses'  of larvaceans are marvels of nature(5), and in the ocean twilight zone giant larvaceans secrete and build mucus filtering structures that can reach diameters of more than 1 m(6). Here we describe in situ laser-imaging technology(7) that reconstructs three-dimensional models of mucus forms. The models provide high-resolution views of giant larvacean houses and elucidate the role that house structure has in food capture and predator avoidance. Now that tools exist to study mucus structures found throughout the ocean, we can shed light on some of nature'  s most complex forms.


  
A discussion on influences of turbulent diffusivity and surface drag parameterizations using a linear model of the tropical cyclone boundary layer wind field 期刊论文
ATMOSPHERIC RESEARCH, 2020, 237
作者:  Li, W.;  Hu, Z.;  Pei, Z.;  Li, S.;  Chan, P. W.
收藏  |  浏览/下载：4/0  |  提交时间：2020/07/02
Theoretical model  Surface drag coefficient  Turbulent diffusivity  Typhoon  
Chesapeake Bay acidification buffered by spatially decoupled carbonate mineral cycling 期刊论文
NATURE GEOSCIENCE, 2020, 13 (6) : 441-+
作者:  Su, Jianzhong;  Cai, Wei-Jun;  Brodeur, Jean;  Chen, Baoshan;  Hussain, Najid;  Yao, Yichen;  Ni, Chaoying;  Testa, Jeremy M.;  Li, Ming;  Xie, Xiaohui;  Ni, Wenfei;  Scaboo, K. Michael;  Xu, Yuan-yuan;  Cornwell, Jeffrey;  Gurbisz, Cassie;  Owens, Michael S.;  Waldbusser, George G.;  Dai, Minhan;  Kemp, W. Michael
收藏  |  浏览/下载：9/0  |  提交时间：2020/06/09
DNA-repair enzyme turns to translation 期刊论文
NATURE, 2020, 579 (7798) : 198-199
作者:  Bian, Zhilei;  Gong, Yandong;  Huang, Tao;  Lee, Christopher Z. W.;  Bian, Lihong;  Bai, Zhijie;  Shi, Hui;  Zeng, Yang;  Liu, Chen;  He, Jian;  Zhou, Jie;  Li, Xianlong;  Li, Zongcheng;  Ni, Yanli;  Ma, Chunyu;  Cui, Lei;  Zhang, Rui;  Chan, Jerry K. Y.;  Ng, Lai Guan;  Lan, Yu;  Ginhoux, Florent;  Liu, Bing
收藏  |  浏览/下载：12/0  |  提交时间：2020/07/03

A key DNA-repair enzyme has a surprising role during the early steps in the assembly of ribosomes - the molecular machines that translate the genetic code into protein.


  
Impaired cell fate through gain-of-function mutations in a chromatin reader 期刊论文
NATURE, 2020, 577 (7788) : 121-+
作者:  Wan, Liling;  Chong, Shasha;  Xuan, Fan;  Liang, Angela;  Cui, Xiaodong;  Gates, Leah;  Carroll, Thomas S.;  Li, Yuanyuan;  Feng, Lijuan;  Chen, Guochao;  Wang, Shu-Ping;  Ortiz, Michael V.;  Daley, Sara K.;  Wang, Xiaolu;  Xuan, Hongwen;  Kentsis, Alex;  Muir, Tom W.;  Roeder, Robert G.;  Li, Haitao;  Li, Wei;  Tjian, Robert;  Wen, Hong;  Allis, C. David
收藏  |  浏览/下载：10/0  |  提交时间：2020/07/03

Modifications of histone proteins have essential roles in normal development and human disease. Recognition of modified histones by '  reader'  proteins is a key mechanism that mediates the function of histone modifications, but how the dysregulation of these readers might contribute to disease remains poorly understood. We previously identified the ENL protein as a reader of histone acetylation via its YEATS domain, linking it to the expression of cancer-driving genes in acute leukaemia1. Recurrent hotspot mutations have been found in the ENL YEATS domain in Wilms tumour2,3, the most common type of paediatric kidney cancer. Here we show, using human and mouse cells, that these mutations impair cell-fate regulation by conferring gain-of-function in chromatin recruitment and transcriptional control. ENL mutants induce gene-expression changes that favour a premalignant cell fate, and, in an assay for nephrogenesis using murine cells, result in undifferentiated structures resembling those observed in human Wilms tumour. Mechanistically, although bound to largely similar genomic loci as the wild-type protein, ENL mutants exhibit increased occupancy at a subset of targets, leading to a marked increase in the recruitment and activity of transcription elongation machinery that enforces active transcription from target loci. Furthermore, ectopically expressed ENL mutants exhibit greater self-association and form discrete and dynamic nuclear puncta that are characteristic of biomolecular hubs consisting of local high concentrations of regulatory factors. Such mutation-driven ENL self-association is functionally linked to enhanced chromatin occupancy and gene activation. Collectively, our findings show that hotspot mutations in a chromatinreader domain drive self-reinforced recruitment, derailing normal cell-fate control during development and leading to an oncogenic outcome.


