Volume 517 Number 7532 pp6-116

1 January 2015


Dunes on Titan in a Cassini radar mapper image taken on 21 December 2008 (upper part of cover) resemble those in Conception Bay in the Namib desert, seen here from 283 km altitude in NASA crew image STS107-E-5380 (lower image). NASA’s Cassini spacecraft mission — still out there sending data from the Saturnian system — has revealed extensive aeolian (wind-formed) dunes on the surface of Titan, Saturn’s largest satellite. Devon Burr et al. used a high-pressure wind tunnel to simulate the thick near-surface atmosphere on Titan and, with numerical modelling of the low gravity and low sediment density, derived the wind speeds necessary to move dune sand on Titan. These speeds are significantly higher than those predicted by present models of sediment entrainment by wind that are based on wind-tunnel experiments under conditions relevant for Earth and Mars. Experimental results and theoretical work can be reconciled if the extremely low ratio of particle to fluid density on Titan is taken into account, a correction that is not required for high density ratio environments such as jets on comets. Cover: NASA/JPL-Caltech/ASI/ Johnson Space Center

This Week


  • Time for the social sciences

    Governments that want the natural sciences to deliver more for society need to show greater commitment towards the social sciences and humanities.

World View


    News in Focus


    • Science in 2015

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      From Gradzilla to coffee consumption: the research enterprise quantified for the year to come.

      • Mark Zastrow


    Books and Arts

    • Listings: Science in culture 2015

      Explore the gory glories of forensic science, grapple with Tom Stoppard's take on consciousness, learn what it takes to live on Mars, re-enter Jurassic Park, dive into a coral reef and dally with Robert Oppenheimer. Daniel Cressey reports.

      • Review of Oppenheimer, Countdown to Zero: Defeating Disease, Imagine Science Films, Forensics: The Anatomy of Crime, Emerge, Arsenic and New Medicine: Paul Ehrlich's Pioneering Research, EXPO 2015, Jurassic World, Coral Reefs: Secret Cities of the Sea, A Brief History of the Future, The Martian, The Hard Problem, Designers in Residence 2015: Migration, It's Alive! — Frankenstein on Film, Marvellous Creatures, Frida Kahlo’s Garden, Lava & The Francis Crick Institute





    • Hopes for the year ahead

      To kick off 2015, Nature's Careers section asked several young scientists — all 40 or under — about their plans for the year ahead and their wishes for the future of science.

      • Monya Baker

    naturejobs job listings and advertising features







    • 分子生物学 : Hox の5′ UTR内のRNAレギュロンはリボソームに遺伝子調節の特異性をもたらす

      • Shifeng Xue
      • Siqi Tian
      • Kotaro Fujii
      • Wipapat Kladwang
      • Rhiju Das
      • Maria Barna

      Specialized ribosomes (with a particular protein composition) carry out translation of specific transcripts; analysis of Hox mRNA translation in mice reveals that unique RNA structural elements within their 5′ UTRs, including internal ribosome entry sites and translation inhibitory elements, are responsible for this specialized mode of translation.

      See also
    • 構造生物学 : 哺乳類リアノジン受容体の構造

      • Ran Zalk
      • Oliver B. Clarke
      • Amédée des Georges
      • Robert A. Grassucci
      • Steven Reiken
      • Filippo Mancia
      • Wayne A. Hendrickson
      • Joachim Frank
      • Andrew R. Marks

      Using electron cryomicroscopy, the closed-state structure of rabbit RyR1 is determined at 4.8 Å resolution; analysis confirms that the RyR1 architecture consists of a six-transmembrane ion channel with a cytosolic α-solenoid scaffold, and suggests a mechanism for Ca2+-induced channel opening.

