Volume 503 Issue 7477, 28 November 2013

The cover illustrates an oxide crystal generating electric current from incoming light. The spontaneous electrical polarization that characterizes a ferroelectric material is attractive for solar-cell applications as the positive and negative charges generated by light absorption have a natural tendency to separate, making them easier to harvest efficiently. Unfortunately most known ferroelectrics have wide electronic bandgaps � that is they absorb only higher energy photons that make up a small fraction of the solar spectrum. Ilya Grinberg and colleagues now show that a classic ferroelectric can be chemically engineered to tune the bandgap over a broad range, achieving strong absorption and photocurrent generation across the solar spectrum. (Cover by Felice Macera)

This Week

News In Focus




  • Feature |

    Three-dimensional printing can help researchers to design and build devices without breaking the bank.

    • Neil Savage
  • News |

    The Italian winners of this year's Nature mentoring awards found a way to inspire in a sometimes difficult funding environment.

    • Alison Abbott
  • Futures

  • Futures |

    Happiness on a hard drive.

    • Eric Schwitzgebel
    •  & R. Scott Bakker


    Brief Communications Arising

  • Brief Communications Arising |

    • Clinton P. Conrad
    • , Bernhard Steinberger
    •  & Trond H. Torsvik
  • News & Views

  • News & Views |

    The shifting nature of positive and negative feedbacks in a woodland region invaded by an exotic grass sheds light on the complexity of managing natural systems. See Letter p.517

    • Katharine N. Suding
  • News & Views |

    Analysis of a meteorite found in northwest Africa, prosaically named NWA 7533, indicates that it is the first sample of the regolith, or 'soil', of Mars, and is derived from the earliest Martian igneous crust yet identified. See Letter p.513

    • Harry Y. McSween
  • News & Views |

    After three decades of unsuccessful efforts to develop small molecules that neutralize the cancer-causing Ras proteins, an approach has been found that opens up fresh avenues for anticancer research. See Letter p.548

    • Gideon Bollag
    •  & Chao Zhang
  • News & Views |

    In a bacterial population, some cells stay single and motile, whereas others settle down and form chains. A study now investigates the mechanisms that determine these outcomes. See Article p.481

    • James C. W. Locke
  • News & Views |

    Detailed observations of an intermittent ultraluminous X-ray source indicate that its emission is unlikely to be powered by mass accretion onto an intermediate-mass black hole as previously thought. See Letter p.500

    • K. D. Kuntz
  • News & Views |

    Ketolide antibiotics have been found to induce a ribosomal frameshift — a change in the way that RNA is translated — in bacteria. This promotes the expression of a gene for antibiotic resistance, and may have broader implications.

    • John F. Atkins
    •  & Pavel V. Baranov
  • Articles

  • Article |

    This study shows that Bacillus subtilis switches from a solitary, motile lifestyle to a multicellular, sessile state in a random, memoryless fashion, but that the underlying gene network is buffered against its own stochastic variation to tightly time the reverse transition; thus bacteria keep track of time to force their progeny to cooperate during the earliest stage of multicellular growth.

    • Thomas M. Norman
    • , Nathan D. Lord
    • , Johan Paulsson
    •  & Richard Losick
  • Article |

    Naturally occurring genetic variation between inbred mouse strains is used as a mutagenesis strategy to investigate mechanisms responsible for the selection and function of cis-regulatory elements in macrophages; lineage-determining transcription factors are proposed to select enhancer-like regions in the genome in a collaborative fashion and facilitate the binding of signal-dependent factors.

    • S. Heinz
    • , C. E. Romanoski
    • , C. Benner
    • , K. A. Allison
    • , M. U. Kaikkonen
    • , L. D. Orozco
    •  & C. K. Glass
  • Article |

    An orally active small molecule, AdipRon, that binds to and activates both adiponectin receptors (AdipoR1 and AdipoR2) is identified; it ameliorates diabetes in mice on a high-fat diet and in genetically obese db/db mice, and if this can be extrapolated to humans, orally active agonists such as AdipoRon are a promising new approach to treat obesity-related diseases such as type 2 diabetes.

