4 August 2006 Vol 313, Issue 5787, Pages 588-691
人类大脑中的非理性
如果有人给你50美元，你愿意保留其中的20美元呢，还是丢掉30美元？新研究将某些非理性决定(类似于选择保留20美元，因为“保留”看起来比“丢掉”好)跟踪到大脑中与感情有关的中心。这项研究还把理性的决定(人们意识到保留20还是丢掉30没有差别)与大脑的另一个区域联系起来。Benedetto De Martino和英国的同事研究了所谓的"框架效应," 既用正面或反面的方式给出选择影响一个人的决定。有关经济决策的理论传统地假设人根本上是理性的，所以不会受框架效应的影响。本文作者对参加试验的志愿者在他们选择在两个不同背景下如何处理一笔钱时做脑成像。表现出更易受框架效应影响的志愿者在大脑名为杏仁体的与学习和感情有关的区域中有更高的活性。作者还报告说，他们能够靠测到的大脑另一个区域(腹侧和内侧皮层)中增加的活动来预测哪些志愿者最不易受框架效应的影响，也就是说他们也许是最理性的。
报告：Frames, Biases, and Rational Decision-Making in the Human Brain, Benedetto De Martino, Dharshan Kumaran, Ben Seymour, and Raymond J. Dolan
月球的一个迷得到了解决？
研究人员提出了一个月球几百年问题的可能解决：为什么月球的背面在其赤道附近凸起？自从数学家拉普拉斯在1799年指出这个问题后，这个奇怪的形状一直在困惑着科学家。对这个“化石凸起”的可能解释是，月球的轨道也许在其历史早期与现在的不同，那时月球的岩浆海洋正在固化。但是这个过程的模型至今未能给出与月球精确尺度相符的结果。Ian Garrick-Bethell和同事现在显示，月球的形状能够用在其形成后的1亿年后，其轨道是椭圆形的来解释。文章作者的模型缩小了具体轨道的可能选择，其中一个与水星的类似。Kimmo Innanen 撰写的一篇相关的研究评述描述了研究人员在地球和月球轨道的重力场三体问题上做得努力。
报告：Evidence for a Past High-Eccentricity Lunar Orbit, Ian Garrick-Bethell, Jack Wisdom, and Maria T. Zuber
研究评述：Solving Laplace's Lunar Puzzle, Kimmo Innanen
血栓纤维的超弹性
新研究提出，形成血栓的网状母体的纤维出人意料地有弹性。Wenhua Liu和同事在本期的一篇简报中报告说，这种纤维能延伸到其长度的三倍而不失去弹性，而且只有在延伸到其长度6倍时才断掉。当血浆的一个可溶解的成分纤维素原被转变为纤维蛋白的分支网络时，就形成了血栓。文章作者说，对单个纤维蛋白的机械型能过去了解甚少，虽然这种信息对测试血栓的机械模型是必需的。他们用一个原子里显微镜的探针来拉长这些纤维。整体的纤维蛋白栓“只有”百分之100到200的延伸性，意味着血栓变形是通过单个纤维的拉伸发生的，而且栓的破裂一定是纤维连接断开的结果。这个结果出人意料，因为许多网络对张力的响应是首先排列纤维，然后拉伸，这样的网络比单个纤维更有伸缩性。
简报：Fibrin Fibers Have Extraordinary Extensibility and Elasticity, W. Liu, et al.
