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

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World View

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Seven Days

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  • Seven days: 7–13 February 2014

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News in Focus

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comment

Books and Arts

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  • Environmental sciences: The long goodbye

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  • Q&A: Acoustic archaeologist

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Careers

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  • Web design: Webcraft 101

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

    • Roberta Kwok

Columns

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    • Alexandra Lucs

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Futures

research

Brief Communications Arising

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Review

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Articles

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    • Seth G. Grant
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  • Molecular control of δ-opioid receptor signalling

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Letters

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    See also
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    See also
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    • Thorfinn Sand Korneliussen
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    • Tracey L. Pierre
    • Jesper Stenderup
    • Lauri Saag
    • Vera M. Warmuth
    • Margarida C. Lopes
    • Ripan S. Malhi
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    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

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

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

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    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

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    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.

Corrigenda

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Erratum

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