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This press release is copyright Nature.
VOL.444 NO.7117 DATED 16 NOVEMBER 2006
This press release contains:
* Summaries of newsworthy papers:
Cell biology: Getting to the heart of cardiac repair
Stem cells: Treatments for muscular dystrophy
Commentary: Five grand challenges for safe nanotechnology
Avian Flu: Mutations mark pandemic potential?
Earthquakes: Predicting the endpoint of earthquake ruptures
Relics: Infant burial by early modern humans
Species invasion: Discovery may help defeat gypsy moth
Oceanography: Flushing submarine canyons
Materials physics: Graphene in a spin
And finally… Cutting-edge Damascus sabres
* Mention of papers to be published at the same time with the same embargo
* Geographical listing of authors
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[1] Cell biology: Getting to the heart of cardiac repair (AOP)
***This paper will be published electronically on Nature's website on 15 November 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 16 November, but at a later date.***
A protein that stimulates repair in mouse heart is described in a paper published online by Nature this week. The researchers demonstrate that thymosin beta4 (Tbeta4), known to be vital in the initial development of heart tissue, can also promote new vasculature in failing adult heart muscle.
Using mice with Tbeta4 deficiency, Paul Riley and colleagues have determined that Tbeta4 can stimulate the movement of cells from an outer layer of the heart into the heart muscle, where they then form endothelial and smooth muscle cells as part of the process of new vessel formation and stabilization. A second small molecule, AcSDKP, is shown to contribute to the repair process. The team finds that when Tbeta4 is not present, AcSDKP cannot entirely rescue the heart defect, although it does have some protective effect.
The researchers believe Tbeta4 could have therapeutic potential in humans as it could promote heart cell survival after cardiac injury, and understanding how it works is a step towards this aim.
CONTACT
Paul Riley (University College London Institute of Child Health, UK)
Tel: +44 207 905 2345; E-mail: [email protected]
[2] Stem cells: Treatments for muscular dystrophy (AOP; N&V)
***This paper will be published electronically on Nature's website on 15 November 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 16 November, but at a later date.***
A potential stem cell treatment for muscular dystrophy is reported in a paper published online by Nature this week. The team transplanted a specific type of stem cell into the bloodstream of an animal model with the disease, demonstrating that they correct most of the dystrophic abnormalities.
Muscular dystrophy causes muscle degeneration, progressive paralysis and eventually death. Giulio Cossu and colleagues used mesoangioblasts in their study - stem cells, gathered from small blood vessels, that are 'programmed' to develop into muscle cells. They isolated these cells from normal and dystrophic dogs - that is, with an altered dystrophin protein. This animal is the only model system to present with the full spectrum of the disease pathology in humans. Stem cells isolated from dystrophic animals were modified to contain a corrected version of the dystrophin protein. The animals were injected five times at monthly intervals and improvements were seen in all cases. Those receiving unmodified donor cells showed a generally greater improvement than those injected with the corrected versions, but the potential success of using genetically corrected stem cells means that this form of transplant may be used on patients in the absence of life-long immune suppression treatment.
A News and Views article by Jeffrey Chamberlain reports that given the results in the paper, 'a fairly straightforward infusion of stem cells into the blood-stream might one day be able to treat muscular dystrophy.'
CONTACT
Giulio Cossu (San Raffaele Scientific Institute, Milan, Italy)
Tel: +39 02 2643 4954; E-mail: [email protected]
Jeffrey Chamberlain (University of Washington School of Medicine, Seattle, WA, USA)
Tel: +1 206 221 5363; E-mail: [email protected]
A press briefing related to this paper will take place in Italy on 15 November. Please check the press site or contact Laura Arghittu for more details:
Laura Arghittu (Media Relation Manager, Fondazione San Raffaele del Monte Tabor, Italy)
Tel: + 39 02 2643 3000 - 4465; E-mail: [email protected] or [email protected]
Commentary: Five grand challenges for safe nanotechnology
The spectre of possible harm threatening to slow the development of nanotechnology needs to be addressed, according to a consortium of researchers. In a Commentary in Nature this week, Andrew Maynard and his co-authors argue that the promise of this field could be compromised if the science community does not seize the initiative and implement a programme of systematic risk research. To stimulate thinking about this research they propose five challenges to be completed over the next 15 years.
