WWW.NATURE.COM/NATURE
This press release is copyright Nature.
VOL.452 NO.7188 DATED 10 APRIL 2008
This press release contains:
· Summaries of newsworthy papers:
Atmospheric chemistry: Tracing gases over the pristine Amazon forest
Nanotechnology: Extraordinary light
Cell biology: New mode of pathogen attack revealed?
Materials: A new route to ferroelectricity
Heat flow: A counterintuitive phenomenon
And finally… Should schools close if H5N1 strikes?
· Mention of papers to be published at the same time with the same embargo
· Geographical listing of authors
Editorial contacts: While the best contacts for stories will always be the authors themselves, in some cases the Nature editor who handled the paper will be available for comment if an author is unobtainable. Editors are contactable via Ruth Francis on +44 20 7843 4562. Feel free to get in touch with Nature's press contacts in London, Washington and Tokyo (as listed at the end of this release) with any general editorial inquiry.
Warning: This document, and the Nature papers to which it refers, may contain information that is price sensitive (as legally defined, for example, in the UK Criminal Justice Act 1993 Part V) with respect to publicly quoted companies. Anyone dealing in securities using information contained in this document or in advanced copies of Nature’s content may be guilty of insider trading under the US Securities Exchange Act of 1934.
The Nature journals press site is at http://press.nature.com
· PDFs for the Articles, Letters, Progress articles, Review articles, Insights and Brief Communications in this issue will be available on the Nature journals press site from 1400 London time / 0900 US Eastern time on the Friday before publication.
· PDFs of News & Views, News Features, Correspondence and Commentaries will be available from 1400 London time / 0900 US Eastern time on the Monday before publication
PICTURES: While we are happy for images from Nature to be reproduced for the purposes of contemporaneous news reporting, you must also seek permission from the copyright holder (if named) or author of the research paper in question (if not).
HYPE: We take great care not to hype the papers mentioned on our press releases, but are sometimes accused of doing so. If you ever consider that a story has been hyped, please do not hesitate to contact us at [email protected], citing the specific example.
PLEASE CITE NATURE AND OUR WEBSITE www.nature.com/nature AS THE SOURCE OF THE FOLLOWING ITEMS. IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO http://www.nature.com/nature
[1] Atmospheric chemistry: Tracing gases over the pristine Amazon forest (pp 737-740; N&V)
Tropical rainforests release huge amounts of volatile organic compounds such as isoprene, which are thought to be important for attracting pollinators and repelling herbivores, for example. However, these compounds are oxidized within hours by the atmosphere’s ‘detergent’ — hydroxyl radicals produced by the action of solar ultraviolet on ozone. A paper in this week’s Nature shows how the biosphere itself unexpectedly sustains this oxidation capacity of the atmosphere.
Jos Lelieveld and colleagues measured atmospheric trace gases from an aircraft over the tropical Atlantic Ocean and the pristine Amazon forests of Suriname and the nearby Guyanas. They found high concentrations of hydroxyl radicals there, when these would be presumed to be depleted by reaction with the rainforest’s volatile emissions.
The authors suggest that the natural oxidation of the forest’s biogenic compounds actually enables the atmosphere’s hydroxyl radicals to be recycled. Their results illustrate the remarkable balance that the biosphere maintains with its atmospheric environment.
CONTACT
Jos Lelieveld (Max Planck Institute for Chemistry, Mainz, Germany)
Tel: +49 6131 305458; E-mail: [email protected]
Alex Guenther (National Center for Atmospheric Research, Boulder, CO, USA) N&V author
Tel: +1 303 497 1447; E-mail: [email protected]
[2] Nanotechnology: Extraordinary light (pp 728-731)
Light transmitted through a metal film perforated with apertures smaller than its wavelength behaves in a surprising way — much more is transmitted than would be expected for such small openings. A paper in this week’s Nature offers an explanation.
It is believed that so-called surface plasmons — electronic excitations in a metal film — help in the transmission of light under these circumstances. Haitao Liu and Philippe Lalanne have put together a detailed microscopic picture of waves scattering at the subwavelength holes. They use this as the basis for their proposed mechanistic explanation of the phenomenon, which takes into account surface plasmon modes as well as other electromagnetic fields.
The authors suggest that their new model, which accurately predicts various features in the transmission spectra, could be used as a basis for the design of nano-optics devices.
