Hotspots aren't all equally hot, Pleistocene park, Quasicrystals keep out the light, Hair and telomere, The challenges of hepatitis C, A newly discovered pathway to haemoglobin production, Factors provoking lion attacks on Tanzanians



* Ecology: Hotspots aren't all equally hot
* Commentary: Pleistocene park
* Photonics: Quasicrystals keep out the light
* Stem cells: Hair and telomere
* Astrophysics: Bagging bursts swiftly
* Insight: The challenges of hepatitis C
* Materials: The big blue
* Molecular biology: A newly discovered pathway to haemoglobin production
* Atmospheric science: Cleaning agent monitored
* Cell biology: RNAi and viral replication in the worm
* And finally... Factors provoking lion attacks on Tanzanians

[1] Ecology: Hotspots aren't all equally hot (pp 1016-1019; N&V)

Conservationists use hotspots - species-rich areas - to identify
geographical areas that require greatest protection. But scientists disagree
on what type of hotspot best defines such areas. Should the hotspot harbour
the highest number of species in general, the highest number of threatened
species, or the highest number of species restricted to a specific area?
A new global study of the breeding ranges of all known bird species shows
that there is no easy answer. The three hotspot types hardly overlap at all,
report Ian Owens and colleagues in this week's Nature. The authors conclude
that there is no single hotspot type that can be used for setting
conservation priorities.

But "all is not doom and gloom for the hotspots principle," write Hugh
Possingham and Kerrie Wilson in an accompanying News and Views piece. The
study finds that hotspots of endemic species also have high numbers of
threatened species and total species "If resources are expended on
endemic-species hotspots, they are likely to go a long way in protecting
both species-richness and threatened-species hotspots," they conclude.

Ian P. F. Owens (Imperial College London, Ascot, UK)
Tel: +44 20 7594 2215; E-mail: [email protected]

Hugh Possingham (The University of Queensland Brisbane, Australia)
Tel: +61 7 3365 9766; E-mail: [email protected]
<mailto:[email protected]>

Commentary: Pleistocene park (pp 913-914)

A plan to preserve some of our threatened large mammals by restoring proxies
for extinct species to North America is discussed in a Commentary in Nature
this week. Josh Donlan and colleagues present an alternative vision for
twenty-first century conservation biology that they argue is justified on
evolutionary, economic, aesthetic and ethical grounds.

The vision they present involves re-introducing large wild
vertebrates such as elephants, lions, cheetah and horses into North America
- species that are similar to those that would have existed during the
Pleistocene, 13 000 years ago. Donlan and colleagues argue that because we
arepartly responsible for the extinctions in the late Pleistocene and
subsequently forrestricting the evolutionary potential of large mammals, we
have an ethical responsibility to redress the problems. Texas already has
around 77,000 large mammals roaming free on ranches, although their
significance for conservation remains unevaluated. The authors note that
areas of the Great Plains have a declining human population and may offer
future conservation opportunities.

Donlan and colleagues also believe that given the risk of further
large-mammal extinctions in Africa and Asia, the potential of regional
rewilding in North America carries global conservation implications.

Josh Donlan (Cornell University, Ithaca, NY, USA)
Tel: +1 607 227 9768; E-mail: [email protected] <mailto:[email protected]>

[2] Photonics: Quasicrystals keep out the light (pp 993-996)

Quasicrystals look a lot like crystals, but their arrangements of atoms
never repeat exactly. In a crystal, the pattern of atoms repeats at regular
intervals, like patterned wallpaper.

Paul Steinhardt and co-workers show in this week's Nature that quasicrystals
have another crystal-like property: they may be impervious to light within a
certain band of wavelengths, which bounces back as if from a mirror.

Materials that behave this way are said to have a photonic bandgap, and they
could be useful for directing and controlling light signals in optical
technologies such as telecommunications.

Previous photonic-bandgap materials have been crystals, with regularly
repeating units. Steinhardt and colleagues have compared such 'photonic
crystals' with quasicrystals by making large-scale models out of plastic
rods. They joined several thousand one-centimetre rods into a model of the
arrangement of chemical bonds between atoms in diamond - such a structure is
known to have a photonic bandgap - and also into the corresponding
quasi-regular lattice of bonds between atoms in a quasicrystal. In these
scaled-up arrays, photonic bandgaps will appear at longer wavelengths,
corresponding not to visible light but to microwaves.