    • Miki Okada-Iwabu
    • , Toshimasa Yamauchi
    • , Masato Iwabu
    • , Teruki Honma
    • , Ken-ichi Hamagami
    • , Koichi Matsuda
    • , Mamiko Yamaguchi
    • , Hiroaki Tanabe
    • , Tomomi Kimura-Someya
    • , Mikako Shirouzu
    • , Hitomi Ogata
    • , Kumpei Tokuyama
    • , Kohjiro Ueki
    • , Tetsuo Nagano
    • , Akiko Tanaka
    • , Shigeyuki Yokoyama
    •  & Takashi Kadowaki
  • Letters

  • Letter |

    The ultraluminous X-ray source M 101 ULX-1 consists of a black hole orbiting a Wolf-Rayet star; optical spectroscopy now shows that the orbital period is 8.2 days, suggesting that the black hole has a mass in the range 5 to 30 solar masses, though the X-ray spectra are unlike what is expected from accretion onto a stellar-mass black hole—accretion must occur from captured stellar wind, which has hitherto been thought to be so inefficient that it could not power an ultraluminous source.

    • Ji-Feng Liu
    • , Joel N. Bregman
    • , Yu Bai
    • , Stephen Justham
    •  & Paul Crowther
  • Letter |

    The characteristic relaxation and dephasing times of the electronic spins in thin-film copper phthalocyanine are long enough that this common, low-cost organic semiconductor has potential for both quantum and classical information processing.

    • Marc Warner
    • , Salahud Din
    • , Igor S. Tupitsyn
    • , Gavin W. Morley
    • , A. Marshall Stoneham
    • , Jules A. Gardener
    • , Zhenlin Wu
    • , Andrew J. Fisher
    • , Sandrine Heutz
    • , Christopher W. M. Kay
    •  & Gabriel Aeppli
  • Letter |

    Most known ferroelectric photovoltaic materials have very wide electronic bandgaps (that is, they absorb only high-energy photons) but here a family of perovskite oxides is described that have tunable bandgaps, allowing their use across the whole visible-light spectrum.

    • Ilya Grinberg
    • , D. Vincent West
    • , Maria Torres
    • , Gaoyang Gou
    • , David M. Stein
    • , Liyan Wu
    • , Guannan Chen
    • , Eric M. Gallo
    • , Andrew R. Akbashev
    • , Peter K. Davies
    • , Jonathan E. Spanier
    •  & Andrew M. Rappe
  • Letter |

    Chemical analysis of the meteorite NWA 7533 indicates that it may be a Martian regolith breccia and, if so, that the crust of Mars may have formed in the first 100 million years of the planet’s history.

    • M. Humayun
    • , A. Nemchin
    • , B. Zanda
    • , R. H. Hewins
    • , M. Grange
    • , A. Kennedy
    • , J.-P. Lorand
    • , C. Göpel
    • , C. Fieni
    • , S. Pont
    •  & D. Deldicque
  • Letter |

    Plant invasions are thought to alter the ecosystem in a way that disadvantages the native species, making re-establishment after eradication difficult; here, on returning to a site at which an invasive plant altered nitrogen-mineralization levels several decades ago, mineralization is found to have returned to pre-invasion levels, although these new conditions favour new invaders over the natives.

    • Stephanie G. Yelenik
    •  & Carla M. D’Antonio
  • Letter |

    Cortical inhibitory interneurons expressing vasoactive intestinal polypeptide (VIP) are shown to specialize in suppressing the activity of other inhibitory interneurons and are activated by reinforcement signals, thus increasing the activity of excitatory neurons by releasing them from inhibition; these results reveal a cell-type-specific microcircuit that tunes cortical activity under certain behavioural conditions.

    • Hyun-Jae Pi
    • , Balázs Hangya
    • , Duda Kvitsiani
    • , Joshua I. Sanders
    • , Z. Josh Huang
    •  & Adam Kepecs
  • Letter |

    Induced pluripotent stem-cell characterization reveals phenotypical differences between humans and non-human primates (NHPs): gene expression analysis shows differences in the regulation of long interspersed element-1 (L1) transposons, and in the expression of L1-restricting genes APOBEC3B and PIWIL2, correlating with higher L1 mobility in NHPs; this indicates that L1 mobility differences may have differentially shaped the human and NHP genomes.

