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12 January 2007 Vol 315, Issue 5809, Pages 158-257
现代人类走出非洲；走入俄罗斯
本期两篇报告为现代人的起源和分散提供了新信息。现有的证据意味着现代人在大约5万年前从非洲分散出来，导致了遍及欧洲和亚洲的旧石器文化。然而，迄今找到的来自撒哈拉以南非洲的人科化石极少，以至不能对这个观点进行检验。Frederick E. Grine和同事重新分析了1952年在南非Hofmeyr附近发现的一个头盖骨化石。由于化石没有足够的胶原可用于准确的碳定年测定，研究人员用先进的光学和铀方法相结合确定出该头盖骨的年代约为3.5万年前。虽然该头盖骨具有几个比同时期的欧洲头盖骨更原始的特征，但是它看来代表了一个从撒哈拉以南非洲迁徙到欧洲和亚洲的早期现代人。
来自莫斯科以南约400公里的俄罗斯顿河岸的Kostenki考古点的新证据显示，现代人类到达欧洲东北部的时间与他们进入欧洲西部的时间相同或更早。人们过去认为现代人类在大约4万年前迁徙到欧洲中部和西部。 Mikhail V. Anikovich和文章共同作者为在Kostenki找到了的文物提供了改进的、更老的年代，这些文物包括工具、个人饰物、雕刻的象牙等。新确定的年代为4.5万到4.2万年前，与在欧洲西部发现的文物同时，或年代更早。这些文物被认为是现代人制造的，但当地找到的唯一人化石只有一些牙齿。 Ted Goebel在一篇研究评述中讨论了这两篇报告以及Anna Olivieri发表在2006年12月15日《科学》的另一篇报告，称其为仍在形成的人类迁移故事重要的早期篇章。
报告：Late Pleistocene Human Skull from Hofmeyr, South Africa, and Modern Human Origins, F. E. Grine, et al.
报告：Early Upper Paleolithic in Eastern Europe and Implications for the Dispersal of Modern Humans, M. V. Anikovich, et al.
研究评述：The Missing Years for Modern Humans, Ted Goebel
一个性疾病病原体的基因组序列
研究人员测序了阴道毛滴虫(Trichomonas vaginalis)的基因组，这是一种常见的通过性传染的病原体，虽然可以治疗，但是它与宫颈癌、增加HIV的感染、以及早产有关。这个异常大并有许多重复的基因组也许能为该生物体如何适应泌尿生殖道提供线索，也许还能揭示可能的药物和疫苗靶标。Jane Carlton和同事报告说，阴道毛滴虫基因组的大约三分之一由重复序列和“可转座因子”组成，可转座因子指在基因组上移动的DNA序列。文章作者提出，在其历史的某个时刻，该寄生虫从肠道迁移到泌尿生殖道，那时它的遗传材料发生了巨大的扩展。更大的基因组也许导致更大的细胞，这也许给该寄生虫带来了选择优势。基因组为该寄生虫的代谢路径、以及它如何入侵宿主造成感染提供了线索。这些发现也许能为新的疗法和诊断提供切入点。文章作者说，世界范围内，阴道毛滴虫每年造成约1.7亿例感染。
报告：Draft Genome Sequence of the Sexually Transmitted Pathogen Trichomonas vaginalis, Jane M. Carlton, et al.
热带森林砍伐后保留的小片栖息地不帮助鸟类
一项长达13年的研究显示，把亚马孙森林砍伐成小块的、相互隔离的栖息地片对森林中许多当地鸟的物种强的负面作用。Goncalo Ferraz 和同事对巴西的森林片段的生物动力学项目(Biological Dynamics of Forest Fragments Project)做了大规模的实验研究，量化了地片大小与隔离程度对来自亚马逊中部的55种森林鸟类的影响。研究开始时所有23个地片都在连续的森林地带，但后来其中的11个地片被大农场地隔离开。研究方法将地片大小与隔离的作用区分开，并将不同物种的不同检测方式考虑进来。Ferraz和同事发现，地片大小对物种的数量有负面作用：较小的地片中的物种数也少。较大地片与森林的隔离通常也对物种有负面作用，但对不同种类的鸟的作用有很大的不同。这些科学家预测，“森林的进一步破坏会造成更多的物种消失以及更大的隔离作用”。
报告：A Large-Scale Deforestation Experiment: Effects of Patch Area and Isolation on Amazon Birds, Goncalo Ferraz, et al.
