| 2005年12月02日 Science中文摘要 | 点击： 作者： 来源： 时间： 2006-11-12 本站论坛
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|  | 2005年12月2日 美国《科学》周刊310卷 第5753期
最早的鸟有类似恐龙脚的爪子
始祖鸟(Archaeopteryx)是已知的最早的鸟，新研究报告说，对保存最好的始祖鸟化石的研究发现，它有类似兽足目恐龙的爪子。这些标本为鸟的爪和头骨提供了重要的详细信息，加强了一个被广泛（但不是完全）接受的观点：现代鸟是由兽足目恐龙进化而来的。这个新的喜鹊大小的化石标本揭示，这种鸟能超伸展它爪子的第二个指头，这是该鸟与它最近的亲戚“恐爪龙”的又一个相似之处。新样品保存完好的头骨的部分与兽足目恐龙的头骨有明显的类似之处。Gerald Mayr和同事报告说，与现代鸟不同，这个原始鸟爪的第一个指头不是反转的。相反，它的第一个指头指向内，有点像人类的拇指，意味着该鸟没有所谓的“栖居爪”。作者说，这个细节显示，始祖鸟与现代鸟的类似之处比过去认为的要少。这个被称为“Thermopolis标本”的鸟来自德国巴伐利亚的索侯芬石灰岩沉积，它大约生活在1.5亿年前的侏罗纪。
报告：A Well-Preserved Archaeopteryx Specimen with Theropod Features, Gerald Mayr, Burkhard Pohl, and D. Stefan Peters
味觉的神经递质
新研究提出，ATP是把信息从味蕾送到神经系统的信使，这使人能尝到食物的味道。研究人员过去曾认为干这件事的分子信使是血清素，但是他们后来发现没有血清素受体的小鼠人仍有正常的味觉，于是寻找这个神秘的神经递质的工作重新开始，这里有一些复杂因素，因为每个味蕾包含有多种细胞类型，它们与味觉神经纤维以及相互之间都有通信。Thomas E. Finger和同事现在报告说，缺少两个关键的ATP受体的小鼠的味觉神经对味觉刺激没有响应，而且不能区别大多数味道的不同。这些发现，加上味蕾在刺激下释放ATP的事实显示ATP的确是这些突触的神经递质。
报告：ATP Signaling Is Crucial for Communication from Taste Buds to Gustatory Nerves, Thomas E. Finger, et al.
了解人工耳蜗如何工作
对电刺激如何影响聋猫大脑的深入了解也许解释为什么一个类似的方法能帮助生下来就失聪的儿童获得听觉。对内耳中听觉神经的人工电刺激使生下来耳聋的猫恢复了听觉神经突触的许多正常特征。听觉神经将内耳与脑干连接，从而将环境声音传到大脑。研究人员给先天耳聋的猫装上饶过不工作的内耳的人工耳，来直接刺激听觉神经。经过三个月的定期刺激后，David Ryugo和同事将听力正常的猫、天生耳聋的猫、以及天生耳聋但植入了电子耳蜗的猫做了比较。他们观察了被称为“Held端球(endbulb of Held)”结构中的突触，发现聋猫的突触有许多异常，但是植入电子耳的猫的突触大多正常。对这些突触的营救大概使将听觉神经信号真实地传到脑干成为可能。给失聪的儿童植入人工耳蜗也许有类似的工作方式，文章作者说，它为大脑提供了准确和有益的声音表象。
报告：Restoration of Auditory Nerve Synapses in Cats by Cochlear Implants, D. K. Ryugo, E. A. Kretzmer, and J. K. Niparko
雷达探测火星环境
一个国际研究小组报告了首次火星表面以下雷达探测的结果，揭示出火星北极下面1公里深的分层沉积，以及一个可能是撞击盆地的掩埋的浅结构。Giovanni Picardi 和同事分析了欧洲航天局的火星快车飞船上装载的火星地下和电离层探测高新雷达(Mars Advanced Radar for Subsurface and Ionospheric Sounding，简称MARSIS) 早期探索期发回的火星深下表(几百到几千米深的)的首次雷达回声数据。火星的北极下面有分层的沉积，由一个被认为主要是水冰的上层和一个可能与冰混合的沙下层构成。研究人员报告说，MARSIS似乎测到了这些沉积的底部。来自火星北部Chryse Planitia 山谷地的数据揭示了一个大约250公里的半圆结构，文章作者提出，它是一个掩埋了的撞击盆地。
MARSIS还能用来探测其它火星环境，另一篇文章报告了对火星电离层雷达测量的详细结果。D. A. Gurnett和同事描述了记录到的几种电离层回声。比如斜回声被认为部分地产生于与火星复杂的地壳磁场的相互作用。
科学特快报告：Radar Soundings of the Subsurface of Mars, Giovanni Picardi, et al.