The researchers found that indeed the quasicrystal lattice would block
microwaves at certain angles, just as the diamond lattice did. As well as
being potentially useful for optical technology, such quasicrystalline
structures might be made at even larger scales to block sound waves.

Paul J. Steinhardt (Princeton University, Princeton, NJ, USA)
Tel: +1 609 258 1509; E-mail: [email protected]

[3] Stem cells: Hair and telomere (pp 1048-1052; N&V)

A connection between stem cell function and a molecule well known for
enabling cells to multiply indefinitely could suggest new ways of treating
disorders associated with tissue injury, ageing and cancer. In this week's
Nature, Steven Artandi and colleagues describe how activating the protein in
skin cells results in rapid hair growth.

Regenerating tissues such as skin and blood requires high rates of cell
turnover, which occurs through the tightly regulated division of tissue stem
cells. The genes and proteins that control stem-cell behaviour remain
largely unknown. Here the authors engineered a transgenic system for
conditionally activating the protein, a component of telomerase called TERT,
in adult tissues. The protein is activated in 90% of human cancers, and
remarkably, its induction in skin activates resting hair follicle stem cells
to initiate the active phase of the hair follicle cycle. This paper
identifies the first activity for TERT that is distinct from its previously
described role of adding caps to the ends of our chromosomes, and suggests
new strategies for manipulating TERT for therapeutic purposes.

Steven Artandi (Stanford University, CA, USA)
Tel: +1 650 736 0975; E-mail: [email protected]
<mailto:[email protected]>

Elizabeth H. Blackburn (University of California at San Francisco, CA, USA)
Tel: +1 415 476 4912; E-mail: [email protected] <mailto:[email protected]>

[4] Astrophysics: Bagging bursts swiftly (pp 985-988; N&V)

The intense X-ray radiation from certain types of exploding massive stars
seems to dim surprisingly quickly, according to research published in this
week's Nature.

Gianpiero Tagliaferri and colleagues report two such explosions seen by
NASA's Swift satellite, which can point its telescopes to focus on sudden
gamma-ray bursts within minutes of picking them up. The 'long' gamma ray
bursts they saw are thought to signal the deaths of particularly massive

Their observations of X-rays from the stars now supports suggestions that
the first burst of energy, lasting less than a few minutes, is produced by
shockwaves within the collapsing star, whereas the longer, less energetic
afterglow is produced by collisions between ejected matter and the material
around the star.

"With the high sensitivity and excellent time coverage of Swift, we are now
witnessing the X-ray light curves in the transition period from prompt
emission to afterglow," comments Dieter Hartmann in a related News and Views

Gianpiero Tagliaferri (Osservatorio Astronomico di Brera, Merate, Italy)
Tel: +39 039 9991127; E-mail: [email protected]

Dieter Hartmann (Clemson University, CA, USA)
Tel: +1 864 656 5298; E-mail: [email protected]
<mailto:[email protected]>

Insight: The challenges of hepatitis C

Combinations of multiple drugs will be required for the successful treatment
of hepatitis C virus (HCV), according to a review article in a special
Insight in this week's Nature. Raffaele De Francesco and Giovanni Migliaccio
argue that the chronic nature of HCV infection means that the disease, which
is estimated to affect 170 million people worldwide, will continue to be a
global health threat for years to come.

The biggest concern in the field of HCV treatment is of the virus
becoming drug-resistant, which it can do quickly, owing to the low fidelity
of HCV replication. The authors describe the problems faced by a lack of
small-animal models for HCV and, until recently, an inability to infect
cultured cells with the virus. Looking to the future, De Francesco and
Migliaccio argue that RNA interference, nucleic-acid-based antiviral agents
and inhibitors of important molecules should all be investigated as the
basis of new treatments. Several new drugs are close to the clinical trial
stage, and it is vital to their success that they not only combat HCV but
prevent the emergence of new mutant strains of the disease.

