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2007年9月6日Nature中文摘要
 BIOX.CN  来源：生命经纬    2007年09月06日
封面故事：惯性、引力与阻力
Dragging of inertial frames
当汽车加速、刹车和转弯时我们感觉到的拉力和推力是惯性在物理上的表现——
不是我们早上不想起床的那种惰性，而是在没有外力时使身体在一条直线上保持
不动或保持一定运动速度的那种惯性。“经典”惯性（一般是按照牛顿第一定律
定义的）的性质，以及根据爱因斯坦广义相对论一个旋转的物体所具有的惯性系
阻力，长期以来使物理学家为其着迷。在一篇Review Article中，Ignazio
Ciufolini 对最近根据由地球卫星所得到的测量结果在理解惯性阻力方面所取得
的进展进行了分析。封面所示为由全球引力势模型EIGEN-GL04C得出的引力异常
情况，该模型是利用来自美国国家航空航天局的GRACE探测器所得到的精确引力
数据建立的。地球转动时阻滞了空间甚至时间，从而在宏观尺度上说明了惯性系
阻力的存在。（Review Article p. 41）封面内容：: Model: GFZ Potsdam/
GRGS Toulouse, F?rste et al. 2007; graphics: A. Helm


造成6500万年前物种大灭绝的小行星来自哪里（Baptistina of fire）
An asteroid breakup 160 Myr ago as the probable source of the K/T
impactor
几个方面的证据都表明，在过去1亿年里，撞击月球和地球大气层的直径在一公
里大小的天体的长期平均撞击流量增加了两倍以上。Bottke等人通过数值模拟发
现，这一增加很可能是由小行星Baptistina的母天体的灾难性解体触发的，该天
体是在距今大约1.60亿年前在主小行星带内侧解体的。解体后所产生的碎片进入
了它们有可能撞击陆地行星的轨道。这一“小行星雨”是Chixulub小行星最有可
能的来源，后者撞击了地球，造成了距今6500万年前的白垩纪-第三纪物种大灭
绝事件。（Article p. 48; News & Views）


基因复制和损失在酵母中所发挥的作用（Double or quits）
Natural history and evolutionary principles of gene duplication in
fungi
基因复制和损失是演化创新的一个关键机制，但我们对决定该机制的演化原理却
知之甚少。SYNERGY是一种新开发出的算法，利用序列相似性及物种系统发生学
来建立一组物种中基因复制和损失的演化史。这种办法已被用于17种子囊菌（包
括常用的模型生物酿酒酵母和裂殖酵母）的基因组，来确定基因复制和损失在酵
母这个分支中所发挥的作用。研究人员所获得的发现之一是，基因复制可能会简
化一个系统，而不是使其更复杂，其作用方式是使相关通道更为专业化和模块
化。（Article p. 54）


相距1米的离子之间的量子纠缠（METRE MADE）
Entanglement of single-atom quantum bits at a distance
纠缠现象是量子信息学中一个关键概念。原子系统是量子“记忆系统”很有希望
的候选系统。这些“记忆装置”又可通过光子交换发生耦合和纠缠，为量子信息
处理器提供基础。最近，研究人员通过实验演示了相距遥远的原子团之间所发生
的纠缠现象的特征。现在，Moehring等人在两个相距1米的单个离子量子记忆系
统之间实现了纠缠。采用单个离子而不是原子团，对于随后的量子运算来说有一
定优势。（Letter p. 68）


触发固体中相变的新方法（Exciting vibrations）
Control of the electronic phase of a manganite by mode-selective
vibrational excitation
触发固体中的相变有各种不同的微妙方法：例如，可用一个光脉冲或电流来注射
能够改变一个系统的电子状态的“热”电荷。现在，Rini等人报告了一种很不相
同的方法：用太赫兹(THz)辐射来激发一种磁阻性水锰矿中某一振动模式。这一
体系具有强关联的电子，在该体系中，晶体结构即便是微小的变化也能对电子性
能和磁性能产生深远影响。被激发的震动足以使材料从一种稳定的绝缘相变成一
种亚稳定的金属相。通过对所选择的振动模式（尤其是金属氧声子）的相干操控
来进行相控制，有可能在其他复杂固体中派上用场，如用来研究Cu-O振动怎样影
响高温超导体的电子性能。（Letter p. 72）