CONTACT
Philippe Lalanne (Ecole Polytechnique Laboratoire Charles Fabry, Palaiseau, France)
Tel: +33 16 453 3282; E-mail: [email protected]
[3] Cell biology: New mode of pathogen attack revealed? (pp 755-758)
Researchers studying a bacterium that infects many different plant species report in this week’s Nature that it does so using a previously unseen mode of action. What’s more, the mechanism used by this pathogen to attack plants may also aid the search for a new class of anti-cancer drugs in humans.
The bacterium, called Pseudomonas syringae pv. syringae, causes a wide range of plant diseases, such as brown spot disease in beans. Robert Dudler and colleagues have now identified one molecule, or ‘virulence factor’, that increases virulence, and have shown that the mechanism by which it causes disease is a newly discovered one.
The virulence factor, called SylA, enters plant host cells and inhibits a protein structure called the proteasome, usually responsible for breaking down other, unwanted proteins. Notably, it also has this effect in human cells, and SylA has previously been shown to shrink certain cancers, meaning that this and similar molecules might be developed as new cancer therapies.
CONTACT
Robert Dudler (University of Zurich, Switzerland)
Tel: +41 44 634 82 52; E-mail: [email protected]
[4] Materials: A new route to ferroelectricity (pp 732-736)
Scientists have discovered a totally unexpected type of electronic behaviour in artificially layered structures known as superlattices. An atomic rearrangement occurs at the interfaces within the lattice, leading to an unusual, ‘improper’ ferroelectric effect. The findings indicate a route to create materials with both ferroelectric and magnetic properties, with implications for the future of electronic devices.
In the field of ‘oxide electronics’, artificially layered structures or lattices based on thin films of complex oxides are designed to obtain technologically interesting properties. These properties make them suitable for electronic components such as tunable capacitors and memory cells.
In this week’s Nature, Philippe Ghosez and colleagues study artificial superlattices made from two materials — lead titanate (a ferroelectric) and strontium titanate (a dielectric). By using interfacial engineering at the nanoscale, they demonstrate the ability to introduce new material properties created by a form of interface coupling within the lattice. The new system has a very large dielectric constant that, in contrast to conventional ferroelectricity, is fairly temperature independent.
The authors suggest that this type of interfacial engineering is a promising route for producing improved materials with magneto-electric applications.
CONTACT
Philippe Ghosez (Université de Liège, Belgium)
Tel: +32 4 366 3611; E-mail: [email protected]
[5] Heat flow: A counterintuitive phenomenon (pp 724-727; N&V)
Heat flow between a large ‘bath’ and a smaller system brings each gradually closer to the same temperature while the molecular disorder, or entropy, of the system increases — in just the way you would expect from the second law of thermodynamics. But a paper in this week’s Nature reveals that this behaviour alters in a purely quantum mechanical setting.
Measurements of two-level quantum systems can cause their relaxation either to speed up (known as the anti-Zeno effect) or to slow down (the Zeno effect). Goren Gordon and colleagues find that the former effect is associated with a decrease in the entropy and temperature of the system and the bath, whereas the latter effect results in heating and higher entropy. This behaviour is surprising because it runs contrary to standard thermodynamical rules.
From a practical viewpoint, these anomalies may offer the possibility of very fast control of heat and entropy in quantum systems — allowing cooling and purification over an interval much shorter than the time needed for thermal equilibration or for a feedback control loop.
CONTACT
Gershon Kurizki (Weizmann Institute of Science, Rehovot, Israel)
Tel: +972 8 934 2365; Mobile: +972 525 110 090 E-mail: [email protected]
Marlan Scully (Texas A&M University, College Station TX, USA) N&V author
Tel: +1 979 845 1534; E-mail:[email protected]
Kimberly Chapin (Texas A&M University, College Station TX, USA) N&V author
Tel: +1 979 845 1534; E-mail: [email protected]
[6] And finally… Should schools close if H5N1 strikes? (pp 750-754)
School closures could help to slow the spread of a pandemic flu strain, but is unlikely to have a dramatic impact, according to a study published in this week’s Nature. Shutting down schools in the event of new flu pandemic could cut the overall number of cases by around 15%, the research suggests. The main effect would be to slow and flatten the outbreak, so the numbers becoming ill in the worst week of the outbreak might be up to 40% less, reducing peak demand on healthcare systems.
