Tạp chí khoa học số 2005-12-02

2 December 2005 Vol. 310 No. 5753 Pages 1373–1568 $10 IT’S SCIENCE IN SUPERDRIVE The New Label IT ® miRNA Labeling Kit from Mirus Bio. It cuts time, not corners. Accurate microRNA labeling and detection just got faster. Designed by bench scientists for bench scientists, our direct labeling technology labels miRNA in one easy step. Identify miRNA molecules in high or low abundance with super speed and precision, and reach your discoveries faster. Because your research begins at the bench – it doesn’t end there. Visit mirusbio.com for more information and a special savings offer.                       © 2005 Mirus Bio Corporation. Label IT is a registered trademark of the Mirus Bio Corporation. .00 Label IT ® miRNA Kit Detection Limit of Labeled miRNA (fmol) Enzymatic Labeling 1 1 RNA(2005), 11(9): 1461-1470 .04 .16 .12 .08 SUPERIOR SENSITIVITY for miRNA Detection MICRORNA LABELING Ni Sepharose ™ products from GE Healthcare give you the greatest binding capacity available for histidine-tagged protein purification. They offer the flexibility to use a variety of formats and protocols, ensuring the highest possible purity. And with our His GraviTrap ™ and HisTrap ™ FF crude columns, you can now get pure histidine-tagged proteins directly from unclarified lysate in just 30 minutes. Maximum target protein activity is assured with Ni Sepharose, thanks to its tolerance of a wide range of additives and negligible nickel ion leakage. With up to four times the capacity of competing products, dramatically increasing your yield while saving on time and resin/buffer costs is no longer pure imagination. www.amershambiosciences.com/his GE Healthcare © 2005 General Electric Company - All rights reserved. Amersham Biosciences AB, a General Electric company, going to market as GE Healthcare. Greater flexibility and binding capacity in histidine-tagged protein purification GE18-05 www.sciencemag.org SCIENCE VOL 310 2 DECEMBER 2005 1377 DEPARTMENTS 1383 SCIENCE ONLINE 1385 THIS WEEK IN SCIENCE 1389 EDITORIAL by Michael S.Turner Bullish on Particles 1391 E DITORS’CHOICE 1396 CONTACT SCIENCE 1401 NETWATCH 1517 NEW PRODUCTS 1526 SCIENCE CAREERS NEWS OF THE WEEK 1402 STEM CELL RESEARCH Korean Cloner Admits Lying About Oocyte Donations 1403 G LOBAL CLIMATE CHANGE The Atlantic Conveyor May Have Slowed, But Don’t Panic Yet 1405 C ANADA Animal Rules Keep Grad Students Out of the Lab 1405 S CIENCESCOPE 1406 NUCLEAR POWER Congress Tells DOE to Take Fresh Look at Recycling Spent Reactor Fuel 1407 S CIENTIFIC PUBLISHING NIEHS Journal Is on the Block 1407 U.S. G RADUATE EDUCATION Universities Must Pay to Play in Ph.D. Program Rankings 1409 S PACE SCIENCE Fuel Shortage Imperils Asteroid-Sampling Mission 1409 E PIDEMIOLOGY Talk on ‘Underground’ Bird Flu Deaths Rattles Experts NEWS FOCUS 1410 ECOLOGY Winning the War Against Island Invaders 1414 A COUSTIC ENGINEERING String Theory Meets Practice as Violinmakers Rethink Their Craft 1417 P ROFILE:FRANK WOLF The Congressman With His Hand on Science’s Purse Strings 1418 P ALEONTOLOGY Best Archaeopteryx Fossil So Far Ruffles a Few Feathers related Report page 1483 1421 RANDOM SAMPLES LETTERS 1425 Issues in Bringing New Drugs to the Market R. Ansbacher; A. J. Ammann;W. R. Tracey. Response J. Avorn. Invariant Ratios Vs. Dimensionless Ratios M. Mangel. Worldwide Decline of Sturgeons D. E. Lorke and D.T.Yew 1429 Corrections and Clarifications BOOKS ET AL. 1432 NATURAL HISTORY Return to Wild America A Yearlong Search for the Continent’s Natural Soul S.Weidensaul, reviewed by J. Greenberg 1433 BEHAVIORAL ECOLOGY In the Company of Crows and Ravens J. M. Marzluff and T. Angell, reviewed by J. Dally ESSAY 1435 GLOBAL VOICES OF SCIENCE Following the Light: Opening Doors to Science in Tunisia Z. B. Lakhdar Contents continued 1410 SPECIAL ISSUE GETTING ACROSS THE MEMBRANE A variety of proteinaceous pores translocate ions, proteins, and DNA across cell mem- branes.A special section in this issue looks at how they accomplish this essential task. [Image: Chris Bickel] INTRODUCTION 1451 Crossing the Bilayer REVIEWS 1452 Protein Translocation Across Biological Membranes W.Wickner and R. Schekman 1456 The Ins and Outs of DNA Transfer in Bacteria I. Chen, P. J. Christie, D. Dubnau 1461 Principles of Selective Ion Transport in Channels and Pumps E. Gouaux and R. MacKinnon Volume 310 2 December 2005 Number 5753 For related online content in STKE see page 1383 or go to www.sciencemag.org/sciext/membranes/ 1418 & 1483 Results clearly demonstrate a shift from predominantly primer-dimers to the specific target when HotStart-IT is included in the reactions. without with HotStart-IT HotStart-IT M- - ++ numb, 306 bp 1 ng DNA For a FREE sample of new HotStart-IT, call 800.321.9322 or visit www.usbweb.com/hotstart “ Are