16 December 2005 Vol 310, Issue 5755, Pages 1737-1828
影响皮肤颜色的基因
研究浅颜色斑马鱼的科学家发现了一个可能在决定人类皮肤颜色中起作用的基因。了解人类皮肤颜色显著不同的遗传起源是生物学中现存的几个难题之一。研究人员发现，“金色”斑马鱼的浅色斑纹是由slc24a5基因的变异引起的，这个变异使黑色素体变小，其数量减少、密度降低。人类这个基因的版本与斑马鱼基因在序列上极为相似，而且能使变异斑马鱼的“金色”细胞复原为野生色素型。根据名为HapMap的人类遗传变异数据库，不同人群中，欧洲籍人带有一个与非洲和东亚洲人略微不同的slc24a5 基因的版本。改变这个基因编码区域一个氨基酸的遗传变异或多态性与色素水平关联，说明slc24a5 基因能导致人类皮肤颜色的不同。文章作者之一Cheng 说，SLC24a5 基因的某些变异也许是浅的眼睛和头发颜色出现的先决条件。
研究文章：SLC24A5, a Putative Cation Exchanger, Affects Pigmentation in Zebrafish and Humans, Rebecca L. Lamason, et al.
早期恐龙在不同年龄成年
对最早的大型恐龙的新研究显示，这些原蜥蜴在不同的年龄达到“成年”大小，从而产生同一物种中大小不同的版本。Martin Sander和Nicole Klein说，这种生长模式与包括乌龟和鳄鱼在内的爬行动物的生长类似，但是与后来的恐龙、鸟类、以及哺乳类的生长模式的相似性小。爬行动物能根据环境条件改变它们的生长率，有时它们长得很快比较早地达到成年大小，有时它们长的慢比较晚地达到成年大小。但哺乳类和鸟类的生长几乎是独立于环境条件的，它们差不多在同一年龄达到成年大小。Sander和Klein研究了来自德国的大量板龙(Plateosaurus engelhardti)化石中长骨的微观结构，在其中发现了完全成长发育的不同大小的板龙。研究人员说，板龙也许代表了向热血恐龙进化的第一步，这一发展使动物能够更好地调节自身的代谢，切断生长与环境条件的联系。
报告：Developmental Plasticity in the Life History of a Prosauropod Dinosaur, P. Martin Sander and Nicole Klein
干旱、蜗牛和盐沼死亡
一项新的野外研究发现，美国南方盐沼最近大面积死亡的主要原因是干旱和蜗牛吃草。这些发现帮助澄清了盐沼大面积死亡中干旱和蜗牛的作用，也许对北美或北美以外的盐沼和其它沿海生态系统的保护和管理有意义。Brian Silliman和同事调查了佐治亚州和路易斯安纳州1200公里的海岸线，发现很多地方的吃植物蜗牛密度很高，最高可达每平方米1500个蜗牛，它们在12个死亡盐沼的11个中正在清除互花米草(学名Spartina alterniflora)和其它沼泽植物。科学家发现，虽然干旱胁迫被认为是盐沼死亡的初始原因，但在这些死亡区域边缘发现的大量的蜗牛乘虚而入，很快地扩展到健康的盐沼区将其变成裸露的滩地。作者说，这些野外实验与模型分析相结合，揭示了干旱胁迫与蜗牛吃草之间的强相互作用，两者都可能与人类的环境影响有关。这种相互作用可能导致这些面临环境和经济危机的沿海生态系统的进一步恶化、甚至崩溃。
报告：Drought, Snails, and Large-Scale Die-Off of Southern U.S. Salt Marshes, Brian R. Silliman, Johan van de Koppel, Mark D. Bertness, Lee E. Stanton, and Irving A. Mendelssohn
用微小芯片制造PET扫描探头
研究人员制造出一个美分硬币大小的微反应器，该设备能廉价和高效地制造用于医学正电子发射断层(PET)扫描的化学探头，PET扫描设备能给出体内部位的三维影像。用于PET扫描的化合物是最广范使用的分子探头之一，在美国2004年一年中用于病人诊断的化合物就超过了1百万剂。这个由Chung-Cheng Lee和同事设计的、用计算机控制的“芯片上的实验室”设备能快速地制备类似PET扫描探头的不稳定化合物，作者们说该技术可能被扩展到各种化学靶标。微反应器用极小的微流体回路将几种化学过程集成到一个小空间，不需要担心交叉污染。研究人员还说，能在大约两天的时间内想出和建成新的回路设计。
报告：Multistep Synthesis of a Radiolabeled Imaging Probe Using Integrated Microfluidics, Chung-Cheng Lee, et al.
