Comet Collisions Every Six Seconds Explain 17-Year-Old Stellar Mystery

Every six seconds, for millions of years, comets have been colliding with one another near a star in the constellation Cetus called 49 CETI, which is visible to the naked eye.

Over the past three decades, astronomers have discovered hundreds of dusty disks around stars, but only two -- 49 CETI is one -- have been found that also have large amounts of gas orbiting them.

Young stars, about a million years old, have a disk of both dust and gas orbiting them, but the gas tends to dissipate within a few million years and almost always within about 10 million years. Yet 49 CETI, which is thought to be considerably older, is still being orbited by a tremendous quantity of gas in the form of carbon monoxide molecules, long after that gas should have dissipated.

"We now believe that 49 CETI is 40 million years old, and the mystery is how in the world can there be this much gas around an otherwise ordinary star that is this old," said Benjamin Zuckerman, a UCLA professor of physics and astronomy and co-author of the research, which was recently published in theAstrophysical Journal. "This is the oldest star we know of with so much gas."

Zuckerman and his co-author Inseok Song, a University of Georgia assistant professor of physics and astronomy, propose that the mysterious gas comes from a very massive disk-shaped region around 49 CETI that is similar to the sun's Kuiper Belt, which lies beyond the orbit of Neptune.

The total mass of the various objects that make up the Kuiper Belt, including the dwarf planet Pluto, is about one-tenth the mass of Earth. But back when Earth was forming, astronomers say, the Kuiper Belt likely had a mass that was approximately 40 times larger than Earth's; most of that initial mass has been lost in the last 4.5 billion years.

By contrast, the Kuiper Belt analogue that orbits around 49 CETI now has a mass of about 400 Earth masses -- 4,000 times the current mass of the Kuiper Belt.

"Hundreds of trillions of comets orbit around 49 CETI and one other star whose age is about 30 million years. Imagine so many trillions of comets, each the size of the UCLA campus -- approximately 1 mile in diameter -- orbiting around 49 CETI and bashing into one another," Zuckerman said. "These young comets likely contain more carbon monoxide than typical comets in our solar system. When they collide, the carbon monoxide escapes as a gas. The gas seen around these two stars is the result of the incredible number of collisions among these comets.

"We calculate that comets collide around these two stars about every six seconds," he said. "I was absolutely amazed when we calculated this rapid rate. I would not have dreamt it in a million years. We think these collisions have been occurring for 10 million years or so."

Using a radio telescope in the Sierra Nevada mountains of southern Spain in 1995, Zuckerman and two colleagues discovered the gas that orbits 49 CETI, but the origin of the gas had remained unexplained for 17 years, until now.

Journal Reference:

1.      B. Zuckerman, Inseok Song. A 40 Myr Old Gaseous Circumstellar Disk at 49 Ceti: Massive CO-rich Comet Clouds at Young A-type Stars. The Astrophysical Journal, 2012; 758 (2): 77 DOI: 10.1088/0004-637X/758/2/77

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Earth on Acid: Present & Future of Global Acidification

Climate change and extreme weather events grab the headlines, but there is another, lesser known, global change underway on land, in the seas, and in the air: acidification.

It turns out that combustion of fossil fuels, smelting of ores, mining of coal and metal ores, and application of nitrogen fertilizer to soils are all driving down the pH of the air, water, and the soil at rates far faster than Earth's natural systems can buffer, posing threats to both land and sea life.

"It's a bigger picture than most of us know," says Janet Herman of the Department of Environmental Sciences at University of Virginia in Charlottesville.

Herman and her colleague, Karen Rice of the USGS, discovered that despite the fact that they worked on different kinds of acidification in the environment, they were not well informed about the matter beyond their own specialties. So they have done an extensive review of science papers about all kinds of environmental acidification and are presenting their work in a poster session on Nov. 6, at the annual meeting of the Geological Society of America (GSA) in Charlotte, North Carolina, USA.

