Predicting the severity of asthma attacks; Fruit bats may carry deadly Ebola virus; How to keep a cat coherent; Rocks hold clues to early martian climate history; Common truths for tropical forests; Fossil footprints of a man-sized water scorpion

Summaries of newsworthy papers from Nature Vol.438 No.7068 Dated 01 December 2005

This press release is copyright Nature.
VOL.438 NO.7068 DATED 01 DECEMBER 2005

This press release contains:
* Summaries of newsworthy papers:
* Planetary science: New views of Titan
* Medicine: Predicting the severity of asthma attacks
* Disease: Fruit bats may carry deadly Ebola virus
* Relics: A step too far
* Physics: How to keep a cat coherent
* Planetary science: Rocks hold clues to early martian climate history
* Chemistry: Metal bead game
* Insight: Membrane biology
* Ecology: Study finds common truths for tropical forests
* And finally... Fossil footprints of a man-sized water scorpion
* Mention of papers to be published at the same time with the same embargo
* Geographical listing of authors

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[1] Medicine: Predicting the severity of asthma attacks (pp 667-670)

For the first time, researchers have calculated the risk of severe asthma
attacks occurring within 30 days depending on the current airway condition.
They used twice-daily measurements of airway obstruction in 80 asthma
patients for 18 months to make their predictions.
In this week's Nature, Urs Frey and colleagues report that, surprisingly,
one type of asthma medication - a short-acting beta-agonist bronchodilator -
actually increased future risk, while another type - a long-acting
bronchodilator - decreased it. The reason is that the short-term treatment
made the attacks more random and variable than the long-term treatment, the
authors say. "Long-acting bronchodilators are more effective at stabilizing
airway function over extended periods," the researchers conclude.
Overall, in patients with more severe asthma, attacks also tended to be more
variable and random, possibly because the airways become hypersensitive to
even apparently minor environmental factors such as small amounts of
pollutants or allergens, the researchers speculate. Similar modelling could
be applied to other chronic disease conditions.
Urs Frey (University Hospitals of Berne, Switzerland)
Tel: +41 31 632 9353; E-mail: [email protected] <mailto:[email protected]>

[2] Disease: Fruit bats may carry deadly Ebola virus (pp 575-576)

Fruit bats may be acting as reservoirs of the killer Ebola virus, which has
been responsible for several deadly outbreaks in humans and great apes in
central Africa. Three bat species captured during outbreaks between 2001 and
2003 in Gabon and the Republic of Congo show evidence of symptomless
infection, which means that they may be potential spreading agents for the
Bats of the three species - Hypsignathus monstrosus, Epomops franqueti and
Myonycteris torquata - had either RNA sequences from the virus or evidence
of an immune response to it, despite showing no symptoms themselves. Eric
Leroy and colleagues made this discovery after trapping and testing more
than 1,000 small animals in Ebola-affected areas. They report their findings
in a Brief Communication in this week's Nature.
If the bats act as carriers and can indeed spread the virus, the number of
human cases could be reduced by encouraging local residents to avoid the
current practice of catching bats for food, the authors add.
Eric Leroy (Centre International de Recherches Médicales de Franceville,
Tel: +241 07 85 06 13; E-mail: [email protected] <mailto:[email protected]>

[3] Relics: A step too far (Online publication)

A report of human footprints preserved in 40,000-year-old volcanic ash near
Puebla, Mexico is challenged in an online Brief Communication Arising in
this week's Nature. This report was the subject of a press conference that
stirred international media attention in July this year.
If true, the claims of Silvia Gonzalez and colleagues would debunk
prevailing theories about the timing of human migration into the Americas
(believed to be some 25,000 to 30,000 years later). But Paul Renne and
colleagues use argon dating and palaeomagnetic analysis to show that the
basaltic tuff on which the purported footprints were found is in fact very
much older than Gonzalez and colleagues claim - at about 1.30 million years
old, the footprints would even predate the first known appearance of Homo
sapiens in Africa by more than a million years.
This discovery means that either hominid migration into the Americas
occurred very much earlier than previously believed, or that the footprints
were not made by humans at all.
Paul R. Renne (Berkeley Geochronology Center, Berkeley, CA, USA)
Tel: +1 510 644 1350; E-mail: [email protected] <mailto:[email protected]>

