Volume 435 Number 7042 pp537-712封面故事：宇宙中星系生长的模拟
现代星系调查提供了数量惊人的数据，以前所未有的准确度绘制出了星系在宇宙中的位置，并且显示了它们的物理性质作为环境和宇宙时间的一个函数的分布。现在，科学家利用计算机模拟，将由这些调查所提供的关于宇宙历史的一幅幅快照组合成一个连贯的画面，来展示宇宙演化表象背后的物理过程。在研究中，科学家对2000万个星系在一个巨大的宇宙空间中的生长进行了模拟，并且证明了识别第一批明亮类星体不寻常的形成地点和最终命运是有可能的。模拟表明，大型调查很可能包括星系分布中直接反映早期宇宙中物理过程的一些特点，也许还能弄清驱动宇宙当前加速扩张的神秘的暗能量的性质。本期封面所示为暗物质在穿过所模拟的宇宙的一个薄片中的分布。
染色体间的相互影响
认为染色体彼此独立发挥作用的常见假设可能该修订了。研究人员首次发现，一个染色体上的一个遗传要素能指挥另一个染色体上的基因活性。该发现是在对原始“帮助者”T细胞分异成TH1细胞和TH2细胞的过程所做的一项研究中获得的。TH1细胞激活作为由细胞调节的免疫系统构成部分的干扰素-g；TH2细胞打开由抗体调节的免疫系统中的白介素-4及其他细胞因子。由TH2打开的白介素和细胞因子在11号染色体上；干扰素-g在10号染色体上。荧光技术证实，这两个相互配合的染色体将它们的DNA连接在一起。关于染色质在细胞核内的位置是基因活性的一个重要限制因素的证据越来越多，本研究获得的这些结果又为这一观点增添了新证据。
细胞的基因组编辑
本期Nature上报告的一项发现有可能极大地改变基因疗法领域。目前的方法是，试图通过将一个新版本的正常基因插入进细胞中来补偿缺陷基因。本期Nature报告的这一新工作，解决了一个影响在活体中对人类基因组进行有效编辑的长期未能解决的问题，所以现在，基因纠正是可以做到的了。在活体中对人类基因组进行编辑因同源重组频率低而受阻。现在，用特殊设计的“锌手指”核酸酶作为分子剪刀来在细胞内的特定序列上切割DNA，便能绕开这个问题。然后，利用新的遗传信息将断开的DNA补上。这一方法效率很高，而且又能设计几乎能以任何DNA序列为目标的“锌手指”核酸酶，这意味着人体细胞中的基因组编辑很可能成为一个重要的研究工具，并且还有潜力成为治疗疾病的一个强大手段。
物质外流是宇宙中的普遍现象
褐矮星的质量介于正常恒星和行星之间。它们的质量是如此之小（不到木星质量的70倍），以至于其内核温度太低，不能点燃氢，所以它们有时被称作“失败了的恒星”。一个正常恒星的诞生伴随着物质的累积和排出。越来越多的证据表明，褐矮星周围有小的累积（增长）盘，所以问题是，褐矮星是否也向外排出物质？Whelan等人发现，它们的确向外排出物质，而且它们的物质外流是由T Tauri恒星（像太阳一样的恒星的前身）所产生的物质外流的缩微版本。这说明，物质外流现象是普遍的，它不仅伴随恒星和褐矮星的形成，而且甚至还可能伴随行星的形成。
北极在“Younger Dryas”中的作用
大约12800年前，当地球在上个冰期至间冰期过渡期间变暖时，变暖过程却突然被中断，而中断这一过程的是向近乎完全冰期状态的一次千年尺度的回归。这一被称为“Younger Dryas”的冷间期出现的原因一直难以搞清。它曾被与“北大西洋深水”形成的速度的降低以及由于表层海水淡化而出现的海洋环流的变化联系起来。现在，研究发现，表层海水淡化所涉及的淡水的一个可能的来源，是短时间内来自北极的由冰雪融化后形成的水。
短脖子的蜥脚类动物
蜥脚类动物是每个人心中所想象的典型的恐龙形象：体形庞大，脖子长，尾巴长。这种认识也反映了这样一个观点，即它们是非专性食草动物，不同类群之间没有明显的生态差异。在“巴塔哥尼亚”晚侏罗纪（这是一个大陆分离、环境变化的时期）地层中新发现的一种短颈蜥脚类动物表明，并不是所有蜥脚类动物都是长脖子。新发现的化石说明，蜥脚类动物实际上能够迅速适应新环境。
信任感的生物学基础
我们对人类中信任感的产生所依赖的生物学基础知之甚少，但现在，对用真钱玩一种投资游戏的近200名苏黎世学生所做的一项研究，获得了一个简单得让人吃惊的发现。名为“缩宫素”（在本实验中作为鼻腔喷剂使用）的激素能使一个人更信任其他人。以前研究发现，“缩宫素”在非人类哺乳动物中调节积极的社会互动中起关键作用。本期Nature报告的这项工作预计会掀起对人类中信任感的产生所依赖的生物学基础进行研究的一个新高潮。对于患有与社会恐惧症、孤独症和反社会性格障碍等社交障碍相关的精神疾病的患者来说，该研究工作也许还有临床意义。