Acidification is both a local and global problem, since it can be as close as a nearby stream contaminated by mine tailings or as far-reaching as the world's oceans, which are becoming more acidic as sea water absorbs higher concentrations of carbon dioxide that humans dump into the atmosphere by burning fossil fuels.

Coal gives a double whammy by being the biggest contributor of anthropogenic carbon dioxide to the global atmosphere as well as creating regional acidification. Coal burning is famous for creating acid rain, which had dramatic environmental impacts on forests, streams, and lakes in eastern North America and Europe and led to major policy changes.

"It's not at all clear that other regions are considering such policy restrictions to be important," Herman says, regarding places where population growth is expected to increase acidifying activities.

Normally, acids in the environment are buffered by alkaline compounds released by the weathering of minerals in rocks. The problem today, according to Herman, is that the rate of acidification by human activities has outstripped the weathering rate and buffering capacity of the planet.

In their work, Herman and Rice look at the population projections by country over the next four decades to see where the increased industrialization and agriculture will likely lead to new acidification hot spots. Their hope is that by doing this people can anticipate the problem and plan to mitigate the harmful environmental effects, says Herman.

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Molecular Epidemiological Conditions Relating to Tuberculous and Non-Tuberculous Mycobacteria

A research project studying molecular epidemiological conditions relating to diseases caused by tuberculous and non-tuberculous mycobacteria in the Mubende region of Uganda has increased our understanding of how the interplay between humans, animals and the environment affects the development of such diseases. The project focused in particular on social and risk factors which may possibly prevent the success of a disease control programme in the region. 

The diseases concerned -- for example tuberculosis in humans or cattle and other host-specific tuberculosis -- are caused by pathogenic bacteria of theMycobacterium tuberculosiscomplex (MTC). Non-tuberculous mycobacteria (NMT) have not been so frequently documented as pathogenic agents, but they occur widely in the environment. However, more advanced methods of diagnosis and the fact that immunodeficiency disorders such as HIV/AIDS are widespread have led to NTM now being associated with a broad range of diseases. These bacteria also sometimes occur in larger numbers than MTC in tuberculous lesions.

Adrian Muwonge's doctoral research has revealed a wide range of pathogenic and non-pathogenic mycobacteria in the environment of the Mubende region and this gives cause for concern, given the high occurrence of HIV amongst the local population. He has studied the role that non-tuberculous mycobacteria play in the establishment and development of disease, especially since these bacteria are resistant to anti-mycobacterial drugs.

Most of the isolated non-tuberculous mycobacteria come from drinking water and the soil, but animals also play an important role in the spreading of these bacteria in the environment. Humans are exposed to mycobacteria mostly via untreated drinking water from water sources that they share with domestic and/or wild animals.

Pig farming is widespread in Mubende and the pigs are usually kept in a "free-range" system, where they wander around in the surroundings in search of food. In this way, they become infected with mycobacteria from the soil and water while at the same time infecting the environment themselves. The local people eat a great deal of pork and the occurrence of pathogenic mycobacteria such as M. avium and M. bovis in slaughtered pigs is therefore a cause for concern. Mycobacterial infections are easiest to detect in checks carried out on meat, but the quality control procedures at the abattoirs in this region were found to be unsatisfactory.

A study of the occurrence of tuberculosis in humans in the region showed a high prevalence of tuberculosis, especially amongst those infected by HIV and amongst smokers who live in households of more than six persons. Multi-resistant tuberculous bacteria and high travel costs associated with medical treatment pose problems for the efforts being made to control these infections.

The large number of heterogeneous genotypes of M. tuberculosis in Mubende points to a dynamic and complex tuberculosis epidemiology in this area. Typically, tuberculosis patients were found to be infected with more than one strain ofM. tuberculosis and this wasparticularly evident amongst female patients living in urban districts. The occurrence of specific variants of M. tuberculosis in certain geographic areas also indicates that the infection dynamics in urban areas differ from those in rural areas.

