Table of Contents

Volume 506 Number 7487 pp131-260

13 February 2014

About the cover

A representation of hysteresis in a quantized superfluid atomtronic circuit based on an image of a trapped ring-shaped Bose–Einstein condensate (BEC). Hysteresis, a phenomenon by which the physical properties of a system depend strongly on the history of the applied perturbation, is widely exploited in electronic circuits including hard disk drives and flux-gate magnetometers and is essential to the function of radio-frequency SQUIDs (superconducting quantum interference devices). Hysteresis is also fundamental to superfluidity and has been predicted to occur in superfluid atomic-gases, such as BECs. Gretchen Campbell and colleagues now report the first direct detection of hysteresis between quantized circulation states in a circuit formed from a ring of superfluid BEC obstructed by a rotating weak link. The presence of hysteresis in this system is of importance in the emerging field of ‘atomtronics‘, in which ultracold atoms have a role analogous to that of the electrons in electronics. Controlled hysteresis in atomtronic circuits may prove to be a crucial feature for the development of practical devices. Cover: Emily Edwards.

This Week


  • Suicide watch

    Despite a high death toll, public-health efforts to combat suicide lag far behind those focused on preventing accidents and diseases such as cancer. A US initiative aims to redress the balance.

  • Number crunch

    The correct use of statistics is not just good for science — it is essential.

  • Lone wolves

    A declining island wolf population underlines the influence that humans have on nature.

World View


Seven Days

  • Seven days: 7–13 February 2014

    The week in science: Italian space head resigns; NIH teams up with big pharma; and US court rules some stem-cell treatments should be regulated as drugs.

News in Focus




Books and Arts

  • Environmental sciences: The long goodbye

    A study of Earth's declining biodiversity deftly traces patterns and processes, finds Bob Bloomfield.

    • Review of The Sixth Extinction — An Unnatural History
      Elizabeth Kolbert
  • Q&A: Acoustic archaeologist

    Rupert Till at the University of Huddersfield, UK, studies the sonic properties of caves containing prehistoric paintings. As he addresses a conference in Malta on the archaeology of sound, he talks about the hum of Stonehenge, acoustic fingerprinting and simulating primeval concerts in the dark.



  • Web design: Webcraft 101

    An eye-pleasing website can boost the appeal of a laboratory, and creating one has never been easier.

    • Roberta Kwok


  • Self-taught soft skills

    Junior researchers can learn career-boosting skills by forming their own groups, says Alexandra Lucs.

    • Alexandra Lucs

naturejobs job listings and advertising features



Brief Communications Arising



  • Cold dark matter heats up

    • Andrew Pontzen
    • Fabio Governato

    In the ΛCDM paradigm, 95% of the Universe consists of dark energy and cold dark matter, but the low-density cores of dark matter measured at the centre of galaxies are hard to explain using this model; here a review of recent work shows that the action of stars and gas can significantly alter the distribution of cold dark matter through a coupling based on rapid gravitational potential fluctuations.


  • De novo mutations in schizophrenia implicate synaptic networks

    • Menachem Fromer
    • Andrew J. Pocklington
    • David H. Kavanagh
    • Hywel J. Williams
    • Sarah Dwyer
    • Padhraig Gormley
    • Lyudmila Georgieva
    • Elliott Rees
    • Priit Palta
    • Douglas M. Ruderfer
    • Noa Carrera
    • Isla Humphreys
    • Jessica S. Johnson
    • Panos Roussos
    • Douglas D. Barker
    • Eric Banks
    • Vihra Milanova
    • Seth G. Grant
    • Eilis Hannon
    • Samuel A. Rose
    • Kimberly Chambert
    • Milind Mahajan
    • Edward M. Scolnick
    • Jennifer L. Moran
    • George Kirov
    • Aarno Palotie
    • Steven A. McCarroll
    • Peter Holmans
    • Pamela Sklar
    • Michael J. Owen
    • Shaun M. Purcell
    • Michael C. O’Donovan

    The authors report the largest family-trio exome sequencing study of schizophrenia to date; mutations are overrepresented in genes for glutamatergic synaptic proteins and also genes mutated in autism and intellectual disability, providing insights into aetiological mechanisms and pathopshyisology shared with other neurodevelopmental disorders.