新型强力抗癌化合物
Bcl-2家族的蛋白是细胞程序死亡（细胞凋亡）的重要调节因子，在很多癌症中都过度表达，帮助肿瘤生长，并增强其对治疗措施的抵抗力。药物设计中的一些最新技术（包括基于NMR的筛选技术、并行合成技术和基于结构的设计技术等）被用来开发一种新的小分子Bcl-2抑制剂，名为ABT-737。它比以前描述过的任何抑制剂强度大三个数量级，可能会具有疗效。ABT-737本身就能杀死某些癌细胞，包括来自淋巴瘤和小细胞肺癌的细胞。另外，该物质还能增强其他癌细胞的化疗和放射疗法的疗效。
“微RNA”在病毒生物学中的作用
“微RNA”（MicroRNA）是一大类别的非编码小RNA，长度约为22个核苷酸，它们被认为以其他基因为目标，并调节它们的表达。它们的调节作用已在低等生物中被发现。“微RNA”存在于包括人类在内的哺乳动物中，尽管它们在高等生物中的作用尚不清楚。现在，科学家发现它们在病毒生物过程中有一个功能。SV40病毒编码几个在猴子细胞感染后期所涉及的“微RNA”。这些“微RNA”通过减少多余的抗原生产来维持病毒复制效率。有人曾提出，哺乳动物体内的抑制性RNA系统的存在是为了防卫病毒的。这个实验说明正常情况下的抗病毒通道被病毒为了自己的目的破坏掉了。
阿尔法-血红素稳定蛋白（AHSP）的晶体结构
自由阿尔法-血红素是作为一种结构不稳定的单体存在的，易于氧化和沉淀，使人易患乙型地中海贫血和其他血液病。有人早就提出，陪伴分子帮助稳定自由阿尔法-血红素，几年前，这样一种蛋白被发现，即阿尔法-血红素稳定蛋白（AHSP），该蛋白专门与阿尔法-血红素发生相互作用并稳定之。现在，科学家确定了与氧化铁（III）阿尔法-血红素结合在一起的AHSP的晶体结构，该结构显示了这一血红素集团是怎样通过一个机制受到保护的，这个机制要求阿尔法-血红素进行很大的结构重排。
本期目录：
Editorials
An auspicious victory p537
A vote by the US House of Representatives to ease restrictions on embryonic stem-cell research marks an important turning point — whether President Bush vetoes the change or not.
doi: 10.1038/435537a
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Seeds in threatened soil p537
US hostility towards Syria is undermining the stability of an important seed bank for dry areas.
doi: 10.1038/435537b
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Too much, too soon p538
How not to promote your latest research findings in the media.
doi: 10.1038/435538a
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Top of pageResearch Highlights
Research highlights p540
doi: 10.1038/435540a
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Top of pageNews
Flu in wild birds sparks fears of mutating virus p542
Experts pressure China for samples that can be analysed.