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Pregnancy and Birth Complications More Likely in Mothers With Bipolar Disorder

Babies born to mothers with bipolar disorder are at increased risk of preterm birth (before 37 weeks) a study published on bmj.com suggests.

Infants of mothers with untreated bipolar disorder are also at increased risks of outcomes related to fetal growth restriction.

Bipolar disorder (sometimes called manic depression) is a serious, long term condition involving extreme mood swings. Treatment with mood stabilizing drugs like lithium, anticonvulsants or antipsychotics can help keep mood within normal limits.

Previous studies have suggested that these drugs may be linked to pregnancy and birth complications, whereas little is known about adverse outcomes in untreated women with bipolar disorder.

So researchers from Uppsala University and the Karolinska Institutet in Sweden investigated the risks of adverse pregnancy and birth outcomes in both treated and untreated women with bipolar disorder.

Using data from three national health registers, they identified 320 mothers with treated bipolar disorder and 554 untreated mothers. Treated and untreated women were compared with all other women giving birth (331,263) between 1 July 2005 and 31 December 2009. Results were adjusted for several factors including maternal age, weight, smoking status, cohabitation and a diagnosis of alcohol or substance use disorder.

Mothers with bipolar disorder were more often smokers, overweight and alcohol or substance abusers than unaffected mothers.

Both treated and untreated mothers with bipolar disorder had increased risks of caesarean delivery, instrumental delivery (use of a vacuum or forceps), and a non-spontaneous start to delivery (120/320 or 37.5% of treated women, 171/554 or 30.9% of untreated women, 68 533/331 263 or 20.7% of other women). Treated and untreated mothers also had 50% increased risks of preterm birth compared with unaffected mothers (26/320 or 8.1% of treated women, 42/554 or 7.6% of untreated women, 15 785/331 263 or 4.8% of other women).

Untreated mothers were also more likely to give birth to a baby with a small head (microcephaly) and with episodes of low blood sugar levels (neonatal hypoglycaemia) compared with unaffected mothers.

The researchers conclude that "mood-stabilizing treatment is probably not the sole reason for the increased risk of adverse pregnancy and birth outcomes previously observed in mothers with bipolar disorder." They also suggest that the role of treatment is still unclear as the overall outcomes "generally did not support a significant difference between untreated and treated" mothers.

In an accompanying editorial, mental health expert, Dr Salvatore Gentile says the question is not "to treat or not to treat?" but "how to treat optimally?" Because no drug is without risks, clinicians cannot hope to identify a "safe choice," but merely a "less harmful" one.

He adds that patients must be properly counselled about the risks of treatment versus the risks associated with the untreated psychiatric disorder, and doctors should "encourage and facilitate social integration, especially for women from disadvantaged social groups and those who are isolated."

Journal References:

1.      R. Boden, M. Lundgren, L. Brandt, J. Reutfors, M. Andersen, H. Kieler. Risks of adverse pregnancy and birth outcomes in women treated or not treated with mood stabilisers for bipolar disorder: population based cohort study. BMJ, 2012; 345 (nov07 6): e7085 DOI:10.1136/bmj.e7085

2.      S. Gentile. Bipolar disorder in pregnancy: to treat or not to treat? BMJ, 2012; 345 (nov09 1): e7367 DOI:10.1136/bmj.e7367

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Antioxidants May Ease Peripheral Arterial Disease (PAD) Blood Pressure Increase, Study Suggests

Low antioxidant levels contribute to increased blood pressure during exercise for people with peripheral arterial disease, according to researchers at Penn State Hershey Heart and Vascular Institute.

Peripheral arterial disease, or PAD, affects an estimated 10 million Americans and increases the chance of death from a cardiovascular event. Reduced blood flow causes pain in the legs and increases blood pressure in people who have PAD. However, the causes of the disease are unknown.