Epidemiologists led by Simon Cauchemez made their predictions by comparing surveillance records of flu-like disease in France with the timing of the French school holidays. They discovered that school holidays reduce normal seasonal flu transmission among children by almost a quarter, but have a very limited effect on spread among adults.
By extrapolating from these figures, the researchers conclude that school closures — which were implemented in the United States during the 1918 flu pandemic, for example — will have only a modest restraining effect on any future outbreak of severe flu, such as a mutated H5N1 strain. What’s more, they add that the effectiveness of this strategy could dwindle during a prolonged school closure, because children might resume social contact outside school.
CONTACT
Simon Cauchemez (Imperial College London, UK)
Tel: +44 20 7594 1933; E-mail: [email protected]
Neil Ferguson (Imperial College London, UK)
Tel: +44 20 7594 3296; Mobile: +44 7974 921856; E-mail: [email protected]
ALSO IN THIS ISSUE…
[7] Clathrin is a key regulator of basolateral polarity (pp 719-723; N&V)
[8] Endothelins are vascular-derived axonal guidance cues for developing sympathetic neurons (pp 759-763)
[9] The earliest thymic progenitors for T cells possess myeloid lineage potential (pp 764-767; N&V)
[10] Adult T-cell progenitors retain myeloid potential (pp 768-772; N&V)
ADVANCE ONLINE PUBLICATION
***These papers will be published electronically on Nature's website on 9 April at 1800 London time / 1300 US Eastern time (which is also when the embargo lifts) as part of our AOP (ahead of print) programme. Although we have included them on this release to avoid multiple mailings they will not appear in print on 10 April, but at a later date. ***
[11] Crystal structure of the l repressor and a model for pairwise cooperative operator binding
DOI: 10.1038/nature06831
[12] Upper intestinal lipids trigger a gut–brain–liver axis to regulate glucose production
DOI: 10.1038/nature06852
GEOGRAPHICAL LISTING OF AUTHORS…
The following list of places refers to the whereabouts of authors on the papers numbered in this release. For example, London: 4 - this means that on paper number four, there will be at least one author affiliated to an institute or company in London. The listing may be for an author's main affiliation, or for a place where they are working temporarily. Please see the PDF of the paper for full details.
BELGIUM
Liege: 4
CANADA:
Edmonton: 12
Toronto: 12
CHINA
Tianjin: 2
FRANCE
Palaiseau : 2
Paris : 6
GERMANY
Dortmund: 3
Essen: 3
Garching: 3
Martinsried: 3
Potsdam: 5
Mainz: 1
ISRAEL
Rehovot: 5
JAPAN
Kawasaki: 10
Tokyo: 10
Yokohama: 10
SWITZERLAND
Geneva: 4
Zurich: 3
UNITED KINGDOM
Cardiff: 3
London: 6
UNITED STATES OF AMERICA
California
Berkeley: 3
Los Angeles: 8
Pasadena: 11
Georgia
Athens: 10
Hawaii
Honolulu: 3
Maryland
Baltimore: 8
Massachusetts
Boston: 11
Michigan
Ann Arbor: 8
New York
Bronx: 12
New York: 7
Stony Brook: 4
Pennsylvania
Philadelphia: 9, 11
Texas
Dallas: 8
PRESS CONTACTS…
For North America and Canada
Katie McGoldrick, Nature Washington
Tel: +1 202 737 2355; E-mail: [email protected]
For Japan, Korea, China, Singapore and Taiwan
Mika Nakano, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]
For the UK/Europe/other countries not listed above
Jen Middleton, Nature London
Tel: +44 20 7843 4502; E-mail [email protected]
About NPG
Nature Publishing Group (NPG) is a division of Macmillan Publishers Ltd, dedicated to serving the academic, professional scientific and medical communities. NPG's flagship title, Nature, was first published in 1869. Other publications include Nature research journals, Nature Reviews, Nature Clinical Practice and a range of prestigious academic journals including society-owned publications. NPG also provides news content through [email protected]. Scientific career information and free job postings are offered on Naturejobs.
NPG is a global company with headquarters in London and offices in New York, San Francisco, Washington DC, Boston, Tokyo, Paris, Munich, Hong Kong, Melbourne, Delhi, Mexico City and Basingstoke. For more information, please go to www.nature.com.