my PCR reactions specific enough? Will my experiment be contaminated from animal-sourced antibodies? Will the DNA be damaged from extensive heat denaturation? Will my results be compromised?” If these are some of the questions you’re asking yourself, try HotStart-IT. ™ Developed by USB scientists, HotStart-IT is an elegant new method that doesn’t use antibodies or chemically modified enzymes. Instead, HotStart-IT relies on a unique protein that binds and sequesters primers at lower temperatures which prevents mispriming and the formation of primer-dimers. When PCR is initiated, the protein is inactivated during the heat denaturation step and the primers are free to participate in the subsequent amplification cycles. The result? Higher specificity. Higher yield. And, most importantly, a higher level of confidence for you. www.sciencemag.org SCIENCE VOL 310 2 DECEMBER 2005 1379 PERSPECTIVES 1439 PLANETARY SCIENCE The Changing Picture of Volatiles and Climate on Mars B. M. Jakosky,R. M. Haberle, R. E.Arvidson 1440 G EOPHYSICS The Ghost of an Earthquake W. C. Hammond related Report page 1473 1442 IMMUNOLOGY Tipping the Scales Toward More Effective Antibodies J. M.Woof related Report page 1510 1443 CELL BIOLOGY Keeping Survivin Nimble at Centromeres in Mitosis W. C. Earnshaw related Report page 1499 SCIENCE EXPRESS www.sciencexpress.org IMMUNOLOGY: A Clonogenic Bone Marrow Progenitor Specific for Macrophages and Dendritic Cells D. K. Fogg, C. Sibon, C. Miled, S. Jung, P. Aucouturier, D. R. Littman, A. Cumano, F. Geissmann One bone marrow cell type is the precursor for two key immune cells,both of which process foreign antigens. PLANETARY SCIENCE: Radar Soundings of the Subsurface of Mars G. Picardi et al. Mars Express radar data reveal that 2 kilometers of layered deposits rich in pure water ice underlie the North Polar Cap, but that their weight barely deforms the underlying crust. PLANETARY SCIENCE: Radar Soundings of the Ionosphere of Mars D.A. Gurnett, D. L. Kirchner, R. L. Huff, D. D. Morgan, A. M. Persoon,T. F.Averkamp, F. Duru, E. Nielsen, A. Safaeinili, J. J. Plaut, G. Picardi Radar observations from Mars Express map the bulging of the Martian ionosphere in areas where the magnetic field in Mars’ crust is oriented vertically. TECHNICAL COMMENT ABSTRACTS GEOPHYSICS Comment on “The Great Sumatra-Andaman Earthquake of 26 December 2004” S. Neetu, I. Suresh, R. Shankar, D. Shankar, S. S. C. Shenoi, S.R. Shetye, D. Sundar, B. Nagarajan full text at www.sciencemag.org/cgi/content/full/310/5753/1431a Response to Comment on “The Great Sumatra-Andaman Earthquake of 26 December 2004” T. Lay, H. Kanamori, C. J. Ammon, M. Nettles, S. N.Ward, R. Aster, S. L. Beck, S. L. Bilek, M. R. Brudzinski, R. Butler, H. R. DeShon, G. Ekström, K. Satake, S. Sipkin full text at www.sciencemag.org/cgi/content/full/310/5753/1431b BREVIA 1467 EVOLUTION: Evidence for a One-Allele Assortative Mating Locus D. Ortíz-Barrientos and M. A. F. Noor A single shared allele reduces mating between individuals in two diverging species, confirming a theoretically predicted mode of speciation. RESEARCH ARTICLE 1469 OCEAN SCIENCE: Radiocarbon Variability in the Western North Atlantic During the Last Deglaciation L. F. Robinson, J. F. Adkins, L. D. Keigwin, J. Southon, D. P. Fernandez, S-L Wang, D. S. Scheirer A record of the 14 C content of deep water from the North Atlantic shows that warming during deglaciation in the Northern Hemisphere was indeed associated with vigorous deep-water formation. REPORTS 1473 GEOPHYSICS: Postseismic Mantle Relaxation in the Central Nevada Seismic Belt N. Gourmelen and F.Amelung Radar interferometry data from a 10-year period shows that the crust in western Nevada is still relaxing from four large earthquakes that occurred between 1915 and 1954. related Perspective page 1440 1477 GEOCHEMISTRY: Active Microbial Sulfur Disproportionation in the Mesoproterozoic D.T. Johnston, B.A.Wing,J. Farquhar,A. J. Kaufman, H. Strauss,T.W. Lyons, L. C.Kah, D.E. Canfield Three sulfur isotopes show that microbes metabolized intermediate sulfur species by 1.3 billion years ago, implying that the atmosphere then was more oxidizing than had been supposed. Contents continued 1442 & 1510                                     . histidine-tagged protein purification GE18-05 www.sciencemag.org SCIENCE VOL 310 2 DECEMBER 2005 1377 DEPARTMENTS 1383 SCIENCE ONLINE 1385 THIS WEEK IN SCIENCE 1389 EDITORIAL by Michael S.Turner Bullish. (1-800-424-6723); outside the US, contact your local sales office. 1383 www.sciencemag.org SCIENCE VOL 310 2 DECEMBER 2005 sciencenow www.sciencenow.org DAILY NEWS COVERAGE Clones Express Themselves Like.  www.sciencemag.org SCIENCE VOL 310 2 DECEMBER 2005 1381 1513 1480 MATERIALS SCIENCE: Electrowetting in Carbon Nanotubes J.Y. Chen, A. Kutana,