WWW.NATURE.COM/NATURE
This press release is copyright Nature.
VOL.453 NO.7198 DATED 19 JUNE 2008
This press release contains:
· Summaries of newsworthy papers:
Planetary science: Saturn’s second aurora
Medical physics: Magnetic resonance images in colour
Commentary: Research misconduct: The tip of the iceberg
Genomics: Insight into each end of the chordate lineage
Space: ‘Identical twins’, years apart
Ecology: Solution for global puzzle of nitrogen-loving trees
Developmental biology: Ticking of the segmentation clock
Climate: Warming and rising of oceans
Nanotechnology: Taking the strain in electronic devices
And finally… In pursuit of happiness
· 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] Planetary science: Saturn’s second aurora (pp 1083-1085)
A study of Saturn’s polar lights has uncovered a secondary auroral oval, about a quarter as bright as the main one. The properties of this oval show it to be similar to Jupiter’s main oval, which is formed through interactions with its volcanic moon Io — the relative dimness is due to the lack of as large a source of ions as Jupiter’s moon.
The main auroral oval was first seen in Hubble Space Telescope images more than a decade ago and has since been studied in detail, yet there is continued debate about its origins. One theory was that Saturn’s aurorae were a hybrid between those seen on Earth, primarily formed by interaction with the solar wind, and those on Jupiter, formed by interaction with plasma flows. Tom Stallard and colleagues report their discovery of a secondary oval at Saturn, around 25 per cent as bright as the main oval, in Nature this week.
The finding suggests that the underlying aurora formation processes on Saturn and Jupiter are very similar, with scaling differences accounting for the differences in appearance.
CONTACT
Tom Stallard (University of Leicester, UK)
Tel: +44 116 252 3589; E-mail: [email protected]
[2] Medical physics: Magnetic resonance images in colour (pp 1058-1063; N&V)
Magnetic resonance imaging (MRI) is widely used in medicine as a diagnostic and a research tool, but has so far been limited by having to rely on ‘grey-scale’ contrast agents to highlight biological areas of interest. A paper in this week’s Nature describes the engineering of ‘coloured’ agents that greatly enhance the sensitivity of the technique.
Gary Zabow and his colleagues use microfabrication to develop a family of magnetic microstructures. They show that careful control of the geometry of these magnetic particles yields well-defined spectral signatures in the radio-frequency spectrum used for MRI — effectively giving them characteristic 'colours' that can be readily distinguished from one another.
The microstructures also function as subcellular-sized spectral radio-frequency identification tags, enabling increased MRI functionality, high sensitivity and greatly extended spectral ranges.
CONTACT
Gary Zabow (National Institute of Standards and Technology, Boulder, CO, USA)
Tel: +1 303 4974657; E-mail@ [email protected]
Richard Bowtell (University of Nottingham, UK) N&V author
Tel: +44 115 951 4737; E-mail: [email protected]
Commentary: Research misconduct: The tip of the iceberg (pp 980-982)
A survey of more than 2,000 scientists reveals that misconduct in research may be far more prevalent than suspected. The results are published in a Commentary in Nature this week.
The authors, based at the US Department of Health and Human Services’s Office of Research Integrity (ORI) surveyed 2,212 scientists at 605 institutions and found that nearly 9% believed they had witnessed potential research misconduct in the preceding three years. Extrapolating to the larger research community supported by the National Institutes of Health (NIH), this suggests that as many as 2,300 observations of misconduct occur each year with roughly 1,000 going unreported. It is unlikely that such behaviour is confined to the United States.
The finding suggests that falsified and fabricated research records, publications, dissertations and grant applications are much more prevalent than has been suspected to date. The number of cases of misconduct reported to the ORI is very low — about 24 investigations per year from institutions for cases that involve NIH funding. The authors, Sandra L. Titus, James A. Wells and Lawrence J. Rhoades suggest possible reasons why so few cases reach regulatory authorities, and recommend how institutional leaders can create and maintain a culture of integrity.
CONTACT
Sandra Titus (Office of Research Integrity, Rockville, MD, USA)
Please contact through:
Jennifer Koentop (Director of Communications, Office of Public Health and Science, Rockville, MD, USA)
Tel: +1 202 205 2367; E-mail: [email protected]
James Wells (University of Wisconsin-Madison, WI, USA)
Tel: +1 608 262 0558; E-mail: [email protected]
[3] Genomics: Insight into each end of the chordate lineage (pp 1064-1071; N&V)
Besides being curious worm-like creatures that spend most of their lives buried in the sea floor, lancelets — also known as ‘amphioxus’, meaning sharp at both ends — are the modern survivors of the ancient chordate lineage. A paper in this week’s Nature announces the draft genome sequence of the Florida lancelet Branchiostoma floridae, considered to be a living proxy for the chordate ancestor, and analyses it in the context of chordate evolution.
Although Kowalevsky, Darwin and others recognized the evolutionary relationship between chordate groups, the greater morphological, physiological and neural complexity of vertebrates posed a puzzle: how did the chordate ancestor — presumably a simple creature that resembled a modern amphioxus or ascidian larva — make such a transition?
