2006年3月17日 美国《科学》周刊311卷 第5767期
禽流感进入人类的一个可能路径
一项新研究指出，对禽流感病毒H5N1的表面蛋白之一的仔细观察发现，某些突变可能会给H5N1病毒传播到人类提供方便。用从一位2004年死于禽流感的越南男孩身上分离出来的H5N1病毒样品上，James Stevens和同事确定出红细胞凝集素(hemagglutinin)蛋白的结构。红细胞凝集素让病毒进入宿主细胞，它在禽类和人类流感中与不同的细胞受体结合，这也许解释了问什么大多数禽流感病毒不在人与人之间传播。有几种已知的突变能将H2和H3型的禽流感病毒从偏向与禽类受体结合转化为偏向与人类受体结合，Stevens和同事演示，这些突变不能让H5型禽流感病毒转化为偏向人类受体。但是，这些研究人员说，这些突变中有一些可能使H5N1红细胞凝集素更容易地与人类型受体结合，从而为病毒进入人群提供一个可能的 "立足点”。
科学特快报告：Structure and Receptor Specificity of the Hemagglutinin from an H5N1 Influenza Virus, James Stevens, et al.
海洋越暖 飓风越强
一项新研究指出，世界上海洋表面温度的上升是1970年以来全球飓风强度增加的一个主要原因，这个结论会使有关全球变暖与飓风强度联系的争论更加激烈。Carlos Hoyos和同事用统计分析和信息论模型将6个海洋盆地中飓风强度的因素分离出来，这些海洋盆地分别位于北大西洋、太平洋、和印度洋。他们发现，全球这个时期内造成4、5类飓风数量增多的许多变量中，只有海洋表面温度上升是有统计意义的主要因素。其它因素能影响飓风的形成，所以它们也许在短期的变化中起作用。文章作者说，哪些气候条件对飓风强度最有影响近来成为一个重大的科学和政治争议的主题，这篇文章也许能帮助人们更好地了解飓风强度增加趋势的原因。
科学特快报告：Deconvolution of the Factors Contributing to the Increase in Global Hurricane Intensity, Carlos D. Hoyos, Paula A. Agudelo, Peter J. Webster, and Judith A. Curry
不需要电池的人工肌肉
一项新研究说，科学家发明了一个方法可以避开在人工肌肉和马达或促动器中储存电荷的需要，比如像现有的靠电池的假肢。Von Howard Ebron和同事报告了两种设计，能将人工肌肉转化为燃料电池，从而消除了对电池的需要，现有的人工肌肉需要花很多时间来再充电。在一种设计中，一个用碳纳米管做的催化剂同时起三个作用，它既是肌肉、又是燃料电池的电极、也是超电容的电极。在另一个设计中，一种能“记住”其初始形态的记忆合金被用来给肌肉一个促动器闪击，它的能量密度与正常的骨骼肌相当，当有100倍以上的应力。John Madden 在相关的研究评述中写道，这两种设计都是将燃料的化学能，比如氢和甲醇，通过与氧混合转化成机械能，实际上制造出“呼吸”的人工肌肉。作者说，这些结果提示，也许有朝一日能为人或自治机器人提供持续时间久、能干重活的人工肌肉。
报告：Fuel-Powered Artificial Muscles, Von Howard Ebron, et al.
研究评述： Chemical Detectives, John D. Madden
吃起来像小鼠的蚂蚱
本期一篇简报报告说，新西兰的一种巨大的、不会飞的蚂蚱干一件通常由小鼠完成的重要工作：它们吃掉肉果通过其消化道帮助传播种子。被这种名为weta 的大蚂蚱消化过的种子的高发芽率意味着，这些种子比没有被大蚂蚱吃掉的种子有选择优势。Catherine Duthie 和同事进行了一系列的实验室喂食测试、种子发芽试验、果实比较、以及大田普查来检验weta是否帮助传播肉果的种子。他们的结果显示，weta既是种子的捕食者也是有效的种子传播者，其作用与世界其他地方的小型哺乳动物类似。新西兰是世界上最孤立的陆地之一，而且在19世纪、20世纪人类达到之前没有小鼠。新西兰现有的小鼠威胁weta的生存，使其濒于灭绝，文章作者写道，需要对weta在植物繁殖中作用的更详细的信息，来确定它们的灭绝会给新西兰的森林带来哪些变化。
简报：Seed Dispersal by Weta, Catherine Duthie, George Gibbs, and K. C. Burns
实时观察蛋白生产
研究人员研究出一个能将活细胞中单个蛋白的生产可视化的方法，这一高超技艺使科学家能在单个分子水平跟踪基因表达。用一个荧光标志和以细胞膜为靶标的肽做成的融合蛋白，Ji Yu和同事能够观察活的大肠杆菌细胞中来自单个mRNA转录的蛋白生产的爆发。研究人员发现，每个“爆发”中的蛋白质分子的个数不同。这个敏感的技术也许对研究那些细胞中的存在量极低的蛋白。
报告：Probing Gene Expression in Live Cells, One Protein Molecule at a Time, Ji Yu, Jie Xiao, Xiaojia Ren, Kaiqin Lao, and X. Sunney Xie
专题部分：化学检测技术
本周，《科学》和其在线系列网站之一信号转导知识环境(STKE)审视了直接检测技术领域的进展, 这些技术在解决将基础分析化学与生物学或地球科学结合起来的问题上正在变得越来越重要。《科学》刊登的两篇综述介绍了质谱分析和电化学检测目前的发展情况，另有三篇原始论文展示了一些进一步改进检测的技术。STKE网站相关的研究评述探讨了这些进展的意义、面临的挑战、以及研究细胞信号的新检测技术。
专题介绍： Chemical Detectives, Nancy Gough, Phil Szuromi, Jake Yeston
Contents
Special Issue
Detection Technologies
Chemical Detectives
Nancy Gough, Phil Szuromi, and Jake Yeston
Science 17 March 2006: 1565.
