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This press release is copyright Nature.
VOL.456 NO.7222 DATED 04 DECEMBER 2008
This press release contains:
· Summaries of newsworthy papers:
Venus: Into the clouds
Space science: Tycho’s supernova classified
Commentary: Education and well-being
Cell biology: Cancer stem cells and melanoma
Climate: Arctic freezing triggers methane burst
Feature: Five crop researchers who could change the world
Developmental biology: Video captures stem cell niche
Earthquakes: Locked-in potential
Applied physics: On–off switch for a superconductor
Reproductive biology: Core fold in animal egg coats
And finally… Mechanism for a stress-free, low-calorie, long life
· Mention of papers to be published at the same time with the same embargo
· Geographical listing of authors
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[1] Venus: Into the clouds (pp 620-623)
New data and images from the Venus Express spacecraft reveal a clearer picture of the atmosphere of Earth’s ‘twin’ planet, showing temperature, conditions, cloud structure and dynamics. The observations, presented in Nature this week, will enable scientists to better understand the meteorology of Venus and compare it to that of Earth.
Venus is shrouded in a dense cloud layer of sulphur dioxide and sulphuric acid that reflects most sunlight back into space, preventing direct observation of the surface. When seen in ultraviolet (UV) light, the clouds do not appear uniform, indicating spatial and vertical distribution of unknown atmospheric absorbers.
Dmitri Titov and colleagues analysed data from the UV and infrared imaging instruments onboard Venus Express. The resulting images show a broad global symmetry between the two hemispheres, and substantial convective mixing at low latitudes, which brings the UV absorbers up from depth. In low and middle latitudes, the visible cloud top is located about 72 kilometres above the surface in both the UV dark and UV bright regions, indicating that the brightness variations result from compositional differences caused by the colder environment.
CONTACT
Dmitri Titov (Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany)
Tel: +49 5556 979 212; E-mail: [email protected]
[2] Space science: Tycho’s supernova classified (pp 617-619; N&V)
One of the most famous supernovae in the history of astronomy, first identified over 400 years ago, is a normal type Ia supernova, according to research in Nature this week.
Type Ia supernovae are believed to be thermonuclear explosions of white dwarf stars, and they play an important role as cosmological distance indicators. Tycho Brahe, a Danish astronomer, was one of the first to observe an unexpectedly bright ‘new star’ appear in 1572, in the constellation Cassiopeia, and concluded from accurate observations that it must be located ‘far beyond the Moon’. His discovery partly led to the eventual abandonment of the theory that the planets and stars are fixed in space with the Earth at the centre of the Universe. Given the importance of type Ia supernovae to cosmology, a 'local' example to study closely is useful.
Oliver Krause and colleagues report an optical spectrum of Tycho’s supernova near maximum brightness, obtained from a scattered-light echo more than 400 years after the direct light from the explosion swept past the Earth. Their observations reveal that the supernova, now known as SN 1572, belongs to the class of normal type Ia supernovae.
CONTACT
Oliver Krause (Max Planck Institute for Astronomy, Heidelberg, Germany)
Tel: +49 6221 528 352; E-mail: [email protected]
Andrea Pastorello (Queen's University, Belfast, UK) N&V author
Tel: +44 28 9097 3509; E-mail: [email protected]
Commentary: Education and well-being (pp 572-573)
The value of universal education is undeniable, but most developing nations around the world have committed only to primary education. Secondary education has many additional benefits for health, wealth and well-being.
One benefit of education that deserves more attention than it currently receives is its capacity to slow population growth, says Joel Cohen in a Commentary in Nature this week. The United Nations Population Division projects that a fertility difference of a single child per woman, on average, could mean a difference in of 3 billion in the world’s population in 2050. That's almost half of today's current population and nearly a third of the medium projection for 2050. Studies have shown that in many areas of the world, when women receive 10-12 years of education, they have on average at least one child fewer than those who have only received primary education, and the health of mothers and children is greatly improved, among other important benefits.
If rich and poor nations collaborate to make universal secondary education a priority now, it is an affordable proposition that could greatly benefit them all.
CONTACT
Joel Cohen (Rockefeller University & Columbia University, New York, NY, USA)
Tel: +1 212 327 8883; E-mail: [email protected]
Please note this author is currently travelling and is best contacted by e-mail. He can be contacted on the following numbers on the dates specified:
Tel: +1 802 896 6200 (Until 29 November)
Hotel Mercure Secession, Vienna, Austria; Tel: +43 1 588 380 (From 29 November – 4 December)
[3] Cell biology: Cancer stem cells and melanoma (pp 593-598; N&V)
Research in Nature this week casts doubt on whether cancer stem cells alone encourage tumour development in melanoma, the most deadly form of skin cancer.
In recent years, many researchers have found that some cancers, including breast, bowel and prostate, have a small sub-population of ‘stem-like’ cells that drives the formation of the rest of the tumour. The evidence for this was the observation that only a tiny proportion of cells taken from a given tumour could spark the development of new cancers when transplanted into mice.