Nicholas Putnam and colleagues describe the structure and gene content of the organism’s genome. They show subsequent reorganizations that occurred in the vertebrate lineage and identify sequences that are conserved in the modern amphioxus and vertebrate genomes, despite over half-a-billion years of independent evolution. The genome-scale events that shaped the vertebrate genome provided additional genetic variation for exploitation during vertebrate evolution, suggest the authors.
CONTACT
Nicholas Putnam (Department Of Energy Joint Genome Institute, Walnut Creek, CA, USA)
Tel: +1 510 717 1500; E-mail: [email protected]
Henry Gee (Senior Editor Nature, London, UK) N&V author
Tel: +44 20 7843 4546; E-mail: [email protected]
[4] Space: ‘Identical twins’, years apart (pp 1079-1082)
Twins are born at almost the same time, but this isn’t always the case in space, according to a paper in Nature this week. Scientists have found a pair of ‘identical twin’ stars with surface temperatures and luminosities that suggest one of the twins may have formed several hundred thousand years after its sibling.
Keivan Stassun and colleagues describe their discovery, a pair of stellar twins in the Orion nebula. The siblings are in a newborn binary system, each one with the same mass but with surface temperatures differing by about 10 per cent and luminosities differing by around 50 per cent. Their findings reveal that birth order in ‘identical twin’ stars can be seen in physical differences — at least when the stars are very young.
CONTACT
Keivan Stassun (Vanderbilt University, Nashville, TN, USA)
Tel: +1 615 322 2828; E-mail: [email protected]
[5] Ecology: Solution for global puzzle of nitrogen-loving trees (AOP)
DOI: 10.1038/nature07028
***This paper will be published electronically on Nature's website on 18 June 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 it on this release to avoid multiple mailings it will not appear in print on 19 June, but at a later date. ***
A new analysis may have solved the riddle of why plants associated with bacteria that convert nitrogen gas into living matter only tend to flourish in particular regions of the globe. The research offers an explanation for why symbiotic N2-fixing plants are predominantly found in tropical regions, and not at higher latitudes, where they might be expected to occur.
Converting nitrogen gas (N2) into biomass offers an advantage when other forms of nitrogen, such as nitrate, are in short supply. So why, then, are N2 fixers not found in mature temperate and boreal forests where soil nitrogen is limiting? And conversely, why are they so prevalent in tropical savannas and lowland tropical forests, where nitrogen is in ample supply and they might be expected to be out-competed by other species?
Benjamin Houlton and colleagues perform a meta-analysis in combination with modelling to answer these questions. Writing in this week's Nature, they suggest that the temperature at high latitudes is too low for N2 fixers to flourish, whereas in some tropical regions the unique metabolism of the symbiotic partners gives them an advantage where levels of another nutrient, phosphate, are low.
CONTACT
Benjamin Houlton (University of California, Davis, CA, USA
Tel: +1 530 752 2210; E-mail: [email protected]
[6] Developmental biology: Ticking of the segmentation clock (AOP)
DOI: 10.1038/nature07020
***This paper will be published electronically on Nature's website on 18 June 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 it on this release to avoid multiple mailings it will not appear in print on 19 June, but at a later date. ***
Frogs have ~10 vertebrae along their backbones, humans have 33 and some snakes have more than 300 — so what determines how many a given species will have, and why should the number be so variable between species? A paper in this week’s Nature comes up with answers to both of these questions.
The number of segments, or ‘somites’, in a developing embryo reflects the number of vertebrae it will end up with. Olivier Pourquié and his colleagues investigate how somite number is controlled by comparing genes that determine their development in the corn snake (Pantherophis guttatus) with those in zebrafish, chicken and mice — who between them end up with far fewer vertebrae.
They find that segment number is controlled by the ratio between the pace of what is known as the ‘segmentation clock’ — a periodic signal governing rhythmic production of nascent vertebrae — and growth rate. Snakes make more vertebrae because their clocks tick faster relative to their growth rate, leading to a greater number of smaller somites from an equivalent amount of embryonic tissue.
The team concludes that all vertebrates, irrespective of somite number, use a similar mechanism to generate them.
CONTACT
Olivier Pourquié (Stowers Institute for Medical Research, Kansas City, MO, USA)
Tel: +1 816 926 4442; E-mail: [email protected]
[7] Climate: Warming and rising of oceans (pp 1090-1093)
The rapid warming of the upper ocean helps to explain multi-decadal variations in sea-level rise, say researchers in Nature this week. The team report improved estimates of ocean heat content and thermal expansion for the upper ocean from 1950 to 2003, reducing biases in common ocean temperature observations.
Catia Domingues and colleagues look at upper ocean trends for both the upper 300 m and 700 m. They report that ocean warming and thermal expansion trends from 1961 to 2003 are about 50 per cent larger than earlier estimates but are 40 per cent smaller for the decade from 1993 to 2003 due to previously recognised instrumental errors introducing bias during the 1990s. The team conclude that previous work is in agreement with their own observations of upper-ocean thermal expansion contributions to sea-level rise compared to other factors.