大花植物终于有了科
一种有最大单花的开花植物，其花的直径通常有1米，对如何将其放到植物生命之树的合适位置上，科学家曾一直面临困难。这些巨花植物的花不同寻常，它长在葡萄藤科的植物上，颜色是血红的，并具有腐肉的臭味。由于两个主要的挑战，确定该植物所属的科用了近200年的时间。它是一种寄生物，没有诸如叶子和主干等植物结构。而且它具有改变的花型，给分类带来困难。Charles C. Davis和论文共同作者报告，他们用多个分子标志确定了巨花植物rafflesiaceae属于大戟科(Euphorbiaceae),该科的植物通常有小得多的花，包括爱尔兰吊钟和一品红，该科还包括具有重要农业价值的橡胶树、蓖麻、以及树薯灌木。
科学特快简报：Floral Gigantism in Rafflesiaceae, Charles C. Davis, Maribeth Latvis, Daniel L. Nickrent, Kenneth J. Wurdack, and David A. Baum
改进汽车用的燃料电池
两项新研究为改进用于某些汽车的燃料电池的效率提出了建议。这些燃料电池通常用氢燃料和氧反应来产生电，氧在一个铂阴极还原。但是这个氧化过程缓慢的速度是一个主要的局限，而且当开车的人重复加速和刹车时，总在变化的燃料电池负荷使阴极趋于分解。 Junliang Zhang和同事现在报告说，在碳衬底上的铂粒子沉积纳米尺度的金簇，在电化学循环试验中能抑制阴极的分解。出乎意料的是，金没有极大地抑制氧降解，文章作者提出其通过提高铂的氧化电位而起作用。
在另一项研究中，Vojislav Stamenkovic和同事报告，用铂合金制造的催化剂比常规的催化剂可能更有用，因为合金催化剂更稳定也更有活性。文章作者制作了镍-铂合金的单晶表面，发现其活性是传统铂表面的10倍。
报告：Stabilization of Platinum Oxygen-Reduction Electrocatalysts Using Gold Clusters, J. Zhang, K. Sasaki, E. Sutter, and R. R. Adzic
科学特快报告： Improved Oxygen Reduction Activity on Pt3Ni(111) via Increased Surface Site Availability , Vojislav R. Stamenkovic, et al.
新的极小新海洋浮游生物
欧洲的研究人员在北部海洋浮游生物中找到一群极小的海藻。Fabrice Not和同事通过分析采集到的海水中的DNA发现了这些生物体。在研究了基因组信息后，这些研究人员在海水中检测到一些细胞，并称其为“皮浮游生物(picoplankton)”因为它们极小。这些海藻包含名为藻胆素的色素，在蓝光下产生橙色荧光。文章作者推测这些生物体是内共生体，既它们生活在其它生物体内，也许为其提供能量。
报告：Picobiliphytes: A Marine Picoplanktonic Algal Group with Unknown Affinities to Other Eukaryotes, Fabrice Not, et al.
Contents
This Week in Science
Editor summaries of this week's papers.
Science 12 January 2007: 158.
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Editorial:
Outreach Training Needed
Alan I. Leshner
Science 12 January 2007: 161.
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Editors' Choice
Highlights of the recent literature.
Science 12 January 2007: 162.
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Science Podcast
Science 12 January 2007: 257.
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NEW PRODUCTS
Science 12 January 2007: 257.
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News of the Week
STEM CELLS: Versatile Stem Cells Without the Ethical Baggage?
Constance Holden
Science 12 January 2007: 170.
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ENERGY: Consortium Wins Big Drilling Technology Contract
Eli Kintisch
Science 12 January 2007: 171.
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U.S. NATIONAL SECURITY: Head of Weapons Program Fired
Eli Kintisch
Science 12 January 2007: 171.
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CHEMISTRY: Platinum in Fuel Cells Gets a Helping Hand
Robert F. Service
Science 12 January 2007: 172.
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HUMAN GENETICS: In Asians and Whites, Gene Expression Varies by Race
Jennifer Couzin
Science 12 January 2007: 173-174.
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NUCLEAR WASTE: With Plutonium, Even Ceramics May Slump
Valerie Brown
Science 12 January 2007: 174.
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OCEAN POLICY: Panel Urges Environmental Controls on Offshore Aquaculture
Erik Stokstad
Science 12 January 2007: 175.
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ScienceScope
Science 12 January 2007: 173.
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Random Samples
Science 12 January 2007: 167.
