2006年3月10日 美国《科学》周刊311卷 第5766期 啮齿动物填补化石记录的空白[To top]
一项新研究指出，去年在老挝发现的一种新啮齿动物是人们认为已经灭绝了1100万年的物种的一个幸存者。Mary Dawson和同事将这个类似松鼠的动物的骨骼残骸，与一个人们了解甚少的、灭绝了的东南亚啮齿动物作了比较，确认该动物其实是这个消失了的家族的一个现今仍存活的成员。这个新物种在2005年被发现时曾引起广泛的注意，因为它被认为是一个全新的活着的哺乳动物家族。但是，本文作者说这个啮齿动物是“拉撒路效应(Lazarus effect)”的一个典型表现，该效应是指一个生物体在化石记录中消失了很长时间后的突然重新出现。这些研究人员写道，这个现象在哺乳动物和其它脊椎动物的纪录中罕见，这表明东南亚的史前“动物园”能为过去和现在的生物多样性提供极为宝贵的线索。
报告：Laonastes and the "Lazarus Effect" in Recent Mammals, Mary R. Dawson, Laurent Marivaux, Chuan-kui Li, K. Christopher Beard, and Grégoire Métais
人到复活节岛的时间比过去认为的要晚[To top]
新研究指出，对复活节岛上土壤的放射性碳年代测定表明，第一批波利尼亚人到达这个岛的时间大约是公元1200年，比过去认为的晚得多，而且他们很快开始修建大型的石头雕塑以及开采岛上的自然资源。Terry Hunt 和Carl Lipo描述了最近发掘出来的新证据，并分析了过去的研究，他们对一个假说提出挑战。该假说认为复活节岛是在公元前1000到400年间开始有人的，只是到了大约公园1200年时，岛上的居民才开始修建雕塑和大量地砍伐岛上曾经很丰富的森林。本文作者提出，其实波利尼亚人是在1200年才到了岛上的，并且很快就开始了不可逆转的森林砍伐，这一活动持续了几百年。当荷兰水手1722年到复活节岛时，他们看到的是生活在有许多石头雕塑的不毛之岛上的饥饿的人群。南太平洋中远离任何岛屿的复活节岛是研究人类造成的环境变化及其后果对人群的影响的备受关注的地方。
科学特快报告：Late Colonization of Easter Island, Terry L. Hunt and Carl P. Lipo
北白令海变暖[To top]
一项新研究指出，由于气候的变化，北白令海正在变暖。北白令海是一个富有底栖喂食海洋哺乳动物和潜水海鸟的生态环境，它的变暖可能会威胁商业的和当地人赖以生存的渔业。Jacqueline Grebmeier和同事描述了过去10年中的一些生态和海洋学数据，这些数据显示北白令海浅海环境正在从北极带转变为亚北极带。这些变化包括海洋哺乳动物种群向北迁移，底栖喂食动物减少，表面冰消失，以及空气和海洋温度上升。文章作者说，来自大气、冰层、或水流的变化对海洋生物有潜在的快速联级效应。他们预计北白令海的变化也许会影响到更大的受太平洋影响的北冰洋部分，尤其是这些地区冰的继续减少。
报告：A Major Ecosystem Shift in the Northern Bering Sea, Jacqueline M. Grebmeier, et al.