The first challenge is to be able to assess exposure to water and airborne nanomaterials in the next three to ten years. This is followed by a call to find ways to measure the toxicity of these materials within the next 15 years. Prediction models to estimate the impact of engineered nanomaterials on human health and the environment should be developed within ten years, along with systems to evaluate the health and environmental impact of these materials over their entire life within the next five years. Finally, they argue that strategic programmes enabling relevant risk-focused research should be developed over the next 12 months.
A global understanding of nanotechnology-specific risks is essential, and mechanisms and networks must be established that enable information-sharing and coordination between different sectors and around the world. The group says that if the global research community can take advantage of networks and infrastructures already out there for the worlds of biotechnology and computation, and rise to the five grand challenges, then we can look forward to the advent of safe nanotechnologies.
CONTACT
Andrew Maynard (Project on Emerging Nanotechnologies, Woodrow Wilson International Center for Scholars, Washington, DC, USA)
Tel: +44 202 691 4311; E-mail: [email protected]
Robert Aitken (Institute of Occupational Medicine, Edinburgh, UK)
Tel: +44 131 449 8003; E-mail: [email protected]
Sally Tinkle (National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA)
Tel: +1 919 541 0993; E-mail: [email protected]
[3] Avian Flu: Mutations mark pandemic potential? (pp 378-382)
Researchers have discovered two mutations in the H5N1 avian influenza virus that enable it to recognise human receptor proteins. The amino acid changes, reported online this week in Nature, might prove useful molecular markers for assessing the pandemic potential of H5N1 samples.
To replicate efficiently in humans and acquire the potential to cause a pandemic, it’s thought that bird influenza viruses must acquire the ability to recognize human host cell receptors. Yoshihiro Kawaoka and colleagues looked for mutations in a protein called haemagglutinin that sits on the surface of the H5N1 virus and binds with host receptor proteins. They found two separate mutations in the haemagglutinin of H5N1 viruses known to recognize avian receptors that enabled these viruses to recognize human receptors.
CONTACT
Yoshihiro Kawaoka (Institute of Medical Science, University of Tokyo, Japan)
Tel: +81 3 5449 5310: E-mail: [email protected] or [email protected]
[4] Earthquakes: Predicting the endpoint of earthquake ruptures (pp358-360; N&V)
A study of 22 historical strike-slip earthquakes has revealed new insights into how an earthquake propagates along a fault and where the end point of a future earthquake rupture is likely to occur. The study, compiled by Steven Wesnousky, is published in this week’s Nature.
Earthquake faults are made up of lots of differently sized segments or ‘steps’, so that when an earthquake occurs, the rupture trace is often discontinuous. The length of an earthquake rupture along the fault will therefore depend on how much stress builds up at the junctions between these fault segments.
Wesnousky studied maps of historical strike-slip earthquakes such as the 1992 Landers quake in California and the 1999 Izmit quake in Turkey. The rupture lengths of these earthquakes ranged from 10 to 420 km. He found that two-thirds of the endpoints of strike-slip earthquake ruptures are associated with these fault steps or with the ends of active fault traces. There appears to be a critical distance of fault step - 3 to 4 km - above which earthquake ruptures do not propagate, and below which rupture propagation ceases only 40% of the time. This limiting dimension observed also seems to be largely independent of the total length of the fault.
The results from this study may be of practical importance in assessing seismic hazards along a fault and how far any future earthquake is likely to propagate along it.
CONTACT
Steven Wesnousky (University of Nevada, Reno, NV, USA)
Tel: +1 702 784 6067; E-mail: [email protected]
James F. Dolan (University of Southern California, Los Angeles, CA, USA)
Tel: +1 213 740 8599; E-mail: [email protected]
[5] Relics: Infant burial by early modern humans (p 285)
The analysis of two burial sites of three infants, dated at 27,000 years old, is reported in a Brief Communication in this week's Nature. Two of the babies, estimated to have died shortly after birth and probably twins, were found together. A third, thought to have died after less than three months, was found one metre away.