能弯曲的单晶硅
科学家制造出了薄的、能弯曲的单晶硅带，这种材料可能用于制造能拉伸可变形的高性能电子设备。虽然单晶硅很脆，但它和大多数材料一样，如果将单晶硅变得很薄，它也能弯曲。Dahl-Young Khang和同事在这项新研究中将单晶硅带沉积到预先拉长了的橡皮衬底上。当把拉橡皮材料的应力取消后，硅带变成波浪形的，这样的硅带能通过改变波的大小和频率承受拉伸或压缩。文章作者还演示他们能用这样的硅带制造出几种基本的电子元件，比如三极管和二极管，他们指出，许多其它弯曲电子元件也是可以的。
科学特快报告：A Stretchable Form of Single-Crystal Silicon for Electronics on Elastomeric Substrates, Dahl-Young Khang, Hanqing Jiang, Young Huang, and John A. Rogers
接近玻璃转变
玻璃是粘性极大而不能流动的液体。一个法国研究小组现在给出了一个确定玻璃态起始的测量。一些间接的证据指出，在降温过程中越来越多的液体部分一起运动时，液体开始进入玻璃态，这是因为粘性增加越来越多的部分需要同时运动液体才能流动。Ludovic Berthier和同事用过冷的甘油以及悬浮在液体中的小硬球来模拟和直接实验，计算出一起运动区域的大小，他们显示，这些区域的大小在液体向玻璃的转变中增加。
报告：Direct Experimental Evidence of a Growing Length Scale Accompanying the Glass Transition, L. Berthier, et al.
This Week in Science
Editor summaries of this week's papers.
Science 16 December 2005: 1737.
|Full Text »
Editorial:
Doing More for Kate
Thomas Cech and Donald Kennedy
Science 16 December 2005: 1741.
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Editors' Choice
Highlights of the recent literature.
Science 16 December 2005: 1743.
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NetWatch
Best of the Web in science.
Science 16 December 2005: 1747.
|Full Text »
NEW PRODUCTS
Science 16 December 2005: 1828.
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News of the Week
STEM CELLS: Korean University Will Investigate Cloning Paper
Dennis Normile and Gretchen Vogel
Science 16 December 2005: 1748-1749.
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SPACE SCIENCE: ESA Hits the Right Note, and Funding Flows
Daniel Clery
Science 16 December 2005: 1749.
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PALEONTOLOGY: How Fast Does Your Dinosaur Grow?
Carolyn Gramling
Science 16 December 2005: 1751.
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U.S. COMPETITIVENESS: Summit Lists Ways--but Not Means--to Strengthen Science
Jeffrey Mervis
Science 16 December 2005: 1752.
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AFTER KATRINA: Struggling New Orleans Universities Cut Hundreds of Faculty
Jocelyn Kaiser
Science 16 December 2005: 1753.
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GENETICS: Zebrafish Researchers Hook Gene for Human Skin Color
Michael Balter
Science 16 December 2005: 1754-1755.
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INDIAN SCIENCE: Booming Computer Sector Seen as a Mixed Blessing
Pallava Bagla
Science 16 December 2005: 1754.
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SCIENTIFIC PUBLISHING: Echoing Other Cases, NEJM Says Vioxx Safety Data Withheld
Jennifer Couzin
Science 16 December 2005: 1755.
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ScienceScope
Science 16 December 2005: 1751.
|Full Text »
Random Samples
Science 16 December 2005: 1764.
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News Focus
SPONGIFORM DISEASES: After the Crisis: More Questions About Prions
Martin Enserink
Science 16 December 2005: 1756-1758.
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SPONGIFORM DISEASES: Waiting for the Final Experiment
Martin Enserink
Science 16 December 2005: 1758.
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CONSERVATION BIOLOGY: Hawaii's Coral Trees Feel the Sting of Foreign Wasps
Carolyn Gramling
Science 16 December 2005: 1759-1760.
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ENVIRONMENTAL EPIGENOMICS MEETING: Food, Tobacco, and Future Generations
Elizabeth Pennisi
Science 16 December 2005: 1760-1761.
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ENVIRONMENTAL EPIGENOMICS MEETING: Supplements Restore Gene Function via Methylation
Elizabeth Pennisi
Science 16 December 2005: 1761.
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ELECTRONICS: Organic LEDs Look Forward to a Bright, White Future
Robert F. Service
Science 16 December 2005: 1762-1763.
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Letters
This Week's Letters
Science 16 December 2005: 1767.
