2006年1月20日 美国《科学》周刊311卷 第5759期
环境中的抗生素耐药性
科学家最近普查了来自土壤的480种不同芽胞微生物，发现其中每一种对至少7种现有的抗生素有耐药性，包括对一些最新开发出的药物。类似这样的更好地了解自然界中存在的抗生素耐药性的努力，将为未来可能困扰人类的新抗生素耐药性提供线索。Vanessa D'Costa和同事分离和分析的这批土壤微生物属于链霉菌属，许多临床有用的抗生素来自这个菌属。一篇相关研究评述的作者写道，这项工作显示，合成对控制细菌疾病有重大作用的化合物的微生物本身，也具有同样复杂的保护自身不受它们的有毒产物破坏的机制，揭示了"抗生素观念黑暗的一面"。文章作者说，虽然这项研究并没有给出抗生素耐药性从土壤到致病细菌直接转移的证据，但是它发现了一个过去人们认识不够的高密度和集中的环境抗生素耐药性。
报告：Sampling the Antibiotic Resistome, Vanessa M. D'Costa, Katherine M. McGrann, Donald W. Hughes, and Gerard D. Wright
研究评述：Weapons of Microbial Drug Resistance Abound in Soil Flora, Alexander Tomasz
火星热带冰川的来源
几百万年前，冰川曾覆盖过火星热带地区火山和山脉的四周，现在一项新研究提出，这些冰川来自大气层的降水而不是地下水源。火星如今的表面寒冷和干燥，使除极地以外的所有表面上的水冰不稳定，研究人员提出了火星热带地区曾有过的冰川是来自大气中的水还是来自地表下的水源的问题。Francois Forget和同事的新高分辨率气候模型用的是如今火星上的水循环信息，但是将几百万年前火星旋转轴的45度倾斜考虑进来，他们得到的结果指出，倾斜的轴会增加极地水向大气层的蒸发，然后水在大气中循环，最终降落到热带地区积累成冰川，它们的位置和大小与现有的过去冰川的地质痕迹一致。
报告：Formation of Glaciers on Mars by Atmospheric Precipitation at High Obliquity, F. Forget, R. M. Haberle, F. Montmessin, B. Levrard, and J. W. Head
天生的几何概念
在一系列的实验中，来自亚马逊土著部落Mundurukú的儿童和成年人显示，他们懂得并能应用不同的几何概念，虽然他们没有描述这些概念的词汇。心理学家和哲学家对语言如何影响思维的争论由来已久，这项工作这个讨论提供了新证据，看来几何学的概念性原理在Mundurukú人脑中天生存在，虽然他们缺少几何术语和概念的词汇。Mundurukú儿童和成年人都能懂得平行线和直角三角形等几何概念，而且能用纸上的几何关系图来找到隐藏的东西，他们表现出的能力与美国儿童一样好，但比受过教育的美国成年人差些。作者写道，这些结果为不是学来的几何直观提供了证据。
报告：Core Knowledge of Geometry in an Amazonian Indigene Group, Stanislas Dehaene, Véronique Izard, Pierre Pica, and Elizabeth Spelke
电纺小分子
研究人员用一个叫电纺(electrospinning)的单步骤高分子处理技术用卵磷脂制造了非编织的膜，卵磷脂是细胞膜中的一个主要脂类。Matthew McKee和同事说，这些纺出的膜是血液净化膜、人工心脏瓣膜、人工器官以及其它生物适合设备的具有吸引力的候选材料。电纺指用压力将高分子溶液通过暴露在电场中的细管喷出，高分子形成纤维并快速地变细，此法得到的纤维直径比用其他方法得到的都小。虽然卵磷脂是一个小分子，但是在某个浓度下这些分子会排列成类似虫子的结构。在更高的浓度下，这些类似虫子的结构以类似高分子的方式重叠和纠缠，使电纺成为可能。
报告：Phospholipid Nonwoven Electrospun Membranes, Matthew G. McKee, John M. Layman, Matthew P. Cashion, and Timothy E. Long
观察磁性材料中的自旋结构
日本研究人员对磁性材料中的一个特殊自旋结构的新观察也许对自旋子器件(spintronic devices)比如计算机硬盘在真实世界中如何表现提供了一点线索。自旋是电子的一个量子性质，磁性材料中的电子自旋能以几种方式排列。在一种被称为螺旋自旋序的结构中，电子自旋从材料的一个平面到另一个平面以一个固定的角度旋转，使自旋的取向构成一个螺旋。Masaya Uchida和同事用一种名为洛伦兹显微镜的成像技术观察了这个自旋结构，发现它比理论预测的更复杂，也更动态。研究人员发现，就像在压力下材料晶体结构中会形成微小位错一样，在温度和磁场的应力下，磁缺陷会在自旋取向的界面发生。一篇相关研究评述的作者说，新图像揭示了“磁性材料和这些材料所制备的器件性质的基本信息”。
报告：Real-Space Observation of Helical Spin Order, Masaya Uchida, Yoshinori Onose, Yoshio Matsui, and Yoshinori Tokura
研究评述： Helical Spin Order on the Move, Franco Nori and Akira Tonomura
没排好的染色体如何相等分离
新的正在分裂的哺乳动物细胞的图像使科学家对一些染色体在相等地分离和分布到两个子细胞之前如何排列有了更好的了解。如果细胞分裂过程中出错，分离后的子细胞得到过多或过少的染色体，会导致出生缺陷和某些癌症的发生。为了保证相等分离，在细胞分裂过程中染色体“双轴取向”，分别用微管与细胞的相反两极连接，然后聚集在细胞赤道板，最后分裂开。Tarun Kapoor和同事现在揭示，出乎意料的是，只与细胞一极连接的染色体，能靠其它双轴取向的染色体建立的微管，也聚集到细胞的赤道板。研究人员还发现了一个帮助这些没有双轴取向的染色体沿微管向赤道板滑动的蛋白，在赤道板这些染色体与细胞的另一极建立连接。一篇相关的研究评述进一步讨论了这些发现。本期封面与这篇报告有关。
报告：Chromosomes Can Congress to the Metaphase Plate Before Biorientation, Vanessa M. D'Costa, Tarun M. Kapoor, et al.
研究评述：Serving Up a Plate of Chromosomes, Rebecca Heald
This Week in Science
Editor summaries of this week's papers.
Science 20 January 2006: 299.
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Editorial:
