中文版 | English

在结果中检索

GSTDTAP

浏览/检索结果: 共112条，第1-10条 帮助

已选(0)清除 条数/页：   排序方式：
中国领衔研究强调评估森林碳汇潜力时考虑林龄的重要性 快报文章
气候变化快报，2024年第11期
作者:  裴惠娟
Microsoft Word(14Kb)  |  收藏  |  浏览/下载：481/0  |  提交时间：2024/06/05
Stand Age  Carbon Sink  China  
最新研究揭示金星表面年龄保持年轻的机制 快报文章
地球科学快报，2023年第15期
作者:  张树良
Microsoft Word(16Kb)  |  收藏  |  浏览/下载：497/0  |  提交时间：2023/08/10
geophysical model  Venus  volcanism  young surface age  early collisions  
研究提出白令陆桥形成于末次冰期晚期 快报文章
地球科学快报，2023年第3期
作者:  王立伟
Microsoft Word(40Kb)  |  收藏  |  浏览/下载：598/0  |  提交时间：2023/02/10
bering land bridge  ice age  
适老性城市规划与发展迫在眉睫 快报文章
资源环境快报，2022年第07期
作者:  李恒吉
Microsoft Word(18Kb)  |  收藏  |  浏览/下载：734/2  |  提交时间：2022/04/15
The World Bank  Age-Ready Cities  
温暖的海洋推动了人类从亚洲到北美的首次迁徙 快报文章
资源环境快报，2021年第2期
作者:  薛明媚,吴秀平
Microsoft Word(20Kb)  |  收藏  |  浏览/下载：475/0  |  提交时间：2021/01/29
Last Ice Age  Circulation of the North Pacific  Human Migration  
The timing and effect of the earliest human arrivals in North America 期刊论文
NATURE, 2020
作者:  Lorena Becerra-Valdivia;  Thomas Higham
收藏  |  浏览/下载：27/0  |  提交时间：2020/08/09

The peopling of the Americas marks a major expansion of humans across the planet. However, questions regarding the timing and mechanisms of this dispersal remain, and the previously accepted model (termed '  Clovis-first'  )-suggesting that the first inhabitants of the Americas were linked with the Clovis tradition, a complex marked by distinctive fluted lithic points(1)-has been effectively refuted. Here we analyse chronometric data from 42 North American and Beringian archaeological sites using a Bayesian age modelling approach, and use the resulting chronological framework to elucidate spatiotemporal patterns of human dispersal. We then integrate these patterns with the available genetic and climatic evidence. The data obtained show that humans were probably present before, during and immediately after the Last Glacial Maximum (about 26.5-19 thousand years ago)(2,3)but that more widespread occupation began during a period of abrupt warming, Greenland Interstadial 1 (about 14.7-12.9 thousand years beforead 2000)(4). We also identify the near-synchronous commencement of Beringian, Clovis and Western Stemmed cultural traditions, and an overlap of each with the last dates for the appearance of 18 now-extinct faunal genera. Our analysis suggests that the widespread expansion of humans through North America was a key factor in the extinction of large terrestrial mammals.


A Bayesian age model suggests that human dispersal to the Americas probably began before the Last Glacial Maximum, overlapping with the last dates of appearance for several faunal genera.


  
Clonally expanded CD8 T cells patrol the cerebrospinal fluid in Alzheimer's disease 期刊论文
NATURE, 2020, 577 (7790) : 399-+
作者:  Gate, David;  Saligrama, Naresha;  Leventhal, Olivia;  Yang, Andrew C.;  Unger, Michael S.;  Middeldorp, Jinte;  Chen, Kelly;  Lehallier, Benoit;  Channappa, Divya;  De Los Santos, Mark B.;  McBride, Alisha;  Pluvinage, John;  Elahi, Fanny;  Tam, Grace Kyin-Ye;  Kim, Yongha;  Greicius, Michael;  Wagner, Anthony D.;  Aigner, Ludwig;  Galasko, Douglas R.;  Davis, Mark M.;  Wyss-Coray, Tony
收藏  |  浏览/下载：6/0  |  提交时间：2020/07/03

