Genetic susceptibility to Crohn disease
A genome-wide assessment of genetic variation in individuals with Crohn disease has identified seven genes or regions that are associated with elevated risk of the disease, according to a study.Three of the genes were previously known, but four are newly associated with the disease.
Crohn disease is one of the most common forms of inflammatory bowel disease, affecting 100–150 per 100,000 individuals of European ancestry. John Rioux and colleagues assessed more than 300,000 genetic variants in individuals with Crohn disease, as well as controls, and identified three previously reported risk factors (CARD15, IL23R, and ATG16L1), and four new ones (PHOX2B, NCF4, FAM92B, and a region on chromosome 10).
In combination with other studies, these ‘genome-wide association studies’ promise to flesh out the entire catalogue of genetic variants that predispose to Crohn disease, as well as provide new insight into the causes of the disease. In this case, the authors show that ATG16L1 might have a role in the degradation and processing of bacteria by the body’s inflammatory response—a process known as autophagy. This is consistent with other evidence that an inappropriate response to bacteria in the gut is important in the initiation of Crohn disease.
Author contact:
John Rioux (University of Montreal, Québec, Canada)
Tel: +1 514 376 3330; E-mail: rioux@broad.mit.edu

IMPORTANT ANNOUNCEMENT AND INFORMATIONS
EAGLES Health Lecturer Tour Grants
The European Action on Global Life Sciences (EAGLES) Health Programme is offering grants of up to €5,000 to leading biomedical scientists and other health specialists, including commentators and journalists, from developing countries to undertake lecture tours around Europe to communicate the needs of developing countries to the European public and European institutions. Applications should be submitted before 11 June 2007. Further details can be found on the EAGLES website: www.efb-central.org/eagles/site.

International Workshop on Cities, Science and Sustainability
An international workshop examining successful approaches to 'cities, science and sustainability' will be held at TWAS's headquarters in Trieste, Italy, from 20 to 22 September 2007. Institutions in developing countries are invited to respond by 1 July 2007 indicating their interest in participating in the workshop and presenting a report highlighting successful initiatives in using science and technology in solving problems of sustainability associated with large urban areas, including (but not limited to) access to safe drinking water, sanitation, air pollution, housing and construction, land use planning, transport, traffic congestion and waste disposal in a city in the developing world. The project 'Cities, Science and Sustainability' is a collaborative effort between TWAS, the Consortium for Science, Technology and Innovation for the South (COSTIS) and the United Nations Development Programme's Special Unit for South-South Cooperation (UNDP-SSC).

African Materials Research Conference in December
The 4th International Conference of the African Materials Research Society will be held in Dar-es-Salaam, Tanzania, from 10 to 14 December 2007. Main topic of the conference: "Cementing Collaborations in Materials Research in Africa." Deadline for pre-registration and abstracts: 30 June 2007


Award in Medical Sciences in the UAE
The 'Sheikh Hamdan Bin Rashid Al Maktoum Awards for Medical Sciences' (SHAMS) are accepting nominations in three categories: international, Arab world, and UAE. The awards honour "medical researchers worldwide who enrich scientific research and enhance the nature of scientific exchanges among medical doctors in UAE and medical centers abroad." Deadline for nominations is November. For more information on the Awards, please visit: www.hmaward.org.ae

Fossils: Tell it to the trees
A spectacular fossilized tree gives an unprecedented insight into the appearance of the world’s earliest forests.
William E. Stein and colleagues found their fossil tree in Schoharie County, New York. It stood at least eight metres high with fern-like branches, a long trunk and small anchoring roots. Its crown belongs to a previously known plant taxon, the cladoxylopsid Wattieza. But its trunk and base match a different group, named Eospermatopteris.
The evolution of trees was fundamental to the Earth’s terrestrial ecosystem. And until now, the earliest-known evidence of forests came from fossil tree stumps found in Gilboa, New York, that are about 385 million years old. The trees were designated Eospermatopteris but their aerial portions were missing. The new find sheds light on their possible full appearance.
CONTACT
William E. Stein (State University of New York, Binghamton, NY, USA)
Tel: +1 607 777 4391; E-mail: stein@binghamton.edu
Albert Gnidica (Media Relations, New York State Museum, NY, USA)
Tel: +1 518 474 0068 or +1 518 474 8730; E-mail: Agnidica@mail.nysed.gov
Brigitte Meyer-Berthaud (CIRAD-CNRS, Montpellier, France) N&V author
Tel: +33 4 67 61 75 22; E-mail: meyerberthaud@cirad.fr

Geology: The big melts
The Earth’s continental crust was not formed gradually but in stages, punctuated by large, potentially global, melting events. A report analyses the helium isotopic ratios from ocean island basalts, which reveal several distinct episodes of crustal growth.
Most Earth scientists agree that the continental crust formed by a process of partial melting from the mantle, although the timing and details of this process has remained controversial. Stephen Parman studied the chemical fingerprint of continental crust formation in the isotopic composition of helium isotopes recorded in ocean island basalts. The volatility of helium isotopes means that they are not reintroduced into the mantle during subduction and the record of mantle depletion is thus preserved for helium, whereas most other isotopes are continually recycled by mantle convection, largely obscuring such a record.
Parman found that peaks in the occurrence of helium isotope ratios are globally consistent and correspond with the ages of what have been proposed to be continental growth pulses. He concludes that the ultimate cause of these large melting events is still unclear, but could be related to large releases of heat from the mantle.
CONTACT
Stephen Parman (University of Durham, UK)
E-mail: stephen.parman@durham.ac.uk
Please note that the author is travelling in the US but should be contactable by email and mobile: Tel: +1 302 588 7369
Don Porcelli (University of Oxford, UK) N&V author
Tel: +44 1865 282 121; E-mail: don.porcelli@earth.ox.ac.uk

Quantum physics: Losing a grip on realit
It seems common sense that an object will retain its fundamental properties regardless of whether or not we are looking at it. But in the microscopic quantum world, everyday rules do not apply. Even our concept of reality may be challenged.
Classical physics clings tightly to the notions of realism (where external reality exists independent of observation) and locality (where sufficiently distant objects cannot influence each other). Quantum experiments in which the properties of distant but entangled particles are linked seem hard to reconcile with such notions, making local realistic theories untenable.
Markus Aspelmeyer, Anton Zeilinger and colleagues developed an inequality that relaxes the assumption of locality, allowing a test of non-local realism. They studied correlations between pairs of entangled photons, and found that the correlations violate non-local realistic theories. The result suggests that giving up the concept of locality is not sufficient to be consistent with quantum experiments, unless certain intuitive features of realism are abandoned.
CONTACT
Markus Aspelmeyer (University of Vienna, Austria)
Please contact the author through:
Ursula Gerber (University of Vienna, Austria)
Tel: +43 1 4277 51205; E-mail: ursula.gerber@univie.ac.at
Alain Aspect (Institut d'Optique, Palaiseau, France) N&V author
Tel: +33 1 64 53 31 03; E-mail: alain.aspect@institutoptique.fr

Announcement-Four leading researchers from Japan and the UK meet in London to present:
“Frontiers of Neuroscience” Major advancements in medical research and their applications
Keio University, University College London (UCL), and Japan Society for the Promotion of Science (JSPS), London Office will host the Keio University 150th Anniversary International Symposium, “Frontiers of Neuroscience”. Four leading scholars specialising in neuroscience will present their cutting-edge research and discuss its potential for curing today’s most devastating injuries and diseases of the brain. The event, which is free and open to the public, will take place on April 27 from 3 p.m. to 6 p.m. at UCL’s Cruciform Lecture Theatre 2, Gower Street, London, UK.
Two island countries, two universities, four scientists and an office
Two universities, on two island countries at either end of the Eurasian continent, have played a leading role in the liberalisation of science and education from their respective beginnings, in 1826 (UCL) and 1858 (Keio), that continues today. Four pioneering scientists, two from each university, will gather on the UCL campus for an international symposium exploring issues surrounding ground-breaking advancements in neuroscience and related topics relevant to our current, fast-changing society. In addition to promoting collaboration between the three participating organizations and celebrating the 150th anniversary of Keio University, the event will commemorate the launch of the Keio University London Office, established in alliance with JSPS.
Frontiers of Neuroscience – Opportunities for better understanding ourselves –
Keio University’s Prof Hideyuki Okano is a specialist in damaged Central Nervous System (CNS) regeneration. His current research is breaking new ground in adult neurogenesis (birth of new neuronal cells) and brain damage repair, and may open up a number of possibilities including therapeutic intervention for spinal cord injuries and treatments for neurodegenerative disorders including Alzheimer's disease. He will discuss both the principles of regeneration and his research group’s latest findings. Prof Masato Yasui, also from Keio University, specialises in a class of integral membrane proteins known as aquaporin, which functions as a channel for transporting water through biological cell membranes. Aquaporin is a recent discovery, and has led to a series of studies into its relation to a wide range of human diseases. Prof Yasui’s interest is in aquaporin-4 (AQP4), a particular type of aquaporin that is predominantly expressed in mammalian brains. On the basis of precedent findings, including its involvement in brain edema formation, he will discuss potential connections between AQP4 and mental disorders such as bipolar diseases.
Participating scientists from UCL are prominent authorities on the fundamentals of brain function. Prof Richard Frackowiak, a specialist in brain plasticity and recovery from injury, is conducting pioneering research that is serving to clarify the relationship between the brain’s functions and its physical structure. His lecture will focus on brain organisation as observed using advanced imaging technologies and methods. Prof Semir Zeki’s research focuses on the relationship between vision, art and the brain. He has lectured on the subject worldwide and is the founder of the Institute of Neuroesthetics. His insightful and careful analyses suggest that visual consciousness is distributed in both time and space. Prof Zeki will discuss the nature of visual consciousnesses in his lecture.
The symposium will begin with a welcome from Prof Yuichiro Anzai, president of Keio University and an eminent cognitive scientist, followed by the four lectures and a panel discussion. It will conclude with a reception at 6 p.m.
Members of the press are invited to attend the symposium, which is free and open to the public. Interview requests can be forwarded to press contact Juli Morizawa (Ms) or Akiko Kurata (Ms).
For more information and to register, visit http://keio150.jp/english/events/2007/20070427e.html or email sympo-rsvp@adst.keio.ac.jp.
General Inquiries: Yuko Sakuma (Ms)
International Programme Coordinator, Keio University London Office, UK
Email: sympo-rsvp@adst.keio.ac.jp 　Tel: (020) 7629 3577 Fax: (020) 7629 3588
Media Inquiries: Juli Morizawa (Ms), Akiko Kurata (Ms)
Office of Communications and Public Relations, Keio University, Japan
Email: m-koho@adst.keio.ac.jp　 Tel: +81-3-5427-1541 Fax: +81-3-5441-7640
Meeting information
“Frontiers of Neuroscience” April 27 (3 p.m. to 6 p.m.) at UCL’s Cruciform Lecture Theatre 2, Gower Street, London, UK.