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Newsmakers
Science 12 January 2007: 169.
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News Focus
EPIDEMIOLOGY: Agent Orange's Bitter Harvest
Richard Stone
Science 12 January 2007: 176-179.
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NEUROBIOLOGY: Fruit Fly Fight Club
Greg Miller
Science 12 January 2007: 180-182.
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AGBIOTECH: GM Technology Develops in the Developing World
Gunjan Sinha
Science 12 January 2007: 182-183.
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Letters
This Week's Letters
Science 12 January 2007: 184.
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PTSD and Vietnam Veterans
Eric Vermetten, James D. Bremner, Leigh Skelton, David Spiegel;, Dean G. Kilpatrick;, Todd C. Buckley;, B. Christopher Frueh;, Richard J. Mcnally;, Bruce P. Dohrenwend, J. Blake Turner, Nicholas A. Turse, Ben G. Adams, Karestan C. Koenen, and Randall Marshall
Science 12 January 2007: 184-187.
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Disbelievers in Evolution
Allan Mazur
Science 12 January 2007: 187.
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Corrections and Clarifications
Science 12 January 2007: 187.
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Books et al.
HISTORY OF SCIENCE: Scientia Sinesis
Thomas S. Mullaney
Science 12 January 2007: 188-189.
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SOCIOLOGY: Bringing Down the House to Add a (Nice) Room
Saskia Sassen
Science 12 January 2007: 189.
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Books Received
Science 12 January 2007: 189.
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Policy Forum
SCIENCE AND LAW: The Obvious War
Michael R. Samardzija
Science 12 January 2007: 190-191.
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Perspectives
ECOLOGY: Dipping into the Rare Biosphere
Carlos Pedrós-Alió
Science 12 January 2007: 192-193.
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ASTRONOMY: A Supernova Riddle
Douglas C. Leonard
Science 12 January 2007: 193-194.
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ANTHROPOLOGY: The Missing Years for Modern Humans
Ted Goebel
Science 12 January 2007: 194-196.
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PHYSICS: Electron Nematic Phase in a Transition Metal Oxide
Eduardo Fradkin, Steven A. Kivelson, and Vadim Oganesyan
Science 12 January 2007: 196-197.
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MICROBIOLOGY: A Proteomic Snapshot of Life at a Vent
Charles R. Fisher and Peter Girguis
Science 12 January 2007: 198-199.
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MOLECULAR BIOLOGY: Amplified Silencing
David C. Baulcombe
Science 12 January 2007: 199-200.
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Review
Proteasome-Independent Functions of Ubiquitin in Endocytosis and Signaling
Debdyuti Mukhopadhyay and Howard Riezman
Science 12 January 2007: 201-205.
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Brevia
Haploid Females in the Parasitic Wasp Nasonia vitripennis
Leo W. Beukeboom, Albert Kamping, Marina Louter, Laas P. Pijnacker, Vaishali Katju, Patrick M. Ferree, and John H. Werren
Science 12 January 2007: 206.
Although males in most Hymenoptera (bees, wasps, ants, and certain flies) are haploid and produced from unfertilized eggs, haploid females are found in a parasitic wasp.
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Research Article
Draft Genome Sequence of the Sexually Transmitted Pathogen Trichomonas vaginalis
Jane M. Carlton, Robert P. Hirt, Joana C. Silva, Arthur L. Delcher, Michael Schatz, Qi Zhao, Jennifer R. Wortman, Shelby L. Bidwell, U. Cecilia M. Alsmark, Sébastien Besteiro, Thomas Sicheritz-Ponten, Christophe J. Noel, Joel B. Dacks, Peter G. Foster, Cedric Simillion, Yves Van de Peer, Diego Miranda-Saavedra, Geoffrey J. Barton, Gareth D. Westrop, Sylke Müller, Daniele Dessi, Pier Luigi Fiori, Qinghu Ren, Ian Paulsen, Hanbang Zhang, Felix D. Bastida-Corcuera, Augusto Simoes-Barbosa, Mark T. Brown, Richard D. Hayes, Mandira Mukherjee, Cheryl Y. Okumura, Rachel Schneider, Alias J. Smith, Stepanka Vanacova, Maria Villalvazo, Brian J. Haas, Mihaela Pertea, Tamara V. Feldblyum, Terry R. Utterback, Chung-Li Shu, Kazutoyo Osoegawa, Pieter J. de Jong, Ivan Hrdy, Lenka Horvathova, Zuzana Zubacova, Pavel Dolezal, Shehre-Banoo Malik, John M. Logsdon, Jr., Katrin Henze, Arti Gupta, Ching C. Wang, Rebecca L. Dunne, Jacqueline A. Upcroft, Peter Upcroft, Owen White, Steven L. Salzberg, Petrus Tang, Cheng-Hsun Chiu, Ying-Shiung Lee, T. Martin Embley, Graham H. Coombs, Jeremy C. Mottram, Jan Tachezy, Claire M. Fraser-Liggett, and Patricia J. Johnson
Science 12 January 2007: 207-212.