科学特快报告：Radar Soundings of the Ionosphere of Mars, D. A. Gurnett, et al.
预测抗体效果
一个用来预测了某些抗体行为的新方法也许能为治疗癌症以及开发疫苗提供帮助，研究人员在本期一篇报告中说。Jenny Woof在一篇相关的研究评述中指出，针对具体抗原的单克隆抗体正成为癌症研究中的热门题目，而且被越来越多地用于抗微生物疗法。不同门类的抗体或“免疫球蛋白”在免疫系统中有不同的功能，免疫球蛋白IgG进一步演化为不同类型免疫响应效力变化很大的不同子类。每个IgG子类对吸引抗体分子“恒定区”的抑制或激活受体有一定范围的结合亲和力。Falk Nimerjahn和Jeffrey Ravetch显示，一个IgG抗体的两个受体的比率，既其激活细胞响应与抑制细胞响应受体的比率，能被用来预测这个抗体在活小鼠身上的作用。如果同一方法能用于人类，它也许能用来预测抗体在临床应用中的效果。
报告：Divergent Immunoglobulin G Subclass Activity Through Selective Fc Receptor Binding, Falk Nimmerjahn and Jeffrey V. Ravetch
研究评述：Tipping the Scales Toward More Effective Antibodies, Jenny M. Woof
专题部分：穿越细胞膜
本期专题部分聚焦细胞让蛋白、DNA、和离子穿越生物膜的机制。构成生物膜的脂双层具有半渗透性，小的不带电荷的分子几乎能自由地穿越膜，但离子、蛋白以及DNA通常被膜挡住。但是细胞需要将蛋白、DNA、和离子穿越脂双层运进或运出，使这种运输成为可能的机制被认为是生命的构成原则的一部分。专题部分的三篇综述介绍了目前我们对这些细胞和组织生理的基本过程的了解。
专题介绍：Crossing the Bilayer, Stella M. Hurtley
Special Issue
For all checked items
Crossing Membranes
Crossing the Bilayer
Stella M. Hurtley
Science 2 December 2005: 1451.
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Review
Protein Translocation Across Biological Membranes
William Wickner and Randy Schekman
Science 2 December 2005: 1452-1456.
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The Ins and Outs of DNA Transfer in Bacteria
Inês Chen, Peter J. Christie, and David Dubnau
Science 2 December 2005: 1456-1460.
Abstract »| Full Text »| PDF »|
Principles of Selective Ion Transport in Channels and Pumps
Eric Gouaux and Roderick MacKinnon
Science 2 December 2005: 1461-1465.
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Contents
For all checked items
This Week in Science
Editor summaries of this week's papers.
Science 2 December 2005: 1385.
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Editorial:
Bullish on Particles
Michael S. Turner
Science 2 December 2005: 1389.
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Editors' Choice
Highlights of the recent literature.
Science 2 December 2005: 1391.
|Full Text »
NetWatch
Best of the Web in science.
Science 2 December 2005: 1401.
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NEW PRODUCTS
Science 2 December 2005: 1517.
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News of the Week
STEM CELL RESEARCH: Korean Cloner Admits Lying About Oocyte Donations
Constance Holden
Science 2 December 2005: 1402-1403.
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GLOBAL CLIMATE CHANGE: The Atlantic Conveyor May Have Slowed, But Don't Panic Yet
Richard A. Kerr
Science 2 December 2005: 1403-1405.
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CANADA: Animal Rules Keep Grad Students Out of the Lab
Wayne Kondro
Science 2 December 2005: 1405.
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NUCLEAR POWER: Congress Tells DOE to Take Fresh Look at Recycling Spent Reactor Fuel
Eli Kintisch
Science 2 December 2005: 1406.
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SCIENTIFIC PUBLISHING: NIEHS Journal Is on the Block
Jocelyn Kaiser
Science 2 December 2005: 1407.
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U.S. GRADUATE EDUCATION: Universities Must Pay to Play in Ph.D. Program Rankings
Jeffrey Mervis
Science 2 December 2005: 1407.
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SPACE SCIENCE: Fuel Shortage Imperils Asteroid-Sampling Mission
Dennis Normile
Science 2 December 2005: 1409.