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Reviews
Ambient Mass Spectrometry
R. Graham Cooks, Zheng Ouyang, Zoltan Takats, and Justin M. Wiseman
Science 17 March 2006: 1566-1570.
Abstract »| Full Text »| PDF »|
Probing Cellular Chemistry in Biological Systems with Microelectrodes
R. Mark Wightman
Science 17 March 2006: 1570-1574.
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Contents
This Week in Science
Editor summaries of this week's papers.
Science 17 March 2006: 1517.
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Editorial:
Fighting Tropical Diseases
Jeffrey D. Sachs and Peter J. Hotez
Science 17 March 2006: 1521.
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Editors' Choice
Highlights of the recent literature.
Science 17 March 2006: 1523.
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NetWatch
Best of the Web in science.
Science 17 March 2006: 1529.
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NEW PRODUCTS
Science 17 March 2006: 1625.
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News of the Week
NUCLEAR PHYSICS: Researchers Raise New Doubts About 'Bubble Fusion' Reports
Robert F. Service
Science 17 March 2006: 1532-1533.
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CHEMISTRY: Columbia Lab Retracts Key Catalysis Papers
Robert F. Service
Science 17 March 2006: 1533.
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COSMOLOGY: Magnet Experiment Appears to Drain Life From Stars
Michael Schirber
Science 17 March 2006: 1535.
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PLANETARY SCIENCE: Minerals Point to a Hot Origin for Icy Comets
Richard A. Kerr
Science 17 March 2006: 1536.
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U.S. REGULATORY POLICY: Courts Ruled No Forum for Data-Quality Fights
Jocelyn Kaiser
Science 17 March 2006: 1536.
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U.S. DEPARTMENT OF ENERGY: Can Energy Research Learn to Dance to a Livelier Tune?
Eli Kintisch
Science 17 March 2006: 1537.
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RUSSIAN SCIENCE: Moscow Plans Tighter Control of Science Academy's Research Money
Andrey Allakhverdov and Vladimir Pokrovsky
Science 17 March 2006: 1538.
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PARTICLE PHYSICS: Linear Collider Partners Woo Newly Opened India
Pallava Bagla
Science 17 March 2006: 1538.
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INFECTIOUS DISEASES: Report Concludes Polio Drugs Are Needed--After Disease Is Eradicated
Jennifer Couzin
Science 17 March 2006: 1539.
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SCIENTIFIC COMMUNITY: Bias Claim Stirs Up Ghost of Dolly
Gretchen Vogel and Eliot Marshall
Science 17 March 2006: 1539.
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ScienceScope
Science 17 March 2006: 1535.
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Random Samples
Science 17 March 2006: 1531.
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Newsmakers
Science 17 March 2006: 1551.
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News Focus
SPACE SCIENCE: A Space Race to the Bottom Line
Andrew Lawler
Science 17 March 2006: 1540-1543.
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SPACE SCIENCE: Bumpy Ride for Data-Driven NASA Chief
Andrew Lawler
Science 17 March 2006: 1542-1543.
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GENE SEQUENCING: The Race for the $1000 Genome
Robert F. Service
Science 17 March 2006: 1544-1546.
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PATIENT PRIVACY: Rule to Protect Records May Doom Long-Term Heart Study
Jocelyn Kaiser
Science 17 March 2006: 1547-1548.
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RESEARCH FUNDING: China Bets Big on Big Science
Hao Xin and Gong Yidong
Science 17 March 2006: 1548-1549.
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Letters
This Week's Letters
Science 17 March 2006: 1552.