科学家发现第一对行质天体
轨道运行的质量物体简称“行质天体(planemo)”，天文学家发现了第一对行质天体。这些新发现的褐矮行质天体不完全是恒星，也不完全是行星。这个发现为这些自由运行物体的形成提供了新线索。这些行质天体的色谱和颜色提示它们的年代相同，减少了解释它们如何形成的可能理论的数目。还需要更多的研究才能确定行质天体是更像由破碎的质量云形成的恒星，还是更像由大恒星附近的残留盘状物形成的行星。Ray Jayawardhana 和Ivanov用欧洲南方天文台的新技术望远镜以及特大望远镜UT2捕获到名为Oph 16225-240515AB 对的照片以及光普数据。
科学特快报告：Discovery of a Young Planetary Mass Binary, Ray Jayawardhana and Valentin D. Ivanov
抗体的双重作用与发炎
某些抗体有双重身份，它们有时处于支持发炎的状态、有时处于抵抗发炎的状态，新研究显示它们是靠修饰附着在其上的糖来转变状态的。发炎对身体有好处，因为它帮助抵抗感染，但是如果发炎失去控制，它也可能损害身体的组织。类似地，IgG类的抗体通常是不发炎的，但是它们能在感染是帮助补充发炎细胞。Yoshikatsu Kaneko和同事报告，IgG抗体通过修饰抗体上与免疫细胞结合部位的糖体来实现这个转变。通常，免疫细胞的受体与糖增强的抗体形式的结合相对较弱，这就给细胞信号使它们在表面上带很多的抵抗发炎的蛋白。但是在感染时，糖体消失，使抗体与免疫细胞的结合变得很强，这就“上调”了支持发言信号的表达。一篇相关的研究评述讨论了这些发现。
报告：Anti-Inflammatory Activity of Immunoglobulin G Resulting from Fc Sialylation, Yoshikatsu Kaneko, Falk Nimmerjahn, and Jeffrey V. Ravetch
研究评述：Sugar Determines Antibody Activity, Dennis R. Burton and Raymond A. Dwek
石笋与气候研究
石笋以及岩洞中其他碳酸盐沉积会不会成为21世纪气候变化研究的“冰芯”？从冰芯得来的气候记录在过去20年中彻底改变了气候变化的研究，但是Gideon Henderson在本期一篇研究评述中指出，洞穴碳酸盐结构比冰芯有更多的优越性。冰芯主要在远离人群分布的地方形成，与冰芯不同，世界各地都有洞穴，而且它们能用铀的放射性衰变来精确地测定年代。精确测出年代的洞穴记录能帮助建立跨越地球不同地点气候变化的关联，比如北大西洋的变冷与亚洲干旱，而且还能帮助搞清影响长期冰川周期的因素。
研究评述：Caving In to New Chronologies, Gideon M. Henderson
Contents
This Week in Science
Editor summaries of this week's papers.
Science 4 August 2006: 588.
|Full Text »
Editorial:
The G8 on Energy: Too Little
Martin Rees
Science 4 August 2006: 591.
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Editors' Choice
Highlights of the recent literature.
Science 4 August 2006: 592.
|Full Text »
NetWatch
Best of the Web in science.
Science 4 August 2006: 595.
|Full Text »
Science Podcast
Science 4 August 2006: 691.
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NEW PRODUCTS
Science 4 August 2006: 691.
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News of the Week
SCIENTIFIC PUBLISHING: The Undisclosed Background of a Paper on a Depression Treatment
Constance Holden
Science 4 August 2006: 598-599.
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PLANETARY SCIENCE: At Last, Methane Lakes on Saturn's Icy Moon Titan--But No Seas
Richard A. Kerr
Science 4 August 2006: 598.
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EARTH SCIENCE: China Grapples With Seismic Risk in Its Northern Heartland
Richard Stone
Science 4 August 2006: 599.
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INTERNATIONAL SCIENCE: Singapore-Hopkins Partnership Ends in a Volley of Fault-Finding
Dennis Normile
Science 4 August 2006: 600.
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NEUROSCIENCE: The Emotional Brain Weighs Its Options
Greg Miller
Science 4 August 2006: 600-601.
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AVIAN INFLUENZA: Hybrid Viruses Fail to Spread
Jocelyn Kaiser
Science 4 August 2006: 601-602.
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PHYSICS: High-Temperature Superconductors Feel the Vibe After All
Adrian Cho
Science 4 August 2006: 602.
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PHYSICS: Physicists See Solid Helium Flow, But Not in the Most Exciting Way
Adrian Cho
Science 4 August 2006: 603.
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ScienceScope
Science 4 August 2006: 601.
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Random Samples
Science 4 August 2006: 597.
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Newsmakers
Science 4 August 2006: 611.
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News Focus
SOCIOLOGY: Making Connections
Karen Heyman
Science 4 August 2006: 604-606.
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SOCIOLOGY: Looking for Patterns
Karen Heyman
Science 4 August 2006: 606.
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SOLAR PHYSICS: Space Weather Forecasters Plan a Boost in Surveillance Missions
Dennis Normile and Richard Stone
Science 4 August 2006: 607.
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CLIMATE RESEARCH: Waiting for the Monsoon
Catherine Brahic
Science 4 August 2006: 608-609.
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U.S. HOMELAND SECURITY: Congress Dials Back Research on Understanding Terrorism
Yudhijit Bhattacharjee
Science 4 August 2006: 610.
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Letters
This Week's Letters
Science 4 August 2006: 612.
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Boycott of Israeli Academics Misguided
Mike Fainzilber
Science 4 August 2006: 612.
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Keeping Bandits at Bay?
Helen Scales, Andrew Balmford, Min Liu, Yvonne Sadovy, Andrea Manica;, T. P. Hughes, F. Berkes, R. S. Steneck, J. A. Wilson, D. R. Bellwood, B. Crona, C. Folke, L. H. Gunderson, H. M. Leslie, J. Norberg, M. Nyström, P. Olsson, H. Österblom, M. Scheffer, and B. Worm
Science 4 August 2006: 612-614.
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Making U.S. Graduate Education More Diverse
Cecilio R. Barrera
Science 4 August 2006: 614.
