2006年2月17日 美国《科学》周刊311卷 第5763期格林兰岛冰川运动速度加快
一项新研究指出，格林兰岛的冰川输送到大西洋的冰在过去5年中增加了两倍，这是因为冰川运动的速度在加快。这项研究的作者提出，许多目前对格林兰岛对未来海平面上升的贡献的估计可能过低。这些科学家说，表面空气温度的不断升高看来引起了格林兰岛北半部冰川运动速度的加快。他们计算出格林兰岛对全球海平面升高的贡献是每年0.5毫米，而在目前其它的估计中，这个数是每年0.3毫米。最近格林兰岛冰川运动速度的增加占格林兰岛对海平面升高贡献的三分之二强。1996年以来，由冰川流动造成的冰损失主要是在格林兰岛东南部冰川出口处。2000年以后，更北部的冰川的流速也加快了。Eric Rignot和Pannir Kanagaratnam用来自卫星的监视冰川运动的数据绘制了一幅几乎全部格林兰岛在2000年的冰川速度图，数据包括从1996年到2005年的过去10年中冰川速度变化的卫星测量。冰川运动所造成的冰损失由1996年的50立方公里增加为2005年的150立方公里。
报告：Changes in the Velocity Structure of the Greenland Ice Sheet, Eric Rignot and Pannir Kanagaratnam
研究评述：The Greenland Ice Sheet and Global Sea-Level Rise, Julian A. Dowdeswell
面临重大的决定? 先忘掉它再说
一项新研究提出，复杂的决定最好让你的无意识来做。科学家说，如果你面对一个大的决定，比如买车或买房子，搜集有关的信息是重要的。但是一旦信息都搜集够了，最好把这件事忘掉一段时间，让你的无意识来处理各种可能的选择，这样做出的决定，与主要靠有意识的思考作出的同样决定相比，会让你更满意。
Ap Dijksterhuis和同事通过在实验室和商场观察人买车、家具、洗头液、烤箱手套等商品，研究了人们如何做简单或复杂的决定。在研究人员的买车试验中，参与者首先被要求读一系列的有关车的复杂信息，然后马上解一些拼字猜谜分散他们的意识。玩完拼字猜谜后再做出车型选择的组，比看完信息后没有玩猜谜就马上有意识地考虑信息做出车型选择的组，对他们的选择更满意。文章作者说，在这样的有意识思考中，人们只考虑了有关信息的一个子集，而且可能不适当地估量了这些部分信息。与此相比，人的无意识能整合更广范围的信息，从而在做复杂决定时带来更满意的结果。文章作者还显示，简单的决定，比如选择哪种洗发液，在马上认真考虑后也是满意的，大概是因为简单决定只需要考虑几条因素所以能比较容易地处理。
报告：On Making the Right Choice: The Deliberation-Without-Attention Effect, Ap Dijksterhuis, Maarten W. Bos, Loran F. Nordgren, and Rick B. van Baaren
制造更好的锂电池
一种新的锂电池设计比现有的锂电池设计能更快地提供电能，这也许正是依赖电池的技术，比如电力混合动力车、便携电钻等电动工具、以及靠电池的备用设备所需要的。这些设备需要在较小体积内存更高电能的快速充电和放电的电池。手机和手提摄影机中常见的锂离子电池能在小体积内储存高电能，但不能足够快地提供某些新技术所需的电能。现在，Kisuk Kang和同事用计算机模型设计了一种新的电池电极，使锂离子在电极结构中能更快地运动，加快了电池充电的速度。研究人员用这个模型制造了一个试验电极，得到了比现有离电池设计快的电能输送速度。
报告：Electrodes with High Power and High Capacity for Rechargeable Lithium Batteries, Kisuk Kang, Ying Shirley Meng, Julien Bréger, Clare P. Grey, and Gerbrand Ceder
治疗早老症的可能药物
用小鼠做的研究也许有朝一日能为早老症带来有希望的新疗法，早老症是把儿童变老的一种罕见的遗传紊乱。患有早老症的儿童蒙受与衰老有关的症状的困扰，比如骨质疏松、头发脱落、心脏病等，而且通常活不到20岁。在一个早老症的小鼠模式中， Loren Fong和同事用药物阻止了一个叫lamin A蛋白质的修饰，lamin A在一些早老症中有突变。Lamin A是细胞核膜内骨架结构的一个关键组分，它帮助组织DNA复制等功能。有突变的该蛋白版本不是被释放到细胞核纤层中，而是被一个脂锚黏在核膜的内层，从而破坏关键的细胞核功能。研究人员显示，给这些小鼠一种药物来停止对lamin A蛋白的修饰，减轻了它们的骨骼酥松等类似早老症的症状，而且在这个短期的研究中，这些小鼠的寿命稍微延长了一点。Fong和同事说，两种这类药物已经正在作为抗肿瘤药物在进行临床试验，这也许能帮助加快它们用于早老症患儿的试验。
科学特快报告：A Protein Farnesyltransferase Inhibitor Ameliorates Disease in a Mouse Model of Progeria, Loren G. Fong, et al.