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EPIDEMIOLOGY: Talk on 'Underground' Bird Flu Deaths Rattles Experts
Martin Enserink
Science 2 December 2005: 1409.
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ScienceScope
Science 2 December 2005: 1405.
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Random Samples
Science 2 December 2005: 1421.
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News Focus
ECOLOGY: Winning the War Against Island Invaders
Kevin Krajick
Science 2 December 2005: 1410-1413.
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ACOUSTIC ENGINEERING: String Theory Meets Practice as Violinmakers Rethink Their Craft
Adrian Cho
Science 2 December 2005: 1414-1415.
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FRANK WOLF PROFILE: The Congressman With His Hand on Science's Purse Strings
Jeffrey Mervis and Eli Kintisch
Science 2 December 2005: 1417-1418.
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PALEONTOLOGY: Best Archaeopteryx Fossil So Far Ruffles a Few Feathers
Erik Stokstad
Science 2 December 2005: 1418-1419.
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Letters
This Week's Letters
Science 2 December 2005: 1425.
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Issues in Bringing New Drugs to the Market
Rudi Ansbacher;, Arthur J. Ammann;, W. Ross Tracey;, and Jerry Avorn
Science 2 December 2005: 1425-1426.
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Invariant Ratios Vs. Dimensionless Ratios
Marc Mangel
Science 2 December 2005: 1426-1427.
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Worldwide Decline of Sturgeons
Dietrich E. Lorke and David T. Yew
Science 2 December 2005: 1427-1429.
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Corrections and Clarifications
Science 2 December 2005: 1429-1431.
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Books et al.
NATURAL HISTORY: Still Worthy of Our Land?
Joel Greenberg
Science 2 December 2005: 1432-1433.
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BEHAVIORAL ECOLOGY: Crowing About Culture
Joanna Dally
Science 2 December 2005: 1433.
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Books Received
Science 2 December 2005: 1433.
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Essays on Science and Society
GLOBAL VOICES OF SCIENCE: Following the Light: Opening Doors to Science in Tunisia
Zohra Ben Lakhdar
Science 2 December 2005: 1435-1437.
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125th Anniversary Series
Science 2 December 2005: 1435.
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Perspectives
PLANETARY SCIENCE: The Changing Picture of Volatiles and Climate on Mars
Bruce M. Jakosky, Robert M. Haberle, and Raymond E. Arvidson
Science 2 December 2005: 1439-1440.
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GEOPHYSICS: Enhanced: The Ghost of an Earthquake
William C. Hammond
Science 2 December 2005: 1440-1442.
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IMMUNOLOGY: Tipping the Scales Toward More Effective Antibodies
Jenny M. Woof
Science 2 December 2005: 1442-1443.
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CELL BIOLOGY: Keeping Survivin Nimble at Centromeres in Mitosis
William C. Earnshaw
Science 2 December 2005: 1443-1444.
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Brevia
Evidence for a One-Allele Assortative Mating Locus
Daniel Ortíz-Barrientos and Mohamed A. F. Noor
Science 2 December 2005: 1467.
A single shared allele reduces mating between individuals in two diverging species, confirming a theoretically predicted mode of speciation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Research Articles
Radiocarbon Variability in the Western North Atlantic During the Last Deglaciation
Laura F. Robinson, Jess F. Adkins, Lloyd D. Keigwin, John Southon, Diego P. Fernandez, S-L Wang, and Daniel S. Scheirer
Science 2 December 2005: 1469-1473.
Published online 3 November 2005 [DOI: 10.1126/science.1114832] (in Science Express Research Articles)
A record of the 14C content of deep water from the North Atlantic shows that warming during deglaciation in the Northern Hemisphere was indeed associated with vigorous deep-water formation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Postseismic Mantle Relaxation in the Central Nevada Seismic Belt
Noel Gourmelen and Falk Amelung
Science 2 December 2005: 1473-1476.
Radar interferometry data from a 10-year period shows that the crust in western Nevada is still relaxing from four large earthquakes that occurred between 1915 and 1954.
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Active Microbial Sulfur Disproportionation in the Mesoproterozoic
David T. Johnston, Boswell A. Wing, James Farquhar, Alan J. Kaufman, Harald Strauss, Timothy W. Lyons, Linda C. Kah, and Donald E. Canfield
Science 2 December 2005: 1477-1479.
Three sulfur isotopes show that microbes metabolized intermediate sulfur species by 1.3 billion years ago, implying that the atmosphere then was more oxidizing than had been supposed.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Electrowetting in Carbon Nanotubes
J. Y. Chen, A. Kutana, C. P. Collier, and K. P. Giapis
Science 2 December 2005: 1480-1483.