    • 構造生物学 : ウサギ由来リアノジン受容体RyR1のニア原子分解能での構造

      • Zhen Yan
      • Xiao-chen Bai
      • Chuangye Yan
      • Jianping Wu
      • Zhangqiang Li
      • Tian Xie
      • Wei Peng
      • Chang-cheng Yin
      • Xueming Li
      • Sjors H. W. Scheres
      • Yigong Shi
      • Nieng Yan

      Using electron cryomicroscopy, the structure of the closed-state rabbit ryanodine receptor RyR1 in complex with its modulator FKBP12 is solved at 3.8 Å; in addition to determining structural details of the ion-conducting channel domain, three previously uncharacterized domains help to reveal a molecular scaffold that allows long-range allosteric regulation of channel activities.


    • 天体物理学 : 太陽の内部温度での予想よりも高かった鉄オパシティーの測定値

      • J. E. Bailey
      • T. Nagayama
      • G. P. Loisel
      • G. A. Rochau
      • C. Blancard
      • J. Colgan
      • Ph. Cosse
      • G. Faussurier
      • C. J. Fontes
      • F. Gilleron
      • I. Golovkin
      • S. B. Hansen
      • C. A. Iglesias
      • D. P. Kilcrease
      • J. J. MacFarlane
      • R. C. Mancini
      • S. N. Nahar
      • C. Orban
      • J.-C. Pain
      • A. K. Pradhan
      • M. Sherrill
      • B. G. Wilson

      Laboratory measurements of iron opacity made under conditions similar to those inside the Sun reveal much higher opacity than predicted, helping to resolve inconsistencies within stellar models of the internal temperatures of stars.

    • 惑星科学 : タイタンの予測より大きな躍動運動のしきい値風速

      • Devon M. Burr
      • Nathan T. Bridges
      • John R. Marshall
      • James K. Smith
      • Bruce R. White
      • Joshua P. Emery

      Wind tunnel experiments designed to simulate the conditions on Saturn’s moon Titan yield threshold wind speeds for particle saltation higher than those predicted by models derived from simulations of terrestrial-planet conditions; the results can be reconciled by modifying the models to take into account the low ratio of particle density to fluid density on Titan.

    • 量子物理学 : 中性物質における量子化コンダクタンスの観測

      • Sebastian Krinner
      • David Stadler
      • Dominik Husmann
      • Jean-Philippe Brantut
      • Tilman Esslinger

      Quantized conductance in the transport of neutral atoms is observed in an optically produced channel — either a quantum point contact or a quantum wire — between two atom reservoirs; the lowest non-zero conductance value is the universal conductance quantum, the reciprocal of Planck’s constant.

    • 材料化学 : 平行配向ナノシート間の静電反発力に起因する異方的力学特性を示すヒドロゲル

      • Mingjie Liu
      • Yasuhiro Ishida
      • Yasuo Ebina
      • Takayoshi Sasaki
      • Takaaki Hikima
      • Masaki Takata
      • Takuzo Aida

      Usually materials design focuses on attractive interactions, but here a hydrogel is described whose properties are dominated by electrostatic repulsion between negatively charged titanate nanosheets embedded within it; the material, inspired by articular cartilage, deforms easily when sheared parallel to the sheets but resists compressive forces applied orthogonally.

      See also
    • 気候科学 : 最終氷期サイクルにおける大西洋深部の南北方向の強い鉛直循環

      • E. Böhm
      • J. Lippold
      • M. Gutjahr
      • M. Frank
      • P. Blaser
      • B. Antz
      • J. Fohlmeister
      • N. Frank
      • M. B. Andersen
      • M. Deininger

      Reconstruction of the Atlantic meridional overturning circulation from a highly resolved marine sedimentary record shows that a deep, vigorous overturning circulation mode has persisted for most of the last glacial cycle, dominating ocean circulation in the Atlantic, but that a shallower glacial mode prevailed during glacial maxima.

      See also
    • 分子進化学 : 古細菌の主要分岐群の出現は細菌からの遺伝子獲得に対応している

      • Shijulal Nelson-Sathi
      • Filipa L. Sousa
      • Mayo Roettger
      • Nabor Lozada-Chávez
      • Thorsten Thiergart
      • Arnold Janssen
      • David Bryant
      • Giddy Landan
      • Peter Schönheit
      • Bettina Siebers
      • James O. McInerney
      • William F. Martin

      A comparison of protein-coding genes from 134 archaeal genomes with their homologues in 1,847 bacterial genomes reveals that, during evolution, genes are transferred more often from bacteria to archaea than vice versa, and that gene influxes from bacteria can bring about the origin of major archaeal groups.

