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This press release is copyright Nature.
VOL.447 NO.7140 DATED 03 MAY 2007
This press release contains:
• Summaries of newsworthy papers:
Ageing: Gene has key role in calorie-restriction-mediated longevity
Neuroscience: Mapping functional brain anatomy
Planetary science: Measuring Martian ice
Seismology: A new class of earthquake
Physics: Noisy magnets
Chemistry: Super-heavy elements stay with the group
Ecology: The water of life
• Mention of papers to be published at the same time with the same embargo
• Geographical listing of authors
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[1] Ageing: Gene has key role in calorie-restriction-mediated longevity (AOP)
DOI: 10.1038/nature05837
***This paper will be published electronically on Nature's website on 02 May 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 03 May, but at a later date.***
Researchers are one step closer to understanding how reducing food intake can increase lifespan in nematode worms with the discovery of a gene that is essential for this type of ageing.
Dietary restriction is connected with increased lifespan in a wide variety of animals, including mice, fruitflies and worms. In a paper published online in this week’s Nature, Andrew Dillin and colleagues show that pha-4, a gene that plays an essential part in embryonic development of the worm foregut, has a newly discovered, adult-specific function — increased activity of the gene is associated with diet-restricted longevity in worms.
pha-4 shares a similar sequence with the genes encoding the mammalian family of Foxa transcription factors, which play important parts during development and act later in life to regulate glucagons and glucose levels, particularly in response to fasting. So when nutrient signalling is low, PHA-4/Foxa may mediate glucagon levels or other changes in hormones ultimately able to regulate the ageing process.
CONTACT
Andrew Dillin (The Salk Institute, La Jolla, CA, USA)
Tel: +1 858 453 4100 x1099; E-mail: [email protected]
Please note the author is travelling and it may be best to contact him by mobile: +1 858 504 1564. Alternatively, you may wish to contact:
Gina Kirchweger (Media Relations, The Salk Institute, La Jolla, CA, USA)
Tel: +1 858 453 4100 x1340; E-mail: [email protected]
[2] Neuroscience: Mapping functional brain anatomy (pp 83-86; N&V)
A technique that allows fundamental brain circuits to be mapped out, and might also allow them to be compared across species, is reported in a paper in this week’s Nature. The study shows that spontaneous fluctuations in brain activity that occur continuously, and even in a deeply anaesthetized state, can be used to describe functional networks in the monkey brain.
Many studies of brain function use fMRI (functional magnetic resonance imaging) to measure changes in brain activity in response to a specific task or stimulus. However, the activation signal detected by fMRI is also known to fluctuate when the brain is in the ‘resting state’ and no particular stimulus occurs. In the present study, Marcus Raichle and colleagues performed fMRI on monkeys that had been anaesthetized to levels known to induce profound loss of consciousness. Despite this, the monkeys’ brains still showed highly organised patterns of spontaneous brain activity, which were coherent and matched underlying patterns of anatomical connectivity.
In addition, the brain systems involved were similar to those commonly engaged during task performance in awake animals. By comparing with data from humans, the authors suggest that coherent network fluctuations might be a tool for examining conserved aspects of brain functional organization.
CONTACT
Marcus Raichle (Washington University Medical Centre, St. Louis, MO, USA)
Tel: +1 314 362 6907; E-mail: [email protected]
Sabine Kastner (Princeton University, NJ, USA) N&V author
Tel: +1 609 258 0479; E-mail: [email protected]
[3] Planetary science: Measuring Martian ice (pp 64-67)
It's already thought that water ice exists under the surface of Mars. But a new method can now help scientists measure with high resolution how far down and where the ice is located.
Joshua L. Bandfield used thermal emission observations from the Mars Odyssey spacecraft to map seasonal changes in the temperature of the Martian surface to infer the depth of ice beneath the Martian surface. The results, reported in this week's Nature, indicate that the depth to the ‘ice table’ varies considerably over local and regional scales.
In particular, the data show that the depth to the ice layer is highly variable within the potential landing areas of the Phoenix spacecraft, which will attempt to drill down to the ice layer when it lands on Mars next year. Previous gamma ray spectrometer measurements made from the Mars Odyssey spacecraft have been limited to footprints spanning several hundred kilometres, so the new method offers more than a hundred-fold increase in spatial resolution.
CONTACT
Joshua L. Bandfield (Arizona State University, Tempe, AZ, USA)
Tel: +1 480 965 0601; E-mail: [email protected]
[4] Seismology: A new class of earthquake (pp 76-79; N&V)
Scientists have identified a scaling law that unifies a group of recently discovered earthquake phenomena. This new scaling relationship for all ‘slow earthquakes’ links a seemingly diverse series of phenomena, and is presented in this week’s Nature.
Satoshi Ide and colleagues analysed a group of earthquake events, previously studied separately, such as deep episodic tremor, low frequency earthquakes, slow slip and silent earthquakes, which have all been found to occur along the Nankai trough in Western Japan. Similar phenomena have also been detected elsewhere, such as in the Cascadia subduction zone in the USA and Canada. All such events are defined by the fact that they have longer durations (taking place over hours to years) than ordinary earthquakes and radiate much less seismic energy. The authors found that these diverse ‘slow earthquake’ phenomena all share some significant characteristics. Most striking is that for each type of event, the duration was found to be proportional to the seismic moment — a measure of the magnitude of the event. By comparison, for regular earthquakes, the duration is proportional to the cube root of the seismic moment.