缅甸沿海地区有发生大地震和海啸的风险（Myanmar’s tsunami hazard）
The potential for giant tsunamigenic earthquakes in the northern Bay
of Bengal
苏门答腊-安达曼地震和2004年印度洋海啸的发生，对地球科学界大多数人来说
都很突然。虽然现在人们普遍认为在中苏门答腊附近紧靠2004年地震震中东面的
地方发生另一次大地震的风险很高，但似乎人们对北部的俯冲带（在孟加拉北部
湾沿缅甸沿海地区）相对来说却不是很担心。不过，Phil Cummins提出，大地震
活动在这一地区是有可能的，而且众多脆弱的人口将面临一次相当大的地震和海
啸的风险。（Letter p. 75; News & Views）


海鳝捕食猎物的不同方式（Up in the mouth）
Raptorial jaws in the throat help moray eels swallow large prey
大多数鱼类捕获猎物的方法是：张开嘴，将猎物吸进来，然后用咽部的颌骨来处
理它们。咽部的颌骨是其第二组颌骨，是鱼鳃的骨架形成的，在喉咙的深部。不
过海鳝却有一个问题：尽管是凶猛的捕食者，但它们太长、太窄，所以一般吸猎
物的办法是行不通的。所以，它们不是将猎物向下吸到咽部的颌骨，而是这些颌
骨向前伸到最里，将猎物抓住。这也许是使得海鳝作为礁石捕食者能够成功的一
个“创新”。（Letter p. 79; News & Views）


宿主和噬菌体之间的演化合作（Phage and host in it together）
Genome-wide expression dynamics of a marine virus and host reveal
features of co-evolution
人们知道，细菌和它们的病毒（或噬菌体）之间的相互作用能导致宿主和噬菌体
之间一定程度的共同演化。通过对在感染过程中海洋藻青菌Prochlorococcus及
其T7一样的噬藻体（cyanophage）进行全基因组表达分析，研究人员对这种关系
的亲近程度有了一个整体认识。在噬藻体感染过程中，若干个宿主基因得到协调
的表达，该噬藻体则似乎能够很好地利用基因产物。这些藻青菌在海洋中普遍存
在，并且在它们自己的小环境中居支配地位。看来，宿主与噬菌体之间的演化合
作似乎有助于二者都获得成功。（Letter p. 83）


哺乳动物内耳中“端部联结”的构造（Tip-link structure revealed）
Cadherin 23 and protocadherin 15 interact to form tip-link filaments
in sensory hair cells
内耳的毛细胞之所以被这么称呼，是因为有毛一样的东西（立纤毛）从它们的顶
部表面伸出。由声音诱导的立纤毛运动，被认为是通过将立纤毛彼此连接起来的
“端部联结”（tip links）与机电传导通道耦合在一起的。现在，Kazmierczak
等人报告了哺乳动物“端部联结”的构造。它们是由钙依赖型细胞粘附蛋白家族
的两个成员cadherin 和protocadherin 15之间的相互作用形成的。有趣的是，
这些cadherins的突变引起人失聪，而且这样一个突变破坏了两个分子之间的相
互作用。（Letter p. 87）


视觉尖峰信号的准确度（Precision in vision）
Temporal precision in the neural code and the timescales of natural
vision
在哺乳动物视觉系统中，由视觉刺激激发的信号尖峰持续时间在毫秒尺度上，虽
然视觉处理本身的相关时间尺度要慢得多。因此，关于尖峰时间本身是否携带某
种形式的神经编码早就有争论。现在，在大鼠侧膝核（lateral geniculate
nucleus）（脑的一部分，是视觉信息的主要处理器）中所做的实验表明，尖峰
时间准确度对所有类别的视觉刺激并不是绝对的。相反，其准确度是与刺激的时
间尺度相对的，要对刺激构建一个准确的表述需要这种相对较高的准确度。
（Letter p. 92）


一个新颖的肿瘤抑制机制（A delicate balance）
Polo inhibits progenitor self-renewal and regulates Numb asymmetry by
phosphorylating Pon
自我更新和分异之间的平衡是干细胞和癌症生物学的基础。果蝇神经干细胞通过
非对称细胞分裂做到这一点，在非对称细胞分裂期间，影响自我更新和分异的因
素被非均等地隔离。现在，Wang等人发现，有丝分裂激酶Polo通过磷酸化Pon
（Numb的接头蛋白）调控肿瘤抑制蛋白Numb的非对称定位。Polo通过调控
Pon/Numb来起一个肿瘤抑制剂的作用。这些发现表明在细胞周期与非对称蛋白定
位之间存在一个直接的生化联系，同时也揭示了一个新颖的肿瘤抑制机制。
（Letter p. 96）


双管齐下的疫苗（Double-barrelled vaccines）
Fc receptor but not complement binding is important in antibody
protection against HIV
很多有效疫苗通过诱导中和抗体来发挥作用，这种方法是HIV疫苗的一个研究重
点。但一项新的研究表明，抗HIV抗体在以两种方式发挥作用时最有效：一种是
通过中和，即直接杀死病毒，阻止其进入T-细胞；另一种是通过杀死感染的细
胞。研究人员将保护人体不受HIV感染的一种具有中和作用的人体抗体的基因工
程版本用于一个猴子模型，发现保护作用不仅依赖于该抗体的中和活性，而且依
赖于其与促动细胞（effector cells）上的Fc受体的相互作用，该受体的作用可
能是降低被感染细胞所产生的病毒数量。这项工作说明，用能够同时利用具有中
和作用的抗体和通过巨噬细胞及细胞分裂素等实现的由细胞调控的免疫力的疫
苗，也许能够获得最好的结果。（Letter p. 101: News & Views）




----------------------
NEWS AND VIEWS
----------------------
HIV/AIDS: Allied responses pp29 - 30
The main function of neutralizing antibodies is to block viral entry
into host cells. But, for maximal protection against HIV, such
antibodies must call upon other elements of the immune system to help
with the job.
John R. Mascola
doi:10.1038/449029a
http://www.nature.com/nature/journal/v449/n7158/full/449029a.html

Solar System: Lethal billiards pp30 - 31
A huge collision in the asteroid belt 160 million years ago sent
fragments bagatelling around the inner Solar System. One piece might
have caused the mass extinction that wiped out the dinosaurs 65
million years ago.
Philippe Claeys and Steven Goderis
doi:10.1038/449030a
http://www.nature.com/nature/journal/v449/n7158/full/449030a.html

Earthquakes: Burma's fault p33
Ninad Bondre
doi:10.1038/449033a
http://www.nature.com/nature/journal/v449/n7158/full/449033a.html

Zoology: Twice bitten pp33 - 34
The toothy visage of a moray eel is a fearsome sight. The discovery
that morays can thrust a second pair of jaws out from their throat to
wolf down prey whole increases their predatory reputation still
further.
Mark W. Westneat
doi:10.1038/449033b
http://www.nature.com/nature/journal/v449/n7158/full/449033b.html

Physical oceanography: Super spin in the southern seas pp34 - 35
The southern oceans are generally considered as isolated systems, much
like their northern counterparts. But a combination of historical data
and new density profiles suggests that they may be connected on a
global scale.
Dean Roemmich
doi:10.1038/449034a
http://www.nature.com/nature/journal/v449/n7158/full/449034a.html

Cell biology: Taxi service for lipids pp35 - 37
With its role in intracellular protein transport already known, the
FAPP2 protein has now also been implicated in lipid transfer and
synthesis. What is more, these two FAPP2-mediated events seem to be
linked.
Anthony H. Futerman
doi:10.1038/449035a
http://www.nature.com/nature/journal/v449/n7158/full/449035a.html

----------------------
NEWS AND VIEWS Q&A
----------------------
Technology: Biometric recognition pp38 - 40
Whether in passports, credit cards, laptops or mobile phones,
automated methods of identifying people through their anatomical
features or behavioural traits are an increasing feature of modern
life.
Anil K. Jain
doi:10.1038/449038a
http://www.nature.com/nature/journal/v449/n7158/full/449038a.html

----------------------
REVIEWS
----------------------
Dragging of inertial frames pp41 - 47
Inertial frames of reference permeate our daily life, such as the pull
and push that is felt when a vehicle brakes or turns. These inertial
and centrifugal forces arise because of changes in velocity relative
to uniformly moving inertial frames. In the context of the theory of
general relativity, a spinning mass was predicted to 'drag' inertial
frames along with it. This paper reviews the current state of the
measurement of frame dragging using satellites orbiting Earth.
Ignazio Ciufolini
doi:10.1038/nature06071
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06071.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06071.html

----------------------
ARTICLES
----------------------
An asteroid breakup 160 Myr ago as the probable source of the K/T
impactor pp48 - 53
The impact flux from kilometre-sized bodies has increased by at least
a factor of two over the long-term average during the last ～100 Myr.
This surge probably was triggered by the catastrophic disruption of
the parent body of the asteroid Baptistina, which broke up in the
inner main asteroid belt. Fragments evolved to orbits where they could
strike the terrestrial planets.
William F. Bottke, David Vokrouhlicky and David Nesvorny
doi:10.1038/nature06070
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06070.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06070.html

Natural history and evolutionary principles of gene duplication in
fungi pp54 - 61
A new method, SYNERGY, has been developed to systematically map the
detailed evolutionary history of gene duplication and loss. This
strategy was applied to the genomes of 17 Ascomycota fungal species to
provide a comprehensive overview of gene duplication and loss in the
yeast lineage and the biological constraints that govern gene
evolution.
Ilan Wapinski, Avi Pfeffer, Nir Friedman and Aviv Regev
doi:10.1038/nature06107
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06107.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06107.html

Glycosphingolipid synthesis requires FAPP2 transfer of
glucosylceramide pp62 - 67
FAPP2 is a key component of the glycosphingolipid synthetic pathway,
mediating non-vesicular transport of glucosylceramide from its site of
synthesis at the cis-Golgi to the trans-Golgi for conversion into
complex glycosphingolipids. FAPP2 therefore has an important role in
determining the lipid composition of the plasma membrane, which is
highly enriched in glycosphingolipids.
Giovanni D'Angelo et al.
doi:10.1038/nature06097
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06097.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06097.html

----------------------
LETTERS
----------------------
Entanglement of single-atom quantum bits at a distance pp68 - 71
Entanglement between two single-ion quantum memories separated by a
metre has been achieved. The use of single ions, rather than atomic
ensembles, has distinct advantages for subsequent quantum operations:
long coherence times, enhanced stability, and ease of measurement
without ejection of the ion from the trap.
D. L. Moehring et al.
doi:10.1038/nature06118
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06118.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06118.html

Control of the electronic phase of a manganite by mode-selective
vibrational excitation pp72 - 74
Ultrafast pulses of terahertz radiation are used to excite individual
vibrational modes in a magnetoresistive manganite. In a system such as
this, with strongly correlated electrons, even subtle changes of
crystal structure can have a profound effect on material properties,
and this is indeed what they see: the activated vibration is
sufficient to drive the material from a stable insulating phase to a
metastable metallic one.
Matteo Rini et al.
doi:10.1038/nature06119
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06119.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06119.html

The potential for giant tsunamigenic earthquakes in the northern Bay
of Bengal pp75 - 78
There is a high potential for giant earthquake activity along the
coast of Myanmar. Indications that this may be the case include the
tectonic environment, historical earthquake activity, and stress and
crustal strain observations. These findings suggest that giant
earthquakes do occur off the coast of Myanmar, and that a very large
and vulnerable population is thereby exposed to a significant
earthquake and tsunami hazard.
Phil R. Cummins
doi:10.1038/nature06088
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06088.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06088.html

Raptorial jaws in the throat help moray eels swallow large prey pp79 -
82
Moray eels, despite being rapacious predators, are too long and narrow
for conventional fish suction mechanisms to work for ingesting prey.
So instead of sucking food down to the pharyngeal jaws, these jaws
project forward into the mouth cavity and seize the prey - a
remarkable innovation which may have contributed to the success of
morays as reef predators.
Rita S. Mehta and Peter C. Wainwright
doi:10.1038/nature06062
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06062.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06062.html

Genome-wide expression dynamics of a marine virus and host reveal
features of co-evolution pp83 - 86
Phages have a major impact on the evolution of their bacterial hosts.
Providing the first whole genome expression profiling of the marine
cyanobacterium Prochlorococcus and its T7-like cyanophage during lytic
infection reveals potential mechanistic features of this
co-evolutionary process.
Debbie Lindell et al.
doi:10.1038/nature06130
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06130.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06130.html

Cadherin 23 and protocadherin 15 interact to form tip-link filaments
in sensory hair cells pp87 - 91
Hair cells of the inner ear have stereocilia that protrude from their
apical surface. Sound-induced stereocilial motion is thought to be
coupled to mechanoelectrical transduction channels by means of the
'tip links' that connect stereocilia to one another. This paper
reports the composition of mammalian tip links cadherin 23 and
protocadherin 15 and show how the two molecules interact.
Interestingly, mutation of these cadherins causes deafness in humans.
Piotr Kazmierczak et al.
doi:10.1038/nature06091
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06091.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06091.html

Temporal precision in the neural code and the timescales of natural
vision pp92 - 95
In the mammalian visual system, spikes evoked by visual stimuli have
millisecond-scale timing, even though the relevant time scales of
visual processing themselves are much slower. In cat lateral
geniculate nucleus, spike timing precision is not absolute for all
classes of visual stimuli, but is relative to the time scale of the
stimulus. Further, it is demonstrated that this relatively high level
of precision is required to construct an accurate representation of
the stimulus.
Daniel A. Butts et al.
doi:10.1038/nature06105
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06105.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06105.html

Polo inhibits progenitor self-renewal and regulates Numb asymmetry by
phosphorylating Pon pp96 - 100
The mitotic kinase Polo regulates the asymmetric localization of the
tumour-suppressor protein Numb through phosphorylating Pon, the
adaptor protein for Numb, and Polo acts as a tumour-suppressor through
regulating Pon/Numb. This provides the first direct biochemical link
between the cell cycle and asymmetric protein localization machinery
and reveals a novel mechanism underlying the tumour suppressor
function of Polo.
Hongyan Wang et al.
doi:10.1038/nature06056
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06056.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06056.html

Fc receptor but not complement binding is important in antibody
protection against HIV pp101 - 104
Passively administered neutralizing antibodies have been shown to
protect macaques against challenge by the HIV/SIV chimeric SHIV. The
antiviral effects of the monoclonal antibody b12 are crucially
dependent on antibody effector mechanisms.
Ann J. Hessell et al.
doi:10.1038/nature06106
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06106.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06106.html

p53 is regulated by the lysine demethylase LSD1 pp105 - 108
LSD1 reverses methylation of p53 at lysine 370 to repress p53-mediated
transcriptional activation and apoptosis, and to prevent the
interaction of p53 with 53BP1.
Jing Huang et al.
doi:10.1038/nature06092
Abstract:
http://www.nature.com/nature/journal/v449/n7158/abs/nature06092.html
Article:
http://www.nature.com/nature/journal/v449/n7158/full/nature06092.html

 
    
 


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