Elsewhere in the Insight, Michael Houghton and Sergio Abrignani
investigate the prospects for a vaccine that have recently emerged,
following the discovery of natural immunity to HCV and the efficacy of
vaccine treatment in chimpanzee models. This knowledge, coupled with studies
showing that some individuals can clear the virus while others need
antiviral treatment, could help to improve the outcome of work towards
vaccines. David Bowen also looks at the immunological response to the virus,
and in particular, the role of T cells.

The Insight also features reviews on how HCV combats immune
responses, new systems for culturing the virus, past and future directions
for antiviral therapies, and the need for liver transplantation in HCV

[5] Materials: The big blue (pp 997-1000)

Liquid-crystal 'blue phases' can be just about any colour in the rainbow.
This makes them potentially useful for all sorts of applications, from
electrically switchable colour displays to light filters and lasers. But
blue phases have a significant limitation: they exist over a very small
range in temperature, typically no more than two degrees Celsius at most.
Harry Coles and Mikhail Pivnenko report a solution to this instability in
this week's Nature. They have discovered a class of blue-phase liquid
crystals that remain stable over a very much wider range: from 16 to 60
degrees. The researchers show that their ultrastable blue phases could find
some useful applications in optical technology.

Typically, liquid crystals are made from rod-like molecules that line up in
at least one direction while remaining mobile and disorderly in the others.
In blue phases, this alignment of molecules takes a complicated form: the
molecules assemble into cylindrically shaped arrays in which the direction
of alignment twists in a helix, while the helices themselves criss-cross in
three dimensions. The structure repeats regularly every several hundred
nanometres, which means that it reflects visible light of a particular

The new blue phases are made from molecules in which two stiff, rod-like
segments are linked by a flexible chain. The researchers say that this
unusual structure is what makes the blue phase so stable. They show that the
colour of the reflected light can be switched by applying an electric field
to the material, and that this could be used to produce three-colour
(red-green-blue) pixels for full-colour displays.

Harry J. Coles (University of Cambridge, Cambridge, UK)
Tel: +44 12237 41874; E-mail: [email protected]

[6] Molecular biology: A newly discovered pathway to haemoglobin production
(pp 1035-1039)

Haemoglobin proteins in red blood cells have a vital role in delivering
oxygen to tissues throughout the body. A decrease in the production of
haemoglobin, or the haem molecules embedded within haemoglobin, can lead to
anaemia. A study in this week's Nature provides a new link between two
fundamental processes - haem production and the formation of iron-sulphur
clusters on proteins.

Leonard Zon and his colleagues have shown that the anaemia found in
a zebrafish mutant called shiraz is caused by a defect in the glutaredoxin 5
gene. This gene is essential in yeast for the assembly of iron-sulphur
clusters. The research team found that this gene performs the same function
in zebrafish, and that the loss of these assembled iron-sulphur clusters
also prevented the production of haem molecules in mutant zebrafish. Based
on these results, they suggest that a deficiency in iron-sulphur clusters
could be an overlooked cause of anaemia in humans.

Leonard I. Zon (HHMI, Harvard Medical School, Boston, MA, USA)
Tel: +1 617 919 2069; E-mail: [email protected]

[7] Atmospheric science: Cleaning agent monitored (pp 1001-1004; N&V)

Scientists have developed a way to track naturally occurring hydroxyl
radicals, which remove a wide range of trace gases from the atmosphere,
including greenhouse gases such as methane.

In this week's Nature, Martin Manning and colleagues reveal how they infer
concentrations of the reactive hydroxyl radicals by tracking carbon monoxide
containing radioactive carbon atoms (14CO) in the Southern Hemisphere over
thirteen years. This carbon monoxide survives in the atmosphere for about
three months before being oxidized by hydroxyl radicals, and can therefore
be used to identify short-term variations in hydroxyl-radical

The team find short-term variations of around ten per cent in hydroxyl
concentrations persisting for a few months, but no significant long-term
trend over the thirteen years up to 2003. They also note that natural
events, such as the eruption of Mount Pinatubo in 1991 and the Indonesian
forest fires in 1997, can deplete hydroxyl-radical concentrations by up to
twenty per cent.