David Cyranoski
doi: 10.1038/435542a
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UK research councils claim success for open-access publishing plan p543
Papers based on funded research will be posted on free websites.
Jim Giles
doi: 10.1038/435543a
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Special report: Back in the race p544
An almost unthinkable defeat for President Bush in Congress has put embryonic stem-cell research firmly back on the US agenda. But with South Korea setting a pace the United States will still struggle to match, the field's future is fraught. Nature reports on the key political battles surrounding this issue.
Erika Check
doi: 10.1038/435544a
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Protein structures hint at the shape of things to come p547
Consortium rapidly unravels dozens of structure puzzles.
Alison Abbott
doi: 10.1038/435547a
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Sidelines p547
doi: 10.1038/435547b
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Drug giants fail to name compounds in trial database p548
Critics charge that negative results are deliberately obscured.
Meredith Wadman
doi: 10.1038/435548b
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Yeast feeds debate on prolonging life p548
Fruitflies grow older when certain foods are cut.
Carina Dennis
doi: 10.1038/nature03861
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US treasury seeks bright ideas to beat bogus dollars p549
Technology helps counterfeiters but may also hinder them.
Emma Marris
doi: 10.1038/435549a
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News in brief p550
doi: 10.1038/435550a
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Top of pageNews Features
Scientists with disabilities: Access all areas p552
Scientific research can be tricky at the best of times, but people with disabilities face additional challenges both in the lab and when dealing with data. Jessica Ebert meets the researchers who are building their own customized solutions to overcome these problems.
doi: 10.1038/435552a
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Molecular medicine: Lost in translation p556
A mysterious disease that causes children's brains to melt away is caused by errors in RNA translation. But biologists are realizing that this horrifying condition could shed light on more common problems. Claire Ainsworth reports.
doi: 10.1038/435556a
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Top of pageBusiness
More flavour up front p559
Emma Marris
doi: 10.1038/435559a
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In brief p559
doi: 10.1038/435559b
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Top of pageCorrespondence
Technology managers do their bit for world health p561
Ashley J. Stevens
doi: 10.1038/435561a
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Ampicillin threat leads to wider transgene concern p561
Gundula Azeez
doi: 10.1038/435561b
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Activists should accept mainstream view of GM p561
David T. Dennis
doi: 10.1038/435561c
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Top of pageCommentary
A fresh start for Europe's space agency p563
The European Space Agency has a strong track record and plenty of ambition to propel it into its next 30 years, says Giovanni Bignami. But key decisions must be made in the context of a new Europe.
doi: 10.1038/435563a
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Top of pageBooks and Arts
Expanding evolution p565
A broader view of inheritance puts pressure on the neo-darwinian synthesis.
Massimo Pigliucci reviews Evolution in Four Dimensions: Genetic, Epigenetic, Behavioral, and Symbolic Variation in the History of Life by Eva Jablonka and Marion J. Lamb
doi: 10.1038/435565a
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Death and taxas p566
Norman Myers reviews Insect Diversity Conservation by Michael J. Samways
doi: 10.1038/435566a
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Taking a tip from the past p567
John Carmody reviews Poison Arrows: The Amazing Story of How Prozac and Anaesthetics Were Developed From Deadly Jungle Poison Darts by Stanley Feldman
doi: 10.1038/435567a
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Top of pageEssay
Concept
The best solution p569
Optimization: this beguilingly simply idea allows biologists not only to understand current adaptations, but also to predict new designs that may yet evolve.
William J. Sutherland
doi: 10.1038/435569a
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Top of pageNews and Views
Human behaviour: Brain trust p571
As is the case with other social interactions, financial transactions depend on trust. That fact is behind ingenious experiments that explore the neurobiological underpinnings of human behaviour.
Antonio Damasio
doi: 10.1038/435571a
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Cosmology: Digitizing the Universe p572
For years, cosmologists have been racing each other to develop ever more sophisticated and realistic models of the evolution of the Universe. The competition has just become considerably stiffer.
Nickolay Y. Gnedin
doi: 10.1038/435572a
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Stem cells: The road not taken p573
Developmental 'road maps' chart the steps from simple cells to mature, specialized cells. A newly discovered variety of blood-cell progenitor doesn't fit into the accepted blood map, but should that map be redrawn?