Frontiers of Neuroscience - Major advancements in medical research and their applications
hosted by
Keio University, Japan
University College London, UK and Japan Society for the Promotion of Science
Friday April 27, 2007
3:00-6:00pm Entry Free Cruciform Lecture Theatre 2, UCL
Gower Street, London WC1
It is with great pleasure that Keio University, University College London, and Japan Society for the Promotion of Science (JSPS) invite you to the first Keio University 150th Anniversary International Symposium on “Frontiers of Neuroscience”.
Keio University is the oldest modern comprehensive university in Japan and will celebrate its 150th anniversary in 2008. It takes pride in having led Japanese society through innovations in both research and education from its earliest years when founder Yukichi Fukuzawa, who travelled to Europe as early as 1862, became convinced that Japan should transform itself through the introduction of western learning. In reaching this important milestone in its history, Keio is redoubling its commitment to strengthening its international profile and enhancing its global activities. To advance this endeavor, Keio has organized this symposium to highlight the university’s School of Medicine, renowned in Japan for its world-class and cutting-edge research and education, and has invited two of its distinguished academic members to participate.
Today, both the UK and Japan face the daunting reality of having become rapidly aging societies, largely as a result of major advancements in medical research and their applications. It is therefore timely and relevant for leading researchers in both countries to cooperate and share the results of their respective cutting-edge research activities in this field. It is a great pleasure for Keio University to co-host this event with University College London, the institution that introduced systematic medical education to England, and to welcome two of its leading professors as participants. The symposium will provide an opportunity to exchange current knowledge and research outcomes between UK and Japan at the highest level, which will be of interest both to academic experts and the general public.
This symposium will also commemorate the launch of the Keio University London Office, established in alliance with the JSPS London Office, a Japanese non-governmental organization committed to promoting bottom-up UK-Japan research collaboration. It is anticipated that this event will be the first of many joint activities advancing UK-Japan relations stimulated by the new partnership.

Speakers (In alphabetical order)

Professor Richard SJ Frackowiak
Vice-Provost (Special Projects)
Wellcome Department of Imaging Neuroscience, Institute of Neurology
University College London

Professor Hideyuki Okano
Department of Physiology
Keio University School of Medicine

Professor Masato Yasui
Professor and Chair, Department of Pharmacology
Keio University School of Medicine, Tokyo Japan

Professor Semir Zeki
Wellcome Department of Imaging Neuroscience
University College London

Programme

15:00-15:10 Opening address - Keio President Yuichiro Anzai
15:10-15:15 Introduction to the symposium - Professor Hideyuki Okano
15:15-15:40 "Modern Human Brain Imaging: structure-function correlations" Professor Richard Frackowiak
15:40-16:05 "Water Neurobiology: potential roles of water channel, aquaporin" Professor Masato Yasui
16:05-16:30 "Challenges toward Regeneration of the Damaged Central Nervous System" Professor Hideyuki Okano
16:30-16:55 " The Many Consciousnesses of the Brain " Professor Semir Zeki
16:55-17:15 Break
17:15-17:45 Panel discussion and Q& A
Chair: Professor Hideyuki Okano
Panelists:
President Yuichiro Anzai
Professor Richard SJ Frackowiak
Dr. Yukio Nishizawa, Research Director, Eisai London Research Laboratories
Professor Masato Yasui
Professor Semir Zeki

17:45-17:50 Closing address Ms. Yuko Furukawa, Director, JSPS London Office
-----------------------------------------------------------

18:00-19:30 Reception at the South Cloisters

While serving as a forum for advanced academic exchange, the program is designed to be accessible to all audiences. Admission is free of charge and open to the public.

Advance registration is required: sympo-rsvp@adst.keio.ac.jp (English and Japanese)
Event details: http://keio150.jp/english/events/2007/20070427e.html

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Punish the rich- games of experimental economics We’re more likely to punish the rich than the poor, at least in games of experimental economics. The strategy is emotionally driven and the results suggest that human social behaviour is influenced by egalitarian motives.
James H. Fowler and colleagues set up a game where players were randomly allocated different sums of money, and were then able to ‘reward’ or ‘punish’ others by giving or taking money away. The richest players were penalized the hardest, whereas the poorest players were penalized the least.
The results show that people will reduce and increase others’ incomes at a personal cost, even when there is no cooperative behaviour to be reinforced. Their decisions are emotionally led, and the size and frequency of income alternations are strongly influenced by inequality — the pattern of punishments is designed to minimize inequality between the richest and poorest. The study suggests that egalitarian motives affect whether or not we donate cash to others, and this may be an important factor underlying the evolution of cooperation in humans.
CONTACT
James H. Fowler (University of California San Diego, La Jolla, CA, USA)
Tel: +1 858 534 6807; E-mail: jhfowler@ucsd.edu

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Photochemistry: Quantum tricks in photosynthesis
The weird world of quantum physics meets biology with the discovery that quantum mechanical effects appear to play a role in photosynthesis.
Graham R. Fleming and colleagues used spectroscopy to study what happens inside a bacteriochlorophyll complex, and detected a ‘quantum beating’. The effect occurs when light-induced excitations in the complex meet and interfere constructively — much like the interactions that occur between the ripples formed by throwing stones into a pond.
Photosynthesis is the all-important process that transforms light, carbon dioxide and water into chemical energy in plants and some bacteria. This wavelike characteristic of this energy transfer process can explain its extreme efficiency, in that vast areas of phase space can be sampled effectively to find the most efficient path for energy transfer.
CONTACT
Graham R. Fleming (Lawrence Berkeley National Laboratory & University of California, Berkeley, CA, USA)
Tel: +1 510 643 2735; E-mail: fleming@cchem.berkeley.edu or grfleming@lbl.gov
Roseanne J. Sension (University of Michigan, Ann Arbor, MI, USA) N&V author
Tel: +1 734 763 6074; E-mail: rsension@umich.edu

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Smart materials: A light touch (pp 778-781; N&V)

Researchers have developed crystals that will change their shape repeatedly when exposed to different types of light. The discovery may aid the development of light-driven actuators — mechanical devices that move or control things.
The molecular crystals, developed by Masahiro Irie and colleagues, are based on a particular type of light-absorbing molecule and range from 10 to 100 micrometres in size. When ultraviolet light is shone on one type of crystal, it changes shape from a square to a lozenge. But when the same crystal is exposed to visible light, it undergoes another mechanical deformation to change back to its original form. When put in the spotlight, a rod-shaped crystal of the material attached to a surface will even oblige and use this effect to 'bat' away a micrometre-sized gold particle.
The system is stable and responds quickly, within microseconds. Previous light-responsive systems, made from liquid crystals or polymer gels, can change shape but the effect takes seconds or longer and the deformed states are unstable. And the beauty of using light as a stimulus is that it offers the intriguing prospect of actuators that can be operated remotely.
CONTACT
Masahiro Irie (Rikkyo University, Tokyo, Japan)
Tel: +81 3 3985 2397; E-mail: irie@cstf.kyushu-u.ac.jp
J. Michael McBride (Yale University, New Haven, CT, USA) N&V author
Tel: +1 203 432 3926; E-mail: j.mcbride@yale.edu


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Cancer: Genes set scene for metastasis
Biologists have identified a set of genes expressed in human breast cancer cells that work together to remodel the vasculature at the site of the primary tumour and that also promote the spread of cancer to the lungs. The finding helps to explain how cancer metastasis can occur and highlights targets for therapeutic treatment.
Metastasis is the leading cause of mortality in cancer patients. A number of genes are already known to contribute to the spread of breast cancer cells to the lungs. But Joan Massagué and colleagues now show how four genes cooperate to promote the formation of new tumour blood vessels, the release of cancer cells into the bloodstream, and the penetration of tumour cells from the bloodstream into the lung.
The gene set comprises EREG, MMP1, MMP2 and COX2; drug combinations that target more than one of these components may prove useful for treating metastatic breast cancer.
CONTACT
Joan M Massague (Memorial Sloan-Kettering Cancer Center, Howard Hughes Medical Institute, New York, NY, USA)
Please contact:
Esther Napolitano (Public Affairs, Memorial Sloan-Kettering Cancer Center, New York, NY, USA)
Tel: +1 646 227 3139; E-mail: napolite@mskcc.org
Gerhard Christofori (University of Basel, Switzerland) N&V author
Tel: +41 61 267 3562 E-mail: gerhard.christofori@unibas.ch

Cancer: Genes linked to chemotherapy response
Scientists have identified a number of genes in lung cancer cells which, when downregulated, make the cancer cells especially vulnerable to a type of chemotherapy. The study highlights a new way to screen for alterations in cancer cells that make them specifically sensitive to therapeutics, so that treatment may leave normal tissue relatively unharmed.
Michael A. White and colleagues used a genome-wide RNA interference screen to identify 87 genes that are involved in the response of cancer cells to paclitaxel. Reducing the expression of a number of these genes sensitizes lung cancer cells to paclitaxel at concentrations 1,000-fold lower than otherwise needed for a significant response. Some of the identified genes are already targets of currently available compounds and could be tested for responses to combinations of drugs, whereas others could be new therapeutic targets.
CONTACT
Michael A. White (University of Texas Southwestern Medical Center, Dallas, TX, USA)
Tel: +1 214 648 2861; E-mail: michael.white@utsouthwestern.edu