Acts of God?
Donald Kennedy
Science 20 January 2006: 303.
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Editors' Choice
Highlights of the recent literature.
Science 20 January 2006: 305.
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NetWatch
Best of the Web in science.
Science 20 January 2006: 311.
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NEW PRODUCTS
Science 20 January 2006: 399.
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News of the Week
AVIAN INFLUENZA: Amid Mayhem in Turkey, Experts See New Chances for Research
Martin Enserink
Science 20 January 2006: 314-315.
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AVIAN INFLUENZA: WHO Proposes Plan to Stop Pandemic in Its Tracks
Dennis Normile
Science 20 January 2006: 315-316.
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COSMOLOGY: Astronomers Push and Pull Over Dark Energy's Role in Cosmos
Robert Irion
Science 20 January 2006: 316.
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PSYCHOLOGY: Hunter-Gatherers Grasp Geometry
Constance Holden
Science 20 January 2006: 317.
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NONPROLIFERATION: India Struggles to Put Its Nuclear House in Order
Richard Stone
Science 20 January 2006: 318-319.
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CNRS SHAKEUP: France's Basic Science Agency Hopes New Lineup Will Resolve Crisis
Barbara Casassus
Science 20 January 2006: 319.
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SOUTH KOREAN SCIENCE: Armed With Cash, Institute Chief Launches an Education 'Blitzkrieg'
Richard Stone
Science 20 January 2006: 321.
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SCIENTIFIC PUBLISHING: Hwang Aftereffects Reverberate at Journals
Jennifer Couzin, Constance Holden, and Sei Chong
Science 20 January 2006: 321.
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ScienceScope
Science 20 January 2006: 317.
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Random Samples
Science 20 January 2006: 313.
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Newsmakers
Science 20 January 2006: 333.
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News Focus
DRUG DEVELOPMENT: Drugs Inspired by a Drug
Jean Marx
Science 20 January 2006: 322-325.
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ARCHAEOLOGY: Rising Water Poses Threat to Egypt's Antiquities
Andrew Lawler
Science 20 January 2006: 326-327.
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ARCHAEOLOGY: Archaeological Pharaoh Sets Determined Course for Egypt
Andrew Lawler
Science 20 January 2006: 326-327.
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BIOMEDICAL TRAINING PROGRAMS: NIH Told to Get Serious About Giving Minorities a Hand
Jeffrey Mervis
Science 20 January 2006: 328-329.
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BIOMEDICAL TRAINING PROGRAMS: Will This Bridge Take Me to the Lab?
Jeffrey Mervis
Science 20 January 2006: 329.