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Recognizing Computational Science
Joss Bland-Hawthorn
Science 4 August 2006: 614-615.
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Books et al.
PSYCHOLOGY: Reflections on Mind
Joan E. Grusec
Science 4 August 2006: 616.
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Books Received
Science 4 August 2006: 616.
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Policy Forum
SUSTAINABILITY: Resolving Mismatches in U.S. Ocean Governance
L. B. Crowder, G. Osherenko, O. R. Young, S. Airamé, E. A. Norse, N. Baron, J. C. Day, F. Douvere, C. N. Ehler, B. S. Halpern, S. J. Langdon, K. L. McLeod, J. C. Ogden, R. E. Peach, A. A. Rosenberg, and J. A. Wilson
Science 4 August 2006: 617-618.
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Perspectives
GEOPHYSICS: A New Class of Earthquake Observations
Fred F. Pollitz
Science 4 August 2006: 619-620.
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CLIMATE: Caving In to New Chronologies
Gideon M. Henderson
Science 4 August 2006: 620-622.
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PLANETARY SCIENCE: Solving Laplace's Lunar Puzzle
Kimmo Innanen
Science 4 August 2006: 622-623.
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CLIMATE: How Do Aerosols Affect Cloudiness and Climate?
François-Marie Bréon
Science 4 August 2006: 623-624.
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CELL BIOLOGY: Extinguishing a Cell Cycle Checkpoint
M. Andrew Hoyt
Science 4 August 2006: 624-625.
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MICROBIOLOGY: Timing the Sexual Development of Parasites
Stephen L. Hajduk
Science 4 August 2006: 626-627.
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IMMUNOLOGY: Sugar Determines Antibody Activity
Dennis R. Burton and Raymond A. Dwek
Science 4 August 2006: 627-628.
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Review
The Primary Cilium as the Cell's Antenna: Signaling at a Sensory Organelle
Veena Singla and Jeremy F. Reiter
Science 4 August 2006: 629-633.
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Brevia
Fibrin Fibers Have Extraordinary Extensibility and Elasticity
W. Liu, L. M. Jawerth, E. A. Sparks, M. R. Falvo, R. R. Hantgan, R. Superfine, S. T. Lord, and M. Guthold
Science 4 August 2006: 634.
The fibrin fibers that support blood clots can be stretched to nearly three times their normal length without losing elasticity and up to six times before rupturing.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Research Articles
Spitzer Spectral Observations of the Deep Impact Ejecta
C. M. Lisse, J. VanCleve, A. C. Adams, M. F. A'Hearn, Y. R. Fernández, T. L. Farnham, L. Armus, C. J. Grillmair, J. Ingalls, M. J. S. Belton, O. Groussin, L. A. McFadden, K. J. Meech, P. H. Schultz, B. C. Clark, L. M. Feaga, and J. M. Sunshine
Science 4 August 2006: 635-640.
Published online 13 July 2006 [DOI: 10.1126/science.1124694] (in Science Express Research Articles)
The nucleus of comet Tempel 1 is made of minerals and organic compounds from throughout the protosolar nebula.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Netrins Promote Developmental and Therapeutic Angiogenesis
Brent D. Wilson, Masaaki Ii, Kye Won Park, Arminda Suli, Lise K. Sorensen, Fréderic Larrieu-Lahargue, Lisa D. Urness, Wonhee Suh, Jun Asai, Gerhardus A.H. Kock, Tina Thorne, Marcy Silver, Kirk R. Thomas, Chi-Bin Chien, Douglas W. Losordo, and Dean Y. Li
Science 4 August 2006: 640-644.
Published online 29 June 2006 [DOI: 10.1126/science.1124704] (in Science Express Research Articles)
The netrins, developmental factors that guide axons as they find their targets, also direct the formation of new blood vessels.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
The Neurospora Checkpoint Kinase 2: A Regulatory Link Between the Circadian and Cell Cycles
António M. Pregueiro, Qiuyun Liu, Christopher L. Baker, Jay C. Dunlap, and Jennifer J. Loros
Science 4 August 2006: 644-649.
Published online 29 June 2006 [DOI: 10.1126/science.1121716] (in Science Express Research Articles)
A fungal ortholog of a key regulator for the mammalian cell cycle links cell division with the circadian cycle, gating the ability of DNA damage to reset the clock.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Imaging the Mott Insulator Shells by Using Atomic Clock Shifts
Gretchen K. Campbell, Jongchul Mun, Micah Boyd, Patrick Medley, Aaron E. Leanhardt, Luis G. Marcassa, David E. Pritchard, and Wolfgang Ketterle
Science 4 August 2006: 649-652.
High-resolution spectroscopy reveals the layered electron band structure that produces an insulating, instead of conducting, cloud of cold rubidium atoms.