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Asian Scientists and the "Glass Ceiling"
Mien-Chie Hung, Kenneth Fong, Joseph K.-K. Li;, Raymond Mejia, Ofelia Olivero, Migdalia Rivera-Goba, Ana Anders, Carlos Caban, Marta Leon-Monzon, Ernest Marquez;, Dianhua Jiang;, Jeffrey B. Stewart;, and Linda J. Pike
Science 16 December 2005: 1767-1768.
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How to Cut World Hunger in Half
Per Lindskog
Science 16 December 2005: 1768.
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Cognitive Unbinding in Sleep and Anesthesia
George A. Mashour;, Giulio Tononi, and Marcello Massimini
Science 16 December 2005: 1768-1769.
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Corrections and Clarifications
Science 16 December 2005: 1769.
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Books et al.
SCIENCE AND CULTURE: Two-Dimensional Science
Jay A. Labinger
Science 16 December 2005: 1770-1771.
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ENVIRONMENT: Learning to Say "Enough"
Norman Myers
Science 16 December 2005: 1771.
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Books Received
Science 16 December 2005: 1771.
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Policy Forum
RESEARCH FUNDING: Science Foundations: A Novelty in Russian Science
Irina Dezhina and Loren R. Graham
Science 16 December 2005: 1772-1773.
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Perspectives
CHEMISTRY: Enhanced: Lateral Hopping Requires Molecular Rocking
Hiromu Ueba and Martin Wolf
Science 16 December 2005: 1774-1775.
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MICROBIOLOGY: Chitin, Cholera, and Competence
Douglas H. Bartlett and Farooq Azam
Science 16 December 2005: 1775-1777.
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GEOPHYSICS: Helium Feels the Heat in Earth's Mantle
Francis Albarede
Science 16 December 2005: 1777-1778.
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ECOLOGY: Population Evolution and Island Biogeography
Roger S. Thorpe
Science 16 December 2005: 1778-1779.
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Brevia
Aphid Protected from Pathogen by Endosymbiont
Claire L. Scarborough, Julia Ferrari, and H. C. J. Godfray
Science 16 December 2005: 1781.
Aphids that harbor certain endosymbiotic bacteria more effectively resist infection by a fungal pathogen.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Research Article
SLC24A5, a Putative Cation Exchanger, Affects Pigmentation in Zebrafish and Humans
Rebecca L. Lamason, Manzoor-Ali P.K. Mohideen, Jason R. Mest, Andrew C. Wong, Heather L. Norton, Michele C. Aros, Michael J. Jurynec, Xianyun Mao, Vanessa R. Humphreville, Jasper E. Humbert, Soniya Sinha, Jessica L. Moore, Pudur Jagadeeswaran, Wei Zhao, Gang Ning, Izabela Makalowska, Paul M. McKeigue, David O'Donnell, Rick Kittles, Esteban J. Parra, Nancy J. Mangini, David J. Grunwald, Mark D. Shriver, Victor A. Canfield, and Keith C. Cheng
Science 16 December 2005: 1782-1786.
Identification of a gene that controls pigmentation in zebrafish points to a similar gene that may play a key role in human skin color.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Complete Photo-Induced Breakup of the H2 Molecule as a Probe of Molecular Electron Correlation
Wim Vanroose, Fernando Martín, Thomas N. Rescigno, and C. William McCurdy
Science 16 December 2005: 1787-1789.
Computations reveal that paired electrons residing between the two protons in molecular hydrogen are more correlated than when surrounding two protons in the helium atom.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Real-Time Observation of Molecular Motion on a Surface
Ellen H. G. Backus, Andreas Eichler, Aart W. Kleyn, and Mischa Bonn
Science 16 December 2005: 1790-1793.
Published online 10 November 2005 [DOI: 10.1126/science.1120693] (in Science Express Reports)
Diffusion of CO molecules on a stepped platinum surface is initiated by rotational motion, rather than the expected translational motion.
Abstract »| Full Text »| PDF »|
Multistep Synthesis of a Radiolabeled Imaging Probe Using Integrated Microfluidics
Chung-Cheng Lee, Guodong Sui, Arkadij Elizarov, Chengyi Jenny Shu, Young-Shik Shin, Alek N. Dooley, Jiang Huang, Antoine Daridon, Paul Wyatt, David Stout, Hartmuth C. Kolb, Owen N. Witte, Nagichettiar Satyamurthy, James R. Heath, Michael E. Phelps, Stephen R. Quake, and Hsian-Rong Tseng
Science 16 December 2005: 1793-1796.