[4] & [5] Physics: How to keep a cat coherent (pp 639-642 & 643-646)

Physicists have created a tiny version of Schrödinger's cat, the famous
feline that was simultaneously alive and dead because of the paradoxical
laws of quantum mechanics. The catch is that the 'cat' is composed of no
more than six atoms.
Quantum systems can exist in two or more states at once - or more precisely,
in a so-called 'superposition' of states. The Austrian physicist Erwin
Schrödinger, one of the fathers of quantum physics, illustrated his
perplexity at this idea by imagining a cat that would be shot if a quantum
system attained a particular state. If, however, the system was in a
superposition of this and some other state, quantum mechanics implies that
the trigger would be both pulled and not pulled, so that the cat was both
alive and dead.
It is now accepted that this situation is virtually impossible to create,
because objects made of many particles - such as a cat whose fate is linked
to a quantum event - interact with their environment so as to scramble or
'collapse' superpositions and produce a well-defined macroscopic outcome.
This is called decoherence.
Decoherence becomes very hard to avoid even for superpositions of just a
handful of particles. And it is especially hard to control for so-called
'cat states', which are superpositions of two maximally different quantum
states - echoing the 'live' and 'dead' states of Schrödinger's cat. But
Dietrich Leibfried and co-workers, writing in this week's Nature, have now
created 'cat states' of up to six atoms of the metal beryllium, held in a
trap by an electromagnetic field.
And Hartmut Häffner and colleagues report in this week's Nature that they
have achieved a similar quantum 'balancing act' by making related (so-called
'W') states of up to eight trapped ions. These states are particularly
robust, resisting collapse even if some particles are removed. As the states
are created 'on-demand' and should be scalable to many more particles, there
is hope that the technology will pave the way for building a large-scale
quantum computer.
Dietrich Leibfried (National Institute of Standards and Technology, Boulder,
Tel: +1 303 497 7880; E-mail: [email protected]
<mailto:[email protected]>

Hartmut Häffner (Österreichische Akademie der Wissenschaften, Innsbruck,
Tel: +43 512 507 4729; E-mail: [email protected]
<mailto:[email protected]>

[6] Planetary science: Rocks hold clues to early martian climate history
(pp 623-627; N&V)

Most scientists now concur that there was liquid water on Mars early in its
history. But François Poulet and colleagues have used spacecraft
observations of clay-like rocks on Mars to develop a more detailed picture
of how its early, wet climate evolved.
The observations, reported in Nature this week, were made by the OMEGA
instrument on board the European Space Agency's Mars Express mission, which
went into orbit around Mars at the end of 2003. OMEGA scans the martian
surface for reflected infrared radiation imprinted with the telltale
signatures of certain minerals, such as phyllosilicates. These rocks are
made when the volcanic rock basalt encounters water, and so their presence
on the surface of Mars indicates that there was once substantial water
OMEGA has detected several deposits of phyllosilicates, all in regions that
date right back to the earliest geological period of martian history, called
the Noachian, which ended between about 3.5 and 3.8 billion years ago. (The
planet formed at the same time as the Earth, around 4.6 billion years ago.)
Poulet and colleagues think that the phase that gave rise to these clay
minerals is probably distinct from a later, relatively mild and perhaps
drier period on Mars that created the sulphate minerals seen elsewhere by
OMEGA. During the drier period, the martian environment seems to have been
more acidic than in the Noachian period, perhaps because of acid gases
emitted by volcanoes.
François Poulet (Université Paris-Sud, Orsay, France)
Tel: +33 1 69 85 85 82; E-mail: [email protected]
<mailto:[email protected]>

Horton Newsom (University of New Mexico, Albuquerque, NM, USA)
Tel: +1 505 277 0375; E-mail: [email protected] <mailto:[email protected]>

[7] Chemistry: Metal bead game (pp 651-654)

