9 June 2006 | $10 NUCLEIC ACID PROTEIN FUNCTION QUANTITATIVE SOFTWARE AMPLIFICATION CELL BIOLOGY CLONING MICROARRAYS ANALYSIS & ANALYSIS PCR SOLUTIONS MX3005P™ System MX3000P® System Most Flexible Most Affordable Performance runs in the family. Choose the personal QPCR system that’s right for you. Stratagene now offers two affordable, fully-featured quantitative PCR (QPCR) • A four- or five-color instrument, with user-selected filters systems. The new five-color Mx3005P ™ QPCR System includes expanded features to support a wider range of real-time QPCR applications, such as • Advanced optical system design for true multiplexing capability, and wider application simultaneous five-target detection and alternative QPCR probe chemistries. support The Mx3000P ® QPCR System is still the most affordably priced four-color • MxPro™ QPCR Software with enhanced data 96-well system available. analysis and export functionality Need More Information? Give Us A Call: Mx3000P ® is a registered trademarkof Stratagene in the United States. x3005 ™ and x r ™ are rade ar S ra a ene in he ni ed S a e Stratagene US and Canada Stratagene Europe M P M P o t m ks of t t g t U t t t s. Order: 800-424-5444 x3 Order: 00800-7000-7000 Technical Service: 800-894-1304 x2 Technical Service: 00800-7400-7400 Stratagene Japan K.K. Order: 3-5821-8077 Technical Service: 3-5821-8076 www.stratagene.com Simplify Gene Silencing Experiments with Silencer® Pre-designed siRNA Fast. Easy. Guaranteed. •ReadytousesiRNAsprovidedinaslittleas4days •SearchabledatabasemakesitsimpletofindsiRNAs forhuman,mouse,andratgenes •Efficientgeneknockdownguaranteed •Nowsave18%whenyoupurchase3siRNAspergene Tired of wasting time with poorly designed siRNAs? 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Experimental tips, new tools for RNAi, and exclusivespecial offers Signup at www.ambion.com/contact/litreq Learnhowyoucangetfast,easyandguaranteedsiRNAsat Via phone: RNAi Specialistsx Assistance with experimental setup, design, and troubleshooting www.ambion.com/info/siRNA See www.ambion.com/contact for our full list of toll free phone numbers Ambion, Inc. Ambion (Europe)Ltd Ambion K.K. (Japan) Direct free phone numbers, distributors: U.S. 800-888-8804 • Canada 800-445-1161 tel +44 (0)1480-373-020 tel +81 (0)3-5638-2181 www.ambion.com/contact U.S. tel +1-512-651-0200 • fax +1-512-651-0201 fax +44 (0)1480-373-010 fax +81 (0)3-5638-2182 © Copyright 2006 Ambion, Inc. All rights reserved. An Applied Biosystems Business GE Healthcare Post impressionism by illustra Experts in the art of nucleic acid amplifi cation Introducing illustra from GE Healthcare. Our name is new. 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GE and GE monogram are trademarks of General Electric Company. 05/22V CONTENTS Volume 312, Issue 5779 COVER DEPARTMENTS Merged satellite images from the 1960s 1435 Science Online and 1990s (30 km east-west by 40 km 1437 This Week in Science north-south) of the landscape of northeastern 1442 Editors’ Choice Syria, before intensive agriculture and other 1444 Contact Science recent development altered ancient sites. 1447 NetWatch The red spot near the center marks Tell Brak, 1449 Random Samples the site of a massive ancient city that may 1469 Newsmakers 1541 have been home to one of the first urban New Products 1542 civilizations. A nearby site yielded a stamp Science Careers seal, dated to about 3500 B.C.E., in the shape of a lioness killing a calf or a gazelle. See page 1458. EDITORIAL Main image: Eric Rupley/University of 1441 Mission Creep in the IRB World Michigan; inset: Hamoukar Expedition/ by C. K. Gunsalus et al. Oriental Institute/University of Chicago NEWS OF THE WEEK LETTERS Florida Law Bans Academics From Doing Research 1450 Don’t Sell Social Science Short D. S. Ojima et al. 1470 in Cuba Photosynthetic Oxygen Production W. Junge and Wild Birds Only Partly to Blame in Spreading H5N1 1451 J. Clausen. Response J. E. Penner-Hahn and C. F. Yocum; H. Dau and M. Haumann Ceramic Sponges