Sean Morrison and colleagues transplanted cells from 12 melanoma patients into mice, and found that around one-quarter of melanoma cells were able to trigger new cancers. The finding suggests that a wide variety of cell types within a melanoma are able to fuel the cancer’s growth, and could have implications for therapies that target only cancer stem cells.
CONTACT
Sean Morrison (University of Michigan, Ann Arbor, MI, USA)
Tel: +1 734 647 6261; E-mail: [email protected]
Connie Eaves (British Columbia Cancer Research Centre, Vancouver, Canada) N&V author
Tel: +1 604 675 8122; E-mail: [email protected]
[4] Climate: Arctic freezing triggers methane burst (pp 628-630)
Large amounts of the greenhouse gas methane are released when the Arctic tundra starts to freeze, a Nature paper reveals. The previously unrecognized phenomenon helps explain oddities in recorded atmospheric methane concentrations.
Torben Christensen and colleagues measured atmospheric methane concentrations in the northern Arctic during the onset of soil freezing in late autumn and early winter. Methane emissions fell to a low, steady level after the growing season but then increased significantly as the freeze began.
Terrestrial wetland emissions are the largest single source of methane, but researchers have struggled to explain the seasonal distribution of methane concentrations in high northern latitudes. This study offers a possible solution.
CONTACT
Torben Christensen (Lund University, Sweden)
Tel: +46 462 223 743; E-mail: [email protected]
Feature: Five crop researchers who could change the world (pp 563-568)
The current crisis in worldwide food prices reinforces the need for more-productive agriculture. In Nature this week Emma Marris meets five ambitious researchers determined to stop the world from going hungry.
The researchers, from the United States, China, United Kingdom and Australia, work on areas ranging from battling the rust that infects many crops, to reducing the amount of water used in agriculture in places such as northern China, to supercharging rice to generate a better yield. The feature investigates the researchers’ backgrounds and inspirations, and estimates when their work will come to fruition.
CONTACT
Emma Marris (Correspondent for Nature, Columbia, MO, USA)
Tel: +1 573 256 0611; E-mail: [email protected]
[5] & [6] Developmental biology: Video captures stem cell niche (AOP)
DOI: 10.1038/nature07434
DOI: 10.1038/nature07639
***These papers will be published electronically on Nature's website on 03 December 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 04 December, but at a later date. ***
The precise location of haematopoietic stem cells (HSCs) within the bone marrow has been resolved, thanks to two detailed imaging studies in this week’s Nature.
It is well known that HSCs, which give rise to all of the different mature blood-cell types, reside in the bone marrow. But researchers don’t know exactly where they are located, and which other cell types they are next to. This is important because the neighbouring cells probably comprise the microenvironment or ‘niche’ that sends out signals controlling stem cell behaviour.
David Scadden and colleagues studied single HSCs in the bone marrow of live mice, and also tracked grafted HSCs as they travelled through the bloodstream to the bone marrow. HSCs were found immediately next to bone and blood vessels where they were arranged in a nonrandom and dynamic way. A related paper by Linheng Li and colleagues also makes use of real-time imaging technology to show this homing to the inner bone and bone marrow through the blood system. The papers show that differentiation — the process by which less-specialized cells become more specialized — influenced position, as did physiological conditions. Transplanted cells, for example, settled closely to bone and bone-forming cells.
CONTACT
David Scadden (Harvard Stem Cell Institute, Boston, MA, USA) Author paper [5]
Tel: +1 617 726 5615; E-mail: [email protected]
Linheng Li (Stowers Institute for Medical Research, Kansas City, MO, USA) Author paper [6]
Tel: +1 816 926 4081; E-mail: [email protected]
[7] Earthquakes: Locked-in potential (pp 631-635)
The potential for a large megathrust earthquake in the Mentawai area off Sumatra remains large, according to new research. A study in this week’s Nature reports that the earthquakes following the 2004 Sumatra–Andaman event only partly ruptured the fault zone, and that the energy released in a pair of 2007 earthquakes was only a fraction of that released in a previous event in 1833.
The Sunda megathrust, a tectonic plate boundary near the coast of Sumatra, consists of a patchwork of creeping and locked areas of the Earth’s crust. There have been several large earthquakes in the region since 2004, including two in 2007 near the Mentawai islands, where large earthquakes also occurred in 1797 and 1833. It is thought that between large events, stress builds up around locked patches of the fault that then later fail during megathrust earthquakes.
Jean-Philippe Avouac and colleagues used a series of field measurements, GPS and radar data to estimate the source parameters of the two 2007 earthquakes. They find that the 2007 sequence was confined to a smaller ‘locked’ portion surrounded by creeping sections, suggesting that these recent event did not release all the energy that has been building up since 1833. They conclude that the seismic strain building up in the area is large enough that a giant subduction earthquake could occur there any time.
CONTACT
Jean-Philippe Avouac (California Institute of Technology, Pasadena, CA, USA)
Tel: +1 626 395 4239; E-mail: [email protected]
[8] Applied physics: On–off switch for a superconductor (pp 624-627; N&V)
A superconductor that can be easily switched on and off with an electric field is revealed in this week’s Nature. The device, which realizes a long-standing goal in applied physics, should aid the development of novel resistance-free electronic circuits.