不掉粒水稻的起源[To top]
研究人员找到了水稻基因的一个变异，该变异使稻子不会很容易地掉粒将种子释放出来。这可能是水稻家化的关键转折点，一个很容易地将种子满地散发的野草从而变成了能夹住成熟的颗粒直到被收获的作物。Changbao Li和同事将这个遗传突变与一个基因联系起来，该基因也许编码一个涉及将大米与谷壳分离的细胞层发育的转录因子。研究人员说，带有这个遗传变异的水稻有一个不完整的分离层，从而使大米不太容易掉粒，但是又使在收割后可能将大米从谷壳中分离出来。
科学特快报告：Rice Domestication by Reducing Shattering, Changbao Li, Ailing Zhou, and Tao Sang
培育薛定谔小猫[To top]
量子计算和量子通讯继电器需要用物质的量子态来实现，但是在此之前很难在试验上产生这些量子态。现在，Alexei Ourjoumtsev和同事在一项新试验中，使一个挤压的光脉冲进入一个被称为“薛定谔小猫”的量子态。薛定谔的猫是用来描述量子态叠加理论的一个著名例子，这个理论提出物质能同时处于几个状态，除非做观察或测量将可能的状态减少为一个。在这个例子中，盒子里的一只猫可能活着、也可能死了，只有打开盒子才能确定猫是死是活。通过从挤压的光脉冲中取出单个的光子，Ourjoumtsev和同事从脉冲中制造出小幅度或被称为“小猫”的状态。研究人员说，这些 “小猫”能够被放大成更大的“猫”，也许对量子应用有用。
科学特快报告：Generating Optical Schrodinger Kittens for Quantum Information Processing, Alexei Ourjoumtsev, Rosa Tualle-Brouri, Julien Laurat, and Philippe Grangier
专题部分：卡西尼访问土卫二[To top]
卡西尼太空探测器自2004年以来一直在环绕土星飞行，探索这个行星著名的光环和它的多个卫星。在2005年中，卡西尼对人们最感兴趣的土卫二 (Enceladus)做了三次探测飞行。土卫二位于环绕土星的宽阔的蓝色E环中，它一直被认为是构成E环的微小颗粒的源泉。本期专题部分发表的来自国际卡西尼小组的9篇论文和两篇研究评述显示，虽然E环起源的迷也许已经被解决了，但是2005年的探测飞行也揭示出土卫二的一些新特征。这个极小的卫星异常地活跃：喷放出大量的水蒸气烟雾，不断给自己明亮的表面镀上新鲜的一层冰，冰在地壳构造力的影响下弯曲，还劈啪作响地破裂。
专题介绍：Tiger, Tiger, Burning Bright, Joanne Baker
ContentsSpecial IssueCassini at Enceladus
Tiger, Tiger, Burning Bright
Joanne Baker
Science 10 March 2006: 1388.
Summary »| PDF »|
Perspectives
Enceladus: Cosmic Gymnast, Volatile Miniworld
Jeffrey S. Kargel
Science 10 March 2006: 1389-1391.
Abstract »| Full Text »| PDF »|
Does Enceladus Govern Magnetospheric Dynamics at Saturn?
Margaret Galland Kivelson
Science 10 March 2006: 1391-1392.
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Research Articles
Cassini Observes the Active South Pole of Enceladus
C. C. Porco, P. Helfenstein, P. C. Thomas, A. P. Ingersoll, J. Wisdom, R. West, G. Neukum, T. Denk, R. Wagner, T. Roatsch, S. Kieffer, E. Turtle, A. McEwen, T. V. Johnson, J. Rathbun, J. Veverka, D. Wilson, J. Perry, J. Spitale, A. Brahic, J. A. Burns, A. D. DelGenio, L. Dones, C. D. Murray, and S. Squyres
Science 10 March 2006: 1393-1401.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Cassini Encounters Enceladus: Background and the Discovery of a South Polar Hot Spot
J. R. Spencer, J. C. Pearl, M. Segura, F. M. Flasar, A. Mamoutkine, P. Romani, B. J. Buratti, A. R. Hendrix, L. J. Spilker, and R. M. C. Lopes
Science 10 March 2006: 1401-1405.
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Reports
Identification of a Dynamic Atmosphere at Enceladus with the Cassini Magnetometer
M. K. Dougherty, K. K. Khurana, F. M. Neubauer, C. T. Russell, J. Saur, J. S. Leisner, and M. E. Burton
Science 10 March 2006: 1406-1409.
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The Interaction of the Atmosphere of Enceladus with Saturn's Plasma
R. L. Tokar, R. E. Johnson, T. W. Hill, D. H. Pontius, W. S. Kurth, F. J. Crary, D. T. Young, M. F. Thomsen, D. B. Reisenfeld, A. J. Coates, G. R. Lewis, E. C. Sittler, and D. A. Gurnett
Science 10 March 2006: 1409-1412.
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Enceladus' Varying Imprint on the Magnetosphere of Saturn
G. H. Jones, E. Roussos, N. Krupp, C. Paranicas, J. Woch, A. Lagg, D. G. Mitchell, S. M. Krimigis, and M. K. Dougherty
Science 10 March 2006: 1412-1415.
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Cassini Dust Measurements at Enceladus and Implications for the Origin of the E Ring
Frank Spahn, Jürgen Schmidt, Nicole Albers, Marcel Hörning, Martin Makuch, Martin Seiß, Sascha Kempf, Ralf Srama, Valeri Dikarev, Stefan Helfert, Georg Moragas-Klostermeyer, Alexander V. Krivov, Miodrag Sremcevic, Anthony J. Tuzzolino, Thanasis Economou, and Eberhard Grün
Science 10 March 2006: 1416-1418.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Cassini Ion and Neutral Mass Spectrometer: Enceladus Plume Composition and Structure
J. Hunter Waite, Jr., Michael R. Combi, Wing-Huen Ip, Thomas E. Cravens, Ralph L. McNutt, Jr., Wayne Kasprzak, Roger Yelle, Janet Luhmann, Hasso Niemann, David Gell, Brian Magee, Greg Fletcher, Jonathan Lunine, and Wei-Ling Tseng
Science 10 March 2006: 1419-1422.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Enceladus' Water Vapor Plume
Candice J. Hansen, L. Esposito, A. I. F. Stewart, J. Colwell, A. Hendrix, W. Pryor, D. Shemansky, and R. West
Science 10 March 2006: 1422-1425.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Composition and Physical Properties of Enceladus' Surface
Robert H. Brown, Roger N. Clark, Bonnie J. Buratti, Dale P. Cruikshank, Jason W. Barnes, Rachel M. E. Mastrapa, J. Bauer, S. Newman, T. Momary, K. H. Baines, G. Bellucci, F. Capaccioni, P. Cerroni, M. Combes, A. Coradini, P. Drossart, V. Formisano, R. Jaumann, Y. Langevin, D. L. Matson, T. B. McCord, R. M. Nelson, P. D. Nicholson, B. Sicardy, and C. Sotin
Science 10 March 2006: 1425-1428.
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ContentsThis Week in Science
Editor summaries of this week's papers.
Science 10 March 2006: 1341.
|Full Text »
Editorial:
Summers and Harvard
Donald Kennedy
Science 10 March 2006: 1345.
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Editors' Choice
Highlights of the recent literature.
Science 10 March 2006: 1347.
|Full Text »
NetWatch
Best of the Web in science.
Science 10 March 2006: 1353.
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NEW PRODUCTS
Science 10 March 2006: 1485.
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News of the Week
PROLIFERATION: Last-Minute Nuclear Deal Has Long-Term Repercussions
Richard Stone and Pallava Bagla
Science 10 March 2006: 1356-1357.
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SOLAR PHYSICS: The Sun's Churning Innards Foretell More Solar Storms
Richard A. Kerr
Science 10 March 2006: 1357.
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SPACE SCIENCE: NASA Agrees to Review What's on the Chopping Block
Andrew Lawler
Science 10 March 2006: 1359-1360.
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ARCHAEOLOGY: Dates Revise Easter Island History
Ann Gibbons
Science 10 March 2006: 1360.
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SOLID STATE PHYSICS: Theory of Shock Waves Clears Up the Puzzling Graininess of Crystals
Adrian Cho
Science 10 March 2006: 1361.
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UNIVERSITIES: Austria's Bid for an Instant MIT Meets Opposition From Researchers
Gretchen Vogel
Science 10 March 2006: 1363.
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U.S. SCIENCE POLICY: Legislator Wants NSF to Offer $1 Billion Energy Prize
Jeffrey Mervis
Science 10 March 2006: 1363.
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ScienceScope
Science 10 March 2006: 1359.
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Random Samples
Science 10 March 2006: 1355.
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Newsmakers
Science 10 March 2006: 1375.
|Full Text »
News Focus
ARCHAEOLOGY: The End of Angkor
Richard Stone
Science 10 March 2006: 1364-1368.
Summary »| Full Text »| PDF »|
ARCHAEOLOGY: Local Elites Cast New Light on Angkor's Rise
Richard Stone
Science 10 March 2006: 1366.
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SAMUEL BODMAN PROFILE: With Energy to Spare, an Engineer Makes the Case for Basic Research
Eli Kintisch
Science 10 March 2006: 1369-1370.
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RESEARCH POLICY: A Dose of Reform to Treat the Malaise Gripping French Science
Martin Enserink
Science 10 March 2006: 1371-1372.
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EVOLUTIONARY BIOLOGY: Speciation Standing in Place
Elizabeth Pennisi
Science 10 March 2006: 1372-1374.
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Letters
This Week's Letters
Science 10 March 2006: 1376.
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Finding Good in the Bad and Vice Versa
David Johns
Science 10 March 2006: 1376.
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Diversity in Tropical Forests
William F. Laurance
Science 10 March 2006: 1376.
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Genetic Polymorphism of Fc
Janardan P. Pandey; and Jenny M. Woof
Science 10 March 2006: 1376-1377.
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Hyposmocoma molluscivora Description
Daniel Rubinoff and William P. Haines
Science 10 March 2006: 1377.
Full Text »| PDF »| Supporting Online Material »|
GPS: A Military/Civilian Collaboration
James F. Zumberge
Science 10 March 2006: 1377-1378.
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Decline of Vultures in Asia
Rhys E. Green
Science 10 March 2006: 1378.
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Books et al.
CLIMATE CHANGE: Humanity Usurps Nature
Bill Chameides
Science 10 March 2006: 1379.
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Books Received
Science 10 March 2006: 1379.
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Policy Forum
ENERGY: Fusion Power: Will It Ever Come?
William E. Parkins
Science 10 March 2006: 1380.
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Perspectives
GENETICS: Total Information Awareness for Worm Genetics
Sean R. Eddy
Science 10 March 2006: 1381-1382.
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BIOCHEMISTRY: Five Golden Rings
David W. Christianson
Science 10 March 2006: 1382-1383.
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CHEMISTRY: Enhanced: Resonances in Reaction Dynamics
Richard N. Zare
Science 10 March 2006: 1383-1385.
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BIOMEDICINE: One Misfolded Protein Allows Others to Sneak By
Gillian P. Bates
Science 10 March 2006: 1385-1386.
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ATMOSPHERIC SCIENCE: Fungi, Weathering, and the Emergence of Animals
Louis A. Derry
Science 10 March 2006: 1386-1387.
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Brevia
Diffusive Separation of the Lower Atmosphere
Yosuke Adachi, Kenji Kawamura, Laurence Armi, and Ralph F. Keeling
Science 10 March 2006: 1429.
As long predicted, diffusion can overcome turbulence in the troposphere under specific conditions to separate heavy and light atoms and molecules.
Abstract »| Full Text »| PDF »|
Research Article
Structure of the Hydrophilic Domain of Respiratory Complex I from Thermus thermophilus
Leonid A. Sazanov and Philip Hinchliffe
Science 10 March 2006: 1430-1436.
Published online 9 February 2006 [DOI: 10.1126/science.1123809] (in Science Express Research Articles)
The x-ray crystal structure of the peripheral part of the largest bacterial respiratory electron-transport complex shows the folds, contacts, and positions of the redox cofactors.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Ultrafast Interfacial Proton-Coupled Electron Transfer
Bin Li, Jin Zhao, Ken Onda, Kenneth D. Jordan, Jinlong Yang, and Hrvoje Petek
Science 10 March 2006: 1436-1440.
Return of an electron from a methanol film to a semiconductor induces rapid (30 femtoseconds) stabilizing motion in the substrate and coupled transfer of a proton.
Abstract »| Full Text »| PDF »|
Observation of Feshbach Resonances in the F + H2 -> HF + H Reaction
Minghui Qiu, Zefeng Ren, Li Che, Dongxu Dai, Steve A. Harich, Xiuyan Wang, Xueming Yang, Chuanxiu Xu, Daiqian Xie, Magnus Gustafsson, Rex T. Skodje, Zhigang Sun, and Dong H. Zhang
Science 10 March 2006: 1440-1443.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Signatures of H2CO Photodissociation from Two Electronic States
H. M. Yin, S. H. Kable, X. Zhang, and J. M. Bowman
Science 10 March 2006: 1443-1446.
Spectroscopy and computations reveal the nuclear vibrations and other motions involved in the dissociations of excited, transient molecules and in collision reactions.
Abstract »| Full Text »| PDF »|
Late Precambrian Oxygenation; Inception of the Clay Mineral Factory
Martin Kennedy, Mary Droser, Lawrence M. Mayer, David Pevear, and David Mrofka
Science 10 March 2006: 1446-1449.
Published online 2 February 2006 [DOI: 10.1126/science.1118929] (in Science Express Reports)
The development of an oxygen-rich atmosphere during the Neoproterozoic was the result of an increase in the rate of clay deposition caused by the spread of terrestrial vegetation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
The Last Deglaciation of the Southeastern Sector of the Scandinavian Ice Sheet
V. R. Rinterknecht, P. U. Clark, G. M. Raisbeck, F. Yiou, A. Bitinas, E. J. Brook, L. Marks, V. Zelcs, J.-P. Lunkka, I. E. Pavlovskaya, J. A. Piotrowski, and A. Raukas
Science 10 March 2006: 1449-1452.
Dating of glacial deposits near the margins of the Scandinavian Ice Sheet reveals that it began to retreat about 19,000 years ago, contributing to an abrupt rise in sea level.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Exposed Water Ice Deposits on the Surface of Comet 9P/Tempel 1
J. M. Sunshine, M. F. A'Hearn, O. Groussin, J.-Y. Li, M. J. S. Belton, W. A. Delamere, J. Kissel, K. P. Klaasen, L. A. McFadden, K. J. Meech, H. J. Melosh, P. H. Schultz, P. C. Thomas, J. Veverka, D. K. Yeomans, I. C. Busko, M. Desnoyer, T. L. Farnham, L. M. Feaga, D. L. Hampton, D. J. Lindler, C. M. Lisse, and D. D. Wellnitz
Science 10 March 2006: 1453-1455.
Published online 2 February 2006 [DOI: 10.1126/science.1123632] (in Science Express Reports)
Deep Impact has found three patches of water ice on comet Tempel 1, but these cannot account for the water output of outgassing, implying a subsurface source.
Abstract »| Full Text »| PDF »|
Laonastes and the "Lazarus Effect" in Recent Mammals
Mary R. Dawson, Laurent Marivaux, Chuan-kui Li, K. Christopher Beard, and Grégoire Métais
Science 10 March 2006: 1456-1458.
A recently discovered living rodent is a survivor of a family thought to have been extinct for 11 million years.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Opposing Effects of Native and Exotic Herbivores on Plant Invasions
John D. Parker, Deron E. Burkepile, and Mark E. Hay
Science 10 March 2006: 1459-1461.
A meta-analysis of 71 experimental studies shows that invasions by exotic plants tend to be suppressed by native herbivores but enhanced by exotic herbivores.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Major Ecosystem Shift in the Northern Bering Sea
Jacqueline M. Grebmeier, James E. Overland, Sue E. Moore, Ed V. Farley, Eddy C. Carmack, Lee W. Cooper, Karen E. Frey, John H. Helle, Fiona A. McLaughlin, and S. Lyn McNutt
Science 10 March 2006: 1461-1464.
Warming has caused the highly productive northern part of the Bering Sea to change from an arctic to a subarctic marine ecosystem.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Structure and Mechanism of the Lantibiotic Cyclase Involved in Nisin Biosynthesis
Bo Li, John Paul J. Yu, Joseph S. Brunzelle, Gert N. Moll, Wilfred A. van der Donk, and Satish K. Nair
Science 10 March 2006: 1464-1467.
The enzyme that performs the final step in the biosynthesis of the antimicrobial food preservative nisin constructs five thioether rings of different sizes in this peptide.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Engineering Cooperativity in Biomotor-Protein Assemblies
Michael R. Diehl, Kechun Zhang, Heun Jin Lee, and David A. Tirrell
Science 10 March 2006: 1468-1471.
Artificial assembly of kinesin proteins on scaffold molecules shows that their transport activity is enhanced by their proximity.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Progressive Disruption of Cellular Protein Folding in Models of Polyglutamine Diseases
Tali Gidalevitz, Anat Ben-Zvi, Kim H. Ho, Heather R. Brignull, and Richard I. Morimoto
Science 10 March 2006: 1471-1474.
Published online 9 February 2006 [DOI: 10.1126/science.1124514] (in Science Express Reports)
In experiments in nematodes that may simulate some neurodegenerative diseases, abnormal, glutamine-rich proteins disrupt the cell’s normal disposal of misfolded proteins.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
The Global Impact of Scaling Up HIV/AIDS Prevention Programs in Low- and Middle-Income Countries
John Stover, Stefano Bertozzi, Juan-Pablo Gutierrez, Neff Walker, Karen A. Stanecki, Robert Greener, Eleanor Gouws, Catherine Hankins, Geoff P. Garnett, Joshua A. Salomon, J. Ties Boerma, Paul De Lay, and Peter D. Ghys
Science 10 March 2006: 1474-1476.
Published online 2 February 2006 [DOI: 10.1126/science.1121176] (in Science Express Reports)
Implementation of AIDS prevention measures targeting sexual transmission and drug users could prevent 30 million new infections in the next 10 years.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Combinatorial Effects of Odorant Mixes in Olfactory Cortex
Zhihua Zou and Linda B. Buck
Science 10 March 2006: 1477-1481.
Specific neurons in the olfactory cortex act as coincidence detectors, responding to a mixture of two odors but not to the individual components of the mixture.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Genome-Wide Prediction of C. elegans Genetic Interactions
Weiwei Zhong and Paul W. Sternberg
Science 10 March 2006: 1481-1484.
Construction of a comprehensive gene interaction network for C. elegans, guided by data from yeast and fruit flies, identifies previously undescribed interacting protein pairs.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