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Herbal supplement may help treat recurrent bladder infections
Washington, Apr 9 -An herbal extract that is sold in
health food stores and promoted as an allergy and fat loss aid
may improve treatment of bladder infections when it is taken
with antibiotics, research suggests.
Some 90 per cent of bladder infections are caused by E.
coli bacteria. They affect women four times more often than
men, sometimes recurring over and over.
The bladder is lined with small pouches that allow it to
stretch as it fills. Researchers at Duke University reported
in yesterday's online edition of Nature Medicine that some
bacteria were able to hide in those pouches, escaping the
antibiotics used to treat the infection.
In tests in mice, the extract forskolin can cause the
pouches to kick out the bacteria, allowing antibiotics to
kill them, said the lead researcher, microbiologist Soman N.
Abraham. Forskolin is derived from the Indian coleus plant.
"If we combine this with antibiotics we would be in a
very good position to eradicate urinary tract infection," he
said in a telephone interview.
In the experiments, forskolin was injected into some
mice and placed directly into the bladders in others, Abraham
said.
The extract is available in health food stores and some
people take it by mouth as a supplement, he said. It is
promoted as a treatment for allergies, breathing problems and
even fat loss.
That availability does "absolutely not" mean people
should attempt to treat themselves for bladder infections,
Abraham said.

IT IS A DOG STORY
Scientists First to Isolate a Single Gene Common to All Small Dogs
From the smallest Chihuahua to the largest Great Dane, dogs dramatically vary in size, much more than most other animals. Now scientists have discovered a genetic basis for this diversity.
A new study published in research journal Science reveals a genetic marker that may determine whether dogs are big or small, and helps answer a burning question in genetics -- how could dogs as a species have such a tremendous variation in size?
"This study is a major milestone in canine genetics, made possible by the help of thousands of dog owners around the world. Together with a team of leading international researchers, we have precisely located the major gene that produces our miniature breeds," said co-author Paul G. Jones, PhD, a genetics researcher at Mars -- a world leader in pet care that has been researching canine genetic science for the last seven years.
Dogs were one of the earliest animals to be domesticated more than 15,000 years ago, although people and wolves have coexisted for some 400,000 years. While all dogs originated from wolves, which are of a fairly standard size and appearance, modern dog breeds display a wide diversity of traits, including size. The genetic origin of this diversity has baffled scientists, who have been trying to explain how and why size difference occurred so rapidly in dogs. It is now thought that a change in the gene detailed in the published paper resulted in the appearance of small dogs in the population many thousands of years ago. It is likely that people soon saw the benefits of smaller dogs, for example for protecting food stores from vermin or catching small game. This further strengthened the bond between people and dogs and led to increasing popularity of smaller dogs as companions.
The international team of researchers -- ranging from scientists at the National Human Genome Research Institute, Cornell and other leading universities in the U.S. to Mars scientists in the United Kingdom -- used 3,200 dog DNA samples provided by Mars Incorporated, which holds the most comprehensive canine genetic database in the world. This has been built up with the help of pet owners who consent to their pets providing saliva and blood samples for the database. Mars' genetic data allowed the study to fill the gap between giant and miniature breeds ensuring coverage across the entire range of sizes of breeds we have today.
"These findings are just the tip of the iceberg in canine genetics," Jones said. "We are well on our way to identifying additional genes that can provide valuable insights into our pets."
With the dog genome now fully mapped, scientists are discovering a range of potential benefits of DNA-based information on man's best friend.
"The ability to isolate a specific genetic marker in such a quick and effective manner has tremendous implications for the future," Jones said. "Applications of this cutting-edge science could be used to develop products that will benefit the health of pets -- for example, developing individualized preventative care plans for dogs that are susceptible to certain diseases will help pet owners and veterinarians. In addition, genetic information about size and behavioral traits, such as trainability and temperament could also help veterinarians identify the most lifestyle-appropriate pet for an owner. "
Dog Facts
Dogs have one of the widest variations in size of any species. The adult bodyweights of the largest breeds are up to 70 times more than those of the smallest breeds. According to the American Kennel Club, in 2006 the most popular large-breed dogs in the USA were the Labrador Retriever, the German Shepherd Dog and Golden Retrievers; the most popular small-breed dogs were Yorkshire Terriers, Dachshunds and Shih Tzus.


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METHODS : Enrichment of metabolites with chemical probes

A general strategy for enriching various classes of metabolites directly from biological samples is described.The method allows researchers to profile small molecule metabolites that are difficult to detect with more conventional discovery-based methods.
The proteomics community has greatly benefited from chemical enrichment methods allowing the targeted isolation of proteins with similar functional or structural properties. The ‘metabolome,’ or entire spectrum of small molecules found in an organism, is even greater than the proteome in terms of numbers and chemical complexity. Benjamin Cravatt and colleagues reasoned that metabolomics researchers would therefore also benefit from targeted chemical enrichment strategies.
The authors synthesized chemical probes to target specific functional groups on small molecules. The probes were attached to a solid bead for easy isolation of the captured small molecules. The captured metabolites were then released from the probe and analyzed by liquid chromatography-mass spectrometry. They demonstrated that the method was able to isolate and profile low mass and polar small molecules, which are usually missed with conventional analysis without enrichment.

Author contact:
Benjamin Cravatt (The Scripps Research Institute, La Jolla, CA, USA)
Tel: +1 858 784 8633; E-mail: cravatt@scripps.edu

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IMMUNOLOGY : How one’s own DNA can cause autoimmunity







A study may shed light on the cause of immune activation associated with systemic lupus erythematosus (SLE) – the second most common autoimmune disease in humans.
Found more often in women than in men, SLE is associated with the abnormal production of antibodies that ‘attack’ normal molecules in the body, including a person’s own DNA. As a result, debilitating inflammation, including skin rashes, hypertension, arthritis, and kidney and nervous system problems, ensues. Anthony Coyle and colleagues studied a protein called HMGB1 that normally binds to DNA in the cell nucleus. HMGB1 is also found in blood plasma, where it can bind to DNA released from dying cells. In many SLE patients, such DNA is also often the target of ‘abnormal’ lupus antibodies. As a result, antibody–HMGB1–DNA protein complexes form. The new study by Coyle and colleagues finds that antibody–HMGB1–DNA complexes in blood plasma from SLE patients can stimulate immune cells to produce potent inflammatory proteins associated with autoimmunity.
By demonstrating a role for HMGB1 in SLE inflammation, Coyle and colleagues provide unique insight into the pathogenesis associated with increasingly prevalent autoimmune diseases such as SLE. However, whether blocking the inflammatory function of HMGB1 will help SLE patients remains a question for future investigation.

Author contact:
Anthony Coyle (MedImmune Inc, Gaithersberg, MD, USA)
Tel: +1 301 398 4520; E-mail: coylea@medimmune.com


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NEUROSCIENCE : Stabilization contra retardation

A paper published online in Nature Neuroscience this week explores the mechanisms underlying fragile X syndrome – the most common inherited form of mental retardation. This disorder is caused by loss of a protein, dubbed FMRP, which interacts with messenger RNAs. (mRNAs are the templates that a cell ‘reads’ to correctly build specific proteins.) The details of how FMRP affects mRNAs and protein synthesis, and how subtle misregulation in absence of FMRP causes mental retardation, are still unclear.
Claudia Bagni and Kirsten S. Dickson and colleagues now report that FMRP stabilizes the mRNA that encodes the protein PSD-95. PSD-95 is crucial for the structure and function of neural synapses. In the brains of mice lacking FMRP, the authors found that the PSD-95 mRNA was rapidly degraded. The level of PSD-95 protein was reduced especially in the hippocampus, a structure crucial for learning, memory and certain kinds of reasoning.
This work suggests an important role for mRNA stabilization in the circuit wiring and communication of nerve cell networks. Though it is unlikely that all fragile X mental retardation symptoms can be explained by instability of PSD-95 mRNA, it may well represent an important part of the disease mechanism.
Author contacts:
Claudia Bagni (Universita di Roma, Italy)
Tel: +39 06 501 703 213; E-mail: claudia.bagni@uniroma2.it
Kirsten S. Dickson (University of Edinburgh, UK)
E-mail: dickson.kris@gmail.com

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GENETICS : Amplification of oestrogen receptor gene in breast cancer

A fifth of breast tumours have extra copies of the gene encoding one form of the oestrogens receptor ESR1, suggests a study. A small-scale initial study shows that women treated with tamoxifen, which blocks the activity of the oestrogens receptor, survive longer if their tumour has this gene amplification.
Oestrogens receptor expression is one of the most important known factors in the development of breast cancer, and assessing its status is important for determining the use of anti-oestrogens receptor therapies like tamoxifen. Ronald Simon and colleagues examined more than 2,000 breast cancer samples for evidence of amplification of ESR1, and detected it in 20.6 % of the tumours. In a small follow-up study of 175 women with breast cancer who were being treated with tamoxifen, they found that women with the amplification survived longer than those who did not, even though the tumours in both groups of women expressed ESR1. The authors suggest that ESR1 amplification may identify a subgroup of breast cancers that would be particularly likely to respond to anti-oestrogens therapy.
Author contact:
Ronald Simon (University Medical Center Hamburg Eppendorf, Germany)
Tel: +49 42803 7214; E-mail: r.simon@uke.uni-hamburg.de