    • Maria C. N. Marchetto
    • , Iñigo Narvaiza
    • , Ahmet M. Denli
    • , Christopher Benner
    • , Thomas A. Lazzarini
    • , Jason L. Nathanson
    • , Apuã C. M. Paquola
    • , Keval N. Desai
    • , Roberto H. Herai
    • , Matthew D. Weitzman
    • , Gene W. Yeo
    • , Alysson R. Muotri
    •  & Fred H. Gage
  • Letter |

    The cytoplasmic DNA receptor cGAS catalyses the synthesis of the second messenger cGAMP, which in turn activates type I interferon via STING; this study shows that cGAMP is transmitted to neighbouring cells via gap junction channels and activates STING, thus inducing an antiviral state in these bystander cells independent of paracrine interferon signalling.

    • Andrea Ablasser
    • , Jonathan L. Schmid-Burgk
    • , Inga Hemmerling
    • , Gabor L. Horvath
    • , Tobias Schmidt
    • , Eicke Latz
    •  & Veit Hornung
  • Letter |

    Whole-genome sequences of two novel SARS-CoV-related bat coronaviruses, in addition to a live isolate of a bat SARS-like coronavirus, are reported; the live isolate can infect human cells using ACE2, providing the strongest evidence to date that Chinese horseshoe bats are natural reservoirs of SARS-CoV.

    • Xing-Yi Ge
    • , Jia-Lu Li
    • , Xing-Lou Yang
    • , Aleksei A. Chmura
    • , Guangjian Zhu
    • , Jonathan H. Epstein
    • , Jonna K. Mazet
    • , Ben Hu
    • , Wei Zhang
    • , Cheng Peng
    • , Yu-Ji Zhang
    • , Chu-Ming Luo
    • , Bing Tan
    • , Ning Wang
    • , Yan Zhu
    • , Gary Crameri
    • , Shu-Yi Zhang
    • , Lin-Fa Wang
    • , Peter Daszak
    •  & Zheng-Li Shi
  • Letter |

    A sub-nanometre reconstruction of a 40S complex containing eIF3 and a hepatitis C virus (HCV)-like internal ribosome entry site (IRES) shows that the IRES displaces eIF3 from the 40S and sequesters it to gain access to the 40S subunit.

    • Yaser Hashem
    • , Amedee des Georges
    • , Vidya Dhote
    • , Robert Langlois
    • , Hstau Y. Liao
    • , Robert A. Grassucci
    • , Tatyana V. Pestova
    • , Christopher U. T. Hellen
    •  & Joachim Frank
  • Letter |

    When all origins of replication are deleted from the archaeon Haloferax volcanii, homologous recombination is used to initiate DNA replication and the growth rate is accelerated.

    • Michelle Hawkins
    • , Sunir Malla
    • , Martin J. Blythe
    • , Conrad A. Nieduszynski
    •  & Thorsten Allers
  • Letter |

    Small molecules are developed that irreversibly bind to the common G12C mutant of K-Ras but not the wild-type protein; crystallographic studies reveal the formation of an allosteric pocket that is not apparent in previous Ras studies, and the small molecules shift the affinity of K-Ras to favour GDP over GTP.

    • Jonathan M. Ostrem
    • , Ulf Peters
    • , Martin L. Sos
    • , James A. Wells
    •  & Kevan M. Shokat
  • Letter |

    Structural and functional studies reveal how the bacterial flavoenzyme EncM catalyses the oxygenation–dehydrogenation dual oxidation of a highly reactive substrate, and show that EncM maintains a stable flavin oxygenating species that promotes substrate oxidation and triggers a rarely seen Favorskii-type rearrangement.

    • Robin Teufel
    • , Akimasa Miyanaga
    • , Quentin Michaudel
    • , Frederick Stull
    • , Gordon Louie
    • , Joseph P. Noel
    • , Phil S. Baran
    • , Bruce Palfey
    •  & Bradley S. Moore


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