A common human parasite has an unusually large and repetitive genome that contains many genes originally from bacteria and viruses.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Reports
Spectropolarimetric Diagnostics of Thermonuclear Supernova Explosions
Lifan Wang, Dietrich Baade, and Ferdinando Patat
Science 12 January 2007: 212-214.
Published online 30 November 2006 [DOI: 10.1126/science.1121656] (in Science Express Reports)
A survey of supernovae shows that brighter ones have more spherical explosions, constraining the physics of burning and improving their use as standard candles.
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Formation of a Nematic Fluid at High Fields in Sr3Ru2O7
R. A. Borzi, S. A. Grigera, J. Farrell, R. S. Perry, S. J. S. Lister, S. L. Lee, D. A. Tennant, Y. Maeno, and A. P. Mackenzie
Science 12 January 2007: 214-217.
Published online 23 November 2006 [DOI: 10.1126/science.1134796] (in Science Express Reports)
A pronounced anisotropy in resistance associated with a quantum phase transition in strontium ruthenate confirms predictions of a new state of matter--a nematic Fermi liquid.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Highly Siderophile Element Constraints on Accretion and Differentiation of the Earth-Moon System
James M. D. Day, D. Graham Pearson, and Lawrence A. Taylor
Science 12 January 2007: 217-219.
Iron-loving elements in the Moon's mantle are 5 percent as abundant as in Earth's mantle, implying that they were replenished less by accretion after the Moon's formation.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Stabilization of Platinum Oxygen-Reduction Electrocatalysts Using Gold Clusters
J. Zhang, K. Sasaki, E. Sutter, and R. R. Adzic
Science 12 January 2007: 220-222.
Nanoscale gold clusters can inhibit degradation of platinum catalysts during oxygen reduction, potentially enhancing the efficiency of fuel cells.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Early Upper Paleolithic in Eastern Europe and Implications for the Dispersal of Modern Humans
M. V. Anikovich, A. A. Sinitsyn, John F. Hoffecker, Vance T. Holliday, V. V. Popov, S. N. Lisitsyn, Steven L. Forman, G. M. Levkovskaya, G. A. Pospelova, I. E. Kuz'mina, N. D. Burova, Paul Goldberg, Richard I. Macphail, Biagio Giaccio, and N. D. Praslov
Science 12 January 2007: 223-226.
Dates from an archaeological site on the Don River, Russia, imply that modern humans occupied the central plain of eastern Europe by 45,000 years ago.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Late Pleistocene Human Skull from Hofmeyr, South Africa, and Modern Human Origins
F. E. Grine, R. M. Bailey, K. Harvati, R. P. Nathan, A. G. Morris, G. M. Henderson, I. Ribot, and A. W. G. Pike
Science 12 January 2007: 226-229.
A skull from South Africa dates to about 35,000 years ago and may represent early modern humans that emigrated from sub-Saharan Africa to populate Europe and Asia.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Regulation of Versus ß T Lymphocyte Differentiation by the Transcription Factor SOX13
Heather J. Melichar, Kavitha Narayan, Sandy D. Der, Yoshiki Hiraoka, Noemie Gardiol, Gregoire Jeannet, Werner Held, Cynthia A. Chambers, and Joonsoo Kang
Science 12 January 2007: 230-233.
A transcription factor controls the development of immune cells, supporting growth of one of the two major subsets of T cells while opposing differentiation of the other.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Systems Approach to Measuring the Binding Energy Landscapes of Transcription Factors
Sebastian J. Maerkl and Stephen R. Quake
Science 12 January 2007: 233-237.
A microfluidic method for measuring low-affinity molecular interactions characterizes transcription factor binding to DNA.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
A Large-Scale Deforestation Experiment: Effects of Patch Area and Isolation on Amazon Birds
Gonçalo Ferraz, James D. Nichols, James E. Hines, Philip C. Stouffer, Richard O. Bierregaard, Jr., and Thomas E. Lovejoy
Science 12 January 2007: 238-241.