生物钟、锂盐和双相障碍
锂盐是治疗双相障碍(bipolar disorders)常用的药物，通过研究锂盐对培养细胞的作用，科学家揭示了生物钟和双相障碍之间一个潜在的分子联系。Lei Yin和同事说，这些结果提出了锂盐为什么对双相障碍患者有好处的可能的分子解释。生物钟调节哺乳动物许多行为和生理的方面，包括睡眠清醒周期以及新陈代谢。人们已经知道锂盐影响人的生物钟，双相障碍和其他精神疾病与生物钟节律的打乱有关。本文作者通过分析培养细胞发现，钟基因表达的一个关键负调节物Rev-erbα核受体，在细胞接触到锂盐后很快降解。这个受体的降解导致钟基因的激活，从而提出锂盐的有益效果也许部分地来自它对Rev-erbα受体作用的可能性。
报告：Nuclear Receptor Rev-erbα Is a Critical Lithium-Sensitive Component of the Circadian Clock, Lei Yin, Jing Wang, Peter S. Klein, and Mitchell A. Lazar
超越性选择理论
本期一篇综述的作者说，也许需要用新理论来取代性选择理论，他们提出了一个基于合作动物之间直接交换生态效益、不考虑遗传效益的新方法。性选择理论是达尔文1871年提出的，在这个理论中，雄性和雌性的繁殖社会行为不一样。雄性用廉价的精子使尽可能多的雌性受精；而雌性只有有限的大个的卵子，所以需要选择遗传质量最高的雄性来赋予后代上等的能力。Joan Roughgarden和同事提出了一个替代性选择的模型，并用一个很少用的、与交易和副支付(side payments)有关的博弈论给其一个数学框架。本文作者指出，地中海的孔雀濑鱼雄性和雌性结对组成的合作游戏可能是他们模型的实际世界的例子。
报告：Reproductive Social Behavior: Cooperative Games to Replace Sexual Selection, Joan Roughgarden, Meeko Oishi, and Erol Akcay
This Week in Science
Editor summaries of this week's papers.
Science 17 February 2006: 913.
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Editorial:
The New Gag Rules
Donald Kennedy
Science 17 February 2006: 917.
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Editors' Choice
Highlights of the recent literature.
Science 17 February 2006: 919.
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NetWatch
Best of the Web in science.
Science 17 February 2006: 925.
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NEW PRODUCTS
Science 17 February 2006: 1023.
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News of the Week
KOREAN STEM CELL SCANDAL: Schatten: Pitt Panel Finds 'Misbehavior' but Not Misconduct
Constance Holden
Science 17 February 2006: 928.
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2007 U.S. BUDGET: How the Competitiveness Initiative Came About
Jeffrey Mervis
Science 17 February 2006: 929.
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PALEOBIOLOGY: Revised Numbers Quicken the Pace of Rebound From Mass Extinctions
Richard A. Kerr
Science 17 February 2006: 931.
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AVIAN INFLUENZA: H5N1 Moves Into Africa, European Union, Deepening Global Crisis
Martin Enserink
Science 17 February 2006: 932.
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PLANETARY SCIENCE: Hunt for Birthplace of Meteorites Yields New View of Earth's Origins
Richard A. Kerr
Science 17 February 2006: 932.
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GENOMIC DATABASES: NIH Goes After Whole Genome in Search of Disease Genes
Jocelyn Kaiser
Science 17 February 2006: 933.
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MEDICINE: Mouse Study Suggests Cancer Drugs Could Help Prematurely Aging Kids
John Travis
Science 17 February 2006: 934-935.
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EPIDEMIOLOGY: Bush Administration Decides It Can't Afford Children's Study
Jocelyn Kaiser
Science 17 February 2006: 934.
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PSYCHOLOGY: Tough Decision? Don't Sweat It
Greg Miller
Science 17 February 2006: 935.
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BIOTECHNOLOGY IN CHINA: Doubts Over New Antibiotic Land Co-Authors in Court
Gong Yidong and Eliot Marshall
Science 17 February 2006: 937.
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ScienceScope
Science 17 February 2006: 931.
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Random Samples
Science 17 February 2006: 927.
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Newsmakers
Science 17 February 2006: 949.
