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Nature press release for 22 August issue

August 23, 2002

[1] LIFELINES: ANTHRAX DETECTOR AND KILLER IN ONE (pp884-889; N&V)

Researchers in this week`s Nature reveal a new antibiotic that could foil bioterrorist`s attempts to engineer antibiotic-resistant strains. The same drug could serve as a rapid detector for anthrax spores.
The strain of Bacillus anthracis used in last October`s US attacks could be killed with antibiotics penicillin and ciprofloxacin. But there is concern that bioterrorists might make new strains that are resistant to these and other antibiotics.
Raymond Schuch and his colleagues at Rockefeller University in New York extracted a killer protein, called PlyG lysine, from a virus that naturally infects B. anthracis. Injections of PlyG lysine saved three-quarters of mice from otherwise lethal infections of a bacterium closely related to B. anthracis. And because the drug binds essential molecular building blocks in the bacterium`s cell wall, it would be virtually impossible to create strains that evade it.
The drug could also be used to rapidly detect areas suspected of anthrax contamination - a procedure that currently takes days. Bacteria ripped open by PlyG release molecules called ATP. These can be detected with a glowing reagent and a hand-held light meter within minutes, the team show.
"The test could be used as a rapid first indicator for contamination by B. anthracis," says Stephen Leppla of the National Institutes of Health in Bethesda, Maryland, in an associated News and Views article.
CONTACT:
Raymond Schuch tel +1 212 327 8167, e-mail vaf@rockefeller.edu
Stephen Leppla tel +1 301 594 2865, e-mail leppla@nih.gov

[2] CHEMISTRY: HEAVY METAL BEHAVES NORMALLY (pp859-862)

Hassium (Hs), with 108 protons in its nucleus, is one of the heaviest known elements. It is now the heaviest element whose chemistry has been investigated, following the report by H. W. G'¤ggeler of the University of Bern and the Paul Scherrer Institute, Villigen, Switzerland, and colleagues in this week`s Nature.
The researchers fused magnesium (element 12) and curium (element 96), to obtain just seven atoms of hassium. These were then probed before they decayed, ususally within about ten seconds.
Hassium`s chemistry follows the predictable patterns of the periodic table, reacting with oxygen to form a volatile oxide, HsO4. Such predictable behaviour from elements at the `heavy` end of the periodic table is not to be taken for granted: the inner electrons of atoms with a very large nucleus are moving so quickly that the atoms` behaviour becomes strange, and the theory of relativity must be invoked to explain it.
A News Feature in this week`s Nature tells the story of research into the chemistry of hassium and other heavy elements.
CONTACT:
H. W. G'¤ggeler tel +41 31 631 4264, e-mail Gaeggeler@iac.unibe.ch


[3] LIFELINES: YOU`VE REALLY LET YOURSELF GO (pp865-869; N&V)

A group of microorganisms once thought to be primitive have turned out to be degenerates.
Microsporidia have cells similar to plants, animals and fungi, except they lack mitochondria. This cellular powerhouse is descended from a bacterium that fused with our ancestor. It was thought that microsporidia had split from the evolutionary lineage that led to multicellular life before the fusion took place, about a billion years ago.
But now T. Martin Embley of The Natural History Museum, London, and colleagues have found the remnants of mitochondria inside the microsporidian Trachipleistophora hominis, they report in Nature this week. The structures have shrunk to about one-tenth the size of normal mitochondria, but the presence of up to 50 of them in each cell suggests they still have an important function.
Trachipleistophora is a parasite that lives within cells. Such degeneration is a common feature of a parasitic lifestyle, as the ready supply of food means many structures are no longer needed.
In an accompanying News and Views article, Andrew J. Roger of Dalhousie University in Halifax, Nova Scotia, Canada, and Jeffrey D. Silberman, of the University of California at Los Angeles discusses the implication for our understanding of microbial cell biology and evolution.
CONTACT:
T. Martin Embley tel +44 7942 5059, e-mail tme@nhm.ac.uk
Andrew J. Roger tel +1 902 494 3569, e-mail aroger@is.dal.ca
Jeffrey D. Silberman tel +1 310 206 0249, e-mail jsilber@ucla.edu


[4] PHYSICS: BREAKING THE WAVES (pp839-844; N&V)

