科学界は、クローニングによるヒト幹細胞の作成成功に浮かれることなく、倫理的問題を率先して議論していく必要がある。
Double vision p.409
Scientists must ensure that they take the lead in the ethical debate surrounding the therapeutic use of stem cells derived from human clones.
doi: 10.1038/497409a
Scientists must ensure that they take the lead in the ethical debate surrounding the therapeutic use of stem cells derived from human clones.
doi: 10.1038/497409a
Budgetary delays exacerbate dire outlook for US research.
doi: 10.1038/497409b
It is risky to oversimplify science for the sake of a clear public-health message.
doi: 10.1038/497410a
Space telescope’s mission to find planets outside the Solar System is probably over.
doi: 10.1038/497417a
Political squabbles leave US science agencies without heads.
doi: 10.1038/497418a
Sequestration threatens records of snow and stream levels in western United States.
doi: 10.1038/497419a
Reform is in the air at the nation’s oldest research body.
doi: 10.1038/497420a
Multi-nation effort is a test of scientific diplomacy.
doi: 10.1038/497421a
Honeycomb lattices in different materials enable experiments impossible in the real thing.
doi: 10.1038/497422a
双子のボイジャー探査機が太陽系外へと到達するのを、心待ちにしている研究者がいる。
doi: 10.1038/497424a
体重超過は必ずしも寿命短縮につながらないことを示す研究成果が増えているが、一部の専門家はこれを無視しようとしている。
doi: 10.1038/497428a
ミトコンドリアでのタンパク質翻訳速度には本来的に変動が見られる。この変動が、寿命と相関していることが見いだされた。このことは、代謝的変化の長寿への影響に対して統一的な機序が働いている可能性を示唆している。
doi: 10.1038/497442a
蚊の細胞内で28°Cで増殖したデングウイルスは、極めて秩序立った構造を持っている。だが、37°Cで増殖したデングウイルスはもっと秩序性が低下した構造を持っているとわかり、ヒトの免疫系はこのウイルスを我々が以前に考えていたようなやり方で認識している訳ではないことが示唆された。
doi: 10.1038/497443a
酵素であるジアシルグリセロールキナーゼが手持ちの数少ないアミノ酸残基を使って、膜と結合するための係留索と活性部位をどのようにして形成するのかは、長らく謎とされてきた。結晶構造から、それが「親しい同僚」からのちょっとした助けによってなされることが明らかになった。
doi: 10.1038/nature12245
分子の掌性、つまりキラリティーを測定し、決定する従来の方法は、いずれも同じ理論的概念に基づいていた。今回、こうした枠組みから離れた方法が報告された。
doi: 10.1038/497446b
エアロゲルには多くの応用が考えられるが、弾性が乏しいことが一般に問題となっている。カーボンナノチューブとグラフェンの相乗的組織化によって、多機能性で超軽量、かつ極めて弾性に富んだエアロゲルが作られた。
doi: 10.1038/497448a
グアニン四重鎖のような珍しいDNA構造は、DNA複製を停止させて、細胞にとって悲惨な結果をもたらすことがある。酵素のPif1ヘリカーゼファミリーは、このような構造を効率よく解きほぐすために進化してきた。
doi: 10.1038/nature12244
Mitochondrial ribosomal proteins have been identified as longevity regulators in C. elegans and mammalian systems, their role in longevity is linked to mitonuclear protein imbalance and the mitochondrial unfolded protein response.
doi: 10.1038/nature12188
In vitro and in vivo, the yeast Pif1 helicase is able to unwind four-stranded G-quadruplex (G4) DNA efficiently and suppress the genomic instability that occurs at such structures; these G4 maintenance activities are conserved among evolutionarily diverse Pif1 family helicases, including human PIF1, demonstrating the importance of this activity throughout evolution.
doi: 10.1038/nature12149
High-resolution simulations show that dynamos can generate organized fields at high conductivity in the form of propagating dynamo waves.
doi: 10.1038/nature12177
A magnetohydrodynamic simulation of a magnetized plasma at high conductivity shows that, whereas the magnetic flux can be considered ‘frozen’ into the medium for laminar flow, in a turbulent medium the motion of the field lines can become indeterministic, leading to a breakdown in flux freezing.
doi: 10.1038/nature12128
A metamaterial is fabricated that yields a ‘left-handed’ response — characterized by a negative refractive index — to ultraviolet light incident at all angles, allowing both passive and active flat lensing of arbitrarily shaped, two-dimensional objects beyond the near field in free space.
doi: 10.1038/nature12158
Microwave spectroscopy is used to map the sign of an electric dipole Rabi frequency — which depends directly on the chirality of the molecule — onto the phase of emitted microwave radiation, thereby determining the chirality of cold gas-phase molecules.
doi: 10.1038/nature12150
In the quasibiennial oscillation, the prevailing wind direction in the tropical stratosphere switches between easterly and westerly and back with a period of about two years; now an analysis of a suite of radiosonde wind data reveals that the amplitude of this oscillation has weakened over the past six decades, most probably as a result of increased tropical upwelling in the lower stratosphere.
doi: 10.1038/nature12140
In an auditory frequency discrimination task in rats, channelrhodopsin-2-mediated stimulation of corticostriatal neurons biases decisions in the direction predicted by the frequency tuning of the stimulated neurons, whereas archaerhodopsin-3-mediated inactivation biases decisions in the opposite direction.
doi: 10.1038/nature12077
Deletion of a single gene, Taar4, in mice abolishes aversion to low concentrations of volatile amines and to the odour of predator urine, indicating that individual olfactory receptor genes can affect odour perception.
doi: 10.1038/nature12114
Sema3A, a member of the semaphorin family of proteins, is shown to regulate bone remodelling indirectly by modulating sensory nerve development in mice.
doi: 10.1038/nature12115
Herpes simplex virus 2-infected individuals are shown to have skin-tissue-resident CD8αα+ T cells that persist at the portal of virus release in genital skin and mucosa, possess oligoclonal T-cell-receptor-β CDR3 sequences that are stable over time, and express gene signatures of antiviral and cytolytic function indicative of viral-specific immune surveillance.
doi: 10.1038/nature12110
TLR4 stimulation is known to contribute to acute lung injury after administration of inactivated influenza virus; here, the synthetic TLR4 antagonist Eritoran is shown to protect mice from death after infection with a lethal dose of the virus.
doi: 10.1038/nature12118
A microRNA, miR-235, is identified that acts downstream of the insulin/insulin growth factor signalling pathway to modulate the quiescence of blast cells in Caenorhabditis elegans.
doi: 10.1038/nature12117
Lamin and emerin mutations causing cardiomyopathies are associated with an impairment in actin dynamics, resulting in aberrant nuclear translocation and downstream signalling of the transcription factor MKL1, which is pivotal for cardiac development.
doi: 10.1038/nature12105
The proteasome degrades ubiquitin-conjugated substrates; here, structural and functional insights from studies in yeast reveal that it is reconfigured during chaperone-mediated assembly.
doi: 10.1038/nature12123
Analysis of whole-genome sequence data of Icelandic individuals has revealed a rare nonsense mutation within the LGR4 gene that is strongly associated with, among other things, low bone mineral density, late onset of menarche, and increased risk of biliary tract cancer.
doi: 10.1038/nature12124
This study presents the crystal structures of three functional forms of diacylglycerol kinase, an integral membrane protein that catalyses a crucial step in oligosaccharide and lipopolysaccharide synthesis and assembly; these X-ray structures are markedly different from the only other structure available for this unique kinase that was solved using solution NMR.
doi: 10.1038/nature12179