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Vaccine Against Spanish Flu
Jens C. Jensenius;, Terrence M. Tumpey, Christopher F. Basler, Patricia V. Aguilar, Hui Zeng, Alicia Solorzano, David E. Swayne, Nancy J. Cox, Jacqueline M. Katz, Jeffery K. Taubenberger, Peter Palese, and Adolfo Garcia-Sastre
Science 17 March 2006: 1552.
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Williams-Beuren Syndrome
James J. Menegazzi
Science 17 March 2006: 1552.
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Smaller, Hungrier Mice
Giovambattista Pani, Salvatore Fusco, Tommaso Galeotti;, Danica Chen, Andrew Steele, Susan Lindquist, and Leonard Guarente
Science 17 March 2006: 1553-1554.
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Sea Urchins as Crystallographers
Kenneth M. Towe;, Stephen Weiner, and Lia Addadi
Science 17 March 2006: 1554-1555.
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Books et al.
APPLIED PHYSICS: Dr. Strangelove Moves Mountains
Hugh Gusterson
Science 17 March 2006: 1556.
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Books Received
Science 17 March 2006: 1556.
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Policy Forum
ECOLOGY: Globalization, Roving Bandits, and Marine Resources
F. Berkes, T. P. Hughes, 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 17 March 2006: 1557-1558.
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Perspectives
MATERIALS SCIENCE: Artificial Muscle Begins to Breathe
John D. Madden
Science 17 March 2006: 1559-1560.
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NEUROSCIENCE: Enhanced: Neuron, Know Thy Neighbor
Emanuel DiCicco-Bloom
Science 17 March 2006: 1560-1562.
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VIROLOGY: Clues to the Virulence of H5N1 Viruses in Humans
Robert M. Krug
Science 17 March 2006: 1562-1563.
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CHEMISTRY: Seamless Proteins Tie Up Their Loose Ends
David J. Craik
Science 17 March 2006: 1563-1564.
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Brevia
Seed Dispersal by Weta
Catherine Duthie, George Gibbs, and K. C. Burns
Science 17 March 2006: 1575.
Weta, giant flightless grasshoppers native to New Zealand, ingest and disperse seeds—-an ecological role played by small mammals in other parts of the world.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Research Article
Large-Scale Sequence Analysis of Avian Influenza Isolates
John C. Obenauer, Jackie Denson, Perdeep K. Mehta, Xiaoping Su, Suraj Mukatira, David B. Finkelstein, Xiequn Xu, Jinhua Wang, Jing Ma, Yiping Fan, Karen M. Rakestraw, Robert G. Webster, Erich Hoffmann, Scott Krauss, Jie Zheng, Ziwei Zhang, and Clayton W. Naeve
Science 17 March 2006: 1576-1580.
Published online 26 January 2006 [DOI: 10.1126/science.1121586] (in Science Express Research Articles)
Sequences from 169 isolates of avian influenza viruses, including many different strains, reveal that all have a motif located in a nonstructural gene that is necessary for virulence.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Fuel-Powered Artificial Muscles
Von Howard Ebron, Zhiwei Yang, Daniel J. Seyer, Mikhail E. Kozlov, Jiyoung Oh, Hui Xie, Joselito Razal, Lee J. Hall, John P. Ferraris, Alan G. MacDiarmid, and Ray H. Baughman
Science 17 March 2006: 1580-1583.
Artificial muscles made with carbon nanotubes or a shape memory alloy can be designed to act as fuel cells, thus alleviating a need for a remote battery power source.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Microstructured Optical Fibers as High-Pressure Microfluidic Reactors
Pier J. A. Sazio, Adrian Amezcua-Correa, Chris E. Finlayson, John R. Hayes, Thomas J. Scheidemantel, Neil F. Baril, Bryan R. Jackson, Dong-Jin Won, Feng Zhang, Elena R. Margine, Venkatraman Gopalan, Vincent H. Crespi, and John V. Badding
Science 17 March 2006: 1583-1586.
Semiconductors and metals can be deposited from high-pressure vapors inside optical fibers to form minute tubes, nanowires, and more complex patterned structures.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Saturn's Spokes: Lost and Found
C. J. Mitchell, M. Horányi, O. Havnes, and C. C. Porco
Science 17 March 2006: 1587-1589.
A model suggests that when Saturn抯 rings are nearly edge-on to the Sun, lofted particles are able to remain positively charged and produce transient spokes in Saturn抯 rings.
Abstract »| Full Text »| PDF »|
Visualizing Picometric Quantum Ripples of Ultrafast Wave-Packet Interference
Hiroyuki Katsuki, Hisashi Chiba, Bertrand Girard, Christoph Meier, and Kenji Ohmori
Science 17 March 2006: 1589-1592.