Alzheimer'  s disease is an incurable neurodegenerative disorder in which neuroinflammation has a critical function(1). However, little is known about the contribution of the adaptive immune response in Alzheimer'  s disease(2). Here, using integrated analyses of multiple cohorts, we identify peripheral and central adaptive immune changes in Alzheimer'  s disease. First, we performed mass cytometry of peripheral blood mononuclear cells and discovered an immune signature of Alzheimer'  s disease that consists of increased numbers of CD8(+) T effector memory CD45RA(+) (T-EMRA) cells. In a second cohort, we found that CD8(+) T-EMRA cells were negatively associated with cognition. Furthermore, single-cell RNA sequencing revealed that T cell receptor (TCR) signalling was enhanced in these cells. Notably, by using several strategies of single-cell TCR sequencing in a third cohort, we discovered clonally expanded CD8(+) T-EMRA cells in the cerebrospinal fluid of patients with Alzheimer'  s disease. Finally, we used machine learning, cloning and peptide screens to demonstrate the specificity of clonally expanded TCRs in the cerebrospinal fluid of patients with Alzheimer'  s disease to two separate Epstein-Barr virus antigens. These results reveal an adaptive immune response in the blood and cerebrospinal fluid in Alzheimer'  s disease and provide evidence of clonal, antigen-experienced T cells patrolling the intrathecal space of brains affected by age-related neurodegeneration.


  
美研究人员发现从工业时代开始冷水浮游生物急剧减少 快报文章
资源环境快报，2020年第9期
作者:  牛艺博
Microsoft Word(16Kb)  |  收藏  |  浏览/下载：352/0  |  提交时间：2020/05/15
The industrial age  Iceland  Cold water plankton  
Constraining the Age and Evolution of the Tuaheni Landslide Complex, Hikurangi Margin, New Zealand, Using Pore-Water Geochemistry and Numerical Modeling 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (11)
作者:  Luo, Min;  Torres, Marta E.;  Kasten, Sabine;  Mountjoy, Joshu J.
收藏  |  浏览/下载：15/0  |  提交时间：2020/05/13
Tuaheni Landslide Complex  pore water  transient state  age constraint  Hikurangi Margin  methane cycling  
Spectroscopic confirmation of a mature galaxy cluster at a redshift of 2 期刊论文
NATURE, 2020, 577 (7788) : 39-+
作者:  Willis, J. P.;  Canning, R. E. A.;  Noordeh, E. S.;  Allen, S. W.;  King, A. L.;  Mantz, A.;  Morris, R. G.;  Stanford, S. A.;  Brammer, G.
收藏  |  浏览/下载：12/0  |  提交时间：2020/07/03

Galaxy clusters are the most massive virialized structures in the Universe and are formed through the gravitational accretion of matter over cosmic time(1). The discovery(2) of an evolved galaxy cluster at redshift z = 2, corresponding to a look-back time of 10.4 billion years, provides an opportunity to study its properties. The galaxy cluster XLSSC 122 was originally detected as a faint, extended X-ray source in the XMM Large Scale Structure survey and was revealed to be coincident with a compact over-density of galaxies(2) with photometric redshifts of 1.9 +/- 0.2. Subsequent observations3 at millimetre wavelengths detected a Sunyaev-Zel'  dovich decrement along the line of sight to XLSSC 122, thus confirming the existence of hot intracluster gas, while deep imaging spectroscopy from the European Space Agency'  s X-ray Multi-Mirror Mission (XMM-Newton) revealed(4) an extended, X-ray-bright gaseous atmosphere with a virial temperature of 60 million Kelvin, enriched with metals to the same extent as are local clusters. Here we report optical spectroscopic observations of XLSSC 122 and identify 37 member galaxies at a mean redshift of 1.98, corresponding to a look-back time of 10.4 billion years. We use photometry to determine a mean, dust-free stellar age of 2.98 billion years, indicating that star formation commenced in these galaxies at a mean redshift of 12, when the Universe was only 370 million years old. The full range of inferred formation redshifts, including the effects of dust, covers the interval from 7 to 13. These observations confirm that XLSSC 122 is a remarkably mature galaxy cluster with both evolved stellar populations in the member galaxies and a hot, metal-rich gas composing the intracluster medium.