"Atmospheric chemists have been struggling to estimate how much the hydroxyl
radical concentration varies in space and time," comment Patrick Jöckel and
Carl Brenninkmeijer in a related News and Views article. "Manning and
colleagues' approach constitutes a big step forward."

Martin R. Manning (IPCC Working Group I Support Unit, Boulder, CO, USA)
Tel: +1 303 497 4479; E-mail: [email protected]

Patrick Jöckel (Max Planck Institute for Chemistry, Mainz, Germany)
Tel: +49 613 130 5452; E-mail: [email protected]
<mailto:[email protected]>

[8] & [9] Cell biology: RNAi and viral replication in the worm (pp 1040-1043
& 1044-1047)

Researchers have relied on the worm Caenorhabditis elegans to study many
aspects of cell biology, including the hot topic of RNA interference (RNAi),
a process by which small RNA molecules directly regulate gene expression.
RNAi is proposed to have antiviral functions, but C. elegans has never been
observed to support viral replication, making it an unsuitable model
organism for studying RNAi-mediated antiviral responses.

Now, studies appearing in Nature from two teams of researchers have
demonstrated that the worm can in fact support viral replication. Shou-Wei
Ding and colleagues show complete replication of the Flock house virus in C.
elegans. The team also found that this process activates the C. elegans RNAi
pathway to specifically destroy the infecting virus RNA.

Similarly, Marie Chow and her fellow researchers show that a mammalian
pathogen called vesicular stomatitis virus (VSV) can replicate inside the
worm, and that RNAi is activated as an immune defence mechanism during VSV
infection. Both studies suggest that C. elegans may prove a useful model
system for the study of host-virus interactions - including the antiviral
effects of RNAi.

Shou-Wei Ding (University of California, Riverside, CA, USA)
Tel: +1 951 827 2341; E-mail: [email protected]

Marie Chow (University of Arkansas for Medical Sciences, Little Rock, AR,
Tel: +1 501 686 5155; E-mail: [email protected]

[10] And finally... Factors provoking lion attacks on Tanzanians (p 1101)

Increases in Tanzania's human population has reduced the territory and prey
that is available to its lions - the largest population of these animals in
Africa. This has led to a rise in the number of lion attacks on humans over
the past 15 years, which is placing lion conservation efforts in jeopardy. A
Brief Communication in this week's Nature reports on the common factors
surrounding these attacks, and suggests how to ease the conflict between man
and beast.

Lion attacks between 1990 and 2004 have killed more than 563 Tanzanians and
injured at least 308. Craig Packer and his colleagues found that almost 40%
of the attacks on villagers happened during the harvest season, and that
more than a quarter of the attacks occurred in the fields. At harvest time,
farmers sleep in makeshift huts to protect their crops against nocturnal
invasion by bush pigs (Potamochoerus larvatus), which, besides being prey to
lions, are also voracious crop pests. There were more lion attacks on humans
in districts where natural prey was scarce but in which there was an
abundance of bush pigs - these two factors accounted for 76% of the lion
attacks per district.

Although it is not feasible to relocate people, or to increase the numbers
of natural prey in these agricultural areas, controlling the numbers of bush
pigs in these regions would make them less attractive hunting grounds for
the lions. It would also reduce the need for farmers to sleep in their

Craig Packer (University of Minnesota, St Paul, MN, USA)
Tel: +1 612 625 5727; E-mail: [email protected] <mailto:[email protected]>


[11] Exotoxin A-eEF2 complex structure indicates ADP ribosylation by
ribosome mimicry (pp 979-984)

[12] Young chondrules in CB chondrites from a giant impact in the early
Solar System (pp 989-992)

[13] In situ Os isotopes in abyssal peridotites bridge the isotopic gap
between MORB and their source mantle (pp 1005-1008)

[14] Earthquake rupture dynamics frozen in exhumed ancient faults (pp

[15] Silurian brachiopods with soft-tissue preservation (pp 1013-1015)

[16] Local translation of RhoA regulates growth cone collapse (pp

[17] ERM is required for transcriptional control of the spermatogonial
stem cell niche (pp 1030-1034)

[18] Endonucleolytic processing of covalent protein-linked DNA
double-strand breaks (pp 1053-1057)

[19] Absolute negative particle mobility (p 1102)


***This paper will be published electronically on Nature's website on 17
August 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 18 August, but at a later date.***

[20] WntD is a feedback inhibitor of Dorsal/NF-kB in Drosophila
development and immunity
DOI: 10.1038/nature 04073


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.