Tiny polymer-like beads containing embedded metal atoms reported in this
week's issue of Nature represent a new class of materials with many
potential applications, according to the two scientists who made them.
Moonhyun Oh and Chad Mirkin hope that their microspheres, made from
so-called coordination polymers, might act as catalysts for conducting
delicate chemical reactions that would combine the superior performance of
homogeneous (dissolved) catalysts with the ease with which heterogeneous
(solid) catalysts can be separated from the product by simple filtration.
Coordination polymers form when metal ions interact with carbon-based
(organic) molecules so as to arrange the molecules into chains or
three-dimensional networks. The building blocks of the materials made by Oh
and Mirkin are organic molecules that each already hold two metal ions of
zinc, copper or nickel in a pincer-like clasp. The researchers find that
when they use additional metal ions to link these molecules together under
the right conditions, the material grows into spherical particles about 100
to 200 nanometres (millionths of a millimetre) across. These particles then
aggregate and fuse into larger spheres measuring about 1 to 5 micrometres
(thousandths of a millimetre) in diameter.
Changing the characteristics of the building blocks - such as the nature of
the organic molecules or the metal ions they hold, or the nature of the
metal ions to link the molecules together - gives the researchers tremendous
scope for tuning the properties of these microspheres, which might also turn
out to have useful behaviour in sensing and data-storage devices.
Chad Mirkin (Northwestern University, Evanston, IL, USA)
Tel: +1 847 467 7302; E-mail: [email protected]
<mailto:[email protected]>

Insight: Membrane biology

Sealed membrane systems are a defining feature of cellular life. They
provide a barrier between the cell and its external environment and, in
eukaryotes, divide the interior of the cell into functionally distinct
compartments. The central role of membrane-linked processes is emphasized by
the genome sequencing projects that have revealed that membrane proteins
comprise around one-third of the gene products in most organisms.
An Insight in this week's Nature looks at how research in this area
is being revolutionized by the structural analysis of increasingly complex
macromolecular systems. A sample of the current hot topics in membrane
biology is presented in this focus, which includes a landmark paper on the
aquaporin structure embedded in the lipid bilayer, and a collection of
reviews exploring the many facets of contemporary membrane biology.
Another article, by Frederick R. Maxfield and Ira Tabas,
investigates the role of cholesterol and lipid organization in disease. New
discoveries concerning the signalling roles of molecules will help our
understanding of diseases such as Alzheimer's and type 2 diabetes, and could
lead to significant discoveries in disease mechanisms and treatments.

[8] Ecology: Study finds common truths for tropical forests (pp 658-661)

Patterns of tree diversity in tropical forests across the world can be
explained using a simple set of theories, according to a new mathematical
analysis of data on the relative abundance of different species. The study
identifies two simple theories that can explain why all tropical forests
seem to show similar patterns of relative species abundance.
Jayanth Banavar and colleagues studied data on the relative abundance of
different tree species in six Old and New World tropical forests. Such
forests show remarkably consistent patterns in the commonness and rarity of
different species. For example, forests tend to contain a handful of very
abundant species, many species of medium abundance, and relatively few
species of very low abundance.
As the group reports in this week's Nature, two different mechanisms can
each explain why low-abundance species are rarer than medium-abundance ones.
One theory states that low-abundance species are rarer because they are more
likely to disappear through extinction. Conversely, they may be rare because
once a new species colonizes a forest, it multiplies rapidly and quickly
graduates into a higher abundance category. The authors add that simply
looking at data on relative species abundance for a given forest is
insufficient to distinguish between these two competing explanations.
Jayanth R. Banavar (The Pennsylvania State University, University Park, PA,
Tel: +1 814 863 1089; E-mail: [email protected]
<mailto:[email protected]>

[9] And finally... Fossil footprints of a man-sized water scorpion (p 576)