  • A polygenic burden of rare disruptive mutations in schizophrenia

    • Shaun M. Purcell
    • Jennifer L. Moran
    • Menachem Fromer
    • Douglas Ruderfer
    • Nadia Solovieff
    • Panos Roussos
    • Colm O’Dushlaine
    • Kimberly Chambert
    • Sarah E. Bergen
    • Anna Kähler
    • Laramie Duncan
    • Eli Stahl
    • Giulio Genovese
    • Esperanza Fernández
    • Mark O. Collins
    • Noboru H. Komiyama
    • Jyoti S. Choudhary
    • Patrik K. E. Magnusson
    • Eric Banks
    • Khalid Shakir
    • Kiran Garimella
    • Tim Fennell
    • Mark DePristo
    • Seth G. N. Grant
    • Stephen J. Haggarty
    • Stacey Gabriel
    • Edward M. Scolnick
    • Eric S. Lander
    • Christina M. Hultman
    • Patrick F. Sullivan
    • Steven A. McCarroll
    • Pamela Sklar

    Exome sequence analysis of more than 5,000 schizophrenia cases and controls identifies a polygenic burden primarily arising from rare, disruptive mutations distributed across many genes, among which are those encoding voltage-gated calcium ion channels and the signalling complex formed by the ARC protein of the postsynaptic density; as in autism, mutations were also found in homologues of known targets of the fragile X mental retardation protein.

  • Molecular control of δ-opioid receptor signalling

    • Gustavo Fenalti
    • Patrick M. Giguere
    • Vsevolod Katritch
    • Xi-Ping Huang
    • Aaron A. Thompson
    • Vadim Cherezov
    • Bryan L. Roth
    • Raymond C. Stevens

    The 1.8 Å high-resolution X-ray crystal structure of the human δ-opioid receptor is presented, with site-directed mutagenesis and functional studies revealing a crucial role for a sodium ion in mediating allosteric control in this receptor.


  • The observable signature of late heating of the Universe during cosmic reionization

    • Anastasia Fialkov
    • Rennan Barkana
    • Eli Visbal

    The hard spectra of X-ray binaries make them ineffective at heating primordial gas, which must have resulted in a delayed and spatially uniform heating during the epoch of reionization; this means that the signature of reionization in spectra of the 21-cm transition of atomic hydrogen will produce a more complex signal than has been predicted, including a distinct minimum at less than a millikelvin.

    See also
  • Hysteresis in a quantized superfluid ‘atomtronic’ circuit

    • Stephen Eckel
    • Jeffrey G. Lee
    • Fred Jendrzejewski
    • Noel Murray
    • Charles W. Clark
    • Christopher J. Lobb
    • William D. Phillips
    • Mark Edwards
    • Gretchen K. Campbell

    Hysteresis is observed between circulation states in an ‘atomtronic’ circuit formed from a ring of superfluid Bose–Einstein condensate obstructed by a rotating weak link (a region of low atomic density), and may prove as crucial in future atomtronic devices as it has done in electronic devices.

    See also
  • Quantum error correction in a solid-state hybrid spin register

    • G. Waldherr
    • Y. Wang
    • S. Zaiser
    • M. Jamali
    • T. Schulte-Herbrüggen
    • H. Abe
    • T. Ohshima
    • J. Isoya
    • J. F. Du
    • P. Neumann
    • J. Wrachtrup

    Error correction is central to fault-tolerant quantum computation, but although various schemes have been developed in theory, there are few experimental realizations; a quantum error correction process is now reported for a single system of electron and nuclear spins residing in a diamond crystal.

  • Mosaic two-lengthscale quasicrystals

    • T. Dotera
    • T. Oshiro
    • P. Ziherl

    The unusual structures of quasicrystals, such as the 18-fold symmetry observed in polymer micelles, lack the repeating cell pattern of conventional hard crystals; here their origin is shown to be an extension of Penrose tiling with a simple, generic interparticle interaction.

  • A two-fold increase of carbon cycle sensitivity to tropical temperature variations

    • Xuhui Wang
    • Shilong Piao
    • Philippe Ciais
    • Pierre Friedlingstein
    • Ranga B. Myneni
    • Peter Cox
    • Martin Heimann
    • John Miller
    • Shushi Peng
    • Tao Wang
    • Hui Yang
    • Anping Chen

    The long-term record of atmospheric carbon dioxide growth rate shows that the sensitivity of this growth rate to tropical temperature variability has increased by a factor of about two in the past five decades, and was greater when tropical land regions experienced drier conditions, implying that moisture regulates this sensitivity.

  • Global conservation outcomes depend on marine protected areas with five key features

    • Graham J. Edgar
    • Rick D. Stuart-Smith
    • Trevor J. Willis
    • Stuart Kininmonth
    • Susan C. Baker
    • Stuart Banks
    • Neville S. Barrett
    • Mikel A. Becerro
    • Anthony T. F. Bernard
    • Just Berkhout
    • Colin D. Buxton
    • Stuart J. Campbell
    • Antonia T. Cooper
    • Marlene Davey
    • Sophie C. Edgar
    • Günter Försterra
    • David E. Galván
    • Alejo J. Irigoyen
    • David J. Kushner
    • Rodrigo Moura
    • P. Ed Parnell
    • Nick T. Shears
    • German Soler
    • Elisabeth M. A. Strain
    • Russell J. Thomson

    Marine protected areas (MPAs) are an important and increasing component of marine conservation strategy, but their effectiveness is variable and debated; now a study has assembled data from a global sample of MPAs and demonstrates that effectiveness depends on five key properties: whether any fishing is allowed, enforcement levels, age, size and degree of isolation.