Natural genetic variant influencing rice grain weight

A study published in Nature Genetics this week identifies a gene that influences rice grain weight and yield. This is only the second such gene that has been found and functionally characterized, and is a step toward understanding and improving grain yield in crops.
Rice is a staple food, and the world’s most important cereal crop. Hong-Xuan Lin and colleagues examined two varieties of rice that exhibit significant differences in grain size, and mapped the gene responsible for this variation in size – GW2. The version of GW2 found in the large-grain variety of rice increased the width and weight of rice grains and increases grain yield per plant by nearly 20%, although the authors caution that its effect on grain yield needs to be further assessed in randomized blocks of plants in paddies.
Initial experiments also show that rice with the high-yield variant of GW2 has no reduction in cooking or eating quality, suggesting that it will be useful for high-yield crop breeding. GW2 encodes a protein that belongs to a family of enzymes that target other proteins for degradation, and the authors speculate that it could affect grain size by regulating the cell division cycle.
Author contact:
Hong-Xuan Lin (Shanghai Institute for Biological Sciences, China)
Tel: +86 21 5492 4129; E-mail: hxlin@sibs.ac.cn

for other topics visit our portal- www.medianowonline.com

CHEMICAL BIOLOGY :Chemical control of neural stem cells
Chemicals that regulate neurotransmitter signalling in neurons can also prevent neural stem cell proliferation, according to a paper in the May 2007 issue of Nature Chemical Biology. Neural stem cells are a potentially important therapeutic target for neurological diseases and brain tumours. However, very little is known about the potential for using small molecules to regulate neural stem cell differentiation and proliferation.
Using cultures of neural precursor cells, Peter B. Dirks and colleagues screened a chemical library for inhibitors of neural precursor cell proliferation. Within the ‘hits’ were a number of small molecules that are known to influence neurotransmitter signalling in neurons. These unexpected results indicate that neurotransmitter signalling pathways may also function in neural stem cells and raises the possibility of using existing drugs that regulate neurotransmitter signalling in the treatment of brain tumours.
Author contact:
Peter B. Dirks (The Hospital for Sick Children and University of Toronto, Canada)
Tel: +1 416 813 6426; E-mail: peter.dirks@sickkids.ca
Additional contact for comment on paper:
Mike Tyers, (Mount Sinai Hospital, Toronto, Canada)
Tel: +1 416 586 8371; E-mail: tyers@mshri.on.ca
for other topics visit our portal- www.medianowonline.com

Algorithm for group success?
Want to know how to make your clique, group or organization last? A new algorithm can help you do just that.
Tamás Vicsek and colleagues studied the patterns of information exchange within two groups of individuals — collaborating scientists and mobile phone users — over time. From this, they devised an algorithm to let them study how information exchange affects group stability.
Small groups, they report, have a few strong relationships at their core. And as long as these persist, the clique remains. But the strategy doesn’t work for large communities, where change seems a good thing. Continuous change helps large groups to remain stable, and over time, nearly all members are exchanged.
The findings help shed light on the basic relationships behind community evolution, and offer insights into the fundamental differences between the dynamics of small groups and large institutions.
CONTACT
Tamás Vicsek (Eötvös Loránd University, Budapest, Hungary)
Tel: +36 1 372 2755; E-mail: vicsek@angel.elte.hu

Atom spectroscopy: The great electron escape
Researchers have 'observed' electrons being stripped away from atoms by intense light fields. The technique used should offer control over, and provide insights into, the dynamics of electrons inside atoms and molecules.
Given enough energy, electrons can ‘tunnel’ through the potential barrier that normally binds them to their nucleus, and escape. Ferenc Krausz and colleagues have now ‘seen’ this light-induced electron tunnelling happen in real time on the attosecond — that’s one billionth of one billionth of a second — timescale.
The team ionized neon atoms with ultrafast far-ultraviolet pulses, and then probed them with near-infrared pulses. From the observed spectra, they were then able to reconstruct the electron tunnelling.
CONTACT
Ferenc Krausz (Max-Planck-Institut für Quantenoptik, Garching, Germany)
Tel: +49 89 3290 5602; E-mail: ferenc.krausz@mpq.mpg.de
Jonathan P. Marangos (Imperial College London, UK) N&V author
Tel: +44 20 7594 7857; E-mail: j.marangos@imperial.ac.uk

Earth sciences: A salty solution

A new modelling study offers an elegant explanation for a curious anomaly seen in the carbon and sulphur isotope records of the Early Cretaceous period.
In modern-day sediments, the rates of pyrite (iron sulphide) and carbon-based organic matter burial are positively related. But during the Early Cretaceous period, which began approximately 140 million years ago, they appear to be negatively related — a relationship that has, until now, been difficult to explain.
Ulrich G. Wortmann and Boris M. Chernyavsky show that this puzzling relationship could be due to the deposition of evaporites — mineral sediments that precipitate from water as it evaporates — on the ocean floor as South Africa and South America moved apart and the South Atlantic Ocean basin formed. The evaporites contain sulphate, so their production removed sulphate from the surrounding waters. Enough, the model suggests, to reduce significantly the rate at which organisms in marine sediments formed pyrite and broke down organic matter, thus explaining the negative relationship between the amount of pyrite and organic matter buried in marine sediments at this time.
Evaporite deposition may have had a similar effect at other times in Earth’s history, and so may explain other changes in carbon and sulphur cycling. These are important to understand because alterations in these cycles can have a direct effect on atmospheric oxygen levels.
CONTACT
Ulrich G. Wortmann (University of Toronto, Canada)
Tel: +1 416 978 7084; E-mail: uli.wortmann@utoronto.ca

Geology: Geomagnetic data captured in crystals

Researchers have used silicate crystals to determine the strength of the Earth’s geomagnetic field around 3.2 billion years ago. Their findings should help to shed light on the evolution of the Earth’s deep interior, surface environment and atmosphere.
John A. Tarduno and colleagues studied silicate crystals from well preserved igneous rocks found in South Africa’s Archaean Kaapvaal craton. The crystals contain minute magnetic inclusions, and the team calculate that 3.2 billion years ago, the Earth’s geomagnetic field strength was within fifty per cent of the present-day value. This means that there was probably a viable magnetosphere to shelter the planet from solar wind erosion at that time.
Little is known about the strength of the Earth’s geomagnetic field before 2.8 billion years ago, so the new data offer a welcome insight into the Earth’s geomagnetic history.
CONTACT
John A. Tarduno (University of Rochester, NY, USA)
Tel: +1 585 275 5713; E-mail: john@earth.rochester.edu
David J. Dunlop (University of Toronto, Canada) N&V author
Tel: +1 905 828 3968; E-mail: dunlop@physics.utoronto.ca

Microbiology: Antibiotic-resistant bacteria meet their match?

Researchers may have found a way of keeping drug-resistant bacteria in check — certain combinations of antibiotics favour the growth of non-resistant strains at the expense of resistant ones. The finding may help combat the spread of these microbes, as well as shed light on microbial ecology and evolution.
Antagonistic drug combinations, in which the drugs' cumulative effects are less than when they are given separately, show such effects, say Roy Kishony and colleagues. At sublethal concentrations, a mixture of doxycycline and ciprofloxacin preferentially selects for wild-type Escherichia coli bacteria over that of a doxycyline-resistant strain in a laboratory culture.
The finding is surprising and counter-intuitive, as the use of antibiotic drugs is responsible for the generation and selection of resistant bacterial pathogen strains. But this study shows that, with the right combinations and concentrations, non-resistant bacterial strains can be selected for.
CONTACT
Roy Kishony (Harvard Medical School, Boston, MA, USA)
Tel: +1 617 432 6390; E-mail: roy_kishony@hms.harvard.edu

Planetary science: Winds of change
Variations in the radiation reflected from the surface of Mars are contributing to climate change on the planet, by causing increased dust transport and wind circulation. A study predicts that the planet has warmed by around 0.65 degrees Celsius from the 1970s to the 1990s, which may in part have caused the recent retreat of the southern polar ice cap.
The fraction of solar radiation reflected from an object is called its albedo — and on Mars, large areas on the surface show a contrast in brightness or darkness with the areas next to them, resulting in albedo patterns, which can change in appearance over time. These changes in brightness have been generally attributed to the presence of dust, but until now their effect on wind circulation and climate has not been clear.
Lori K. Fenton and colleagues present predictions from a Mars global circulation model which show that these changes are having a much larger than expected effect on climate. Large swaths of the surface have darkened over the past three decades as they were swept free of dust, leading to elevated air temperatures and increased wind stresses. This creates a positive feedback loop between dust erosion and albedo. The authors conclude that albedo variations interact with, and can in part drive, other climate-influencing processes on Mars, and should be considered as an important component in future atmospheric and climate studies of the planet.
CONTACT
Lori K. Fenton (Carl Sagan Center, NASA Ames Reserach Centre, Moffett Field, CA, USA)
Tel: +1 510 786 7199; E-mail: lfenton@carlsagancenter.org or fenton@mintz.arc.nasa.gov

Neuroscience: A light-switch for brain cells
An elegant technique using light to control the activity of brain cells is described. By expressing a light-responsive membrane protein in neurons, researchers can inhibit neural activity on a millisecond timescale.
Karl Deisseroth and colleagues introduced NpHR — a light-driven chloride pump that occurs naturally in microorganisms known as archaea — into cultured mammalian neurons and brain tissue in the laboratory. Training light pulses of a particular wavelength onto these cells effectively inhibited neural activity. This builds on the authors’ previous work using the protein ChR2 — a light-responsive channel found in algae — to optically excite nerve cells with light of a different wavelength. By simultaneously expressing both membrane proteins in the muscle cells or motor neurons of the nematode worm Caenorhabditis elegans, the authors were able to control its locomotive behaviour — the worms stopped and started muscle contractions when yellow and blue lights were shone on them.
These findings demonstrate that light-responsive proteins can be used simultaneously to permit fast, bidirectional and reversible control over living neural circuits. They can also be used in conjunction with calcium imaging techniques and, together, provide a powerful tool for studying and manipulating brain activity with high precision.
CONTACTKarl Deisseroth (Stanford University, CA, USA)
Tel: +1 650 736 4325; E-mail: deissero@gmail.com
Michael Hausser (University College London, UK) N&V author
Tel: +44 207 679 6756; E-mail: m.hausser@ucl.ac.uk

The discovery of America: The revolutionary claims of a dead historian
New evidence could rewrite the history of the discovery of America
Dr Alwyn Ruddock, a former reader in history at the University of London, was the world expert on John Cabot’s discovery voyages from Bristol to North America (1496-98). What she was said to have found out about these voyages looked set to re-write the history of the European discovery of America. Yet, when Dr Ruddock died in December 2005, having spent four decades researching this topic, she ordered the destruction of all her research.
In an article published in Historical Research, Alwyn Ruddock’s extraordinary claims are explored by Dr Evan Jones of the University of Bristol.
In Spring 2006, all Dr Ruddock’s research material was destroyed, in line with the instructions in her will. However, her correspondence with her intended publisher, the University of Exeter Press, survived. Using this correspondence Dr Jones has investigated the research that Dr Ruddock had worked on, and kept secret, for so many years.
‘To describe Alwyn Ruddock’s claims as revolutionary,’ said Dr Jones, ‘is not an exaggeration.’ Her apparent findings include information about how John Cabot persuaded Henry VII to support his voyages and why the explorer was able to win the backing of an influential Italian cleric: Fr. Giovanni Antonio de Carbonariis, an Augustinian friar who was also in charge of collecting the Pope’s taxes in England.
Dr Ruddock’s most exciting claims, however, involve John Cabot’s 1498 voyage to America . While the fate of this expedition has long been a mystery, Dr Ruddock appears to have found evidence of a long and complex exploration of the American coastline, which culminated in Cabot’s return to England in the spring of 1500, followed shortly by his death. During this voyage, Dr Ruddock suggests that Cabot explored a large section of the coastline of North America, claiming it for England in the process.
Dr Ruddock intended to reveal that while Cabot was sailing south down the coast of America his chief supporter, Fra Giovanni, was establishing a religious colony in Newfoundland. Having disembarked from his ship, the Dominus Nobiscum, Fra Giovanni apparently established a settlement and built a church. This church, the first to be built in North America, was named after the Augustinian church of San Giovanni a Carbonara in Naples.
Dr Jones said: ‘Ruddock’s claims about the 1498 voyage are perhaps the most exciting of all. For while we have long known that Fra Giovanni accompanied the expedition, along with some other “poor Italian friars”, nothing has been known of what happened to their mission. If Ruddock is right, it means that the remains of the only medieval church in North America may still lie buried under the modern town of Carbonear.’
Dr Ruddock’s claims are clearly extraordinary but are they all correct? This is an issue that remains, in large part, to be resolved. In his article, Dr Jones shows that in many cases Alwyn Ruddock’s claims can be substantiated by reference to previously unknown material. However, much remains to be done.
Dr Jones continued: ‘In publishing this article now my intent was to put into the public domain what appear to be the last vestiges of Dr Ruddock’s research. While her correspondence does not give all the answers, it does provide many clues that historians can use to investigate her claims. I also hope that the publication of this article might persuade people who possess knowledge of Dr Ruddock’s research to come forward. For it is clear from her correspondence that many people must possess useful knowledge, ranging from her ex-students at the British Library to the “old and historic families in Italy” who gave her access to their private archives.’
As to why Alwyn Ruddock should have chosen to have all her research destroyed on her death, Dr Jones confesses that he has no clear answers. In her obituary in the Guardian newspaper, it was suggested that she destroyed the first draft of her book ‘because it did not meet her exacting standards.’ This does not explain, however, why she wanted everything destroyed – including her microfilms, her photographs and the transcripts of the documents she used.
‘What is clear,’ said Dr Jones, ‘is that she had a great sense of possession for her work and she felt this gave her the moral right to take her secrets to the grave. But even if all the documents she claimed to have found do come to light eventually, the mystery of why she sought to suppress her own basic research may never be resolved.’

Associated links
http://www.bristol.ac.uk/news/2007/5333.html
http://www.blackwell-synergy.com/toc/hisr/0/0

Joan of Arc relics exposed as a forgery
The relics of St Joan of Arc are not the remains of the fifteenth-century French heroine after all.European experts who have analysed the sacred scraps say the relics are a forgery, made from the remains of an Egyptian mummy.
Philippe Charlier, a forensic scientist obtained permission to study the relics -- cloth, a human rib and a cat femur -- from the French church last year. He says he was “astonished” by the results. “I’d never have thought that it could be from a mummy.”
The researchers used a range of techniques to investigate the remains, including mass, infrared and atomic-emission spectrometry, electron microscopy, pollen analysis and, unusually, the help of the leading ‘noses’ of the perfume industry: Sylvaine Delacourte from Guerlain, and Jean-Michel Duriez from Jean Patou.
A series of clues led to conclusion that the relics were of the mummy origin, reinforced by carbon-14 analysis dating the remains to between the third and sixth centuries BC. And the spectrometry profiles of the relics matched those from Egyptian mummies from the period, and not those of burnt bones.
Charlier points out that mummies were used in Europe during the Middle Ages in pharmaceutical remedies.
Contact:
Philippe Charlier (Raymond Poincare Hospital in Garches, Paris, France)
Tel: +33 1 40 10 76 89; E-mail: philippe.charlier@rpc.ap-hop-paris.fr

Semi-identical’ twins discovered

Researchers have discovered a pair of twins who are identical through their mother’s side, but share only half their genes on their father’s, reports a News Exclusive from news@nature.com.
The ‘semi-identical’ twins are the result of two sperm cells fusing with a single egg, before becoming two embryos — a previously unknown way for twins to come about, say the team that made the finding. The twins are also chimaeras, meaning that their cells are not genetically uniform. Each sperm has contributed genes to each child.
The twins’ genetic makeup was investigated because one was born with ambiguous genitalia. One turned out to be a ‘true hermaphrodite’, with both ovarian and testicular tissue. The other twin is anatomically male.
Such twins are probably very rare. Their existence and discovery relies on three unusual, and possibly unlinked, events: first, that an egg fertilized by two sperm develops into a viable embryo; second, that this embryo splits to form twins; and third, that the children come to the attention of science.
This was reported in the Journal of Human Genetics, the news of this report comes exclusively from news@nature.com.
CONTACTS
Mikhail Golubovsky (Duke University, Durham, NC, USA)
mgolub@cds.duke.edu
Vivienne Souter (Banner Good Samaritan Medical Center in Phoenix, AZ, USA)
vsouter@yahoo.com
David Bonthron (University of Leeds, UK)
d.t.bonthron@leeds.ac.uk
Contact for background information only:
John Whitfield (Journalist, news@nature.com)
Tel: +44 20 7843 4645;

Geology: The driving force of plate tectonics

The North American plate may be driven by mantle flow and deformation at the base of the continental crust, according to a report in Nature. David W. Eaton and colleagues studied the surface expression of the Great Meteor hotspot track to estimate the relative motion between the surface and the underside of the plate. The results provide new insights into the driving forces of plate motion.
Hotspots — relatively-fixed locations of active volcanism deep beneath the Earth’s surface — allow scientists to track the movements of plates as they pass over them, producing lines of volcanoes. The Great Meteor hotspot is one of the longest tracks in the Atlantic and reveals the movement of the North American plate over time. The authors used seismic images, geochronology and plate-motion reconstruction to compare the location and chronology of the hotspot track at the base and top of the North American lithosphere. They found that there is a displacement between the surface and deep parts of the tracks. This misalignment increases with age along the track, and is best explained by deformation in the mantle lithosphere beneath North America. They suggest that that motion of the plate is driven, rather than impeded, by viscous traction at the base of the plate.
CONTACT
David W. Eaton (University of Western Ontario, London, Canada)
Tel: +1 519 661 3190; E-mail: deaton@uwo.ca

Neuroscience: Emotion and moral judgements

The critical role played by part of the brain in making normal judgements of right and wrong is highlighted by a study in Nature magzine. Patients with damage to an area of the brain involved in the normal generation of emotions have an abnormally ‘utilitarian’ reaction when presented with certain types of moral dilemma.
Antonio Damasio and colleagues studied six patients with focal lesions to the venteromedial prefrontal cortex (VMPC) on both sides of the brain. They presented them with a set of moral dilemmas that pit compelling considerations of aggregate welfare against highly emotionally aversive behaviours, such as having to decide whether to sacrifice one’s child in order to save a number of other people. The authors report that the patients tended to have a utilitarian reaction to these dilemmas – that is, they responded in a manner that favoured the greater good, despite the emotional significance of the decision.
The authors note that the effects of damage to the VMPC on emotion processing depend on context, and that their results are consistent with a model in which a combination of intuitive and rational mechanisms operate to produce moral judgements.
CONTACT
Antonio Damasio (University of Southern California, Los Angeles, CA, USA)
E-mail: damasio@college.usc.edu
Carl Marziali (Sciences Media Relations, University of Southern California, Los Angeles, CA, USA)
Tel: +1 213 740 4751; E-mail: marziali@usc.edu
Ralph Adolphs (California Institute of Technology, Pasadena, CA, USA) Co-author
Tel: +1 626 395 4486; E-mail: radolphs@hss.caltech.edu

Materials: Brute force yields new molecules

Chemists have designed a new type of molecule that changes identity when a mechanical force is applied. Apart from offering new ways to control chemistry, the effect might even result in mechanically responsive polymers that warn of impending structural failures, delay damage or even self-repair.
In most chemical reactions, reactants need to overcome an energy barrier before they are turned into products and the energy needed for this is usually provided by heat, light, pressure or electrical potential. In Nature magzine, Jeffrey S. Moore and colleagues use mechanical force to achieve the same effect.
The team added carefully designed, force-sensitive units called ‘mechanophores’ to the middle of polymer strands. When a mechanical force is applied, the mechanophore undergoes a chemical reaction and turns into a different molecule.
It’s already known that mechanical forces can activate reactions by ‘tugging’ on reactant bonds, but usually this just ruptures the molecules. Critically, these new materials don’t break.
CONTACT
Jeffrey S. Moore (University of Illinois, Urbana, IL, USA)
Tel: +1 217 244 4024; E-mail: jsmoore@uiuc.edu
Virgil Percec (University of Pennsylvania, Philadelphia, PA, USA) N&V author
Tel: +1 215 573 5527; E-mail: percec@sas.upenn.edu

Biochemistry: How to make vitamin B12

Biochemists have worked out the last unknown step involved in the biosynthesis of vitamin B12 (cobalamin). Their discovery, reported in Nature magzine, solves a long-standing puzzle and reveals an unusual bit of biochemistry.
Vitamin B12 is one of the largest known non-polymeric natural products and is the only vitamin that is synthesized exclusively by microorganisms. But despite years of study, the biosynthesis of the lower portion of vitamin B12 is poorly understood.
Graham C. Walker and colleagues have solved the X-ray crystal structure of BluB, an enzyme that is needed in the final stages of vitamin B12 synthesis. They show that the enzyme uses molecular oxygen to cleave another molecule to form 5,6-dimethylbenzimidazole. The 5,6-dimethylbenzimidazole produced in that reaction is then incorporated into vitamin B12 by other enzymes.
The cannibalized molecule is called flavin mononucleotide and it is a cofactor — an organic molecule that binds to an enzyme and is needed for its catalytic activity. The enzymatic destruction of one cofactor to make another is quite unusual, and the authors suggest that BluB represents a new family of enzymes, called 'flavin destructases.'
CONTACT
Graham C. Walker (Massachusetts Institute of Technology, Cambridge, MA, USA)
Please contact co-author:
Christopher T. Walsh (Harvard Medical School, Boston, MA, USA)
Tel: +1 617 432 1715; E-mail: christopher_walsh@hms.harvard.edu
Steven E. Ealick (Cornell University, Ithaca, NY, USA) N&V author
Tel: +1 607 255 7961; E-mail: see3@cornell.edu

Developmental nicotine exposure diminishes attention capacity


Teen smokers who were also exposed to nicotine before birth show a dramatic reduction in attention capacities related to vision and hearing, reports the journal Neuropsychopharmacology this week. The study, led by Leslie Jacobsen and colleagues, also demonstrates that male and female attention capacities are affected by the exposure in different ways.
Jacobsen’s team found that girls who smoke and were subject to nicotine exposure in the womb performed most poorly in both visual and auditory attention tasks. Individuals who do not smoke and did not have prenatal exposure performed most accurately. As expected of a dose-dependent effect, those performing in between were individuals who smoke but whose mothers did not, or individuals who do not smoke themselves but whose mothers did during pregnancy. In boys, nicotine exposure had a greater effect on auditory attention, suggesting that brain regions involved in auditory attention may be more vulnerable to nicotine in boys. These gender-specific effects may result from differences in hormonal control of nicotine’s actions.
Previous studies on smoking have found that rates of tobacco smoking and nicotine dependence are higher among individuals prenatally exposed to maternal smoking. The Center for Disease Control reports that smoking during pregnancy is the single most preventable cause of illness and death among mothers and infants. Prior to this study, very little research was available on the less dramatic effects of exposure to smoking such as the impact on attention capacity.
Author contact:
Leslie Jacobsen, (Yale University School of Medicine, New Haven, CT, USA)
Tel: + 1 203 764 8480; E-mail: leslie.jacobsen@yale.edu

It,s all about FROGS and TODAS in Borneo
(‘Anurans' or tailless amphibians tourism for environmental conservation)

In its decade long research into frogs and toads in Borneo, the Institute for Tropical Biology and Conservation has achieved much including highlighting conservation priority areas, setting up Asia's first Frog Museum and is now working on popularising biodiversity for environmental conservation with 'Anurans Tourism'.
Travelling for over 10 hours on coach and followed by uphill forest trekking to an elevation of more than 850m above sea level for six hours to sojourn amidst pristine nature for a week long of specimen collection is not the job description of most people. On the contrary, it is not just a tacit onus of each and every anuran researcher from the Institute for Tropical Biology and Conservation (ITBC), Universiti Malaysia Sabah, but a pleasurable one too.
Anurans (Amphibia: Anura) are amphibians in the Order Anura which stands for tailless amphibians, or simply frogs and toads. Often deemed as colourful organisms, anurans are also momentous as a component of environmental food web, excellent environmental health indicators, biological control agents for pests (especially insects), and a source of alternative food and medicines for some.
Being a centre of excellence entrusted to spearhead terrestrial research in tropical biology and conservation, ITBC has acknowledged the imperativeness of anuran research since the naissance of the institute in June 1996. For slightly more than a decade now, ITBC is still marching assertively ahead in anuran research at state, national, regional as well as international levels, and blazing a trail for many novel facets of anuran research to play a part in paving the way towards global knowledge expansion. As articulated by Ali bin Abu-Talib, the fourth Caliph of Islam, ‘There is no wealth like knowledge; no poverty like ignorance’.
One of the governing factors enabling ITBC to grow from strength to strength in anuran research for the past decade has been its pool of anuran researchers. Even though without its own anuran researcher before 2003, ITBC under the leadership of Professor Datin Dr. Maryati Mohamed, succumbed to no such situational setback and decided to involve Associate Professor Dr. Abdul Hamid Ahmad, (then) a Lecturer from the School of Science and Technology (SST), Universiti Malaysia Sabah, in a couple of the initial researches. The undertakings were also participated by Ahmad Sudin, Science Officer of ITBC, and Lucy Kimsui, previously a Laboratory Assistant of ITBC, both with strong predilection for anuran research.
In 2000, ITBC received its second postgraduate student working on anurans: Kueh Boon Hee. Kueh was a recipient of the Danish Cooperation for Environment and Development (DANCED) Full Scholarship for his work on the biogeography and distribution mapping (using WORLDMAP Programme) of anurans in Borneo for conservation area prioritization.
The research that was successfully concluded in 2002, pinpointed 22 conservation priority areas in Borneo for complete representation of anuran species richness and narrow endemism, and four suggested new protected areas (following GAP Analyses): Tubau and Sungai Mengiong in Sarawak as well as Sanggau and Kubu in West Kalimantan. The data are much useful for the management of protected areas, and moulding of informed decisions by policy makers pertaining to landuse in Borneo that galvanizes balance between materialistic development and environmental conservation.
The two-year research also included studies that produced several primary anuran inventories for a few localities in Sabah. The anuran inventories are important as baseline data on anuran diversity in order to propel future anuran researches. Inventory-based studies at the limestone area of Tabin Wildlife Reserve (TWR) in October 2000 (which recorded a new locality record for TWR: Metaphrynella sundana), eight populated areas in West Coast and Kudat Divisions between December 2000 and April 2001, southern edge of Maliau Basin Conservation Area in May 2001, and Trus Madi in November 2001 (that contributed voucher specimens for three species to ITBC) set up primary anuran inventory for the respective locality. The localities have been intentionally chosen to epitomize both the protected and non-protected areas in response to the necessity for geographically comprehensive inventory-based studies for an extremely anuran species rich region like Sabah (and even Borneo).
The pool of anuran researchers began growing in 2003 when Kueh was appointed as a Lecturer/Researcher of ITBC, the first to specialize on anurans in the institute. Subsequently, Kueh was joined by Dr. Abdul Hamid and Anna Wong Yun Moi in 2006 (both were previously affiliated to SST). As crucial to the steady advancement of anuran research in ITBC as the researchers are the postgraduate students. Maximus Livon Lo Ka Fu commenced his postgraduate research in 2006 on the prevalence of chytrid fungus on anuran species in Crocker Range, Sabah under the supervision of Kueh, Associate Professor Dr. Markus Atong (School of Sustainable Agriculture, Universiti Malaysia Sabah) and Jodi Rowley (School of Tropical Biology, James Cook University, Australia). Another postgraduate student is Jane Francesca G. Volin who is working on the diversity and distribution of anuran species along Crocker Range, Sabah since the second half of 2006 under the supervision of Kueh.
Collaboration with other researchers in the nation and other countries is utmost vital in upholding the advancement of anuran research in ITBC too. Active research collaborations establish extended pool of anuran researchers for ITBC. Professor Dr. Indraneil Das (Institute of Biodiversity and Environmental Conservation, Universiti Malaysia Sarawak) and Professor Dr. Masafumi Matsui (Graduate School of Human and Environmental Studies, Kyoto University, Japan) are the two earliest research collaborators with ITBC. Professor Das and Professor Matsui are prominent researchers on the anuran species of Borneo, Malaysia and even Asian region. They conduct extensive research on anuran taxonomy, biogeography, ecology, natural history and conservation biology, and possess impressive list of publications under their names. Collaboration with them has helped ITBC in the verification and augmentation of anuran specimens in BORNEENSIS, reference collection centre of ITBC, up to the current status of approximately 1,900 specimens representing about 90 species (out of the 104 species found in Sabah and 150 species found throughout Borneo).
The specimens include those of the species endemic to Borneo and Sabah such as Kalophrynus baluensis, Philautus aurantium and Philautus bunitus. Succeeding international research collaborations have been built with researchers like Dr. Kanto Nishikawa and Tomohiko Shimada from the Graduate School of Human and Environmental Studies, Kyoto University, Japan, Lisa Schloegel, Dr. Peter Daszak and Dr. Alex Hyatt from the Consortium for Conservation Medicine, USA, Associate Professor Dr. Jean Marc Hero from the School of Environmental and Applied Sciences, Griffith University, Australia, and the latest, Professor Dr. Alexander Haas from the Biozentrum Grindel und Zoologisches Museum, Germany.
However, research collaboration with local researchers and institutions is never neglected by ITBC. Incessant research collaborations have been evident between ITBC and local institutions like Sabah Parks (with Maklarin Lakim, Paul I. Yambun and Frederick Francis), Sabah Wildlife Department and Sabah Museum (with Lo Sui Siong @ Albert) since 1996.
Ralph Waldo Emerson said ‘Science does not know its debt to imagination’ and indeed, imagination is the root of each of the finest creation and greatest innovation known to mankind. ITBC has never shied away from exploring novel spectra of anuran research. Such distinctive trait of ITBC is conspicuous when, in 2003, Kueh embarked on a research to prospect (the potential) and eventually, introduce anurans as a new nature tourism product for Sabah, in particular and Malaysia, in general.
The nature tourism product is dubbed as ‘Anurans Tourism’. Potential prospecting of anurans for ‘Anurans Tourism’ is firmly founded on seven criteria, namely endemism, rarity, reliability of sightings, morphological attractiveness, behavioral enticement, safety and linkage to local cultures.
Preliminary outcomes indicated that anurans fulfil the criteria, and showed 67.8% of affirmation by a cohort of international tourists from Asia, Australasia, Europe and North America interviewed for ‘Anurans Tourism’.
‘Anurans Tourism’ has also been introduced to state tourism agencies, tour operators and local mass media via conferences, seminars and promotional excursions. The concept of ‘Anurans Tourism’ was even presented to The Honourable Mr. Shigeru Sumitani, Administrative Vice Minister of the Environment of Japan and his think-tank when Kueh went on a training in ‘Conservation and Management of Terrestrial Natural Environment’ in Japan in September 2005.
At present, Kueh proffers consultation through special lectures on anurans and ‘Anurans Tourism’ to a renowned pioneer tourism training institute in Sabah: Borneo Tourism Institute (BTI). Inevitably, gone were the days when environmental conservation was the sole responsibility of conservation biologists professing the grave need to conserve the nature from laboratories. Under the contemporary context, environmental conservation means sustainable utilization of natural resources which complies with the unavoidable materialistic development for the social well-being of local communities that at the same time, boosts more collective efforts for perpetual environmental conservation. One of the strategies underlining sustainable utilization of natural resources is through nature tourism.
In order to corroborate its endeavour to popularize biodiversity for environmental conservation, ITBC has also handpicked anurans as a model organism group to educate the general public on nature and conservation.
Hence, in November 2002, Professor Datin Maryati mooted the idea of setting up the ‘ITBC Frog Museum’, the first of its kind probably in Asia, as a centre for Education for Sustainable Development (EfSD), especially for the younger generations of Sabah. ‘ITBC Frog Museum’ that is being run by Kueh and Ahmad since its launching in December 2003, constantly receives visits from schools and colleges in Sabah, and tourists as well.
The newest feather in ITBC’s cap relating to anuran research is the appointment of Professor Datin Maryati, on behalf of ITBC, as the Chairperson of the Technical Sub-Committee of Faunal Biodiversity (Amphibia) in November 2005. The appointment directly recognized ITBC as the leading institution to consolidate and coordinate data, specimens, publications and lists of researchers on amphibians (merely anurans and caecilians as Malaysia does not house salamanders and newts), as well as the reference institution for researchers, local and international, interested to conduct amphibian researches in Malaysia.
The technical sub-committee is a part of the Technical Committee of Faunal Biodiversity headed by the Director General of the Department of Wildlife and National Parks Peninsular Malaysia, which is under the National Biodiversity Inventory Committee headed by the Secretary General of the Ministry of Natural Resources and Environment, Malaysia. The abovementioned committees are superintended by the National Biodiversity-Biotechnology Council chaired by The Right Honourable Dato’ Seri Abdullah Ahmad Badawi, Prime Minister of Malaysia.
A decade is a period neither long nor short. It is considered long when noting that majority of the achievements by ITBC in anuran research from the perspective of human resource growth, research collaboration expansion, research progression, innovations, popularization of biodiversity using anurans as the model organism group to culturalize environmental conservation and national recognition in 10 years time were actually accomplished in the later half of the decade.
Conversely, it is regarded as a short period when realizing that there are still much to be done and attained in fulfilling the aspiration to be known regionally and internationally as the best in anuran research for ITBC, in particular and Universiti Malaysia Sabah, in general. From whichever point of view, nothing can prevent anuran research from hopping into a bright future spanning over many more colourful decades to come!

For more information, please contact:
Dayangku Rozlina
Corporate Relations Division
Universiti Malaysia Sabah
Locked Bag 2073
88999 Kota Kinabalu
Malaysia
Telephone: +6088320000
Facsimile: +6088320223
Email: adreen02@yahoo.com
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Robustness of E. coli metabolic network revealed
Tsuruoka, Yamagata, (Japan)March 25, 2007 : Scientists at the Institute for Advanced Biosciences of Keio University located in Tsuruoka City, Yamagata prefecture report in an advanced on-line publication released today in Science magazine (Science Express) a first-of-a-kind quantitative picture of molecular components of the common intestinal bacterium E. coli. Using multiple state-of-the-art analytical technologies, the group studied this unicellular organism at an unprecedented depth to reveal the remarkable overall robustness of its metabolic network to gene deletion and changes in growth conditions.
All cells need to convert energy sources such as simple sugars into ATP, an energy storing and exchange molecule, and other cellular building blocks that are essential for cellular growth and survival. This cellular process, called "energy metabolism" is one of the most fundamental and well-conserved in living cells and its machinery involves about 100 different genes and their encoded proteins.
Making use of a set of nearly 4000 single gene mutants in E. coli the same group previously developed (Keio collection), the researchers selected specific genes whose activity is known to be associated with the main reactions of central energy metabolism. In addition, the non-mutated or wild type cells were also grown at different rates to observe the response to such changes. An exhaustive global survey of intracellular components was then performed using the latest analytical technologies such as DNA microarrays, two-dimensional gel electrophoresis and capillary electrophoresis mass spectrometry (CE-MS) to quantify messenger RNA, proteins, and metabolites. The researchers also performed a more detailed and precise analysis of 85 different intracellular RNAs, 57 enzyme proteins, and about 130 metabolites representing most components of energy metabolism and simultaneously also derived the metabolic fluxes through most reactions by combining quantitative measurements with a computational model of energy metabolism.
Deletion of energy metabolism genes, in most cases, did not result in large compensatory changes in the level of RNA, proteins, or metabolites. On the other hand, while significant changes in RNA and protein levels were seen upon changes in growth rate, the overall metabolite levels remained stable. The results thus demonstrate with a level of details until now never achieved, that E. coli can use different and complementary strategies to maintain a stable metabolic state, according to the circumstances, and also compensate for mutations through functional redundancy in its metabolic network.
The CE-MS methods developed at IAB, which allow to analyze hundreds of intracellular metabolites simultaneously together with an original approach to targeted protein quantification using liquid-chromatography mass spectrometry (LC-MS) that bypasses the common but inconvenient use of isotopic labels, were instrumental in providing the level of quantitative detail necessary.
Masaru Tomita, head of the project and institute remarks “I am proud of this extraordinary and unparalleled large-scale study which was in large part made possible by combining original technologies developed at IAB in Tsuruoka with the help of the local government. I also think that the rich and peaceful natural environment where our institute is located contributed to catalyze this large team effort. We now hope to apply the fruits of this study toward medical and environmental problems and also imagine applications in the food industry.”
Understanding a simple bacterium in a more systematic way is expected to have repercussions in many other organisms too due to the similarities in the core components of metabolic pathways from bacteria to animals and humans. For example eventual applications in the field of cancer biology for developing novel anti-cancer drugs targeting cellular metabolism, and improvements in industrial production of alternative energy sources such as bio-ethanol or environmentally-friendly bio-plastics could be imagined. In addition, computational and systems biologists around the world, attempting to understand the cell in its entirety, have long wanted to put their hands on the type of quantitative data this study provides. It is thus a significant step in the emerging field of quantitative biology that is likely to find even broader applications.
IAB is a research institute closely associated with the Faculty of Environment and Information Studies at Keio University. It employs about 65 scientists and offers an innovative undergraduate bioinformatics program and graduate program in systems biology in which a total of about 130 students are enrolled. Keio University is the oldest modern comprehensive institution of higher education in Japan, with over 30 000 students distributed over several campuses in the Tokyo area in addition to the Tsuruoka Town Campus (TTCK) established in 2001 in Yamagata prefecture.
For more information contact:
Akiko Shiozawa
Public Relations Officer
Institute for Advanced Biosciences
Keio University
Tel: +81-235-29-0802
Fax: +81-235-29-0809
e-mail: akiko@ttck.keio.ac.jp
http://www.iab.keio.ac.jp/

Green tea may help to fight lung cancer

A possible mechanism for green tea’s anticancer activities is reported online this week in Laboratory Investigation. The reported effect of green tea extract on lung cancer cells supports the increasing evidence of green tea’s anticancer properties.

With an estimated 162,246 deaths in 2006, lung cancer is the most common cause of cancer-related death in the USA. The active constituents of green tea - called polyphenols - are recognized antioxidants, but the extent of any anticancer activity remains unclear. Although animal studies offer strong evidence for the anticancer effect of green tea in several organs, including the lung, human population-based studies have shown green tea to increase, decrease, and have no effect on the risk of lung cancer.

Qing-Yi Lu and colleagues now report that, in lung cancer cells, green tea extract (GTE) promotes the polymerization of the cell protein actin. This action counteracts the depolymerisation of actin that characterizes the early stage of cancer development. Researchers also pointed to annexin-I, the actin-binding protein that mediates the effect of GTE on actin, as a novel potential target for GTE-based cancer therapy. The authors suggest that further research and clinical trials are needed to determine how their results relate to actual green tea consumption.

Author contact:

Jian Yu Rao (University of California at Los Angeles, CA, USA)
Tel: +1 310 794 1567; Email: jrao@mednet.ucla.edu
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Fossil sheds light on middle ear evolution (pp 288-293)
The three tiny bones found in the mammalian middle ear are known to have evolved from components of the reptilian lower jaw. But the transition can now be seen in fossil form.

Zhe-Xi Luo and colleagues describe the fossilized remains of a primitive mammal that probably lived around 125 million years ago. The animal’s middle-ear bones remain connected to the lower jaw by Meckel’s cartilage, and the transition to the mammalian state is associated with a corresponding remodelling of the lower back region.

But the situation is not as clear-cut as it seems. The evolutionary relationships of the fossil suggest that either the modern-style middle ear evolved independently twice, or evolved and then was lost in at least one ancient lineage.