  
The water lily genome and the early evolution of flowering plants 期刊论文
NATURE, 2020, 577 (7788) : 79-+
作者:  Zhang, Liangsheng;  Chen, Fei;  Zhang, Xingtan;  Li, Zhen;  Zhao, Yiyong;  Lohaus, Rolf;  Chang, Xiaojun;  Dong, Wei;  Ho, Simon Y. W.;  Liu, Xing;  Song, Aixia;  Chen, Junhao;  Guo, Wenlei;  Wang, Zhengjia;  Zhuang, Yingyu;  Wang, Haifeng;  Chen, Xuequn;  Hu, Juan;  Liu, Yanhui;  Qin, Yuan;  Wang, Kai;  Dong, Shanshan;  Liu, Yang;  Zhang, Shouzhou;  Yu, Xianxian;  Wu, Qian;  Wang, Liangsheng;  Yan, Xueqing;  Jiao, Yuannian;  Kong, Hongzhi;  Zhou, Xiaofan;  Yu, Cuiwei;  Chen, Yuchu;  Li, Fan;  Wang, Jihua;  Chen, Wei;  Chen, Xinlu;  Jia, Qidong;  Zhang, Chi;  Jiang, Yifan;  Zhang, Wanbo;  Liu, Guanhua;  Fu, Jianyu;  Chen, Feng;  Ma, Hong;  Van de Peer, Yves;  Tang, Haibao
收藏  |  浏览/下载：11/0  |  提交时间：2020/07/03

Water lilies belong to the angiosperm order Nymphaeales. Amborellales, Nymphaeales and Austrobaileyales together form the so-called ANA-grade of angiosperms, which are extant representatives of lineages that diverged the earliest from the lineage leading to the extant mesangiosperms(1-3). Here we report the 409-megabase genome sequence of the blue-petal water lily (Nymphaea colorata). Our phylogenomic analyses support Amborellales and Nymphaeales as successive sister lineages to all other extant angiosperms. The N. colorata genome and 19 other water lily transcriptomes reveal a Nymphaealean whole-genome duplication event, which is shared by Nymphaeaceae and possibly Cabombaceae. Among the genes retained from this whole-genome duplication are homologues of genes that regulate flowering transition and flower development. The broad expression of homologues of floral ABCE genes in N. colorata might support a similarly broadly active ancestral ABCE model of floral organ determination in early angiosperms. Water lilies have evolved attractive floral scents and colours, which are features shared with mesangiosperms, and we identified their putative biosynthetic genes in N. colorata. The chemical compounds and biosynthetic genes behind floral scents suggest that they have evolved in parallel to those in mesangiosperms. Because of its unique phylogenetic position, the N. colorata genome sheds light on the early evolution of angiosperms.


  
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.


  
Perturbation Solution for Four-Stream Infrared Radiative Transfer 期刊论文
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2020, 77 (4) : 1497-1507
作者:  Li, Jiangnan;  Barker, Howard W.
收藏  |  浏览/下载：6/0  |  提交时间：2020/07/02
Radiation budgets  Radiative fluxes  Radiative transfer  Clouds  Single column models  
Operation of a silicon quantum processor unit cell above one kelvin 期刊论文
NATURE, 2020, 580 (7803) : 350-+
作者:  Han, Kyuho;  Pierce, Sarah E.;  Li, Amy;  Spees, Kaitlyn;  Anderson, Grace R.;  Seoane, Jose A.;  Lo, Yuan-Hung;  Dubreuil, Michael;  Olivas, Micah;  Kamber, Roarke A.;  Wainberg, Michael;  Kostyrko, Kaja;  Kelly, Marcus R.;  Yousefi, Maryam;  Simpkins, Scott W.;  Yao, David
收藏  |  浏览/下载：8/0  |  提交时间：2020/07/03

Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large numbers-typically millions-of quantum bits (qubits)(1-3). For most solid-state qubit technologies-for example, those using superconducting circuits or semiconductor spins-scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin)(4-6). Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots(7-9). We coherently control the qubits using electrically driven spin resonance(10,11) in isotopically enriched silicon(12 28)Si, attaining single-qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during '  hot'  operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures(13-16). Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full-scale silicon quantum computer and satisfies layout constraints required by error-correction architectures(8),(17). Our work indicates that a spin-based quantum computer could be operated at increased temperatures in a simple pumped He-4 system (which provides cooling power orders of magnitude higher than that of dilution refrigerators), thus potentially enabling the integration of classical control electronics with the qubit array(18,19).