"Past studies have shown that having low antioxidant levels and increased reactive oxygen species -- chemical products that bind to body cells and cause damage -- is related to more severe PAD," said Matthew Muller, postdoctoral fellow in Larry Sinoway's lab at Penn State College of Medicine, and lead author of the study.

Antioxidants prevent the reactive oxygen species from damaging cells.

"This study shows that blood pressure increases more with exercise in more severe PAD cases. By infusing the antioxidant vitamin C into the blood, we were able to lessen the increase in blood pressure during exercise," said Muller.

Vitamin C does not lessen the increase in blood pressure of PAD patients to that of healthy people. As the intensity of exercise increases, the effects of vitamin C decrease but are still seen. The researchers report their findings in the Journal of Physiology.

Penn State Hershey researchers looked at three groups of PAD patients to study the blood pressure increase. A group of 13 PAD patients was compared to people without PAD to see the effects of doing low-intensity exercise on blood pressure. From that group, a second group of nine patients was used to measure the effects of vitamin C. A third group of five PAD patients and five without PAD had their leg muscles electrically stimulated to remove the brain's role in raising blood pressure during muscle contraction in this disease.

Increased blood pressure during exercise occurs in both legs, before pain begins, and relates to the severity of the disease. By using electrical stimulation, the scientists show that the blood pressure increase comes from the muscle itself, since the brain is not telling the leg to contract and the pressure still increases.

"This indicates that during normal, everyday activities such as walking, an impaired antioxidant system -- as well as other factors -- plays a role in the increased blood pressure response to exercise," Muller said. "Therefore, supplementing the diet with antioxidants may help these patients, but more studies are needed to confirm this concept."

Other researchers are Rachel C. Drew, postdoctoral fellow; Cheryl A. Blaha, research coordinator; Jessica L. Mast, research coordinator; Jian Cui, associate professor of medicine; and Amy B. Reed, associate professor of surgery, all of Penn State College of Medicine.

The study was funded by the National Institutes of Health.

Journal Reference:

1.      M. D. Muller, R. C. Drew, C. A. Blaha, J. L. Mast, J. Cui, A. B. Reed, L. I. Sinoway. Oxidative Stress Contributes to the Augmented Exercise Pressor Reflex in Peripheral Arterial Disease Patients. The Journal of Physiology, 2012; DOI: 10.1113/jphysiol.2012.241281

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A new ‘super-Earth’

A new ‘super-Earth’ has been discovered that could have a life-supporting climate and water.

The planet, given the catchy name HD 40307g, was discovered in a multi-world solar system 42 light years from the Sun and lies at exactly the right distance from its star to allow liquid surface water.

It orbits well within the star's “habitable” or “Goldilocks” zone - the region where temperatures are neither too hot nor too cold to sustain life.

Professor Hugh Jones, from the University of Hertfordshire said: “The longer orbit of the new planet means that its climate and atmosphere may be just right to support life.”

”Just as Goldilocks liked her porridge to be neither too hot nor too cold but just right, this planet or indeed any moons that is has lie in an orbit comparable to Earth, increasing the probability of it being habitable.“

The ‘super earth’ is one of six planets believed to circle the dwarf star HD 40307 in the constellation Pictor.

All the others are located outside the habitable zone, too close to their parent star to support liquid water.

Three of these were originally identified in 2009 by European Southern Observatory astronomers who used an instrument called Harps (High Accuracy Radial Velocity Planet Searcher) that reveals planets by detecting changes in starlight colour.

A new analysis of the Harps data has now revealed three more super-Earths – with HD 40307g exciting astronomers considerably more than the others thanks to its greater distance from its star. Scientists believe the planet turns on its axis, giving it a regular day and night cycle and making its environment even more Earth-like. Planets orbiting too close to their stars risk being ”tidally locked“ so they always have the same face pointing towards the star.