The well-preserved burials were recovered as ‘blocks’ and analysed by laser scanning and computer imaging. Christine Neugebauer-Maresch and colleagues believe that the pair of skeletons found together, embedded in red ochre, are twins because their thigh bones are of equal size, indicating they were the same age at death. Their bodies were covered with a mammoth shoulder bone (scapula) supported by part of a tusk, and one of the babies was decorated with over 30 ivory beads.
The burials represent the first findings of such young individuals from the Upper Palaeolithic period and add to the sparse Palaeolithic human remains found so far in Europe. The researchers write that the evidence for ritual burial activities, including the use of red ochre and decoration, indicates that even infants were important members of these hunter-gatherer communities. They also argue that the fossils of these extremely young individuals will contribute valuable insights into the development of early modern humans.
CONTACT
Christine Neugebauer-Maresch (Austrian Academy of Sciences, Vienna, Austria)
Tel: +43 1 51581 2404; E-mail: [email protected]
[6] Species invasion: Discovery may help defeat gypsy moth (pp 361-363)
Ecologists have spotted a never-before-seen pattern in the encroachment of the gypsy moth (Lymantria dispar) in the northeastern United States. The moths' invasion occurs in periodic pulses rather than as a smooth wave - controlling population peaks at the frontiers may therefore help to fight their spread.
The gypsy moth invasion is arguably the most intensively studied species invasion in history. Since its accidental release near Boston in 1869, the species has swarmed across more than a million square kilometres of the United States, defoliating up to 50,000 square kilometres of forest each year.
By analysing more than four decades' worth of data stretching back to 1960, researchers led by Derek Johnson have spotted that the moths' spread happens in pulses, which occur roughly every four years. As they explain in this week's Nature, this is probably because moths that spread far beyond the current frontier cannot establish breeding populations unless they colonize in sufficient numbers. Thus, moths can spread only at times when their populations are high and so targeting large groups of moths near the edges of the current distribution could help to slow their advance.
CONTACT
Derek Johnson (University of Louisiana at Lafayette, LA, USA)
Tel: +1 337 482 6987; E-mail: [email protected]
[7] Oceanography: Flushing submarine canyons (pp 354-357)
Large amounts of sediment can be transported from shallow waters to the deep ocean by the cascading of cold, dense waters, a study in this week's Nature suggests. As climate changes, this could have repercussions for the environment.
Water and sediment are transferred to the bottom of the ocean via steep-sided valleys called submarine canyons. It's currently thought that most of these flows are initiated by river floods or sediment collapse. But now Miquel Canals and colleagues show that the process can also be triggered by changes in seawater density.
Future changes in climate could alter the frequency and intensity of these dense shelf water cascading events, which also reshape the canyon floors. So there may be knock-on effects for deep-sea ecosystems and carbon storage.
CONTACT
Miquel Canals (Universitat de Barcelona, Spain)
Tel: +34 93 402 13 60 / 69; E-mail: [email protected]
The author can also be contacted on their mobile: +34 686 279 592
[8] Materials physics: Graphene in a spin (pp 347-349)
In spintronics, a quantum property of electrons called spin is exploited to permit entirely new kinds of devices, which could lead to faster and more efficient computer circuits. In this week's Nature, Steven Louie and colleagues show how a form of pure carbon called graphene could be used to make wires in which the spin of the electrons carrying a current can be precisely defined and controlled. That would make the material an attractive medium for constructing spintronic devices.
The team show that a 'nanoribbon' of graphene just a few atoms wide can carry 'spin-polarized' currents. An electron's spin can have one of just two values, which can be thought of as spinning in one direction or the opposite. In normal electric currents, the spins of electrons are random, as many having one value of spin as the other. But in spintronics it is necessary to create currents with only one kind of electron spin, which are then said to be spin-polarized.
Louie and colleagues use theoretical calculations of a graphene nanoribbon's electronic behaviour to predict that applying an electric field from one side of the ribbon to the other can produce such a current. The electric field stops electrons with spins of one type moving around the ribbon, so they cannot conduct a current - while spins of the other type remain electrically conducting. So both types of electron spin are present in the material, but only one type contributes to the current, which is therefore spin-polarized. The next step will be to test this prediction experimentally.
CONTACT
Steven Louie (University of California, Berkeley, CA, USA)
Tel: +1 510 642 1709; E-mail: [email protected]
[9] And finally… Cutting-edge Damascus sabres (p 286)
The antique steel in the famously sharp Damascus sabres used by the Muslims against the Crusaders is analysed in a Brief Communication in Nature this week, and the results are surprising. The microstructure reveals that elements introduced during the forging process gave rise to what must be the earliest carbon nanotubes on record, and that these, in turn, may have contributed to the formation of iron carbide nanowires, which might eventually explain the characteristic strength and beautiful banding pattern of Damascus blades.
It is believed that Damascus blades were forged from small cakes of steel known as ‘wootz’ that were produced in ancient India. A sophisticated treatment was then applied to the steel, but details of this were lost in the eighteenth century. It was unclear how mediaeval blacksmiths could have overcome the inherent brittleness of the material to create the finished product.
Peter Paufler and colleagues used high-resolution electron microscopy and analysed a specimen from a genuine Damascus sabre, produced in the seventeenth century. Some remnants show evidence of the nanowires, which could have been encapsulated in carbon nanotubes. They believe that as the structure of this remarkable material emerges, it might be possible to reproduce this long-forgotten recipe for Damascus steel.
CONTACT
Peter Paufler (Technische Universitat Dresden, Germany)
Tel: +49 351 4633 4679; E-mail: [email protected]
ALSO IN THIS ISSUE…
[10] The plant immune system (pp 323-329)
[11] Hydrodynamic turbulence cannot transport angular momentum effectively in astrophysical disks (pp 343-346; N&V)
[12] Free-electron-like dispersion in an organic monolayer film on a metal substrate (pp 350-353)
[13] Bacterial chromatin organization by H-NS protein unravelled using dual DNA manipulation (pp 387-390)
ADVANCE ONLINE PUBLICATION
***These papers will be published electronically on Nature's website on 15 November 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 16 November, but at a later date.***
[14] Repression of p53 activity by Smyd2-mediated methylation
DOI: 10.1038/nature05287
[15] Endogenous neurosteroids regulate GABAA receptors through two discrete transmembrane sites
DOI: 10.1037/nature05324
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.
AUSTRIA
Vienna: 5, 14
FRANCE
Maisons-Alfort: 2
Perpignan: 7
GERMANY
Bremen: 12
Dresden: 9
Wolfen: 9
INDONESIA
Surabaya: 3
ITALY
Milan: 2
Pavia: 2
Rome: 2
JAPAN
Aichi: 3
Gifu: 3
Saitama: 3
Shizuoka: 3
Tokyo: 3
Tottori: 3
NETHERLANDS
Amsterdam: 13
SPAIN
Barcelona: 7
UNITED KINGDOM
London: 1, 3, 15
Norwich: 10
St Andrews: 3
UNITED STATES OF AMERICA
California
Berkeley: 8
Claremont: 11
Louisiana
Lafayette: 6
Massachusetts
Boston: 1
Cambridge: 1
Nevada
Reno: 4
New Jersey
Princeton: 11
New York
Stony Brook: 7
North Carolina
Chapel Hill: 10
Pennsylvania
Philadelphia: 14
University Park: 6
Texas
Houston: 1
West Virginia
Morgantown: 6
Wisconsin
Madison: 3
VIETNAM
Hanoi: 3
PRESS CONTACTS…
For North America and Canada
Katie McGoldrick, Nature Washington
Tel: +1 202 737 2355; E-mail: [email protected]
From Japan, Korea, China, Singapore and Taiwan
Itsumi Kitahara, 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] <mailto:[email protected]>
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