This simple relationship clearly differentiates their behaviour from that of normal earthquakes and unites them as a new category of slow earthquakes. The authors suggest that questions remain about the physical mechanisms behind these events and point to the introduction and diffusion of fluid along the fault as a possible explanation. They propose that understanding these earthquakes more clearly should lead to new insights into the process of plate subduction and the probability of future large earthquakes.
CONTACT
Satoshi Ide (University of Tokyo, Japan)
Tel: +81 3 5841 4653; E-mail: [email protected]
John E. Vidale (University of Washington, Seattle, WA, USA) N&V author
Tel: +1 206 543 6790; E-mail: [email protected]
[5] Physics: Noisy magnets (pp 68-71)
Scientists have directly measured the magnetic noise emanating from the everyday ferromagnet’s less-common cousin, the antiferromagnet. The technique, revealed in this week’s Nature, offers insights into microscopic structure and reveals a new link between antiferromagnets and the bizarre world of quantum mechanics.
Magnets order themselves into regions called magnetic domains. Studying the noise emanating from these regions gives information about the magnet’s microscopic structure. But although noise has been measured from ferromagnets, doing the same for antiferromagnets has proved a harder nut to crack.
Oleg G. Shpyrko and colleagues developed a new X-ray-based technique to measure the magnetic noise originating from chromium, an antiferromagnet. They are able to tell how the magnetic domains are ordered, and also watch them move back and forth over micrometre distances. The measurements also reveal a fundamental finding; although the domain wall motion is thermally activated at temperatures above 100 kelvin, it is not so at lower temperatures. This is consistent with the movement being a quantum mechanical effect.
CONTACT
Oleg G. Shpyrko (Argonne National Laboratory, IL, USA)
Tel: +1 630 252 7540; E-mail: [email protected]
[6] Chemistry: Super-heavy elements stay with the group (pp 72-75; N&V)
Super-heavy element 112 has been chemically characterized, and shown to form bonds typical of elements within its group on the periodic table, according to a report in this week’s Nature.
The chemical characterization of the transactinides or super-heavy elements is plagued with problems. The production and reliable identification of these usually short-lived elements is a challenge in itself, and their huge mass often plays unpredictable havoc with their chemical properties. This means that such elements don’t always sit comfortably within their group.
In this study, Robert Eichler and colleagues produced element 112 via the alpha decay of the short-lived element 114, and developed a gas-phase chemical separation set-up to probe its properties. With just two atoms of the element, they were able to detect that it formed metallic bonds with a gold surface, which is indicative of group 12 elements like mercury (Hg) and zinc (Zn).
This confirmation of the chemical characterization comes more than ten years after the initial discovery of the element.
CONTACT
Robert Eichler (Paul Scherrer Institute, Villigen, Switzerland)
Tel: +41 56 310 4120; E-mail: [email protected]
Andreas Tuerler (Technical University Munich, Garching, Germany) N&V author
Tel: +49 89 2891 2202; E-mail: [email protected]
[7] Ecology: The water of life (pp 80-82)
The availability of water directly shapes the distribution of tree and shrub species in tropical forests, a paper published by Nature suggests. The finding is important because it means that changes in soil moisture caused by global climate change and forest fragmentation are likely to alter the distribution, diversity and composition of tropical species.
Humid tropical forests are commonly considered to be water saturated. But Bettina M. J. Engelbrecht and colleagues demonstrate that drought can play a large part in structuring plant communities in these systems. The team studied the local and regional distribution of 48 tree and shrub species spanning a rainfall gradient along the Isthmus of Panama.
Although much is already known about the distribution of tree species along environmental gradients like this, the new study starts to unravel the mechanisms behind the trend. The findings should help to improve vegetation–climate models used to project shifts in tropical forest composition, diversity and ecosystem function under changing rainfall patterns.
CONTACT
Bettina M. J. Engelbrecht (Smithsonian Tropical Research Institute, Ancon, Panama)
Tel: +507 662 212; E-mail: [email protected]
ALSO IN THIS ISSUE…
[8] An integrated model of kimberlite ascent and eruption (pp 53-57)
[9] The structure of a plant photosystem I supercomplex at 3.4A° resolution (pp 58-63)
ADVANCE ONLINE PUBLICATION
***These papers will be published electronically on Nature's website on 02 May 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 03 May, but at a later date.***
[10] Transcriptional coactivator PGC-1a integrates the mammalian clock and energy metabolism
DOI: 10.1038/nature05767
[11] Alp7/TACC is a crucial target in Ran-GTPase-dependent spindle formation in fission yeast
DOI: 10.1038/nature05773
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.
CANADA
Alberta: 7
FRANCE
Lyon: 1
GERMANY
Kaiserslautern: 7
ISRAEL
Tel Aviv: 9
JAPAN
Tokyo: 4, 11
PANAMA
Ancon: 7
POLAND
Warsaw: 6
SWITZERLAND
Bern: 6
Villigen: 6
UNITED KINGDOM
Lancaster: 8
London: 5, 11
UNITED STATES OF AMERICA
Arizona
Tempe: 3
California
La Jolla: 1
Stanford: 4
Georgia
Athens: 7
Illinois
Argonne: 5
Chicago: 5
Massachusetts
Cambridge: 2
Charlestown: 2
Michigan
Ann Arbor: 10
Missouri
St Louis: 2
Rhode Island
Providence: 8
Utah
Salt Lake City: 7
Vermont
Burlington: 7
PRESS CONTACTS…
For North America and Canada
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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
Helen Jamison, Nature London
Tel: +44 20 7843 4658; E-mail [email protected]
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