As patches of Amazon forest get smaller, they support many fewer species of birds; as they get more isolated, bird species are differentially lost.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Distinct Populations of Primary and Secondary Effectors During RNAi in C. elegans
Julia Pak and Andrew Fire
Science 12 January 2007: 241-244.
Published online 23 November 2006 [DOI: 10.1126/science.1132839] (in Science Express Reports)
In RNA-directed gene silencing in worms, an unanticipated class of small antisense RNAs is synthesized by cellular RNA-directed RNA polymerase.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Secondary siRNAs Result from Unprimed RNA Synthesis and Form a Distinct Class
Titia Sijen, Florian A. Steiner, Karen L. Thijssen, and Ronald H. A. Plasterk
Science 12 January 2007: 244-247.
Published online 7 December 2006 [DOI: 10.1126/science.1136699] (in Science Express Reports)
In RNA-directed gene silencing in worms, an unanticipated class of small antisense RNAs is synthesized by cellular RNA-directed RNA polymerase.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Physiological Proteomics of the Uncultured Endosymbiont of Riftia pachyptila
Stephanie Markert, Cordelia Arndt, Horst Felbeck, Dörte Becher, Stefan M. Sievert, Michael Hügler, Dirk Albrecht, Julie Robidart, Shellie Bench, Robert A. Feldman, Michael Hecker, and Thomas Schweder
Science 12 January 2007: 247-250.
A proteomic survey of an endosymbiotic bacterium from a hydrothermal vent worm reveals its unusual sulfide oxidation and carbon fixation pathways.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
An H-NS-like Stealth Protein Aids Horizontal DNA Transmission in Bacteria
Marie Doyle, Maria Fookes, Al Ivens, Michael W. Mangan, John Wain, and Charles J. Dorman
Science 12 January 2007: 251-252.
A bacterial gene facilitates horizontal transfer of plasmids to other bacteria by inhibiting the deleterious effects to the recipient's fitness that would otherwise occur.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Picobiliphytes: A Marine Picoplanktonic Algal Group with Unknown Affinities to Other Eukaryotes
Fabrice Not, Klaus Valentin, Khadidja Romari, Connie Lovejoy, Ramon Massana, Kerstin Töbe, Daniel Vaulot, and Linda K. Medlin
Science 12 January 2007: 253-255.
A tiny orange eukaryote has been discovered among the plankton of northern seas.
Abstract »| Full Text »| PDF »| Supporting Online Material »|
Technical Comments
Comment on "A Common Genetic Variant Is Associated with Adult and Childhood Obesity"
Christian Dina, David Meyre, Chantal Samson, Jean Tichet, Michel Marre, Beatrice Jouret, Marie Aline Charles, Beverley Balkau, and Philippe Froguel
Science 12 January 2007: 187.
Abstract »| Full Text »| PDF »|
Comment on "A Common Genetic Variant Is Associated with Adult and Childhood Obesity"
Ruth J. F. Loos, Inês Barroso, Stephen O'Rahilly, and Nicholas J. Wareham
Science 12 January 2007: 187.
Abstract »| Full Text »| PDF »|
Comment on "A Common Genetic Variant Is Associated with Adult and Childhood Obesity"
Dieter Rosskopf, Alexa Bornhorst, Christian Rimmbach, Christian Schwahn, Alexander Kayser, Anne Krüger, Grietje Tessmann, Ingrid Geissler, Heyo K. Kroemer, and Henry Völzke
Science 12 January 2007: 187.
Abstract »| Full Text »| PDF »|
Response to Comments on "A Common Genetic Variant Is Associated with Adult and Childhood Obesity"
Alan Herbert, Norman P. Gerry, Matthew B. McQueen, Iris M. Heid, Arne Pfeufer, Thomas Illig, H.-Erich Wichmann, Thomas Meitinger, David Hunter, Frank B. Hu, Graham Colditz, Anke Hinney, Johannes Hebebrand, Kerstin Koberwitz, Xiaofeng Zhu, Richard Cooper, Kristin Ardlie, Helen Lyon, Joel N. Hirschhorn, Nan M. Laird, Marc E. Lenburg, Christoph Lange, and Michael F. Christman
Science 12 January 2007: 187.
Abstract »| Full Text »| PDF »|
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Yeast boiling DNA minipr