Sydney: 13

Guelph: 11
Hamilton: 17
Ottowa: 14

Aarhus: 11

Montpellier: 13
Paris: 12, 13

Bielefeld: 19
Tubingen: 6

Frascati: 4
Merate: 4
Milan: 4
Monteporzio: 4
Padua: 14
Palermo: 4
Rome: 14

Eindhoven: 2

Wellington: 2

Basel: 17

Taipei: 1

Arusha: 10

Ascot: 1
Cambridge: 1, 5
Edgbaston: 1
Leicester: 4, 11
London: 1, 15
Milton Keynes: 13
Oxford: 15
Sheffield: 1

Little Rock: 9
Mountain View: 12
Riverside: 8
South San Francisco: 17
Stanford: 3, 20
Boulder: 7
New Haven: 15
District of Columbia
Washington: 4, 13
Honolulu: 4
Carbondale: 17
Urbana: 17
Baltimore: 4
Columbia: 4
Frederick: 11
Greenbelt: 4
Boston: 6
East Lansing: 1
St. Paul: 10
St. Louis: 17
New Jersey
Princeton: 2
New York
New York: 2, 16, 18
Rochester: 6
Dayton: 17
Philadelphia: 1
University Park: 4
Memphis: 9
Austin: 4, 16
Dallas: 17
Houston: 16
Salt Lake City: 6
Pullman: 17

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]

Editorial contacts: While the best contacts for stories will always be the
authors themselves, in some cases the Nature editor who handled the paper
will be available for comment if an author is unobtainable. Editors are
contactable via Ruth Francis on +44 20 7843 4562. Feel free to get in touch
with Nature's press contacts in London, Washington and Tokyo (as listed at
the end of this release) with any general editorial inquiry.

Warning: This document, and the Nature papers to which it refers, may
contain information that is price sensitive (as legally defined, for
example, in the UK Criminal Justice Act 1993 Part V) with respect to
publicly quoted companies. Anyone dealing in securities using information
contained in this document or in advanced copies of Nature's content may be
guilty of insider trading under the US Securities Exchange Act of 1934.
The Nature journals press site is at <>

* PDFs for the Articles, Letters, Progress articles, Review articles,
Insights and Brief Communications in this issue will be available on the
Nature journals press site from 1400 London time / 0900 US Eastern time on
the Friday before publication.
* PDFs of News & Views, News Features, Correspondence and Commentaries
will be available from 1400 London time / 0900 US Eastern time on the Monday
before publication

PICTURES: While we are happy for images from Nature to be reproduced for the
purposes of contemporaneous news reporting, you must also seek permission
from the copyright holder (if named) or author of the research paper in
question (if not).

HYPE: We take great care not to hype the papers mentioned on our press
releases, but are sometimes accused of doing so. If you ever consider that a
story has been hyped, please do not hesitate to contact us at
[email protected] <mailto:[email protected]>, citing the specific example.


Nature Publishing Group (NPG) is a division of Macmillan Publishers Ltd,
dedicated to serving the academic and professional scientific community.
NPG's flagship title, Nature, is the world's most highly-cited weekly
multidisciplinary journal and was first published in 1869. Other
publications include Nature research journals, Nature Reviews, Nature
Clinical Practice, and a range of prestigious academic journals, including
society-owned publications.

NPG is a global company, with headquarters in London and offices in New
York, San Francisco, Washington DC, Boston, Tokyo, Paris, Munich and
Basingstoke. For more information, please go to

Published: 17 Aug 2005

Contact details:

The Macmillan Building, 4 Crinan Street
N1 9XW
United Kingdom

+44 20 7833 4000
News topics: 
Content type: