30 June 2006 Vol 312, Issue 5782, Pages 1844-1971
质疑二氧化碳增加给作物带来的好处
一篇新分析指出，与全球气候变暖有关的大气二氧化碳的增加给农作物带来的好处可能不像以前所认为的那样。比如，过去政府间气候变化专门委员会(IPCC)曾作出结论说，高二氧化碳量有肥料的作用，能够抵消在全球更暖气候下由于高温和土壤水分降低造成的产量的下降。但是IPCC的数据来自在温室和大棚的老的作物试验，这些试验没有很好地反映大田的情况，Stephen Long和同事说。他们对大田试验的分析的结论是，高二氧化碳量带来的作物的产量只是温室试验的一半。他们指出，在热带地区，二氧化碳的增加也许完全不会使玉米和高粱等作物增加产量。David Schimel在一篇相关的研究评述中写道：这些发现“也许会提高对农业的影响问题在气候变化所带来的紧迫问题清单上的位置”。
研究文章：Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations, Stephen P. Long, Elizabeth A. Ainsworth, Andrew D. B. Leakey, Josef Nosberger, and Donald R. Ort
基因相互作用增加患皮肤癌的风险
太阳造成的损伤是浅肤色人群患皮肤癌的一个已知风险因素，但是在皮肤损伤不多的情况下，患黑色素瘤是什么因素的作用呢？Maria Teresa Landi和同事现在显示，继承了一个色素受体的突变版本的白皙皮肤的人，患带有BRAF癌症基因突变的黑色素瘤的风险增高。BRAF癌症基因与没有慢性皮肤损伤的黑色素瘤有关。Landi和同事提出，带来白皙皮肤、雀斑、以及红头发的黑素皮质素受体1的变异，提高了没有慢性皮肤损伤的人患BRAF癌症基因突变的黑色素瘤的风险，连接这两个基因变异的确切机制现在还不清楚。
科学特快报告：MC1R Germline Variants Confer Risk for BRAF-Mutant Melanoma, Maria Teresa Landi, et al.
肺结核菌株成功的代价低
新研究指出，临床肺结核中最常见的类型是由那些突变的既抗药又不给自身带来多少适应度代价(fitness cost)的肺结核细菌引起的。Sebastien Gagneux和同事说，这可是一个环消息，因为看起来最新的抗药肺结核菌比上几代的细菌还更适应。这些研究人员显示，抗利福平的突变的适应度代价在不同的肺结核菌中不同，取决于具体的突变以及菌的遗传株。Gagneux和同事做出结论：对已经在患者身上繁荣的菌株的适应度没有影响或影响不大的突变最可能再进一步扩散。
报告：The Competitive Cost of Antibiotic Resistance in Mycobacterium tuberculosis, Sebastien Gagneux, et al.
沙漠蚂蚁的步程计
一个不同寻常的试验证实，沙漠蚂蚁用某种内在的“步程计”来测量准确的行程。研究人员知道蚂蚁在它们回蚁巢的路途中用来自天空的光线索给自己定位，但是它们是如何确定准确的距离的问题一直不清楚。Matthias Wittlinger和同事有这样一个想法：蚂蚁靠步的长短这样的内在步程计来测量距离，他们用改变蚂蚁腿长短的方法检验了这个想法。他们在试验中给一些蚂蚁上了“高跷”-将猪鬃黏接到蚂蚁腿上使其增长，用部分切断的方法使另一些蚂蚁的腿变短。腿变短的蚂蚁的步子小了，在前行的试验中没有到达目的地；而踩高跷的蚂蚁的步子大了，在前行的试验中，它们做过了目的地。这些蚂蚁能够适应新的腿，从而准确地达到目的地，这意味着它们用步子的长短做为步程计，研究人员说。
报告：The Ant Odometer: Stepping on Stilts and Stumps, Matthias Wittlinger, Rüdiger Wehner, and Harald Wolf
小鼠也有通情？
研究人员报告说，小鼠有类似同情的感情并且响应其它小鼠的疼痛，但只是在它们认识这些其它小鼠的情况下。真正的通情被认为是高级灵长类独有的，而且也许只有人类才有，但是Dale Langford和同事说，其它动物也许能感受到低等的类似现象，比如“感情的传染”。这些研究人员用小鼠做了一系列的试验，发现仅仅观察到另外一只小鼠感受疼痛，改变了小鼠自身对疼痛的敏感性。尤其有意思的是，这个作用只在相互熟悉的小鼠之间发生，尽管这些小鼠之间不一定有亲缘关系。文章作者宣称他们的发现不能简单地用比如应激、模仿、或条件反射作用解释。
报告：Social Modulation of Pain as Evidence for Empathy in Mice, Dale J. Langford, et al.
专题部分：生命周期的社会科学研究
本期《科学》专题部分介绍了社会科学家对人类从儿童到老年的生命周期不同阶段研究的一些结果，包括7篇研究评述以及一篇有关人类繁殖力下降和政府如何响应的报道。比如，一篇研究评述讨论了这样的问题：如果你更富有你会更幸福吗？大多数人认为如果他们更富有，他们会更幸福，但是在许多国家作的问卷调查的结果正相反。但是在某些情况下，生命的满足的确看起来是随着家庭收入的增加而增加的。Daniel Kahneman和同事解释说，这是因为当人们考虑任何单一因素对他们的福利的影响时，他们倾向于夸大这个因素的重要性。作者把这个趋势称为“焦点幻觉”，他们提出，收入对人幸福的影响不大，因为随着收入的增加，人们的对时间的利用看起来没有转移到使他们得到幸福的活动上去。美国全国范围的一个代表性的采样显示，有更高收入的人花更多的时间在给他们带来压力的活动上，比如工作、采购、照管儿童、以及锻炼。
专题介绍：Science Looks at Life, Barbara Jasny, Donald Kennedy, and Eliot Marshall
研究评述：Would You Be Happier If You Were Richer? A Focusing Illusion, Daniel Kahneman, Alan B. Krueger, David Schkade, Norbert Schwarz, and Arthur A. Stone
Contents
Special Issue
Frontiers of Social Sciences: Life Cycles
Science Looks at Life
Barbara Jasny, Donald Kennedy, and Eliot Marshall
Science 30 June 2006: 1893.
Summary »| PDF »|
News
The Baby Deficit
Michael Balter
Science 30 June 2006: 1894-1897.
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The Bomb That Wasn't
Michael Balter
Science 30 June 2006: 1896.
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Perspectives
Some Frontiers in Social Science
William P. Butz and Barbara Boyle Torrey
Science 30 June 2006: 1898-1900.
Abstract »| Full Text »| PDF »|
Skill Formation and the Economics of Investing in Disadvantaged Children
James J. Heckman
Science 30 June 2006: 1900-1902.
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Studying Adolescence
Linda M. Richter
Science 30 June 2006: 1902-1905.
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Politics and the Life Cycle
Donald R. Kinder
Science 30 June 2006: 1905-1908.
Abstract »| Full Text »| PDF »|
Would You Be Happier If You Were Richer? A Focusing Illusion
Daniel Kahneman, Alan B. Krueger, David Schkade, Norbert Schwarz, and Arthur A. Stone
Science 30 June 2006: 1908-1910.
Abstract »| Full Text »| PDF »|
Redistributing Work in Aging Europe
James W. Vaupel and Elke Loichinger
Science 30 June 2006: 1911-1913.
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The Influence of a Sense of Time on Human Development
Laura L. Carstensen
Science 30 June 2006: 1913-1915.
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This Week in Science
Editor summaries of this week's papers.
Science 30 June 2006: 1844.
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Editorial:
Alarm Bells Should Help Us Refocus
Neal Lane
Science 30 June 2006: 1847.
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Editors' Choice
Highlights of the recent literature.
Science 30 June 2006: 1848.
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NetWatch
Best of the Web in science.
Science 30 June 2006: 1851.
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NEW PRODUCTS
Science 30 June 2006: 1971.
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News of the Week
CLIMATE CHANGE: Yes, It's Been Getting Warmer in Here Since the CO2 Began to Rise
Richard A. Kerr
Science 30 June 2006: 1854.
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AVIAN INFLUENZA: Journal Letter Spotlights China's Bird Flu Reporting
Dennis Normile
Science 30 June 2006: 1855-1857.
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AVIAN INFLUENZA: Human Transmission But No Pandemic in Indonesia
Dennis Normile
Science 30 June 2006: 1855.
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WAR ZONE: Targeted for Murder, Iraqi Scientists Named on a Hit List
Richard Stone
Science 30 June 2006: 1857-1858.
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ETHICS: Blocking a Book, Dutch University Rekindles Furor Over Nobelist Debye
Martin Enserink
Science 30 June 2006: 1858.
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DIVERSITY: Report Urges National Academies to Improve Status of Women
Jeffrey Mervis
Science 30 June 2006: 1859.
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PALEOCLIMATOLOGY: Atlantic Mud Shows How Melting Ice Triggered an Ancient Chill
Richard A. Kerr
Science 30 June 2006: 1860.
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ANIMAL BEHAVIOR: Signs of Empathy Seen in Mice
Greg Miller
Science 30 June 2006: 1860-1861.
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CHEMISTRY: Sugary Recipe Boosts Grow-Your-Own Plastics
Robert F. Service
Science 30 June 2006: 1861.
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ScienceScope
Science 30 June 2006: 1857.
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Random Samples
Science 30 June 2006: 1853.
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Newsmakers
Science 30 June 2006: 1871.
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News Focus
MOUSE GENETICS: A Mouse for Every Gene
David Grimm
Science 30 June 2006: 1862-1866.
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MOUSE GENETICS: NIH Knocks Out Key Mouse House
David Grimm
Science 30 June 2006: 1863.
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MOUSE GENETICS: China Takes Aim at Comprehensive Mouse Knockout Program
Dennis Normile
Science 30 June 2006: 1864.
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HUMAN BEHAVIOR AND EVOLUTION SOCIETY MEETING: Long-Ago Peoples May Have Been Long in the Tooth
Constance Holden
Science 30 June 2006: 1867.
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HUMAN BEHAVIOR AND EVOLUTION SOCIETY MEETING: An Evolutionary Squeeze on Brain Size
Constance Holden
Science 30 June 2006: 1867.
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CELL BIOLOGY: Podosomes and Invadopodia Help Mobile Cells Step Lively
Jean Marx
Science 30 June 2006: 1868-1869.
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WATER QUALITY: High Court Asks Army Corps to Measure Value of Wetlands
Erik Stokstad
Science 30 June 2006: 1870.
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Letters
This Week's Letters
Science 30 June 2006: 1872.
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Testing Climate Reconstructions
Stefan Rahmstorf;, Haus von Storch, Eduardo Zorita, Julie Jones, Fidel Gonzalez-Rouco, and Simon Tett
Science 30 June 2006: 1872-1873.
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Team Science and the NIBIB
Roderic I. Pettigrew
Science 30 June 2006: 1873.
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Funding for Young Investigators at Whitaker
Robert Nerem and Frank Yin
Science 30 June 2006: 1873-1874.
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Caspase-10 in Mouse or Not?
Reiner U. Jänicke, Dennis Sohn, Gudrun Totzke, and Klaus Schulze-Osthoff
Science 30 June 2006: 1874.
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Role of iNOS in Human Host Defense
Carl Nathan;, Philip Liu, John S. Adams, and Robert L. Modlin
Science 30 June 2006: 1874-1875.
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Books et al.
POLITICAL PSYCHOLOGY: The Perils of Prognostication
John T. Jost
Science 30 June 2006: 1876-1877.
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SOCIOLOGY: Fishing Rights and Race Relations
Nicholas J. G. Winter
Science 30 June 2006: 1877-1878.
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POLITICAL SCIENCE: Stoking the Voters' Passions
James N. Druckman
Science 30 June 2006: 1878-1879.
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Books Received
Science 30 June 2006: 1879.
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Education Forum
COMMUNITY COLLABORATIONS: Collaborative Ecological Restoration
Warren Gold, Kern Ewing, John Banks, Martha Groom, Tom Hinckley, David Secord, and Daniela Shebitz
Science 30 June 2006: 1880-1881.
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Perspectives
CELL SIGNALING: H2O2, a Necessary Evil for Cell Signaling
Sue Goo Rhee
Science 30 June 2006: 1882-1883.