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SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY MEETING: Sea Slug Inks Its Way to Safety
Elizabeth Pennisi
Science 20 January 2006: 330-331.
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SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY MEETING: Was Lucy's a Fighting Family? Look at Her Legs
Elizabeth Pennisi
Science 20 January 2006: 330.
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SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY MEETING: Water Launches Spores Like a Rocket
Elizabeth Pennisi
Science 20 January 2006: 331.
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SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY MEETING: Crab, Raccoon Play Tag Team Against Turtle
Elizabeth Pennisi
Science 20 January 2006: 331.
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Letters
This Week's Letters
Science 20 January 2006: 335.
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Editorial Retraction
Donald Kennedy
Science 20 January 2006: 335.
Published online 12 January 2006 [DOI: 10.1126/science.1124926] (in Science Express Letters)
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Madison and Climate Change Policy
Jonathan B. Wiener, Richard B. Stewart, James K. Hammitt, Jean-Charles Hourcade;, David G. Victor, Joshua C. House, and Sarah Joy
Science 20 January 2006: 335-336.
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Advising on Publication
Stewart Simonson
Science 20 January 2006: 336-337.
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HIV Prevention in Adolescents
Rose E. Frisch
Science 20 January 2006: 337.
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Corrections and Clarifications
Science 20 January 2006: 337.
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Books et al.
CHEMISTRY: Light Scattered by Air
Gerald R. Van Hecke
Science 20 January 2006: 338-339.
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NEUROSCIENCE: Linking Neurons and Ethics
Xavier Bosch
Science 20 January 2006: 339.
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Books Received
Science 20 January 2006: 339.
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Policy Forum
PLANETARY SCIENCE: Risks in Space from Orbiting Debris
J.-C. Liou and N. L. Johnson
Science 20 January 2006: 340-341.
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Perspectives
MICROBIOLOGY: Weapons of Microbial Drug Resistance Abound in Soil Flora
Alexander Tomasz
Science 20 January 2006: 342-343.
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CELL BIOLOGY: Serving Up a Plate of Chromosomes
Rebecca Heald
Science 20 January 2006: 343-344.
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APPLIED PHYSICS: Helical Spin Order on the Move
Franco Nori and Akira Tonomura
Science 20 January 2006: 344-345.
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ASTRONOMY: Enhanced: Nucleosynthesis in Binary Stars
C. Simon Jeffery, Christopher A. Tout, and John C. Lattanzio
Science 20 January 2006: 345-346.
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Review
The Impact of Structural Genomics: Expectations and Outcomes
John-Marc Chandonia and Steven E. Brenner
Science 20 January 2006: 347-351.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Brevia
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 20 January 2006: 352.
Published online 5 January 2006 [DOI: 10.1126/science.1122855] (in Science Express Brevia)
Unexpectedly, by disturbing the soil, salvage logging after a fire in a Douglas fir forest reduced conifer seedling regeneration by 73 percent and also added kindling to the forest floor.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Phospholipid Nonwoven Electrospun Membranes
Matthew G. McKee, John M. Layman, Matthew P. Cashion, and Timothy E. Long
Science 20 January 2006: 353-355.
Electrospinning, used to form thin polymer fibers, can be applied to concentrated solutions of phospholipids to form fibers and membranes in a single step.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Covalently Bridging Gaps in Single-Walled Carbon Nanotubes with Conducting Molecules
Xuefeng Guo, Joshua P. Small, Jennifer E. Klare, Yiliang Wang, Meninder S. Purewal, Iris W. Tam, Byung Hee Hong, Robert Caldwell, Limin Huang, Stephen O'Brien, Jiaming Yan, Ronald Breslow, Shalom J. Wind, James Hone, Philip Kim, and Colin Nuckolls
Science 20 January 2006: 356-359.
Precise cutting of single-wall nanotubes yields an electrode tip that reacts to form a single-molecule bridge, providing a robust electronic contact for, for example, a tiny pH meter.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Real-Space Observation of Helical Spin Order
Masaya Uchida, Yoshinori Onose, Yoshio Matsui, and Yoshinori Tokura
Science 20 January 2006: 359-361.
Lorentz microscopy shows that helical spin order groups of electronic spins oriented in a helix in different crystallographic layers is greatly influenced by defects in a crystal.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Solvent-Free Oxidation of Primary Alcohols to Aldehydes Using Au-Pd/TiO2 Catalysts
Dan I. Enache, Jennifer K. Edwards, Philip Landon, Benjamin Solsona-Espriu, Albert F. Carley, Andrew A. Herzing, Masashi Watanabe, Christopher J. Kiely, David W. Knight, and Graham J. Hutchings
Science 20 January 2006: 362-365.
