ナノテクノロジーに対する過激な反発を防ぐには、世間にこの技術がどのようなものであるか、しっかりと示す必要がある。
Small steps p.557
Violent opposition to nanotechnology should be countered with public awareness.
doi: 10.1038/488557b
Violent opposition to nanotechnology should be countered with public awareness.
doi: 10.1038/488557b
If Europe is to achieve the science-investment goals it set for the decade, it must make life easier for researchers coming from abroad.
doi: 10.1038/488557a
doi: 10.1038/488566a
doi: 10.1038/488569a
doi: 10.1038/488571a
doi: 10.1038/488565a
doi: 10.1038/488568a
doi: 10.1038/488570a
ヒッグス粒子の詳細研究へ向け、大型ハドロン衝突型加速器(LHC)に次ぐ最新施設建設への夢が膨らむが、その現実はかなり厳しい。
doi: 10.1038/488572a
メキシコでナノテクノロジー研究施設を標的にした過激行為が頻発しているが、いったいそれはなぜなのか。
doi: 10.1038/488576a
海洋の健全性を評価する指標の1つでは、世界全体の海に対する採点として100点満点の60点という値が出た。だが、1つの数字で環境状態と海が人間に与える恩恵の両方を包括できるという考え方は、議論を呼ぶかもしれない。
doi: 10.1038/488594a
多発性硬化症では、自身の免疫細胞が脳や脊髄を攻撃するようになる。しかし、免疫細胞が末梢組織から脳や脊髄に入り込む仕組みはわかっていなかった。意外にも、中継地点の1つが肺であるらしいことが今回示された。
doi: 10.1038/488595a
4300万〜3300万年前、地球の温暖な「温室」状態が終わって、氷で覆われた惑星に変わっていくのに伴い、太平洋海底では生物起源の炭酸カルシウムの堆積速度が周期的に変化していたことが明らかになった。
doi: 10.1038/488596a
超高強度のX線レーザーを使って、ダイヤモンド中でX線と可視光波を混合することが可能になった。この結果から、原子スケールで材料の微視的光学応答を調べるのが容易になるだろう。
doi: 10.1038/488598a
皮膚の細胞を形質転換して幹細胞にする過程は、大いに関心を集めているが、まだよく解明されていない。しかし、再プログラム化の最初の段階を引き起こす分子がついに明らかになった。
doi: 10.1038/488599a
今から40億年後に、アンドロメダ銀河は天の川銀河と接近遭遇すると予想される。これら2つの銀河は崩壊に向かうダンスを踊り始め、そのさらに20億年後には2つが完全に一体化するだろう。
doi: 10.1038/nature11482
ある種の抗生物質を少量投与されているマウスは体重が増え、脂肪が蓄積する。これは、腸内細菌の一部がほかの細菌よりも抗生物質の投与に耐えて生き残りやすく、消化をエネルギー供給が増える方向にシフトさせるためらしい。
doi: 10.1038/488601a
Light–matter interactions are ubiquitous, and underpin a wide range of basic research fields and applied technologies. Although optical interactions have been intensively studied, their microscopic details are often poorly understood and have so far not been directly measurable. X-ray and optical wave mixing was proposed nearly half a century ago as an atomic-scale probe of optical interactions but has not yet been observed owing to a lack of sufficiently intense X-ray sources. Here we use an X-ray laser to demonstrate X-ray and optical sum-frequency generation. The underlying nonlinearity is a reciprocal-space probe of the optically induced charges and associated microscopic fields that arise in an illuminated material. To within the experimental errors, the measured efficiency is consistent with first-principles calculations of microscopic optical polarization in diamond. The ability to probe optical interactions on the atomic scale offers new opportunities in both basic and applied areas of science.
doi: 10.1038/nature11340
Atmospheric carbon dioxide concentrations and climate are regulated on geological timescales by the balance between carbon input from volcanic and metamorphic outgassing and its removal by weathering feedbacks; these feedbacks involve the erosion of silicate rocks and organic-carbon-bearing rocks. The integrated effect of these processes is reflected in the calcium carbonate compensation depth, which is the oceanic depth at which calcium carbonate is dissolved. Here we present a carbonate accumulation record that covers the past 53 million years from a depth transect in the equatorial Pacific Ocean. The carbonate compensation depth tracks long-term ocean cooling, deepening from 3.0–3.5 kilometres during the early Cenozoic (approximately 55 million years ago) to 4.6 kilometres at present, consistent with an overall Cenozoic increase in weathering. We find large superimposed fluctuations in carbonate compensation depth during the middle and late Eocene. Using Earth system models, we identify changes in weathering and the mode of organic-carbon delivery as two key processes to explain these large-scale Eocene fluctuations of the carbonate compensation depth.
doi: 10.1038/nature11360
The ocean plays a critical role in supporting human well-being, from providing food, livelihoods and recreational opportunities to regulating the global climate. Sustainable management aimed at maintaining the flow of a broad range of benefits from the ocean requires a comprehensive and quantitative method to measure and monitor the health of coupled human–ocean systems. We created an index comprising ten diverse public goals for a healthy coupled human–ocean system and calculated the index for every coastal country. Globally, the overall index score was 60 out of 100 (range 36–86), with developed countries generally performing better than developing countries, but with notable exceptions. Only 5% of countries scored higher than 70, whereas 32% scored lower than 50. The index provides a powerful tool to raise public awareness, direct resource management, improve policy and prioritize scientific research.
doi: 10.1038/nature11397
Antibiotics administered in low doses have been widely used as growth promoters in the agricultural industry since the 1950s, yet the mechanisms for this effect are unclear. Because antimicrobial agents of different classes and varying activity are effective across several vertebrate species, we proposed that such subtherapeutic administration alters the population structure of the gut microbiome as well as its metabolic capabilities. We generated a model of adiposity by giving subtherapeutic antibiotic therapy to young mice and evaluated changes in the composition and capabilities of the gut microbiome. Administration of subtherapeutic antibiotic therapy increased adiposity in young mice and increased hormone levels related to metabolism. We observed substantial taxonomic changes in the microbiome, changes in copies of key genes involved in the metabolism of carbohydrates to short-chain fatty acids, increases in colonic short-chain fatty acid levels, and alterations in the regulation of hepatic metabolism of lipids and cholesterol. In this model, we demonstrate the alteration of early-life murine metabolic homeostasis through antibiotic manipulation.
doi: 10.1038/nature11400
doi: 10.1038/nature11408
doi: 10.1038/nature11374
doi: 10.1038/nature11370
doi: 10.1038/nature11399
doi: 10.1038/nature11310
doi: 10.1038/nature11333
doi: 10.1038/nature11323
doi: 10.1038/nature11282
doi: 10.1038/nature11308
doi: 10.1038/nature11290
doi: 10.1038/nature11337
doi: 10.1038/nature11313