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MATERIALS SCIENCE: Seeking Room-Temperature Ferromagnetic Semiconductors
Koji Ando
Science 30 June 2006: 1883-1885.
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CHEMISTRY: Targeting Specific C-H Bonds for Oxidation
Rubén Mas-Ballesté and Lawrence Que, Jr.
Science 30 June 2006: 1885-1886.
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MOLECULAR BIOLOGY: Enhanced: Accurate RNA Siting and Splicing Gets Help from a DEK-Hand
Tracy L. Kress and Christine Guthrie
Science 30 June 2006: 1886-1887.
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APPLIED PHYSICS: The Neutron Spin-Echo Technique at Full Strength
Joël Mesot
Science 30 June 2006: 1888-1889.
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ECOLOGY: Climate Change and Crop Yields: Beyond Cassandra
David Schimel
Science 30 June 2006: 1889-1890.
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Association Affairs
AAAS News and Notes
Science 30 June 2006: 1891-1892.
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Brevia
Bacterial Diversity in Tree Canopies of the Atlantic Forest
M. R. Lambais, D. E. Crowley, J. C. Cury, R. C. Büll, and R. R. Rodrigues
Science 30 June 2006: 1917.
The leaves of Brazilian coastal forest trees can harbor hundreds of bacterial species, most of them newly described, with a different subset on each species of tree.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Research Articles
Food for Thought: Lower-Than-Expected Crop Yield Stimulation with Rising CO2 Concentrations
Stephen P. Long, Elizabeth A. Ainsworth, Andrew D. B. Leakey, Josef Nösberger, and Donald R. Ort
Science 30 June 2006: 1918-1921.
In open-field experiments testing how increased carbon dioxide improves crop yields, the values were half those of previous experiments conducted in enclosures.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Frictional Afterslip Following the 2005 Nias-Simeulue Earthquake, Sumatra
Ya-Ju Hsu, Mark Simons, Jean-Philippe Avouac, John Galetzka, Kerry Sieh, Mohamed Chlieh, Danny Natawidjaja, Linette Prawirodirdjo, and Yehuda Bock
Science 30 June 2006: 1921-1926.
Since the huge March 2005 earthquake, slip along the plate boundary south of Sumatra is continuing at above-average rates and causing aftershocks.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Spin-Wave Lifetimes Throughout the Brillouin Zone
S. P. Bayrakci, T. Keller, K. Habicht, and B. Keimer
Science 30 June 2006: 1926-1929.
A new high-resolution neutron-scattering technique reveals the fundamental excitations in magnetic systems and shows unexpected effects at very low temperatures.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Surface and Deep Ocean Interactions During the Cold Climate Event 8200 Years Ago
Christopher R. W. Ellison, Mark R. Chapman, and Ian R. Hall
Science 30 June 2006: 1929-1932.
The most prominent cold period during the Holocene, 8200 years ago, spanned several hundred years and was caused by an influx of melt water into the North Atlantic.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Phase Modifiers Promote Efficient Production of Hydroxymethylfurfural from Fructose
Yuriy Román-Leshkov, Juben N. Chheda, and James A. Dumesic
Science 30 June 2006: 1933-1937.
A two-phase solvent efficiently converts fructose to a plastic precursor, providing a possible replacement for petroleum-based plastics.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
An Octahedral Coordination Complex of Iron(VI)
John F. Berry, Eckhard Bill, Eberhard Bothe, Serena DeBeer George, Bernd Mienert, Frank Neese, and Karl Wieghardt
Science 30 June 2006: 1937-1941.
Published online 1 June 2006 [DOI: 10.1126/science.1128506] (in Science Express Reports)
A complex in which iron is in the rare +6 oxidation state and triple bonded to nitrogen is stable to 77 kelvin and can serve as a powerful oxidant upon warming.
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Molecular Recognition in the Selective Oxygenation of Saturated C-H Bonds by a Dimanganese Catalyst
Siddhartha Das, Christopher D. Incarvito, Robert H. Crabtree, and Gary W. Brudvig
Science 30 June 2006: 1941-1943.
