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.