The hypnotic sound of breaking waves results from air bubbles being trapped in the water. The size of these bubbles has a major influence on the way gases travel between the ocean and the atmosphere, thereby influencing climate. Researchers have now worked out how many bubbles of each size a wave creates.
Grant B. Deane and Dale Stokes of the Scripps Institute of Oceanography, University of California at San Diego, studied video and photographic images of breaking waves in a laboratory tank full of sea water, counting bubble sizes by hand. They find that the size distribution follows one law for bubbles smaller than about one millimetre, and another for bubbles larger than this.
Big bubbles are formed when the wave curls over on itself, creating the tube beloved of surfers, say the duo. Smaller ones are created by the splash of the wave`s tip hitting its face.
The bubbles carry carbon dioxide into the sea, influencing algal growth and ultimately the ocean`s ability to absorb this gas from the atmosphere. And, when bubbles burst, they throw water droplets into the air, eventually influencing cloud formation. The sound made by a breaking wave also depends on the size of the bubbles formed.
Mark Loewen of the University of Alberta, Edmonton, Canada. discusses these results in an accompanying News and Views article.
CONTACT:
Grant B. Deane tel +1 858 534 0536, e-mail grant@mpl.ucsd.edu
Mark Loewen tel +1 780 492 3447, e-mail mrloewen@civil.ualberta.ca


[5] LIFELINES: HOW EARS BEAT BEATS (pp837-838)

Rock fans be thankful. The minute bundles of hairs called stereocilia that allow us to hear replace themselves every 48 hours.
Stereocilia are found in the inner ear and, like the stylus on a turntable, convert vibrations detected by the eardrum into electrical nerve signals. Bechara Kachar and colleagues at the National Institute on Deafness and Other Communication Disorders in Bethesda, Maryland, now report in a Brief Communication to this week`s Nature that these hairs are being continually regenerated from tip to base and are totally replaced within about two days.
This time frame is roughly how long it takes to recover from temporary hearing loss, suggesting that damaged stereocilia could be to blame for this transient deafness. But the finding could also eventually help explain how hearing develops in newborns, and how certain permanent hearing abnormalities occur.
CONTACT:
Bechara Kachar tel +1 301 402 1600, e-mail Kacharb@nidcd.nih.gov


[6] LIFELINES: SELECTIVELY DEAF (pp872-876; N&V)

Maybe head-bangers could learn a trick from crickets. These insects turn off their ears so as not to deafen themselves with their own song, researchers report in this week`s Nature. The animal`s auditory neurons become less sensitive in synchronization with the wing strokes that produce its chirping call.
James F. A. Poulet and Berthold Hedwig of the University of Cambridge, UK, isolated the different aspects of the cricket`s sound-producing and -perceiving system: its wing muscles, hearing neurons and the brain centres involved in singing. The suppression comes from within the brain, rather than in response to the muscles, they found. This might explain how crickets can tell between their own and other`s calls.
In an accompanying News and Views article, Ron Hoy of Cornell University, Ithaca, New York, discusses these "technically brilliant" experiments.
CONTACT:
James F. A. Poulet tel +44 1223 336 622, e-mail jfap2@cam.ac.uk
Ron Hoy tel +1 607 254 4318, e-mail rrh3@cornell.edu


[7] SPACE: SMOG IN THE SOLAR SYSTEM (pp853-856; N&V)

Saturn`s moon Titan - one of only two satellites in the Solar System with its own atmosphere - is shrouded in smog. In this week`s Nature, researchers track the smog`s motion to explain Titan`s weather.
Puzzlingly, different layers of Titan`s haze seem to move independently. In a computer model, P. Rannou of the University of Paris 6 and colleagues suggest that this is because the smog particles travel from warm climes to cold, and then back to warm, at different levels of the atmosphere. Titan`s seasons, and so the patterns of circulation, are much longer than ours - a year lasts 30 Earth years.
In an accompanying News and Views article, Robert E. Samuelson of the University of Maryland, College Park, discusses how the model proposed by Rannou and colleagues advances our knowledge of Titan`s atmosphere. Apart from smog, Titan is showered by methane hailstones, and the moon`s surface is nearly -200 °C. Europe`s summer flooding and the Asian brown cloud seem benign by comparison.
CONTACT:
P. Rannou tel +33 1 44 27 49 70, e-mail pra@ccr.jussieu.fr
Robert E. Samuelson (also at NASA-Goddard Space Flight Center)
tel +1 301 286 5978, e-mail u3res@lepvax.gsfc.nasa.gov


