Volume 442 Number 7099 pp109-222 (13 July 2006) 封面故事：人造神经运动装置本期封面所示为BrainGate飞行员临床试验的第一位参与者Matt Nagle。在颈部脊索损伤后，他的胳膊和腿不能动了。布朗大学神经科学系的研究人员与生物技术公司Cyberkinetics及其他三个机构的人员合作，发现与运动有关的信号可通过一个植入的BrainGate芯片从大脑向外传递，使患者能够驱动一个电脑屏幕光标，启动简单的自动装置。这种人造神经运动装置有可能为研制可以代替或恢复瘫痪患者丧失的运动功能的系统铺平道路。（Article p. 164; News and Views; News Feature; ）在这项进展之前，这种类型的工作主要是在猴子身上进行的。在最近的一例这种研究中，研究人员使这类装置的运动速度与当前的装置相比有了很大提高，从而使得研制可在临床上使用的脑机器接口的前景更加乐观。
减数分裂过程的控制中引起减数分裂发生一个缺陷的突变进行甄别过程中识别出来的。在不久前，尽管有大量分子遗传学研究工作证实了该蛋白在减数分裂中所起的中心作用，但科学家对Dmc1的生化性质却知之甚少。Matthew Neal 和 Scott Keeney对最近关于减数分裂重组的分子步骤的研究工作进行了评述，重点是Dmc1及其辅助蛋白。在减数分裂重组过程中DNA链交换的控制是一个复杂的过程，对有性生殖非常关键，而一种将生化和遗传方法结合在一起的研究方法将对染色体行为的这个方面做出解释。
GRB早期余辉开始的时间当观测到一个明亮的伽马射线暴（GRB）时，两种不同类型的光辐射在爆发之后最初几分钟内也会被看到，它们被称为“瞬发”辐射和早期余辉。GRB 050820a是去年8月20日发生的一次GRB，它为天文学家提供了回答下面这一问题的机会：“早期余辉是什么时候开始的？”答案是：它并不是像通常所假设的那样是在GRB触发的时候开始的；相反，它似乎是与根据瞬发光学和伽马射线辐射所测量出的能量释放有关的一种响应或反响。这个结果为GRB研究开辟了一个新领域，因为对脉冲能量的响应可被用来探索喷射流和周围介质的性质。
Odontogriphus omalus的身份已经搞清Odontogriphus omalus是来自加拿大寒武纪中期Burgess页岩的奇异化石中的一个明星，看起来像是一个充气床和一个咖啡研磨机之间的杂交体。它的另一魅力是其“有问题的”状态，因为原始化石不能与任何已知动物类群对应起来。现在，根据对189个新标本所做的一项研究，研究人员发现该化石来自一种无壳软体动物，以古代海床上的藻垫为食。这一重新解释的关键是，研究人员识别出了软体动物典型的一种早期形式的进食器官，被称为齿舌，它是一种像锉刀一样的硬器官，用来将藻类从岩石上剥离。这个结果为了解最重要的一个动物类群之一的早期历史打开了一扇新窗户，并使科学家能够对与寒武纪“爆炸”之前多细胞动物起源有关的其他几种谜一样的化石进行一次重新评估。
性能超过晶体电子装置的液相电子装置今天最好的电子和光电子装置是通过在一个单晶基质上进行半导体晶体生长制成的。近年来Nature上发表了100篇以上关于其他可供选择的装置的论文，这些装置是从溶液相获得的。与传统的晶体化的半导体装置相比，来自溶液的装置有很多优势，如容易制造，物理上具有灵活性，而且最为重要的是成本低。所存在的问题是，与单晶装置相比，来自溶液的装置电子性能比较差。但这种情况现在有可能改变：来自多伦多大学的一个小组报告了这样一个体系，即硫化铅的胶体量子点，它的性能实际上超过了最新的晶体装置。
大气中羟基自由基的变化羟基（OH）自由基主要决定大气的氧化能力。它对于清除影响人类健康、气候变化和作物产量的污染物很重要。人们普遍认为，空气污染的增加从长远来讲会威胁到大气的氧化功效，但关于OH趋势的数据却非常缺乏。因此，1999和2003年间在德国南部Hohenpeissenberg气象观测站所获得的一组长期测量数据非常受欢迎。这些数据表明，OH水平没有可以观测到的趋势。令人吃惊的是，鉴于这种自由基所参与的很多反应，OH的变化与太阳紫外辐射有密切的、线性的关系。
非火山地震的根源非火山地震（与由岩浆在火山下运动所产生的地震活动相似、但却发生在与任何火山活动相距很远的地方的地震活动），大约6年前首次在日本东南的南开海槽消减带被观测到，随后在卡斯卡底古陆消减带和在圣安德列斯断层下都被观测到。造成这种“新型”地震活动的机制仍然不清楚。现在，来自日本西南的地震监测结果被用来确定与非火山地震相关的低频率事件的位置。这些地震发生在板块界面上，这一证据和其他证据表明，它们以及相关的地震是由板块界面上的由流体导致的剪切滑动产生的，而不是由流体的流动直接产生的。
最喜欢酸的产烷生物微生物学家成功培养出了迄今所发现的最喜欢酸的产烷生物。新物种是在纽约州的McLean沼泽中发现的，是被称为“甲烷微生物”的一个类群中的一员。该物种喜欢在pH值为5左右的环境中生长，以前这个纪录的保持者为Methanobacterium espanolae，它的最佳pH值在5.5和6之间。虽然其他一些产烷生物能在pH值低至4.5的环境中存活，但该新物种是第一个在这样的酸性条件下表现出生长和最佳产烷性能的物种。生活在酸性土壤泥炭沼泽中的微生物是大气甲烷的重要来源，这种甲烷与全球变暖有关。
一类新的小RNA：piRNA在RNA干涉中，小RNA（siRNAs 或 miRNAs）被用来调控基因表达。它们作为特征因子，将 RISC复合物引导向互补的mRNA目标。RISC的一个主要成分是Argonaute家族的一种蛋白。现在，独立进行研究工作的两个小组发现了一类新的小RNA，它们与Argonaute家族的一个分支、即Piwi类蛋白发生相互作用。这些睾丸特有的小RNA（被称为piRNA）比以前所描述的小RNA稍长一些。piRNA功能尚未确定，但它们也许在精子的产生中扮演一个角色。