Hanno Hock and Stuart H. Orkin
doi: 10.1038/435573a
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Molecular electronics: Charged with manipulation p575
The ability to control charge transport through individual molecules sandwiched between electrodes could lead to further miniaturization of electronics. A better understanding of how such junctions work is crucial.
Mark Ratner
doi: 10.1038/435575a
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50 and 100 years ago p576
doi: 10.1038/435576a
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Gene therapy: The moving finger p577
DNA-cleaving enzymes trigger a repair process that can now be harnessed to correct mutations in the human genome in vitro. This represents another step towards gene-correction strategies for treating human disease.
Katherine A. High
doi: 10.1038/435577a
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Analytical chemistry: The Renaissance palette p577
Richard Webb
doi: 10.1038/435577b
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Gene regulation: Kissing chromosomes p579
A three-dimensional examination of gene regulation suggests that portions from different chromosomes 'communicate' with each other, and bring related genes together in the nucleus to coordinate their expression.
Dimitris Kioussis
doi: 10.1038/435579a
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Top of pageBrief Communications
Extraterrestrial meteors: A martian meteor and its parent comet p581
An image of an extraterrestrial meteor was captured as a strange streak in the sky over Mars last year.
Franck Selsis, Mark T. Lemmon, Jérémie Vaubaillon and James F. Bell, III
doi: 10.1038/435581a
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Top of pageInsight: Autoimmunity - Free access
Produced with support from:
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Insight: Autoimmunity
Autoimmunity p583
Elaine Bell and Lucy Bird
doi: 10.1038/435583a
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Paths to understanding the genetic basis of autoimmune disease p584
John D. Rioux and Abul K. Abbas
doi: 10.1038/nature03723
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Cellular and genetic mechanisms of self tolerance and autoimmunity p590
Christopher C. Goodnow, Jonathon Sprent, Barbara Fazekas de St Groth and Carola G. Vinuesa
doi: 10.1038/nature03724
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Regulation of immunity by self-reactive T cells p598
Mitchell Kronenberg and Alexander Rudensky
doi: 10.1038/nature03725
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An array of possibilities for the study of autoimmunity p605
C. Garrison Fathman, Luis Soares, Steven M. Chan and Paul J. Utz
doi: 10.1038/nature03726
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Design of effective immunotherapy for human autoimmunity p612
Marc Feldmann and Lawrence Steinman
doi: 10.1038/nature03727
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Treatment of severe autoimmune disease by stem-cell transplantation p620
Megan Sykes and Boris Nikolic
doi: 10.1038/nature03728
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Top of pageArticles
Simulations of the formation, evolution and clustering of galaxies and quasars p629
Volker Springel, Simon D. M. White, Adrian Jenkins, Carlos S. Frenk, Naoki Yoshida, Liang Gao, Julio Navarro, Robert Thacker, Darren Croton, John Helly, John A. Peacock, Shaun Cole, Peter Thomas, Hugh Couchman, August Evrard, J?rg Colberg and Frazer Pearce
doi: 10.1038/nature03597
Abstract | Full Text | PDF (442K) | Supplementary information
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Interchromosomal associations between alternatively expressed loci p637
Charalampos G. Spilianakis, Maria D. Lalioti, Terrence Town, Gap Ryol Lee and Richard A. Flavell
doi: 10.1038/nature03574
Abstract | Full Text | PDF (607K) | Supplementary information
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Highly efficient endogenous human gene correction using designed zinc-finger nucleases p646
Fyodor D. Urnov, Jeffrey C. Miller, Ya-Li Lee, Christian M. Beausejour, Jeremy M. Rock, Sheldon Augustus, Andrew C. Jamieson, Matthew H. Porteus, Philip D. Gregory and Michael C. Holmes