In the same way, the Moon always has its nearside facing the Earth. One side of such a planet is likely to be scorching hot while the other is dark and cold. Scientists doubt that tidally locked planets could be habitable.

Like many other extra-solar planets, HD 40307g was found by observing wobbles in the motion of its parent star caused by the tug of its gravity.

The wobbles stretch or compress the wavelength of light from the star as seen from the Earth, making it redder as it moves away and bluer as it comes closer. Analysing these patterns can provide information about the planet's mass.

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Discovery of small stone blades dating to 71,000 years ago

The date when stone-age humans first invented the lethal technology of spears and arrows has been set back many thousands of years with the discovery of small stone blades dating to 71,000 years ago.

Archaeologists believe the “bladelets” were used as the sharp tips for arrows or spears and were made by a relatively sophisticated technique involving the heat treatment of stone before shaping the final cutting edges.

The fine stone blades were excavated from a prehistoric site called Pinnacle Point on the southern coast of South Africa and are between 6,000 and 11,000 years older than the previous oldest known samples of spear and arrow blades, scientists said.

The discovery suggests that the invention of lethal projectile weapons came far earlier in the course of human prehistory than previously realised and that, once invented, the knowledge was passed down the generations, according to a study in Nature led by Curtis Marean of Arizona State University.

Previously, scholars thought that the technology of “projectile weapons” was first invented about 60,000 years ago and then lost for many thousands of years before being reinvented between 40,000 and 50,000 years ago.

“Every time we excavate a new site in coastal South Africa with advanced field techniques, we discover new and surprising results that push back in time the evidence for uniquely human behaviours,” Dr Marean said.

Arrows and spears were probably the key weapons that allowed anatomically modern Homo sapiens to migrate out of Africa and successfully colonise other parts of the world, including Europe where the Neanderthals lived, he said.

“When Africans left Africa and entered Neanderthal territory they had projectiles with greater killing reach and these early moderns probably also had higher levels of hyper-cooperative behaviour,” he said.

“These two traits were a knockout punch. Combine them, as modern humans did and still do, and no prey or competitor is safe. This probably laid the foundation for the expansion out of Africa of modern humans and the extinction of many prey as well as our sister species such as Neanderthals.”

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Harmless Soil-Dwelling Bacteria Successfully Kill Cancer

A bacterial strain that specifically targets tumours could soon be used as a vehicle to deliver drugs in frontline cancer therapy. The strain is expected to be tested in cancer patients in 2013, says a scientist at the Society for General Microbiology's Autumn Conference at the University of York.

The therapy uses Clostridium sporogenes -- a bacterium that is widespread in the soil. Spores of the bacterium are injected into patients and only grow in solid tumours, where a specific bacterial enzyme is produced. An anti-cancer drug is injected separately into the patient in an inactive 'pro-drug' form. When the pro-drug reaches the site of the tumour, the bacterial enzyme activates the drug, allowing it to destroy only the cells in its vicinity -- the tumour cells.

Researchers at the University of Nottingham and the University of Maastricht have now overcome the hurdles that have so far prevented this therapy from entering clinical trials. They have introduced a gene for a much-improved version of the enzyme into the C. sporogenes DNA. The improved enzyme can now be produced in far greater quantities in the tumour than previous versions, and is more efficient at converting the pro-drug into its active form.

A fundamental requirement for any new cancer therapy is the ability to target cancer cells while excluding healthy cells. Professor Nigel Minton, who is leading the research, explains how this therapy naturally fulfils this need. "Clostridia are an ancient group of bacteria that evolved on the planet before it had an oxygen-rich atmosphere and so they thrive in low oxygen conditions. When Clostridia spores are injected into a cancer patient, they will only grow in oxygen-depleted environments, i.e. the centre of solid tumours. This is a totally natural phenomenon, which requires no fundamental alterations and is exquisitely specific. We can exploit this specificity to kill tumour cells but leave healthy tissue unscathed," he said.