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News Focus
NEUROSCIENCE: New Neurons Strive to Fit In
Greg Miller
Science 17 February 2006: 938-940.
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SCIENTIFIC COMMUNITY: Scientists' Suicides Prompt Soul-Searching in China
Ding Yimin
Science 17 February 2006: 940-941.
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RETROVIRUS MEETING: Novel Attacks on HIV Move Closer to Reality
Jon Cohen
Science 17 February 2006: 943.
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AVIAN INFLUENZA: Combating the Bird Flu Menace, Down on the Farm
Richard Stone
Science 17 February 2006: 944-946.
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INTELLECTUAL PROPERTY: What Good Is a Patent? Supreme Court May Suggest an Answer
Eli Kintisch
Science 17 February 2006: 946-947.
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Letters
This Week's Letters
Science 17 February 2006: 951.
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The Language of Fighting Invasive Species
Philippe Clergeau, Martin A. Nuñez;, Derek Turner, and Michael Patterson
Science 17 February 2006: 951.
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Doing More for Keisha
William S. Barnes
Science 17 February 2006: 951-952.
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Genetic Research into Autism
Angelica Ronald, Francesca Happé, Robert Plomin;, Simon Baron-Cohen, Rebecca C. Knickmeyer, and Matthew K. Belmonte
Science 17 February 2006: 952.
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Acid Growth and Plant Development
U. Kutschera; and Markus Grebe
Science 17 February 2006: 952-954.
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Corrections and Clarifications
Science 17 February 2006: 954.
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Books et al.
METROPOLITAN GEOGRAPHIES: When Suburbs Collide
Jennifer Wolch
Science 17 February 2006: 956.
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ECOLOGY: Land of the Lost
Paul L. Koch
Science 17 February 2006: 957.
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Books Received
Science 17 February 2006: 957.
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Policy Forum
INFORMATION SCIENCE: Enhanced: Cybertools and Archaeology
Dean R. Snow, Mark Gahegan, C. Lee Giles, Kenneth G. Hirth, George R. Milner, Prasenjit Mitra, and James Z. Wang
Science 17 February 2006: 958-959.
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Perspectives
EVOLUTION: Why Sex?
Rasmus Nielsen
Science 17 February 2006: 960-961.
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PLANETARY SCIENCE: Ringing the Changes
Carl D. Murray
Science 17 February 2006: 961-962.
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NEUROSCIENCE: SUMO Wrestles the Synapse
Asim A. Beg and Peter Scheiffele
Science 17 February 2006: 962-963.
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ATMOSPHERIC SCIENCE: The Greenland Ice Sheet and Global Sea-Level Rise
Julian A. Dowdeswell
Science 17 February 2006: 963-964.
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Review
Reproductive Social Behavior: Cooperative Games to Replace Sexual Selection
Joan Roughgarden, Meeko Oishi, and Erol Akçay
Science 17 February 2006: 965-969.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Brevia
Genetic Variation Affects de Novo Translocation Frequency
Takema Kato, Hidehito Inagaki, Kouji Yamada, Hiroshi Kogo, Tamae Ohye, Hiroe Kowa, Kayuri Nagaoka, Mariko Taniguchi, Beverly S. Emanuel, and Hiroki Kurahashi
Science 17 February 2006: 971.
A palindromic sequence on human chromosome 11 causes frequent translocations during meiosis, while a more recently evolved nonpalindromic allele does not.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Research Article
The Second Ring-Moon System of Uranus: Discovery and Dynamics
Mark R. Showalter and Jack J. Lissauer
Science 17 February 2006: 973-977.
Published online 22 December 2005 [DOI: 10.1126/science.1122882] (in Science Express Research Articles)
Uranus has two additional moons and two faint rings that form a highly dynamic system orbiting beyond its known rings.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Electrodes with High Power and High Capacity for Rechargeable Lithium Batteries
Kisuk Kang, Ying Shirley Meng, Julien Bréger, Clare P. Grey, and Gerbrand Ceder
Science 17 February 2006: 977-980.
Ab initio calculations are used to develop an efficient battery containing layered lithium, nickel, and manganese oxide and to optimize its performance.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Plasma Acceleration Above Martian Magnetic Anomalies
R. Lundin, D. Winningham, S. Barabash, R. Frahm, M. Holmström, J.-A. Sauvaud, A. Fedorov, K. Asamura, A. J. Coates, Y. Soobiah, K. C. Hsieh, M. Grande, H. Koskinen, E. Kallio, J. Kozyra, J. Woch, M. Fraenz, D. Brain, J. Luhmann, S. McKenna-Lawler, R. S. Orsini, P. Brandt, and P. Wurz
Science 17 February 2006: 980-983.