Superconductors can be generated at the interface between layers of complex oxide insulators, such as LaAlO3 and SrTiO3. Andrea Caviglia and colleagues have applied a principle from the field-effect transistor to this system, creating a device that flips between superconductor and insulator states depending on the density of the charge carriers, which is adjusted by the strength of an electric field. In its insulating state, the interface is also extremely sensitive to magnetic fields.
CONTACT
Andrea Caviglia (University of Geneva, Switzerland)
Tel: +41 22 379 3523; E-mail: [email protected]
Darrell Schlom (Cornell University, Ithaca, NY, USA) N&V author
Tel: +1 814 863 8579; E-mail: [email protected]
[9] Reproductive biology: Core fold in animal egg coats (pp 653-657; N&V)
The structure of a vertebrate protein that is directly involved in egg–sperm binding is revealed at atomic resolution in this week’s Nature. The information should help infertility research and may aid the development of new, targeted, non-hormonal contraceptives.
The zona pellucida (ZP) is the glycoprotein membrane ‘coating’ that surrounds the egg. Luca Jovine and colleagues describe the structure of part of the sperm receptor ZP3, a ZP protein that is essential for fertilization. The team find that it has an immunoglobulin-like fold and represents a new immunoglobulin superfamily subtype.
The findings offer new insight into reproductive biology and the process of fertilization. Because many disease-causing genetic mutations fall within this region, the study has implications for human disease, including renal and vascular disorders.
CONTACT
Luca Jovine (Karolinska Institute, Stockholm, Sweden)
Tel: +46 8 608 3301; E-mail: [email protected]
Paul Wassarman (Mount Sinai Medical School, New York, NY, USA) N&V author
Tel: +1 212 241 8616; E-mail: [email protected]
[10] And finally… Mechanism for a stress-free, low-calorie, long life (AOP)
DOI: 10.1038/nature07536
***This paper will be published electronically on Nature's website on 03 December 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 04 December, but at a later date. ***
A signalling pathway that helps nematode worms live long and active lives without food is revealed in this week's Nature. The mechanism, which operates in times of stress, appears to influence lifespan and may help other animals survive periods of hibernation or fasting.
In harsh environments, Caenorhabditis elegans larvae can enter a dormant state called dauer. In this state the worms remain active but don't eat, becoming stress-resistant and extremely long lived. Patrick Narbonne and Richard Roy show that without AMP-activated protein kinase (AMPK) signalling, dauers quickly consume their stored energy and die prematurely owing to vital organ failure. The signalling pathway appears to slow the breakdown of triglycerides to ensure that fat reserves last and proper osmoregulation is maintained.
CONTACT
Patrick Narbonne (McGill University, Montreal, Canada)
Tel: +1 514 398 643; E-mail: [email protected]
Richard Roy (McGill University, Montreal, Canada)
Tel: +1 514 398 6437; E-mail: [email protected]
ALSO IN THIS ISSUE…
[11] Mitofusin 2 tethers endoplasmic reticulum to mitochondria (pp 605-610)
[12] Ktu/PF13 is required for cytoplasmic pre-assembly of axonemal dyneins (pp 611-616)
ADVANCE ONLINE PUBLICATION
***These papers will be published electronically on Nature's website on 03 December 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 04 December, but at a later date. ***
[13] Spliceosomal cleavage generates the 39 end of telomerase RNA
DOI: 10.1038/nature07584
[14] A simple model of bipartite cooperation for ecological and organizational networks
DOI: 10.1038/nature07532
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:
Montreal: 10
Quebec: 5
CHINA
Shanghai: 6
DENMARK
Copenhagen: 4
Roskilde: 4
FRANCE
Paris: 1, 8
GERMANY
Augsberg: 8
Berlin: 12
Freiburg: 12
Heidelberg: 2, 12
Katlenburg-Lindau: 1
Nuremberg: 12
ITALY
Padua: 11
Rome: 1
JAPAN
Kashiwa: 2
Kyoto: 12
Maebashi: 12
Saitama: 12
Tokyo: 12
NETHERLANDS
Noordwijk: 2
Utrecht: 4
RUSSIA
Moscow: 1
SINGAPORE
Singapore: 7
SWEDEN
Lund: 4
Stockholm: 9
SWITZERLAND
Geneva: 8, 11
Zurich: 8
UNITED KINGDOM
Glasgow: 7
Oxford: 1, 14
UNITED STATES OF AMERICA
California
Berkeley: 14
La Jolla: 7
Pasadena: 7
Santa Barbara: 7
Colorado
Boulder: 4, 12
Connecticut
Farmington: 5
Hawaii
Hilo: 2
Illinois
Evanston: 14
Kansas
Kansas City: 6, 13
Maryland
Baltimore: 6
Massachusetts
Boston: 5
Cambridge: 5
Michigan
Ann Arbor: 3
Missouri
Kansas City: 6, 13
St Louis:
New Jersey
Kenilworth: 12
New York
Syracuse: 12
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]
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