The research may ultimately lead to a simple and safe procedure for curing a wide range of solid tumours. "This therapy will kill all types of tumour cell. The treatment is superior to a surgical procedure, especially for patients at high risk or with difficult tumour locations," explained Professor Minton. "We anticipate that the strain we have developed will be used in a clinical trial in 2013 led by Jan Theys and Philippe Lambin at the University of Maastricht in The Netherlands. A successful outcome could lead to its adoption as a frontline therapy for treating solid tumours. If the approach is successfully combined with more traditional approaches this could increase our chance of winning the battle against cancerous tumours."

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Scientists Uncover Secrets of How Intellect and Behavior Emerge During Childhood

Scientists from the Florida campus of The Scripps Research Institute (TSRI) have shown that a single protein plays an oversized role in intellectual and behavioral development. The scientists found that mutations in a single gene, which is known to cause intellectual disability and increase the risk of developing autism spectrum disorder, severely disrupts the organization of developing brain circuits during early childhood. This study helps explain how genetic mutations can cause profound cognitive and behavioral problems.

The study was published in the Nov. 9, 2012, issue of the journal Cell.

The genetic mutations that cause developmental disorders, such as intellectual disability and autism spectrum disorder, commonly affect synapses, the junctions between two nerve cells that are part of the brain's complex electro-chemical signaling system. A substantial percentage of children with severe intellectual and behavioral impairments are believed to harbor single mutations in critical neurodevelopmental genes. Until this study, however, it was unclear precisely how pathogenic genetic mutations and synapse function were related to the failure to develop normal intellect.

"In this study, we did something no one else had done before," said Gavin Rumbaugh, a TSRI associate professor who led the new research. "Using an animal model, we looked at a mutation known to cause intellectual disability and showed for the first time a causative link between abnormal synapse maturation during brain development and life-long cognitive disruptions commonly seen in adults with a neurodevelopmental disorder."

Losing Balance

The study focused on a critical synaptic protein known as SynGAP1. Mutations in the gene that encodes this protein cause disabilities in an estimated one million people worldwide, according to the paper.

"There are a few genes that can't be altered without affecting normal cognitive abilities," Rumbaugh said. "SynGAP1 is one of the most important genes in cognition -- so far, every time a mutation that disrupts the function of SynGAP1 has been found, that individual's brain simply could not develop correctly. It regulates the development of synaptic function like no other gene I've seen."

Using animal models that were missing just one copy of SynGAP1, as seen in some patients with intellectual disability, the scientists found that certain synapses develop prematurely in the period shortly after birth. This dramatically enhances what is known as "excitability" -- how often brain cells fire -- in the developing hippocampus, a part of the brain critical for memory. The balance between excitability and inhibition is especially critical during early developmental periods, when neural connections that ultimately give rise to normal cognitive and behavioral functions are forming.

"You might think this accelerated development of brain circuits would make you smarter," Rumbaugh said. "But the increased excitability actually disorganizes brain development. We think that early maturation of these excitatory synapses disrupts the timing of later developmental milestones. It rains down chaos on this complex process, preventing normal intellectual and behavioral development."

A Critical Window

Interestingly, inducing these mutations after the critical development period was complete had virtually no impact on normal synapse function and repairing these pathogenic mutations in adulthood did not improve behavior or cognition.

"A key finding is we were able to remove the mutation and restore SynGAP protein levels in adult mice with obvious cognitive and behavioral problems, but this intervention did not benefit the animals," Rumbaugh said.

These results imply that very early intervention is essential in neurodevelopmental disorders, particularly for cognitive problems. The team is now aggressively searching for the optimal period during development in which repairing these mutations is most beneficial.

Rumbaugh speculates that successfully defining these treatment windows, combined with the fast-approaching ability to identify potential pathogenic mutations in utero, will provide a possible path toward eradicating this type of intellectual disability and lowering the risks for autism. "We believe a cure is possible," he said. "It is likely that there are many other single mutations out there that cause distinct forms of these spectrum disorders. Our strategy could be applied to these disorders as well."