    See also
  • The genome of a Late Pleistocene human from a Clovis burial site in western Montana

    • Morten Rasmussen
    • Sarah L. Anzick
    • Michael R. Waters
    • Pontus Skoglund
    • Michael DeGiorgio
    • Thomas W. Stafford Jr
    • Simon Rasmussen
    • Ida Moltke
    • Anders Albrechtsen
    • Shane M. Doyle
    • G. David Poznik
    • Valborg Gudmundsdottir
    • Rachita Yadav
    • Anna-Sapfo Malaspinas
    • Samuel Stockton White V
    • Morten E. Allentoft
    • Omar E. Cornejo
    • Kristiina Tambets
    • Anders Eriksson
    • Peter D. Heintzman
    • Monika Karmin
    • Thorfinn Sand Korneliussen
    • David J. Meltzer
    • Tracey L. Pierre
    • Jesper Stenderup
    • Lauri Saag
    • Vera M. Warmuth
    • Margarida C. Lopes
    • Ripan S. Malhi
    • Søren Brunak
    • Thomas Sicheritz-Ponten
    • Ian Barnes
    • Matthew Collins
    • Ludovic Orlando
    • Francois Balloux
    • Andrea Manica
    • Ramneek Gupta
    • Mait Metspalu
    • Carlos D. Bustamante
    • Mattias Jakobsson
    • Rasmus Nielsen
    • Eske Willerslev

    The first individual genome from the Clovis culture is presented; the origins and genetic legacy of the people who made Clovis tools have been under debate, and evidence here suggests that the individual is more closely related to all Native American populations than to any others, refuting the hypothesis that the Clovis people arrived via European (Solutrean) migration to the Americas.

    See also
  • Intranasal epidermal growth factor treatment rescues neonatal brain injury

    • Joseph Scafidi
    • Timothy R. Hammond
    • Susanna Scafidi
    • Jonathan Ritter
    • Beata Jablonska
    • Maria Roncal
    • Klara Szigeti-Buck
    • Daniel Coman
    • Yuegao Huang
    • Robert J. McCarter
    • Fahmeed Hyder
    • Tamas L. Horvath
    • Vittorio Gallo

    Diffuse white matter injury is common in very preterm infants; here, enhanced epidermal growth factor receptor signalling in oligodendrocyte precursor cells in a mouse model of such injury is shown to increase cellular and functional recovery.

  • C/EBPα poises B cells for rapid reprogramming into induced pluripotent stem cells

    • Bruno Di Stefano
    • Jose Luis Sardina
    • Chris van Oevelen
    • Samuel Collombet
    • Eric M. Kallin
    • Guillermo P. Vicent
    • Jun Lu
    • Denis Thieffry
    • Miguel Beato
    • Thomas Graf

    A pulse of C/EBPα followed by overexpression of the transcription factors Oct4, Sox2, Klf4 and Myc leads to fast and very efficient reprogramming of B cell precursors to induced pluripotent stem cells; C/EBPα facilitates transient chromatin accessibility and accelerates expression of pluripotency genes through a mechanism that involves activation of the Tet2 enzyme.

  • Leukaemogenesis induced by an activating β-catenin mutation in osteoblasts

    • Aruna Kode
    • John S. Manavalan
    • Ioanna Mosialou
    • Govind Bhagat
    • Chozha V. Rathinam
    • Na Luo
    • Hossein Khiabanian
    • Albert Lee
    • Vundavalli V. Murty
    • Richard Friedman
    • Andrea Brum
    • David Park
    • Naomi Galili
    • Siddhartha Mukherjee
    • Julie Teruya-Feldstein
    • Azra Raza
    • Raul Rabadan
    • Ellin Berman
    • Stavroula Kousteni

    A mouse model shows that osteoblast activating β-catenin mutations alone are sufficient to initiate the development of acute myeloid leukaemia acting through increased Notch signalling.

  • RNA viruses can hijack vertebrate microRNAs to suppress innate immunity

    • Derek W. Trobaugh
    • Christina L. Gardner
    • Chengqun Sun
    • Andrew D. Haddow
    • Eryu Wang
    • Elik Chapnik
    • Alexander Mildner
    • Scott C. Weaver
    • Kate D. Ryman
    • William B. Klimstra

    Here it is proposed that RNA viruses can adapt to use the antiviral properties of microRNAs to limit viral replication and suppress innate immunity in particular cell types, and this restriction can lead to exacerbation of disease severity.