Abstract »| Full Text »| PDF »|
Evidence for a Past High-Eccentricity Lunar Orbit
Ian Garrick-Bethell, Jack Wisdom, and Maria T. Zuber
Science 4 August 2006: 652-655.
The equatorial bulge of the Moon implies that it was in a highly eccentric orbit close to Earth soon after its formation and during its solidification.
Abstract »| Full Text »| PDF »|
Smoke and Pollution Aerosol Effect on Cloud Cover
Yoram J. Kaufman and Ilan Koren
Science 4 August 2006: 655-658.
Published online 13 July 2006 [DOI: 10.1126/science.1126232] (in Science Express Reports)
A higher concentration of aerosol particles increases cloudiness, but this effect is offset by the amount of sunlight absorbed by the clouds.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Crustal Dilatation Observed by GRACE After the 2004 Sumatra-Andaman Earthquake
Shin-Chan Han, C. K. Shum, Michael Bevis, Chen Ji, and Chung-Yen Kuo
Science 4 August 2006: 658-662.
Changes in Earth抯 gravity after the 2004 Sumatra-Andaman earthquake reveal that the quake compressed and extended the local crust and mantle, changing their densities.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Synthesis of Biaryls via Catalytic Decarboxylative Coupling
Lukas J. Gooßen, Guojun Deng, and Laura M. Levy
Science 4 August 2006: 662-664.
A copper catalyst in tandem with palladium can generate useful biaryl compounds from benign carboxylates rather than hazardous organometallics.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Gender Differences in Patenting in the Academic Life Sciences
Waverly W. Ding, Fiona Murray, and Toby E. Stuart
Science 4 August 2006: 665-667.
A longitudinal study shows that women scientists have patented their findings at less than half the rate of men, perhaps because of fewer collaborations and industrial contacts.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Regulation of Sexual Development of Plasmodium by Translational Repression
Gunnar R. Mair, Joanna A. M. Braks, Lindsey S. Garver, Joop C. A. G. Wiegant, Neil Hall, Roeland W. Dirks, Shahid M. Khan, George Dimopoulos, Chris J. Janse, and Andrew P. Waters
Science 4 August 2006: 667-669.
An essential RNA helicase sequesters mRNAs in the developing malaria parasite until they are needed, presenting a likely target for therapeutics.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Anti-Inflammatory Activity of Immunoglobulin G Resulting from Fc Sialylation
Yoshikatsu Kaneko, Falk Nimmerjahn, and Jeffrey V. Ravetch
Science 4 August 2006: 670-673.
Inflammatory antibodies can be converted to potentially useful anti-inflammatory agents by altering their attached sugar residues.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
N- to C-Terminal SNARE Complex Assembly Promotes Rapid Membrane Fusion
Ajaybabu V. Pobbati, Alexander Stein, and Dirk Fasshauer
Science 4 August 2006: 673-676.
A preassembled complex of fusion proteins can fuse membranes in vitro as rapidly as is observed during secretion in intact neurons.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Clamping Mechanism Involved in SNARE-Dependent Exocytosis
Claudio G. Giraudo, William S. Eng, Thomas J. Melia, and James E. Rothman
Science 4 August 2006: 676-680.
Published online 22 June 2006 [DOI: 10.1126/science.1129450] (in Science Express Reports)
The protein complexin prevents synaptic vesicles from fusing until calcium is sensed by another protein, synaptotagmin, to initiate fusion.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Anaphase Inactivation of the Spindle Checkpoint
William J. Palframan, Janet B. Meehl, Sue L. Jaspersen, Mark Winey, and Andrew W. Murray
Science 4 August 2006: 680-684.
Published online 6 July 2006 [DOI: 10.1126/science.1127205] (in Science Express Reports)
The system that ensures that all chromosomes are properly attached to the spindle poles during cell division is later inactivated by the interaction of two proteins.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Frames, Biases, and Rational Decision-Making in the Human Brain
Benedetto De Martino, Dharshan Kumaran, Ben Seymour, and Raymond J. Dolan
Science 4 August 2006: 684-687.
The framing effect—in which the way a question is posed alters the answer—is a result of biases arising in the amygdala, a brain region involved with emotion.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Technical Comments
Comment on "Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk"
M. Newton, S. Fitzgerald, R. R. Rose, P. W. Adams, S. D. Tesch, J. Sessions, T. Atzet, R. F. Powers, and C. Skinner
Science 4 August 2006: 615.
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Comment on "Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk"
B. N. Baird
Science 4 August 2006: 615.
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Response to Comments on "Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk"
D. C. Donato, J. B. Fontaine, J. L. Campbell, W. D. Robinson, J. B. Kauffman, and B. E. Law
Science 4 August 2006: 615.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
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