The first author of the study, "Pathogenic SYNGAP1 Mutations Impair Cognitive Development by Disrupting the Maturation of Dendritic Spine Synapses," is James Clement of TSRI. Other authors include Massimiliano Aceti, Thomas Creson, Emin D Ozkan, Brooke Miller, and Courtney A. Miller of TSRI; Yulin Shi and Xiangmin Xu of The University of California, Irvine; Nicholas Reis and Antoine Almonte of The University of Alabama at Birmingham; and Brian Wiltgen of The University of Virginia.

The study was funded by the National Institute for Neurological Disorders and Stroke (R01NS064079), the Eunice Kennedy Shriver National Institute for Child Health and Human Development (R03HD060672), the National Alliance for Research on Schizophrenia and Depression, and the National Institute for Drug Abuse (DA023700-04S1).

Journal Reference:

1.      James P. Clement, Massimiliano Aceti, Thomas K. Creson, Emin D. Ozkan, Yulin Shi, Nicholas J. Reish, Antoine G. Almonte, Brooke H. Miller, Brian J. Wiltgen, Courtney A. Miller, Xiangmin Xu, Gavin Rumbaugh. Pathogenic SYNGAP1 Mutations Impair Cognitive Development by Disrupting Maturation of Dendritic Spine Synapses.Cell, 2012; 151 (4): 709 DOI: 10.1016/j.cell.2012.08.045

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New Strategy for Fingerprint Visualization Developed

Identifying fingerprints on paper is a commonly used method in police forensic work, but unfortunately it is not easy to make those fingerprints visible. Now, scientists at the Hebrew University of Jerusalem have developed a new approach for making such fingerprints more readily readable.

The new method, created by a team headed by Prof. Yossi Almog and Prof. Daniel Mandler of the Institute of Chemistry at the Hebrew University, uses an innovative chemical process to produce a negative of the fingerprint image rather than the positive image produced under current methods. Unlike the latter, the Hebrew University-developed process is nearly independent of the composition of the sweat residue left behind on the paper.

The new method is described in the current issue of the international, English-language edition of the journal Angewandte Chemie, published by the German Chemical Society.

In many criminal investigations, paper evidence plays an important role, and it is useful to know who has handled such documents as checks, paper currency, notes, etc. Studies have shown that less than half of the fingerprints on paper items can be made sufficiently visible to enable their identification. The main reason for this seems to be the highly variable composition of the sweat left behind on the paper.

The new procedure developed at the Hebrew University avoids these problems. It involves an inversion of an established method in which gold nanoparticles are first deposited onto the invisible fingerprints, followed by elemental silver, similar to the development of a black and white photograph.

In the conventional technique, the gold particles get stuck to the amino acid components of the sweat in the fingerprints, and then silver is deposited onto the gold. The result is quite often low-contrast impressions of the fingerprints. In the new method, the gold nanoparticles stick directly to the paper surface, but not the sweat. This technique utiliizes the sebum from the fingerprints as a medium to avoid this interference. (Sebum is an oily substance secreted by the sebaceous glands that helps prevent hair and skin from drying out.) Treatment with a developer containing silver then turns the areas with gold on them black, resulting in a clear, negative image of the fingerprint.

"Since our method relies only on the fatty components in the fingerprints, the sweaty aspects play no role in the imaging process," said Prof. Almog. This technique also promises to alleviate another problem, he said. "If paper has become wet, it has previously been difficult to detect fingerprints because the amino acids in the sweat, which are the primary substrate for current chemical enhancement reactions, are dissolved and washed away by water, whereas the fatty components are barely affected." Thus, the avoidance of the sweat aspect provides a further enhancement for police laboratory investigation, he observed.