[8] LIFELINES: FUNGUS HIJACKS PLANT DEFENCES (pp889-892)

A plant disease uses its host`s first line of defence to destroy its second, researchers have found. The finding shows a new weapon in plant pathogens` armoury, and may help us to better protect crops, say Anne Osbourn of the John Innes Centre, Norwich, UK, and colleagues in this week`s Nature.
Plants have some defences against disease and herbivores that are always there, and some that are activated in response to an attack. When it arrives in a tomato plant, the tomato leaf spot fungus (Septoria lycopersici) subverts the first kind of defence, breaking up the poisonous alkaloid molecules in the leaves. This broken-down alkaloid then blocks the signals that the plant uses to switch on its other defences.
CONTACT:
A. Osbourn tel +44 1603 450 407, e-mail Annie.osbourn@sainsbury-laboratory.ac.uk


[9] AND FINALLY: EYES WRITE (p838)

Soon it could be possible for people unable to use their limbs to write nearly twice as fast, more accurately, and comfortably than before, according to a Brief Communication to this week`s Nature.
David Ward and David MacKay at the Cavendish Laboratory in Cambridge, UK, created the new software tool, called Dasher, that interprets the direction of a user`s eye gaze to pick letters and words. It then speeds the process up by guessing what words they are trying to write.
Writing tools that interpret eye movements tracked by cameras are already available, but they rely on on-screen keyboards from which users must select a letter by staring at it. But this process is unnatural and tires the eyes. To get around this, users of Dasher begin by selecting a letter on the screen. The screen then fills with letter pairs beginning with that letter and arranged in alphabetical order. The user then scans this virtual library shelf for the pair that starts the word they want to spell.
This process continues until the computer can guess at the word they are writing. The software guesses even faster when the words are in the context of a sentence, further speeding up writing time. Dasher enables users to scan the screen, more closely mimicking the eye`s natural scanning behaviour - making the tool more comfortable and more accurate to use than an on-screen keyboard. Given training, Dasher can work in most languages, Ward and MacKay claim.
CONTACT:
David J. C. MacKay tel +44 1223 339 852, e-mail mackay@mrao.cam.ac.uk


ALSO IN THIS ISSUE

[10]        Emergent excitations in a geometrically frustrated magnet (pp856-858)

[11]        Mantle compensation of active metamorphic core complexes at Woodlark rift in Papua New Guinea (pp862-865)

[12]        Mechanism of magnesium activation of calcium-activated potassium channels (pp876-880)

[13]        Multiple regulatory sites in large-conductance calcium-activated potassium channels (pp880-884)

[14]        Patched acts catalytically to suppress the activity of Smoothened (pp892-897)

[15]        Dynamics of ATP-dependent chromatin assembly by ACF (pp897-900)


GEOGRAPHICAL LISTING OF AUTHORS

The following list of places refers to the whereabouts of authors on the papers numbered in this release. 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.

CHINA
        Lanzhou: 2

FRANCE
        Paris: 7

GERMANY
        Darmstadt: 2
        Dresden: 2
        Garching: 2
        Mainz: 2

PAPUA NEW GUINEA
        Port Moresby: 11

RUSSIA
        Dubna: 2

SWITZERLAND
        Bern: 2
        Villigen: 2

UNITED KINGDOM
        Cambridge: 6, 9
        Dundee: 3
        London: 3
        Norwich: 8

UNITED STATES OF AMERICA
California
        Berkeley: 2
        Moffett Field: 7
        San Diego: 4, 15
Hawaii
        Manoa: 11
Maryland
        Baltimore: 10, 14
        Bethesda: 5
        Gaithersburg: 10
Massachusetts
        Boston: 11
        Cambridge: 10
Missouri
        St. Louis: 13
New Jersey
        Piscataway: 10
New York State
        New York: 1
        Palisades: 11
Ohio
        Cleveland: 12

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