A geologist working in Scotland has uncovered a set of footprints left by a
fearsome water scorpion bigger than a human. The tracks were made
approximately 330 million years ago by a six-legged creature called
Hibbertopterus that was some 1.6 metres long and a metre wide.
The tracks show that this now-extinct group of animals could survive out of
water, says Martin Whyte, who reveals his discovery in a Brief Communication
in this week's Nature. At around the same time, our own four-limbed
ancestors were also making their first steps towards leaving aquatic
environments and colonizing the land.
The six-metre-long trackway reveals strides that were 27 centimetres long,
and also features a central groove left by the creature's dragging tail.
This shows that the creature was probably a very slow, lumbering beast when
moving on land.
Martin Whyte (University of Sheffield, UK)
Tel: +44 114 222 3610; E-mail: [email protected]
<mailto:[email protected]>


[10] An assembly landscape for the 30S ribosomal subunit (pp 628-632;

[11] Lipid-protein interactions in doublelayered two-dimensional AQP0
crystals (pp 633-638; N&V)

[12] Origin of the metallic properties of heavily boron-doped
superconducting diamond (pp 647-650)

[13] The microRNA miR-196 acts upstream of Hoxb8 and Shh in limb
development (pp 671-674)

[14] Endophilin and CtBP/BARS are not acyl transferases in endocytosis or
Golgi fission (pp 675-678)

[15] Global analysis of protein phosphorylation in yeast (pp 679-684)

[16] The APC/C and CBP/p300 cooperate to regulate transcription and
cell-cycle progression (pp 679-684)


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.

Graz: 1, 2, 3, 6, 7
Innsbruck: 12

Brampton: 6
Edmonton: 15
Toronto: 22

Helsinki: 3

Braunschwieg: 5
Cannes-La Bocca: 7
Creteil: 1, 2
Grenoble: 5
Meudon: 2, 3, 5, 6, 13
Nantes: 13
Orleans: 3
Orsay: 13
Paris: 3, 9, 13
Saint Maur: 3
Toulouse: 1, 13
Verneres-le-Buisson: 1, 2

Franceville: 9

Berlin: 13
Bochum: 4
Bonn: 4
Cologne: 3
Darmstadt: 7
Dresden: 4
Katlenburg-Lindau: 5, 13
Saarbrucken: 12

Tel Aviv: 3

Catania: 3
Milan: 3
Padua: 3, 6, 15
Rome: 3, 5, 13

Higashi-Hiroshima: 19
Kyoto: 18
Okayama: 19
Sayo: 12
Shinjuku: 19

Dunedin: 8

Dwingeloo: 4, 7
Noordwijk: 3, 6, 7

Balboa: 15

Warsaw: 6

Moscow: 13

Sandringham: 9

Granada: 3
Murcia: 3

Bern: 5, 8
Geneva: 22

Nakhonpathon: 9

Birmingham: 23
Cambridge: 21
Didcot: 6
Dundee: 22
Leicester: 8
Manchester: 6
Milton Keynes: 3, 6
Oxted: 23
Sheffield: 16
Southampton: 6

Birmingham: 2
Flagstaff: 5
Tucson: 2, 5, 6
Carlsbad: 22
La Jolla: 17
Moffett Field: 3
Pasadena: 4, 5, 7, 22
San Francisco: 20
Stanford: 4
Boulder: 11
Denver: 6
New Haven: 22
Gainesville: 20
Athens: 15
Honolulu: 1, 2
Moscow: 4, 7
Evanston: 14
College Park: 1
Greenbelt: 1, 2
Boston: 3, 8, 18, 19, 21, 23
Cambridge: 20
Ann Arbor: 1, 2
St. Louis: 13
New Mexico
Los Alamos: 11
New York
New York: 4
Pittsburgh: 22
University Park: 15
Rhode Island
Providence: 13
College Station: 5
Houston: 22

For North America and Canada
Katie McGoldrick, Nature Washington
Tel: +1 202 737 2355; E-mail: [email protected]
<mailto:[email protected]>

For Japan, Korea, China, Singapore and Taiwan
Rinoko Asami, Nature Tokyo
Tel: +81 3 3267 8751; E-mail: [email protected]
<mailto:[email protected]>

For the UK/Europe/other countries not listed above
Ruth Francis, Nature London
Tel: +44 20 7843 4562; E-mail [email protected]
<mailto:[email protected]>

Katharine Mansell, Nature London
Tel: +44 20 7843 4658; E-mail: [email protected]

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Published: 30 Nov 2005

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