A device with micrometer-scale valves and channels has been designed and used for efficient synthesis of a molecule used in medical positron emission tomography.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Direct Experimental Evidence of a Growing Length Scale Accompanying the Glass Transition
L. Berthier, G. Biroli, J.-P. Bouchaud, L. Cipelletti, D. El Masri, D. L'Hôte, F. Ladieu, and M. Pierno
Science 16 December 2005: 1797-1800.
Experiments and simulations show that glasses form from liquids upon cooling because increasingly larger regions of a material move simultaneously, inhibiting flow.
Abstract »| Full Text »| PDF »|
Developmental Plasticity in the Life History of a Prosauropod Dinosaur
P. Martin Sander and Nicole Klein
Science 16 December 2005: 1800-1802.
Some early large dinosaurs grew rapidly in response to environmental factors whereas others grew slowly but steadily; later dinosaurs and mammals have fixed life histories.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Drought, Snails, and Large-Scale Die-Off of Southern U.S. Salt Marshes
Brian R. Silliman, Johan van de Koppel, Mark D. Bertness, Lee E. Stanton, and Irving A. Mendelssohn
Science 16 December 2005: 1803-1806.
Salt marshes of the southeastern United States have progressively collapsed as drought has increased their susceptibility to destruction by grazing snails.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Island Biogeography of Populations: An Introduced Species Transforms Survival Patterns
Thomas W. Schoener, Jonathan B. Losos, and David A. Spiller
Science 16 December 2005: 1807-1809.
In the presence of a predatory lizard, anoles that usually thrive on islands with less vegetation survive better on islands with taller shrubbery that provides cover.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Long-Term Modulation of Electrical Synapses in the Mammalian Thalamus
Carole E. Landisman and Barry W. Connors
Science 16 December 2005: 1809-1813.
In inhibitory neurons of the rat thalamus, current flow through gap junctions--conduction pores between neurons--is modulated by electrical activity and neurotransmitters.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Glial Membranes at the Node of Ranvier Prevent Neurite Outgrowth
Jeffrey K. Huang, Greg R. Phillips, Alejandro D. Roth, Liliana Pedraza, Weisong Shan, Wiam Belkaid, Sha Mi, Asa Fex-Svenningsen, Laurence Florens, John R. Yates, III, and David R. Colman
Science 16 December 2005: 1813-1817.
Published online 17 November 2005 [DOI: 10.1126/science.1118313] (in Science Express Reports)
Sections of neuronal axons that are devoid of myelin trapping are prevented from sprouting inappropriately by adjacent glia membranes containing an inhibitory protein.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
The Widespread Impact of Mammalian MicroRNAs on mRNA Repression and Evolution
Kyle Kai-How Farh, Andrew Grimson, Calvin Jan, Benjamin P. Lewis, Wendy K. Johnston, Lee P. Lim, Christopher B. Burge, and David P. Bartel
Science 16 December 2005: 1817-1821.
Published online 24 November 2005 [DOI: 10.1126/science.1121158] (in Science Express Reports)
In mammals, recently discovered small regulatory microRNAs influence the expression or evolution of most genes.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Ubiquitin-Binding Domains in Y-Family Polymerases Regulate Translesion Synthesis
Marzena Bienko, Catherine M. Green, Nicola Crosetto, Fabian Rudolf, Grzegorz Zapart, Barry Coull, Patricia Kannouche, Gerhard Wider, Matthias Peter, Alan R. Lehmann, Kay Hofmann, and Ivan Dikic
Science 16 December 2005: 1821-1824.
The small peptide ubiquitin, known to mark proteins for degradation, also triggers the activity of a group of polymerases specialized for repairing DNA damage.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Chitin Induces Natural Competence in Vibrio cholerae
Karin L. Meibom, Melanie Blokesch, Nadia A. Dolganov, Cheng-Yen Wu, and Gary K. Schoolnik
Science 16 December 2005: 1824-1827.
When grown under natural conditions, cholera bacteria can release and exchange functional DNA, an ability not seen in 60 years of study in the laboratory.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Technical Comments
Comment on "Characterization of Excess Electrons in Water-Cluster Anions by Quantum Simulations"
J. R. R. Verlet, A. E. Bragg, A. Kammrath, O. Cheshnovsky, and D. M. Neumark
Science 16 December 2005: 1769.
Abstract »| Full Text »| PDF »|
Response to Comment on "Characterization of Excess Electrons in Water-Cluster Anions by Quantum Simulations"
László Turi, Wen-Shyan Sheu, and Peter J. Rossky
Science 16 December 2005: 1769.
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