CONTACT
Zhe-Xi Luo (Carnegie Museum of Natural History, Pittsburgh, PA, USA)
Tel: +1 412 622 6578; E-mail: luoz@carnegiemnh.org

Leigh Kish (Media Contact, Carnegie Museum of Natural History, Pittsburgh, PA, USA)

Tel: +1 412 578 2571; E-mail: kishl@carnegiemuseums.org

Planetary science: The aftermath of a catastrophic collision
Scientists have discovered a new family of bodies in the Kuiper belt that they think are the remnants of a catastrophic collision with the belt's third largest object, 2003 EL61. The discovery may have implications for understanding the dynamics of the outer Solar System and the surfaces of Kuiper belt objects.

Michael E. Brown and colleagues found bodies with similar surface properties and orbital dynamics to the dwarf-planet-sized object 2003 EL61. From this, they inferred that something hit this large Kuiper belt object and created a family of objects, along with its satellite system.

There are many families of asteroids in the main asteroid belt that are the remnants of a catastrophic impact. But in the region beyond Neptune, no collisionally created families have hitherto been found. The newly spotted objects are probably fragments of the ejected ice mantle of 2003 EL61.

CONTACT
Michael E. Brown (California Institute of Technology, Pasadena, CA, USA)
Tel: +1 626 395 8423; E-mail: mbrown@caltech.edu

Alessandro Morbidelli (Laboratoire Cassiopee, Nice, France) N&V author
Tel: +33 4 92 00 31 26; E-mail: morby@obs-nice.fr

Surprise addition to flowering plant family tree
Biologists have added a new addition to the base of the flowering plant family tree. The classification, reported in this week’s Nature, should help those trying to fathom the evolutionary history of angiosperms.

Hydatellaceae are a small, obscure family of aquatic herb usually reckoned to be flowering plants akin to grasses. But a new study of their anatomy and molecular biology by Sean W. Graham and co-workers now places them, surprisingly, next to the water lilies as among the most primitive flowering plants.

Although the relationship of flowering plants to other seed plants remains controversial, great progress has been made in identifying some of the most primitive members of the angiosperm family tree. These include water lilies, magnolias and the New Caledonian shrub Amborella trichopoda. The addition of Hydatellaceae at the same level should help biologists as they puzzle over the evolution of the distinctive reproductive structures whose appearance led to the dominance of flowering plants seen in modern ecosystems.

This week’s Nature also includes a package of features about Carl Linnaeus’ legacy as it applies to modern debates concerning conservation and taxonomy. Celebrating the 300th anniversary of Linnaeus’ birthday, the package also includes two commentaries on the future of Linnaean science - not to mention a portrait of his pet racoon.

CONTACTSean W. Graham (University of British Columbia, Vancouver, Canada)
Tel: +1 604 822 4816; E-mail: swgraham@interchange.ubc.ca

James A. Doyle (University of California Davis, CA, USA) Co-author
Tel: +1 530 752 7591; E-mail: jadoyle@ucdavis.edu

Else Marie Friis (The Swedish Museum of Natural History, Stockholm, Sweden) N&V author

Tel: +46 8 5195 4155; E-mail: elsemarie.friis@nrm.se

Developmental biology: Fruit flies shed light on blood cell development
Researchers have shown that a signalling centre in the fruitfly lymph gland controls the maintenance of blood cell precursors. The findings suggest that Drosophila could prove a useful model for studying blood development and immunity.

Blood precursor cells yield all of the different cells found in the blood system. In fruitflies, at least, this system is controlled by signals generated in part of the lymph gland called the posterior signalling centre (PSC), two Nature papers report. Signalling occurs via the JAK/STAT and Notch pathways, already well known for their roles in cell proliferation and differentiation, teams lead by Utpal Banerjee and Michele Crozatier report. And the PSC starts to form early in embryonic development.

Drosophila is relatively easy to modify genetically and so widely used in research. Modification of the genes highlighted in these papers is likely to shed light on the mechanics of blood development. And Drosophila studies also yield the prospect of direct in vivo imaging of blood cell precursors interacting with their stem cell niche.

CONTACTUtpal Banerjee (University of California, Los Angeles, CA, USA) Author paper [1]
Tel: +1 310 206 5439; E-mail: banerjee@mbi.ucla.edu

Michele Crozatier (CNRS-Centre de Biologie du Developpement, Toulouse, France) Author paper [2]
Tel: +33 5 61 55 82 90; E-mail: crozat@cict.fr

Researchers Create World's First Ideal Anti-Reflection Coating
NEW YORK- A team of researchers from Rensselaer Polytechnic Institute has created the world's first material that reflects virtually no light. Reporting in the March issue of Nature Photonics, they describe an optical coating made from the material that enables vastly improved control over the basic properties of light. The research could open the door to much brighter LEDs, more efficient solar cells, and a new class of "smart" light sources that adjust to specific environments, among many other potential applications.
Most surfaces reflect some light -- from a puddle of water all the way to a mirror. The new material has almost the same refractive index as air, making it an ideal building block for anti-reflection coatings. It sets a world record by decreasing the reflectivity compared to conventional anti-reflection coatings by an order of magnitude.
A fundamental property called the refractive index governs the amount of light a material reflects, as well as other optical properties such as diffraction, refraction, and the speed of light inside the material. "The refractive index is the most fundamental quantity in optics and photonics. It goes all the way back to Isaac Newton, who called it the 'optical density,'" said E. Fred Schubert, the Wellfleet Senior Constellation Professor of the Future Chips Constellation at Rensselaer and senior author of the paper.


Schubert and his coworkers have created a material with a refractive index of 1.05, which is extremely close to the refractive index of air and the lowest ever reported. Window glass, for comparison, has a refractive index of about 1.45.


Incredible New Things in Optics and Photonics


Scientists have attempted for years to create materials that can eliminate unwanted reflections, which can degrade the performance of various optical components and devices. "We started thinking, there is no viable material available in the refractive index range 1.0-1.4," Schubert said. "If we had such a material, we could do incredible new things in optics and photonics."
So the team created one. Using a technique called oblique angle deposition, the researchers deposited silica nanorods at an angle of precisely 45 degrees on top of a thin film of aluminum nitride, which is a semiconducting material used in advanced light-emitting diodes (LEDs). From the side, the films look much like the cross section of a piece of lawn turf with the blades slightly flattened.
The technique allows the researchers to strongly reduce or even eliminate reflection at all wavelengths and incoming angles of light, Schubert said. Conventional anti-reflection coatings, although widely used, work only at a single wavelength and when the light source is positioned directly perpendicular to the material.
A Broad Spectrum of Applications
The new optical coating could find use in just about any application where light travels into or out of a material, such as:
-- More efficient solar cells. The new coating could increase the amount
of light reaching the active region of a solar cell by several
percent, which could have a major impact on its performance.
"Conventional coatings are not appropriate for a broad spectral source
like the sun," Schubert said. "The sun emits light in the ultraviolet,
infrared, and visible spectral range. To use all the energy provided
by the sun, we don't want any energy reflected by the solar cell
surface."
-- Brighter LEDs. LEDs are increasingly being used in traffic signals,
automotive lighting, and exit signs, because they draw far less
electricity and last much longer than conventional fluorescent and
incandescent bulbs. But current LEDs are not yet bright enough to
replace the standard light bulb. Eliminating reflection could improve
the luminance of LEDs, which could accelerate the replacement of
conventional light sources by solid-state sources.
-- "Smart" lighting. Not only could improved LEDs provide significant
energy savings, they also offer the potential for totally new
functionalities. Schubert's new technique allows for vastly improved
control of the basic properties of light, which could allow "smart"
light sources to adjust to specific environments. Smart light sources
offer the potential to alter human circadian rhythms to match changing
work schedules, or to allow an automobile to imperceptibly communicate
with the car behind it, according to Schubert.
-- Optical interconnects. For many computing applications, it would be
ideal to communicate using photons, as opposed to the electrons that
are found in electrical circuits. This is the basis of the burgeoning
field of photonics. The new materials could help achieve greater
control over light, helping to sustain the burgeoning photonics
revolution, Schubert said.
-- High-reflectance mirrors. The idea of anti-reflection coatings also
could be turned on its head, according to Schubert. The ability to
precisely control a material's refractive index could be used to make
extremely high-reflectance mirrors, which are used in many optical
components including telescopes, optoelectronic devices, and sensors.
-- Black body radiation. The development could also advance fundamental
science. A material that reflects no light is known as an ideal "black
body." No such material has been available to scientists, until now.
Researchers could use an ideal black body to shed light on quantum
mechanics, the much-touted theory from physics that explains the
inherent "weirdness" of the atomic realm.
Schubert and his coworkers have only made several samples of the new material to prove it can be done, but the oblique angle evaporation technique is already widely used in industry, and the design can be applied to any type of substrate -- not just an expensive semiconductor such as aluminum nitride.
Schubert is featured in an interview about the research in the same issue of Nature Photonics.
Several other Rensselaer researchers also were involved with the project: Professors Shawn-Yu Lin and Jong Kyu Kim; and graduate students J.-Q. Xi, Martin F. Schubert, and Minfeng Chen.
The research is funded primarily by the National Science Foundation, with additional support from the U.S. Department of Energy, the U.S. Army Research Office, the New York State Office of Science, Technology and Academic Research (NYSTAR), Sandia National Laboratories, and the Samsung Advanced Institute of Technology in Korea. The substrates were provided by Crystal IS, a manufacturer of single-crystal aluminum nitride substrates for the production of high-power, high-temperature, and optoelectronic devices such as blue and ultraviolet lasers.
Under Schubert's leadership, the Future Chips Constellation focuses on innovations in materials and devices, in solid state and smart lighting, and applications such as sensing, communications, and biotechnology. A new concept in academia, Rensselaer constellations are led by outstanding faculty in fields of strategic importance. Each constellation is focused on a specific research area and comprises a multidisciplinary mix of senior and junior faculty and postdoctoral and graduate students.