A small molecular catalyst aligns a substrate through hydrogen bonding to oxidize a distant site selectively, a strategy commonly seen in much larger enzymes.
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The Competitive Cost of Antibiotic Resistance in Mycobacterium tuberculosis
Sebastien Gagneux, Clara Davis Long, Peter M. Small, Tran Van, Gary K. Schoolnik, and Brendan J. M. Bohannan
Science 30 June 2006: 1944-1946.
Although the tuberculosis bacterium incurs fitness costs when it acquires resistance to antibiotics, the more prevalent strains in humans exhibit superior compensation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Lhx2 Maintains Stem Cell Character in Hair Follicles
Horace Rhee, Lisa Polak, and Elaine Fuchs
Science 30 June 2006: 1946-1949.
A newly described transcription factor maintains the stem cells in the hair follicle in an undifferentiated state, preventing premature differentiation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Structural Basis of RNA-Dependent Recruitment of Glutamine to the Genetic Code
Hiroyuki Oshikane, Kelly Sheppard, Shuya Fukai, Yuko Nakamura, Ryuichiro Ishitani, Tomoyuki Numata, R. Lynn Sherrer, Liang Feng, Emmanuelle Schmitt, Michel Panvert, Sylvain Blanquet, Yves Mechulam, Dieter Söll, and Osamu Nureki
Science 30 June 2006: 1950-1954.
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Ammonia Channel Couples Glutaminase with Transamidase Reactions in GatCAB
Akiyoshi Nakamura, Min Yao, Sarin Chimnaronk, Naoki Sakai, and Isao Tanaka
Science 30 June 2006: 1954-1958.
Bacteria and archaea use multimeric enzyme complexes to covert glutamate bound to transfer RNA to glutamine before it is added to growing peptide chains.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Rapid Advance of Spring Arrival Dates in Long-Distance Migratory Birds
Niclas Jonzén, Andreas Lindén, Torbjørn Ergon, Endre Knudsen, Jon Olav Vik, Diego Rubolini, Dario Piacentini, Christian Brinch, Fernando Spina, Lennart Karlsson, Martin Stervander, Arne Andersson, Jonas Waldenström, Aleksi Lehikoinen, Erik Edvardsen, Rune Solvang, and Nils Chr. Stenseth
Science 30 June 2006: 1959-1961.
Birds that migrate long distances to Europe from Africa are arriving earlier in the spring, perhaps as an evolutionary response to climate change.
Abstract »| Full Text »| PDF »| Supplemental Online Material »|
Intron Removal Requires Proofreading of U2AF/3' Splice Site Recognition by DEK
Luis Miguel Mendes Soares, Katia Zanier, Cameron Mackereth, Michael Sattler, and Juan Valcárcel
Science 30 June 2006: 1961-1965.
A chromatin- and RNA-associated protein that is frequently mutated in leukemias ensures accurate recognition of splice sites by splicing factors.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
The Ant Odometer: Stepping on Stilts and Stumps
Matthias Wittlinger, Rüdiger Wehner, and Harald Wolf
Science 30 June 2006: 1965-1967.
An experiment in which their legs were shortened or lengthened shows that desert ants measure distance on foraging trips by counting their steps.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Social Modulation of Pain as Evidence for Empathy in Mice
Dale J. Langford, Sara E. Crager, Zarrar Shehzad, Shad B. Smith, Susana G. Sotocinal, Jeremy S. Levenstadt, Mona Lisa Chanda, Daniel J. Levitin, and Jeffrey S. Mogil
Science 30 June 2006: 1967-1970.
Mice show empathy-like behavior, exhibiting enhanced pain sensitivity when they see a familiar mouse experience pain but not when the other mouse is a stranger.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Technical Comments
Comment on "Ancient DNA from the First European Farmers in 7500-Year-Old Neolithic Sites"
Albert J. Ammerman, Ron Pinhasi, and Eszter Bánffy
Science 30 June 2006: 1875.
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Response to Comment on "Ancient DNA from the First European Farmers in 7500-Year-Old Neolithic Sites"
Joachim Burger, Detlef Gronenborn, Peter Forster, Shuichi Matsumura, Barbara Bramanti, and Wolfgang Haak
Science 30 June 2006: 1875.
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