Gold-palladium nanocrystals on titanium dioxide efficiently catalyze aldehyde synthesis from primary alcohols, an important class of industrial reactions.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Internal Rotation and Spin Conversion of CH3OH in Solid para-Hydrogen
Yuan-Pern Lee, Yu-Jong Wu, R. M. Lees, Li-Hong Xu, and Jon T. Hougen
Science 20 January 2006: 365-368.
Methanol in a para-hydrogen matrix can still undergo internal torsion, revealing spin conversions that are obscured in more complex gas-phase spectra.
Abstract »| Full Text »| PDF »|
Formation of Glaciers on Mars by Atmospheric Precipitation at High Obliquity
F. Forget, R. M. Haberle, F. Montmessin, B. Levrard, and J. W. Head
Science 20 January 2006: 368-371.
Climate simulations show that when Mars' axis was tilted by 45° in the recent past, water ice glaciers could have formed on the flanks of Mars' large volcanoes where glacial deposits are now seen.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
South-Seeking Magnetotactic Bacteria in the Northern Hemisphere
Sheri L. Simmons, Dennis A. Bazylinski, and Katrina J. Edwards
Science 20 January 2006: 371-374.
It has been assumed that marine bacteria in the northern hemisphere all swim toward magnetic north, but blooms of south-seeking ones are actually mixed in.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Sampling the Antibiotic Resistome
Vanessa M. D'Costa, Katherine M. McGrann, Donald W. Hughes, and Gerard D. Wright
Science 20 January 2006: 374-377.
Of 480 bacterial strains isolated from diverse soil samples, each was resistant to at least seven antibiotics and some to as many as 20.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Vaccinia Virus-Induced Cell Motility Requires F11L-Mediated Inhibition of RhoA Signaling
Ferran Valderrama, João V. Cordeiro, Sibylle Schleich, Friedrich Frischknecht, and Michael Way
Science 20 January 2006: 377-381.
Vaccinia virus causes infected cells to migrate and alters their adhesion properties by rearranging the actin cytoskeleton.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Core Knowledge of Geometry in an Amazonian Indigene Group
Stanislas Dehaene, Véronique Izard, Pierre Pica, and Elizabeth Spelke
Science 20 January 2006: 381-384.
Children and adults of an indigenous group from Amazonia use geometrical concepts despite the lack of specific words to describe them.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Molecular Framework for Plant Regeneration
Jian Xu, Hugo Hofhuis, Renze Heidstra, Michael Sauer, Jirí Friml, and Ben Scheres
Science 20 January 2006: 385-388.
After a plant is wounded, flow of a growth factor in plant roots is disrupted, causing differentiation of cells that then redirect the growth factor to trigger regeneration.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Chromosomes Can Congress to the Metaphase Plate Before Biorientation
Tarun M. Kapoor, Michael A. Lampson, Polla Hergert, Lisa Cameron, Daniela Cimini, E. D. Salmon, Bruce F. McEwen, and Alexey Khodjakov
Science 20 January 2006: 388-391.
During mitosis, duplicated chromosomes pulled by a fiber toward one pole of the cell move back to the middle by hitching a ride on a fiber of an already-positioned chromosome set.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Metagenomics to Paleogenomics: Large-Scale Sequencing of Mammoth DNA
Hendrik N. Poinar, Carsten Schwarz, Ji Qi, Beth Shapiro, Ross D. E. MacPhee, Bernard Buigues, Alexei Tikhonov, Daniel H. Huson, Lynn P. Tomsho, Alexander Auch, Markus Rampp, Webb Miller, and Stephan C. Schuster
Science 20 January 2006: 392-394.
Published online 20 December 2005 [DOI: 10.1126/science.1123360] (in Science Express Reports)
Recovery and sequencing of large amounts to mitochondrial and nuclear DNA from an 18,000-year-old mammoth support the evolution of mammoths from elephants about 6 million years ago.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Methylation of tRNAAsp by the DNA Methyltransferase Homolog Dnmt2
Mary Grace Goll, Finn Kirpekar, Keith A. Maggert, Jeffrey A. Yoder, Chih-Lin Hsieh, Xiaoyu Zhang, Kent G. Golic, Steven E. Jacobsen, and Timothy H. Bestor
Science 20 January 2006: 395-398.
A methyltransferase widely thought to add methyl groups to DNA actually covalently methylates transfer RNA.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
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