    • ウイルス学 : A型肝炎ウイルスとピコルナウイルスの起源

      • Xiangxi Wang
      • Jingshan Ren
      • Qiang Gao
      • Zhongyu Hu
      • Yao Sun
      • Xuemei Li
      • David J. Rowlands
      • Weidong Yin
      • Junzhi Wang
      • David I. Stuart
      • Zihe Rao
      • Elizabeth E. Fry

      Hepatitis A virus is a picornavirus that causes significant morbidity but remains poorly understood; this paper now provides high-resolution crystal structures of both the mature and the empty hepatitis A virus particle, which show that the three-dimensional structure resembles insect picorna-like viruses.

    • 免疫学 : ヒト細胞内ISG15はインターフェロンα/βの過剰増幅と自己炎症を防ぐ

      • Xianqin Zhang
      • Dusan Bogunovic
      • Béatrice Payelle-Brogard
      • Véronique Francois-Newton
      • Scott D. Speer
      • Chao Yuan
      • Stefano Volpi
      • Zhi Li
      • Ozden Sanal
      • Davood Mansouri
      • Ilhan Tezcan
      • Gillian I. Rice
      • Chunyuan Chen
      • Nahal Mansouri
      • Seyed Alireza Mahdaviani
      • Yuval Itan
      • Bertrand Boisson
      • Satoshi Okada
      • Lu Zeng
      • Xing Wang
      • Hui Jiang
      • Wenqiang Liu
      • Tiantian Han
      • Delin Liu
      • Tao Ma
      • Bo Wang
      • Mugen Liu
      • Jing-Yu Liu
      • Qing K. Wang
      • Dilek Yalnizoglu
      • Lilliana Radoshevich
      • Gilles Uzé
      • Philippe Gros
      • Flore Rozenberg
      • Shen-Ying Zhang
      • Emmanuelle Jouanguy
      • Jacinta Bustamante
      • Adolfo García-Sastre
      • Laurent Abel
      • Pierre Lebon
      • Luigi D. Notarangelo
      • Yanick J. Crow
      • Stéphanie Boisson-Dupuis
      • Jean-Laurent Casanova
      • Sandra Pellegrini

      ISG15 deficiency in humans leads to a failure to maintain adequate levels of USP18, triggering an increase in type I interferon production and signalling, and promoting auto-inflammatory disease.

    • 細胞生物学 : PP1–PP2Aホスファターゼの連携が有糸分裂の進行を制御する

      • Agnes Grallert
      • Elvan Boke
      • Anja Hagting
      • Ben Hodgson
      • Yvonne Connolly
      • John R. Griffiths
      • Duncan L. Smith
      • Jonathon Pines
      • Iain M. Hagan

      The activation and coordination of phosphatase activity is important during mitotic exit; here, a mitotic phosphatase relay is described in fission yeast between the two major phosphatases, PP1 and PP2A, a mode of regulation that may be a feature of signalling networks across eukaryotes.

      See also
    • 構造生物学 : フェムト秒X線パルスによって1.95 Å分解能で明らかにされた、光化学系IIの本来の構造

      • Michihiro Suga
      • Fusamichi Akita
      • Kunio Hirata
      • Go Ueno
      • Hironori Murakami
      • Yoshiki Nakajima
      • Tetsuya Shimizu
      • Keitaro Yamashita
      • Masaki Yamamoto
      • Hideo Ago
      • Jian-Ren Shen

      The radiation-damage-free structure of the photosystem II membrane protein complex, which oxidizes water into dioxygen in an oxygen evolving complex, has been determined by an X-ray free electron laser at a resolution of 1.95 Å; one of the substrate oxygen atoms in this reaction is now identified.

      See also