doi: 10.1038/nature03556
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Top of pageLetters
A resolved outflow of matter from a brown dwarf p652
Emma T. Whelan, Thomas P. Ray, Francesca Bacciotti, Antonella Natta, Leonardo Testi and Sofia Randich
doi: 10.1038/nature03598
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Ultrafast non-thermal control of magnetization by instantaneous photomagnetic pulses p655
A. V. Kimel, A. Kirilyuk, P. A. Usachev, R. V. Pisarev, A. M. Balbashov and Th. Rasing
doi: 10.1038/nature03564
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Field regulation of single-molecule conductivity by a charged surface atom p658
Paul G. Piva, Gino A. DiLabio, Jason L. Pitters, Janik Zikovsky, Moh'd Rezeq, Stanislav Dogel, Werner A. Hofer and Robert A. Wolkow
doi: 10.1038/nature03563
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Arctic freshwater forcing of the Younger Dryas cold reversal p662
Lev Tarasov and W.R. Peltier
doi: 10.1038/nature03617
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Seismological constraints on a possible plume root at the core?mantle boundary p666
Sebastian Rost, Edward J. Garnero, Quentin Williams and Michael Manga
doi: 10.1038/nature03620
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Discovery of a short-necked sauropod dinosaur from the Late Jurassic period of Patagonia p670
Oliver W. M. Rauhut, Kristian Remes, Regina Fechner, Gerardo Cladera and Pablo Puerta
doi: 10.1038/nature03623
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Oxytocin increases trust in humans p673
Michael Kosfeld, Markus Heinrichs, Paul J. Zak, Urs Fischbacher and Ernst Fehr
doi: 10.1038/nature03701
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An inhibitor of Bcl-2 family proteins induces regression of solid tumours p677
Tilman Oltersdorf, Steven W. Elmore, Alexander R. Shoemaker, Robert C. Armstrong, David J. Augeri, Barbara A. Belli, Milan Bruncko, Thomas L. Deckwerth, Jurgen Dinges, Philip J. Hajduk, Mary K. Joseph, Shinichi Kitada, Stanley J. Korsmeyer, Aaron R. Kunzer, Anthony Letai, Chi Li, Michael J. Mitten, David G. Nettesheim, ShiChung Ng, Paul M. Nimmer, Jacqueline M. O'Connor, Anatol Oleksijew, Andrew M. Petros, John C. Reed, Wang Shen, Stephen K. Tahir, Craig B. Thompson, Kevin J. Tomaselli, Baole Wang, Michael D. Wendt, Haichao Zhang, Stephen W. Fesik and Saul H. Rosenberg
doi: 10.1038/nature03579
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SV40-encoded microRNAs regulate viral gene expression and reduce susceptibility to cytotoxic T cells p682
Christopher S. Sullivan, Adam T. Grundhoff, Satvir Tevethia, James M. Pipas and Don Ganem
doi: 10.1038/nature03576
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Insights into E3 ligase activity revealed by a SUMO?RanGAP1?Ubc9?Nup358 complex p687
David Reverter and Christopher D. Lima
doi: 10.1038/nature03588
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Structural basis for nuclear import complex dissociation by RanGTP p693
Soo Jae Lee, Yoshiyuki Matsuura, Sai Man Liu and Murray Stewart
doi: 10.1038/nature03578
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Structure of oxidized -haemoglobin bound to AHSP reveals a protective mechanism for haem p697
Liang Feng, Suiping Zhou, Lichuan Gu, David A. Gell, Joel P. Mackay, Mitchell J. Weiss, Andrew J. Gow and Yigong Shi
doi: 10.1038/nature03609
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Structural characterization of the molecular platform for type III secretion system assembly p702
Calvin K. Yip, Tyler G. Kimbrough, Heather B. Felise, Marija Vuckovic, Nikhil A. Thomas, Richard A. Pfuetzner, Elizabeth A. Frey, B. Brett Finlay, Samuel I. Miller and Natalie C. J. Strynadka
doi: 10.1038/nature03554
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Top of pageNaturejobs
Prospect
Making a move on mobility p709
Grass roots organization seeks more mobility data for Europe
Paul Smaglik
doi: 10.1038/nj7042-709a
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Top of pageFutures
Dial M for middleware p712
Dirty work down on the Pharm.
David Hall
doi: 10.1038/435712a
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