肌浆球蛋白-V的三维结构人们对细胞用来将特定成分送到正确地点的机制越来越感兴趣。运动蛋白肌浆球蛋白执行很多这样的运输功能。现在，Liu等人已经确定了肌浆球蛋白-V一种被抑制状态的三维结构：该结构显示了解决将一个分子马达从其目的地返回出发点的问题的一个新机制。当肌浆球蛋白-V没有运载货物时，它采用一种紧凑的结构，该结构与迅速作踏板运动的肌动蛋白细丝结合在一起。在另一篇论文中，Thirumurugan等人利用各种不同的方法证明，在没有货物时，肌浆球蛋白-V与货物结合的区域结合到其自身的运动区域上一个特定目标上，抑制其自己沿肌动蛋白轨迹的运动，削弱其与肌动蛋白的结合。这两篇论文揭示了细胞所采用的、将货物运输置于控制之下的巧妙方法。
ContentsEditorials
Is this the bionic man? p109
Systems that allow a brain to control a computer are inching ever closer to reality — but their most important applications may be different from those envisaged by science fiction.
doi:10.1038/442109a
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Building bridges p110
An American geneticist advocates a rapprochement with religion.
doi:10.1038/442110a
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The beautiful game p110
Punditry took a hiding in Germany.
doi:10.1038/442110b
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Research Highlights
Research highlights p112
doi:10.1038/442112a
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News
Family tragedy spotlights flu mutations p114
Human-to-human transmission raises demand for DNA data.
Declan Butler
doi:10.1038/442114a
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Genomics luminary weighs in on US faith debate p114
Top geneticist asks the God question.
Erika Check
doi:10.1038/442114b
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Snapshot: Deep-sea wonders p116
From the whimsical to the downright scary, images featuring creatures from the deep are showcased in the BP Kongsberg Underwater Image Competition being held this week at the 11th International Deep-Sea Biology Symposium, UK. Narelle Towie takes a look at some of the most striking entries.
doi:10.1038/442116a
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PS I want all the rights p118
Stakes raised in open-access debate.
Emma Marris
doi:10.1038/442118a
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City state hopes research cash will buy global status p118
Singapore to double research budget.
Ichiko Fuyuno and David Cyranoski
doi:10.1038/442118b
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Sidelines p119
doi:10.1038/442119a
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Is India's 'patent factory' squandering funds? p120
Research agency slammed for patenting everything.