Two laser pulses, the first exciting vibrational modes and the second producing selective fluorescence, directly reveal the wavelike nature of a vibrating iodine molecule.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
MOSFET-Embedded Microcantilevers for Measuring Deflection in Biomolecular Sensors
Gajendra Shekhawat, Soo-Hyun Tark, and Vinayak P. Dravid
Science 17 March 2006: 1592-1595.
Published online 2 February 2006 [DOI: 10.1126/science.1122588] (in Science Express Reports)
The small bending created when biomolecules bind to receptors on a microfabricated cantilever can be detected with an embedded transistor, forming a microsensor.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Broadband Cavity Ringdown Spectroscopy for Sensitive and Rapid Molecular Detection
Michael J. Thorpe, Kevin D. Moll, R. Jason Jones, Benjamin Safdi, and Jun Ye
Science 17 March 2006: 1595-1599.
Coupling of a frequency comb with an optical cavity in which light is systematically absorbed produces a highly sensitive and accurate visible and near-infrared spectrometer.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Probing Gene Expression in Live Cells, One Protein Molecule at a Time
Ji Yu, Jie Xiao, Xiaojia Ren, Kaiqin Lao, and X. Sunney Xie
Science 17 March 2006: 1600-1603.
Visualization of individual proteins shows that translation of single messenger RNAs in E. coli yields random bursts of new protein molecules.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Late Colonization of Easter Island
Terry L. Hunt and Carl P. Lipo
Science 17 March 2006: 1603-1606.
Published online 9 March 2006 [DOI: 10.1126/science.1121879] (in Science Express Reports)
Radiocarbon dates imply that voyaging Polynesians arrived on Easter Island around 1200 A.D., later than previously thought, and soon began depleting timber and other natural resources and erecting statues.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reward Timing in the Primary Visual Cortex
Marshall G. Shuler and Mark F. Bear
Science 17 March 2006: 1606-1609.
Neurons in the primary visual cortex respond differently to a flash of light after it has been paired with a re w a rd, unexpectedly showing that cognitive information is coded at this level in the cortex.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
E-Catenin Controls Cerebral Cortical Size by Regulating the Hedgehog Signaling Pathway
Wen-Hui Lien, Olga Klezovitch, Tania E. Fernandez, Jeff Delrow, and Valeri Vasioukhin
Science 17 March 2006: 1609-1612.
Specialized junctions between neurons during development help control the number of cells in the brain, and thus final brain size.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
State-Dependent Learned Valuation Drives Choice in an Invertebrate
Lorena Pompilio, Alex Kacelnik, and Spencer T. Behmer
Science 17 March 2006: 1613-1615.
Grasshoppers prefer foods that they previously encountered when very hungry, illustrating a sophisticated form of learning unexpected in an insect.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
An Equivalence Principle for the Incorporation of Favorable Mutations in Asexual Populations
Matthew Hegreness, Noam Shoresh, Daniel Hartl, and Roy Kishony
Science 17 March 2006: 1615-1617.
Evolution of asexual populations, as in bacteria, viruses, or cancer cells, is described by a model in which all beneficial mutations have equal effects and occur at the same rate.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Parietal-Eye Phototransduction Components and Their Potential Evolutionary Implications
Chih-Ying Su, Dong-Gen Luo, Akihisa Terakita, Yoshinori Shichida, Hsi-Wen Liao, Manija A. Kazmi, Thomas P. Sakmar, and King-Wai Yau
Science 17 March 2006: 1617-1621.
Lizards?third eye, which senses only light intensity, uses both vertebrate- and invertebrate-like signaling molecules, suggesting an evolutionary path for vertebrate phototransduction.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Protein Farnesyltransferase Inhibitor Ameliorates Disease in a Mouse Model of Progeria
Loren G. Fong, David Frost, Margarita Meta, Xin Qiao, Shao H. Yang, Catherine Coffinier, and Stephen G. Young
Science 17 March 2006: 1621-1623.
Published online 16 February 2006 [DOI: 10.1126/science.1124875] (in Science Express Reports)
A drug that inhibits the addition of lipids to proteins has beneficial effects in a mouse version of a rare premature aging disorder, suggesting that it may be useful in children with the disease.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Technical Comments
Comment on "Ivory-billed Woodpecker (Campephilus principalis) Persists in Continental North America"
David A. Sibley, Louis R. Bevier, Michael A. Patten, and Chris S. Elphick
Science 17 March 2006: 1555.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Response to Comment on "Ivory-billed Woodpecker (Campephilus principalis) Persists in Continental North America"
John W. Fitzpatrick, Martjan Lammertink, M. David Luneau, Jr., Tim W. Gallagher, and Kenneth V. Rosenberg
Science 17 March 2006: 1555.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
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