Heightened motion of electrons and ions in the martian atmosphere produces aurorae above regions of high surface magnetism through a process similar to that on Earth.
Abstract »| Full Text »| PDF »|
Dissociation of MgSiO3 in the Cores of Gas Giants and Terrestrial Exoplanets
Koichiro Umemoto, Renata M. Wentzcovitch, and Philip B. Allen
Science 17 February 2006: 983-986.
Calculations imply that the main silicate compound deep in terrestrial planets should dissociate to MgO and SiO2 at high pressures characteristic of planets larger than Earth.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Changes in the Velocity Structure of the Greenland Ice Sheet
Eric Rignot and Pannir Kanagaratnam
Science 17 February 2006: 986-990.
Velocity measurements of ice flow across Greenland show that Greenland glaciers are accelerating, doubling the mass deficit of the ice sheet in the past 3 years.
Abstract »| Full Text »| PDF »|
Transitions to Asexuality Result in Excess Amino Acid Substitutions
Susanne Paland and Michael Lynch
Science 17 February 2006: 990-992.
Comparison of asexual and sexual strains of the water flea show that asexual reproduction leads to more deleterious mutations, confirming the advantage of sex.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Cdx2 Gene Expression and Trophectoderm Lineage Specification in Mouse Embryos
Kaushik Deb, Mayandi Sivaguru, Hwan Yul Yong, and R. Michael Roberts
Science 17 February 2006: 992-996.
In mice, an RNA that ultimately directs formation of the placenta is already clustered at one pole of the oocyte, indicating prepatterning of the placental precursor.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
X-ray Structure of a Self-Compartmentalizing Sulfur Cycle Metalloenzyme
Tim Urich, Cláudio M. Gomes, Arnulf Kletzin, and Carlos Frazão
Science 17 February 2006: 996-1000.
Microbial sulfur oxygenase reductase, a major contributor to the global sulfur cycle, forms a 24-subunit hollow sphere with channels that provide access to the active sites inside.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Keystone Mutualism Drives Pattern in a Power Function
John Vandermeer and Ivette Perfecto
Science 17 February 2006: 1000-1002.
The spatial distribution of a scale insect species found on coffee bushes deviates from the expected power law only when their protective ant partner is absent.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Nuclear Receptor Rev-erb Is a Critical Lithium-Sensitive Component of the Circadian Clock
Lei Yin, Jing Wang, Peter S. Klein, and Mitchell A. Lazar
Science 17 February 2006: 1002-1005.
Lithium, like triggers of the circadian clock, causes degradation of a nuclear protein, possibly explaining its therapeutic effect in bipolar disorder.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
On Making the Right Choice: The Deliberation-Without-Attention Effect
Ap Dijksterhuis, Maarten W. Bos, Loran F. Nordgren, and Rick B. van Baaren
Science 17 February 2006: 1005-1007.
Although simple decisions are better made after some thought, consciously thinking about complex problems may produce worse results than not thinking at all.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Activity-Dependent Regulation of MEF2 Transcription Factors Suppresses Excitatory Synapse Number
Steven W. Flavell, Christopher W. Cowan, Tae-Kyung Kim, Paul L. Greer, Yingxi Lin, Suzanne Paradis, Eric C. Griffith, Linda S. Hu, Chinfei Chen, and Michael E. Greenberg
Science 17 February 2006: 1008-1012.
A transcription factor that is enriched in the brain and activated by calcium links electrical activity of neurons to the number of functional synapses.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Calcium-Regulated MEF2 Sumoylation Switch Controls Postsynaptic Differentiation
Aryaman Shalizi, Brice Gaudillière, Zengqiang Yuan, Judith Stegmüller, Takahiro Shirogane, Qingyuan Ge, Yi Tan, Brenda Schulman, J. Wade Harper, and Azad Bonni
Science 17 February 2006: 1012-1017.
A transcription factor that is enriched in the brain and activated by calcium links electrical activity of neurons to the number of functional synapses.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Role of Noradrenergic Signaling by the Nucleus Tractus Solitarius in Mediating Opiate Reward
Valerie G. Olson, Carrie L. Heusner, Ross J. Bland, Matthew J. During, David Weinshenker, and Richard D. Palmiter
Science 17 February 2006: 1017-1020.
In mice, the addictive response to morphine requires norepinephrine neurotransmission in a single region of the brain.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Causal Reasoning in Rats
Aaron P. Blaisdell, Kosuke Sawa, Kenneth J. Leising, and Michael R. Waldmann
Science 17 February 2006: 1020-1022.
Experiments show that rats, like humans, can discriminate between events that are coincident in time and those that are causally related to one another.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