K. S. Jayaraman
doi:10.1038/442120a
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News in brief p121
doi:10.1038/442121a
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Business
Giving it away p122
Charities are starting to operate like venture capitalists, putting their cash into fledgling drug companies. Virginia Gewin reports.
doi:10.1038/442122a
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In brief p123
doi:10.1038/442123a
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Market watch p123
Colin Macilwain
doi:10.1038/442123b
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News Features
Neuroprosthetics: In search of the sixth sense p125
Implants in the brain could one day help paralysed people move robotic arms and legs. But first, scientists need to work out how our brains know where our limbs are, says Alison Abbott.
doi:10.1038/442125a
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Geology: The start of the world as we know it p128
Plate tectonics has created oceans and pushed up mountain ranges. But when did the process that shapes the planet get going? Alexandra Witze joins the geologists debating the issue.
doi:10.1038/442128a
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Correspondence
Misconduct: forum should not be used to settle scores p132
Guosheng Wu
doi:10.1038/442132a
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Misconduct: China needs university ethics courses p132
Qizhi Wang
doi:10.1038/442132b
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Rushed decision on collider would limit useful options p132
Robert Aymar
doi:10.1038/442132c
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Speaking for Taiwan about colours, maps and politics p132
Michael Chen
doi:10.1038/442132d
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Commentary
Does gender matter? p133
The suggestion that women are not advancing in science because of innate inability is being taken seriously by some high-profile academics. Ben A. Barres explains what is wrong with the hypothesis.
doi:10.1038/442133a
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Books and Arts
God is bred p137
Religious belief can be viewed as an adaptation that was favoured as the human brain evolved.
Crispin Tickell reviews Six Impossible Things Before Breakfast: The Evolutionary Origins of Belief by Lewis Wolpert
doi:10.1038/442137a
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Keep it in the family p138
Svenn Torgersen reviews Genes and Behavior: Nature–Nurture Interplay Explained by Michael Rutter
doi:10.1038/442138a
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Throwaway culture p139
John Emsley reviews Made to Break: Technology and Obsolescence in America by Giles Slade
doi:10.1038/442139a
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The politics of space p139
Steven Beckwith reviews The Last of the Great Observatories: Spitzer and the Era of Faster, Better, Cheaper by George Rieke
doi:10.1038/442139b
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Science in Culture p140
PowerPoint presentations and the culture of pitch.
Martin Kemp
doi:10.1038/442140a
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News and Views
Neuroscience: Converting thoughts into action p141
There is a clear need to help people who have brain or spinal-cord damage to communicate and interact with the outside world. Progress to that end is being made with brain-implantation technology.
Stephen H. Scott
doi:10.1038/442141a
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Quantum physics: New spin on the Hall effect p143
The spin Hall effect occurs when electrons with opposite spins go their separate ways in an electric field. The phenomenon is crucial to spin-based electronics, and its electrical signal has just been spotted.
Andrew D. Kent
doi:10.1038/442143a
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Atmospheric chemistry: Radicals follow the Sun p145
Hydroxyl free radicals are part of a complex network of atmospheric chemical reactions. But a long-term study shows that their concentration can be predicted by the intensity of ultraviolet sunlight alone.
Paul O. Wennberg
doi:10.1038/442145a
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Palaeontology: A ghost with a bite p146
Witness a snail scraping microbial films from the inside of an aquarium. Go back 505 million years, and this looks to have been the way an enigmatic early animal made its living (but without the aquarium).
Stefan Bengtson
doi:10.1038/442146a
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Solid-state physics: Supersolid simulations p147
Supersolids — substances that are crystalline but also behave as free-flowing superfluids — can exist, according to quantum theory. Models now suggest a route to the clinching experimental evidence.
Dieter Jaksch
doi:10.1038/442147a
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Music: Calculated tones p149
Richard Webb
doi:10.1038/442149a
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Obituary: Raymond Davis Jr (1914–2006) p150
Father of solar neutrino detection.
James R. Distel
doi:10.1038/442150a
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Brief Communications
Quantum engineering: An atom-sorting machine p151
Laser-trapped atoms in strings can be deftly rearranged and the spacing between them precisely adjusted.