That Sop Up Sulfur Could Boost 1453 Making Choices Without Deliberating H. L. Bekker Energy Technologies Response A. Dijksterhuis et al. >> Report p. 1508 CORRECTIONS AND CLARIFICATIONS 1472 SCIENCESCOPE 1453 Diversity Remains Elusive for Flagship NSF Program 1454 BOOKS ET AL. Twenty Years After Chornobyl, Legal Fallout Lingers 1455 Unknown Quantity A Real and Imaginary History 1473 Looking Way Back for the World’s Climate Future 1456 of Algebra >> Review p. 1485 J. Derbyshire, reviewed by V. Katz Measuring the Hidden Cost of a Pay Raise 1456 Browsings 1474 Ancient ‘Reef’ Stirs Debate Over Early Signs of Life 1457 in Australian Rocks POLICY FORUM HIV Testing in China 1475 NEWS FOCUS Z. Wu, X. Sun, S. G. Sullivan, R. Detels North Versus South, Mesopotamian Style 1458 Syria’s Open Door: Will It Last? PERSPECTIVES At Home on a No-Frills Tell Evolutionary Response to Rapid Climate Change 1477 A Rising Star in the Trenches W. E. Bradshaw and C. M. Holzapfel Scandals Shake Chinese Science 1464 Toward Robots That Can Sense Texture by Touch 1478 Crime Scene Investigation: How to Handle Misconduct R. Crowder >> Report p. 1501 1467 DNA’s Molecular Gymnastics Getting a Better Picture of the Ocean’s 1479 Nitrogen Budget Z. S. Kolber >> Report p. 1517 Multiferroics as Quantum Electromagnets 1481 Y. Tokura Microtubules Make Tracks for Cellulose 1482 C. Lloyd >> Research Article p. 1491 Can a Fraction of a Quantum Be Better 1483 Than a Whole One? C. M. Pegrum >> Report p. 1495 1458 CONTENTS continued >> www.sciencemag.org SCIENCE VOL 312 9 JUNE 2006 1429 Assistance! SCIENCE @ WORK At Sigma, we’re pulling with you For a change think inside the box and choose the assay kit that truly facilitates your cell biology research. You have better ways to spend your time than developing and validating cell biology assays. With more than 100 kits available, let our assay kits do the work for you. Inside each kit is everything you need to make assaying simpler than ever before. Plus, we have technical experts on hand worldwide to further assist in getting the very best from your research. Our assay kits are just one of the many cell biology solutions that we offer to more than a million scientists every day. From the widest selection of products to the best technical support, we’re the research partner of choice around the world. So when you need assistance in finding an easier way to assay, count on Sigma. sigma.com/assaykits Accelerating Customers' Success through Leadership in Life Science, High Technology and Service SIGMA-ALDRICH CORPORATION • BOX 14508 • ST. LOUIS • MISSOURI 63178 • USA CONTENTS SCIENCE EXPRESS www.sciencexpress.org ECOLOGY The Importance of Demographic Niches to Tree Diversity ASTROPHYSICS R. Condit et al. Massive-Star Supernovae as Major Dust Factories Data from a vast long-term survey of tropical forests contradict the prevailing B. E. K. Sugerman et al. view that tree species richness results from variability in rates of recruitment A 2003 supernova produced 10 times the dust seen after other such stellar and mortality. explosions, implying that supernovae were dust factories in the early universe. 10.1126/science.1124712 10.1126/science.1128131 MICROBIOLOGY CELL BIOLOGY Selective Silencing of Foreign DNA with Low GC Content Polo-Like Kinase Cdc5 Controls the Local Activation of Rho1 by the H-NS Protein in Salmonella to Promote Cytokinesis W. W. Navarre et al. S. Yoshida et al. Bacteria can recognize and silence invading foreign DNA by virtue of its lower In yeast, regulatory enzymes work together to activate actin in the contractile ring, overall GC content. causing it to constrict and separate daughter cells during cell division. 10.1126/science.1128794 10.1126/science.1126747 REVIEW REPORTS OCEANS APPLIED PHYSICS The Pliocene Paradox (Mechanisms for a 1485 Flip-Flopping Fractional Flux Quanta 1495 Permanent El Niño) T. Ortlepp et al. A. V. Fedorov et al. The d-wave symmetry of high-temperature superconductors can be >> News story p.