Inducing an electrical potential across single-walled carbon nanotubes can drive fluids, including mercury, into and through the tubes.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Well-Preserved Archaeopteryx Specimen with Theropod Features
Gerald Mayr, Burkhard Pohl, and D. Stefan Peters
Science 2 December 2005: 1483-1486.
A tenth Archaeopteryx specimen reveals that its first toe was not reversed as in later birds and that its second toe was extendable, as in proposed theropod ancestors.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Stem Cell Self-Renewal Controlled by Chromatin Remodeling Factors
Rongwen Xi and Ting Xie
Science 2 December 2005: 1487-1489.
Hormonal signals that maintain stem cells in a pluripotent state in the Drosophila ovary act by regulating proteins that control how much transcription occurs from chromatin.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Restoration of Auditory Nerve Synapses in Cats by Cochlear Implants
D. K. Ryugo, E. A. Kretzmer, and J. K. Niparko
Science 2 December 2005: 1490-1492.
In congenitally deaf cats, electrical stimulation of the cochlea for 6 months restored the abnormal synapse structure in the auditory nerve and their ability to hear.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Role for the Phagosome in Cytokine Secretion
Rachael Z. Murray, Jason G. Kay, Daniele G. Sangermani, and Jennifer L. Stow
Science 2 December 2005: 1492-1495.
Published online 10 November 2005 [DOI: 10.1126/science.1120225] (in Science Express Reports)
The specialized segment of immune cell membrane that engulfs microbes and then destroys them is also dedicated to secreting factors that cause local inflammation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
ATP Signaling Is Crucial for Communication from Taste Buds to Gustatory Nerves
Thomas E. Finger, Vicktoria Danilova, Jennell Barrows, Dianna L. Bartel, Alison J. Vigers, Leslie Stone, Goran Hellekant, and Sue C. Kinnamon
Science 2 December 2005: 1495-1499.
The long-sought neurotransmitter that communicates taste information from tongue receptors to the gustatory nerve is ATP, also used in other sensory systems.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Chromosome Alignment and Segregation Regulated by Ubiquitination of Survivin
Queenie P. Vong, Kan Cao, Hoi Y. Li, Pablo A. Iglesias, and Yixian Zheng
Science 2 December 2005: 1499-1504.
Ubiquitin, a peptide tag that usually marks proteins for degradation, unexpectedly also controls the cellular location of a key cell cycle protein during mitosis.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Prostaglandin E2 Promotes Colon Cancer Cell Growth Through a Gs-Axin-ß-Catenin Signaling Axis
Maria Domenica Castellone, Hidemi Teramoto, Bart O. Williams, Kirk M. Druey, and J. Silvio Gutkind
Science 2 December 2005: 1504-1510.
Published online 16 November 2005 [DOI: 10.1126/science.1116221] (in Science Express Reports)
A factor that causes inflammation enhances colon-cancer growth through a newly described signaling pathway.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Divergent Immunoglobulin G Subclass Activity Through Selective Fc Receptor Binding
Falk Nimmerjahn and Jeffrey V. Ravetch
Science 2 December 2005: 1510-1512.
The ability of certain natural and manufactured antibodies to elicit different immune defenses can be predicted by their relative affinities for activating or inhibitory receptors.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Structural Roles for Human Translation Factor eIF3 in Initiation of Protein Synthesis
Bunpote Siridechadilok, Christopher S. Fraser, Richard J. Hall, Jennifer A. Doudna, and Eva Nogales
Science 2 December 2005: 1513-1515.
A protein complex that binds to the ends of mRNAs to position them on the ribosome unexpectedly binds in the same way to internal ribosome entry sites within mRNAs.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Technical Comments
Comment on "The Great Sumatra-Andaman Earthquake of 26 December 2004"
S. Neetu, I. Suresh, R. Shankar, D. Shankar, S. S. C. Shenoi, S.R. Shetye, D. Sundar, and B. Nagarajan
Science 2 December 2005: 1431.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Response to Comment on "The Great Sumatra-Andaman Earthquake of 26 December 2004"
Thorne Lay, Hiroo Kanamori, Charles J. Ammon, Meredith Nettles, Steven N. Ward, Richard Aster, Susan L. Beck, Susan L. Bilek, Michael R. Brudzinski, Rhett Butler, Heather R. DeShon, Göran Ekström, Kenji Satake, and Stuart Sipkin
Science 2 December 2005: 1431.
Abstract »| Full Text »| PDF »|
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