Yevhen Miroshnychenko, Wolfgang Alt, Igor Dotsenko, Leonid Förster, Mkrtych Khudaverdyan, Dieter Meschede, Dominik Schrader and Arno Rauschenbeutel
doi:10.1038/442151a
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Brief Communications Arising
Embryology: Does prepatterning occur in the mouse egg? pE3
Takashi Hiiragi, Sophie Louvet-Vallée, Davor Solter and Bernard Maro
doi:10.1038/nature04907
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Embryology: Does prepatterning occur in the mouse egg? (Reply) pE4
Berenika Plusa, Anna-Katerina Hadjantonakis, Dionne Gray, Karolina Piotrowska-Nitsche, Agnieszka Jedrusik, Virginia E. Papaioannou, David M. Glover and Magdalena Zernicka-Goetz
doi:10.1038/nature04908
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Review
Clarifying the mechanics of DNA strand exchange in meiotic recombination p153
Matthew J. Neale and Scott Keeney
doi:10.1038/nature04885
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Articles
A soft-bodied mollusc with radula from the Middle Cambrian Burgess Shale p159
Jean-Bernard Caron, Amélie Scheltema, Christoffer Schander and David Rudkin
doi:10.1038/nature04894
Abstract | Full Text | PDF (595K) | Supplementary information
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Neuronal ensemble control of prosthetic devices by a human with tetraplegia p164
Leigh R. Hochberg, Mijail D. Serruya, Gerhard M. Friehs, Jon A. Mukand, Maryam Saleh, Abraham H. Caplan, Almut Branner, David Chen, Richard D. Penn and John P. Donoghue
doi:10.1038/nature04970
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Letters
Energy input and response from prompt and early optical afterglow emission in -ray bursts p172
W. T. Vestrand, J. A. Wren, P. R. Wozniak, R. Aptekar, S. Golentskii, V. Pal'shin, T. Sakamoto, R. R. White, S. Evans, D. Casperson and E. Fenimore
doi:10.1038/nature04913
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Direct electronic measurement of the spin Hall effect p176
S. O. Valenzuela and M. Tinkham
doi:10.1038/nature04937
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Ultrasensitive solution-cast quantum dot photodetectors p180
Gerasimos Konstantatos, Ian Howard, Armin Fischer, Sjoerd Hoogland, Jason Clifford, Ethan Klem, Larissa Levina and Edward H. Sargent
doi:10.1038/nature04855
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Strong correlation between levels of tropospheric hydroxyl radicals and solar ultraviolet radiation p184
Franz Rohrer and Harald Berresheim
doi:10.1038/nature04924
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Low-frequency earthquakes in Shikoku, Japan, and their relationship to episodic tremor and slip p188
David R. Shelly, Gregory C. Beroza, Satoshi Ide and Sho Nakamula
doi:10.1038/nature04931
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Isolation of a novel acidiphilic methanogen from an acidic peat bog p192
Suzanna L. Bräuer, Hinsby Cadillo-Quiroz, Erika Yashiro, Joseph B. Yavitt and Stephen H. Zinder
doi:10.1038/nature04810
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A high-performance brain–computer interface p195
Gopal Santhanam, Stephen I. Ryu, Byron M. Yu, Afsheen Afshar and Krishna V. Shenoy
doi:10.1038/nature04968
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A germline-specific class of small RNAs binds mammalian Piwi proteins p199
Angélique Girard, Ravi Sachidanandam, Gregory J. Hannon and Michelle A. Carmell
doi:10.1038/nature04917
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A novel class of small RNAs bind to MILI protein in mouse testes p203
Alexei Aravin, Dimos Gaidatzis, Sébastien Pfeffer, Mariana Lagos-Quintana, Pablo Landgraf, Nicola Iovino, Patricia Morris, Michael J. Brownstein, Satomi Kuramochi-Miyagawa, Toru Nakano, Minchen Chien, James J. Russo, Jingyue Ju, Robert Sheridan, Chris Sander, Mihaela Zavolan and Thomas Tuschl
doi:10.1038/nature04916
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Three-dimensional structure of the myosin V inhibited state by cryoelectron tomography p208
Jun Liu, Dianne W. Taylor, Elena B. Krementsova, Kathleen M. Trybus and Kenneth A. Taylor
doi:10.1038/nature04719
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The cargo-binding domain regulates structure and activity of myosin 5 p212
Kavitha Thirumurugan, Takeshi Sakamoto, John A. Hammer, III, James R. Sellers and Peter J. Knight
doi:10.1038/nature04865
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Top of pageNaturejobs
Prospect
Prospect p217
Being a good scientist means finding a balance between efficiency and enjoyment.
Paul Smaglik
doi:10.1038/nj7099-217a
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Special Report
Physical exercise p218
The opening of the Large Hadron Collider in Europe will offer high-powered opportunities for particle physicists to decode the mysteries of the Universe. Virginia Gewin finds out more.
Virginia Gewin
doi:10.1038/nj7099-218a
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Career Views
Jim Peacock, chief scientist, Canberra, Australia p220
Jim Peacock takes helm as Australia's chief scientist.
Virginia Gewin
doi:10.1038/nj7099-220a
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Science without the red tape p220
Small Chilean centre is big on collaboration and innovation.
Gene Russo
doi:10.1038/nj7099-220b
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Bowled over (but not out) p220
Cricket games teach science lesson.
Mhairi Dupré
doi:10.1038/nj7099-220c
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Futures
The Republic of George's Island p222
One man against the elements.
Donna McMahon
doi:10.1038/442222a
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