The results demonstrate the importance of quality control of observational data, and the authors call for detailed regional and global models and observations so that we can better understand the implications of climate change and sea-level rise.
CONTACT
Catia Domingues (Commonwealth Scientific and Industrial Research Organisation, Hobart, TAS, Australia)
Tel: +61 3 6232 5038; E-mail: [email protected]
[8] Nanotechnology: Taking the strain in electronic devices (pp 1086-1089)
Placing silicon under strain can enhance the ease with which the charge carriers move through the semiconductor, so it’s little wonder that strain is now engineered into the latest high-performance microprocessors. A paper in this week’s Nature describes a technique that opens the way to accurate large-area mapping of the complex strain distributions in electronic devices.
Martin Hÿtch and colleagues have developed a new approach to strain measurement that incorporates two well known techniques — moiré interferometry and electron holography — to yield a method that combines nanometre-scale spatial resolution and precision with a micrometre-scale field of view. Their technique overcomes the limitations of other methods currently used to measure strain, such as transmission electron microscopy.
The authors suggest that their approach could be adopted for nanoscale strain measurement for a host of nanostructured materials.
CONTACT
Martin Hÿtch (Centre d'Elaboration de Matériaux et d'Etudes Structurales, Toulouse, France)
Tel: +33 5 62 25 78 83; E-mail: [email protected]
[9] And finally… In pursuit of happiness (AOP)
DOI: 10.1038/nature06993
***This paper will be published electronically on Nature's website on 18 June 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 it on this release to avoid multiple mailings it will not appear in print on 19 June, but at a later date. ***
Two types of thought processes that drive motivated behaviour are controlled by different parts of the brain suggests a study in this week’s Nature. An imbalance of these two factors is common in neuropsychiatric disorders such as drug addiction and eating disorders, in which responding to general feelings, such as the satisfaction of delicious fast food, may directly contradict desires for the current outcome. By teasing apart the mechanisms for the two processes, this study points to a possible cause for this imbalance.
People learn how to react to situations and objects based on past positive or negative experiences. These reactions are driven by two different thought processes — outcome-specific representations, which reflect a person’s current desire for the outcome of the specific acts, and general affective representations, which are broad feelings towards an act or object and are independent of current desires. These two processes work together to guide our behaviour, but until now the neural basis defining them from one another was not known.
Geoffrey Schoenbaum and colleagues show that damage to the orbitofrontal cortex of the brain, which is important for decision making, causes a deficit in outcome-specific representations in rats but not general feelings towards specific cues.
Their work suggests that imbalances in the activity of separate brain circuits may underlie why diseases such as addiction lead to disruptions in how we weigh up different factors driving our decisions.
CONTACT
Geoffrey Schoenbaum (University of Maryland, Baltimore, MD, USA)
Tel: +1 410 706 3814; E-mail: [email protected]
ALSO IN THIS ISSUE…
[10] Induction and effector functions of TH17 cells (pp 1051-1057)
ADVANCE ONLINE PUBLICATION
***These papers will be published electronically on Nature's website on 18 June 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 19 June, but at a later date. ***
[11] Crystal structure of the ligand-free G-protein-coupled receptor opsin
DOI: 10.1038/nature07063
[12] A new class of homoserine lactone quorum-sensing signals
DOI: 10.1038/nature07088
[13] Assembly reflects evolution of protein complexes
DOI: 10.1038/nature06942
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.
AUSTRALIA
Aspendale : 5
Hobart: 7
FRANCE
Toulouse: 8
GERMANY
Berlin: 11
Frankfurt: 12
Munich: 10
JAPAN
Kanagawa: 3
Kyoto: 3
Okinawa: 3
Shizuoka: 3
Tokyo: 3
SOUTH KOREA
Chonju: 11
SPAIN
Barcelona: 3
SWITZERLAND
Lausanne: 3
UNITED KINGDOM
Cambridge: 13
Leicester: 1
London: 1, 3, 6
Oxford: 3
St Andrews: 3, 4
UNITED STATES OF AMERICA
California
Berkeley: 3
Davis: 5
La Jolla: 3
Livermore: 7
Mountain View: 3
Oakland: 3
Palo Alto: 3, 12
Pasadena: 1, 3
Stanford: 5
Walnut Creek: 3
Colorado
Boulder: 2
Maryland
Baltimore: 9
Bethesda: 2
Massachusetts
Boston: 10
Michigan
Mount Pleasant: 3
Missouri
Kansas City: 6
St Louis: 3
New York
Buffallo: 12
Tennessee
Nashville: 4
Washington
Seattle: 12
Wisconsin
Madison: 4
PRESS CONTACTS…
From North America and Canada
Katherine Anderson, Nature New York
Tel: +1 212 726 9231; E-mail: [email protected]
Katie McGoldrick, Nature Washington
Tel: +1 202 737 2355; E-mail: [email protected]
From Japan, Korea, China, Singapore and Taiwan
Mika Nakano, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]
From 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, Madrid, Munich, Hong Kong, Melbourne, Delhi, Mexico City and Basingstoke. For more information, please go to www.nature.com.