Journal Reference:

1.      Nimer Jaber, Adam Lesniewski, Hadar Gabizon, Sanaa Shenawi, Daniel Mandler, Joseph Almog. Visualization of Latent Fingermarks by Nanotechnology: Reversed Development on Paper-A Remedy to the Variation in Sweat Composition. Angewandte Chemie International Edition, 2012; DOI: 10.1002/anie.201205259

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Virtual Reality Puts Human in Rat World: 'Beaming' Technology Transforms Human-Animal Interaction

Using cutting-edge virtual reality technology, researchers have 'beamed' a person into a rat facility allowing the rat and human to interact with each other on the same scale.

Published October 31 in PLOS ONE, the research enables the rat to interact with a rat-sized robot controlled by a human participant in a different location. At the same time, the human participant (who is in a virtual environment) interacts with a human-sized avatar that is controlled by the movements of the distant rat. The authors hope the new technology will be used to study animal behaviour in a completely new way.

Computer scientists at UCL and the University of Barcelona have been working on the idea of 'beaming' for some time now, having last year digitally beamed a scientist in Barcelona to London to be interviewed by a journalist.

The researchers define 'beaming' as digitally transporting a representation of yourself to a distant place, where you can interact with the people there as if you were there. This is achieved through a combination of virtual reality and teleoperator systems. The visitor to the remote place (the destination) is represented there ideally by a physical robot.

During the human-animal beaming process the human participants in the system were in a virtual reality lab at the Mundet campus of the University of Barcelona. The rat was located around 12 km away in an animal care facility in Bellvitge.

Tracking technology was used to track the movements of the rat in its arena, and the tracking data was transmitted over the internet to the computers running the virtual reality simulation in Mundet. This tracking information was used to control a virtual human character (an avatar) that represented the rat so that whenever the rat moved its avatar moved too, in a representation of the rat arena but scaled up to human size. Hence the human participant shared the virtual arena, which looked like a room with some pictures on the walls, with a humanoid avatar.

The movements of the human in the virtual reality were also tracked, and the data sent to computers in Bellvitge that controlled a small robot that was located in the rat arena. Whenever the human moved in the virtual space the robot moved in the rat space.

Putting all this together -- the rat interacted with a rat sized robot that represented the remotely located human, and the human interacted with a human sized avatar that represented the remotely located rat.

Professor Mandayam Srinivasan, author of the paper from the UCL Department of Computer Science and MIT, said: "Beaming is a step beyond approaches such as video conferencing which do not give participants the physical sensation of being in the same shared space, and certainly not the physical capability to actually carry out actions in that space."

He added: "The process demonstrated here not only shows the range of our technology, but also provides a new tool for scientists, explorers or others to visit distant and alien places without themselves being placed in any kind of danger, and importantly, to be able to see animal behavior in a totally new way -- as if it were the behavior of humans."

Professor Mel Slater, also from the UCL Department of Computer Science and also ICREA, University of Barcelona said: "In the paper we used the idea of representing the rat as if it were a human, but there would be many other possibilities. One idea is that using this technology behavioural scientists could get insights into behavior by observing it, and taking part in it, through this quite different filter. However, our primary goal was to demonstrate the possibilities inherent in this technology."

Journal Reference:

1.      Jean-Marie Normand, Maria V. Sanchez-Vives, Christian Waechter, Elias Giannopoulos, Bernhard Grosswindhager, Bernhard Spanlang, Christoph Guger, Gudrun Klinker, Mandayam A. Srinivasan, Mel Slater. Beaming into the Rat World: Enabling Real-Time Interaction between Rat and Human Each at Their Own Scale. PLoS ONE, 2012; 7 (10): e48331 DOI: 10.1371/journal.pone.0048331

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Mummy Unwrapping Brought Egyptology to the Public

Mummies have been objects of horror in popular culture since the early 1800's -- more than a century before Boris Karloff portrayed an ancient Egyptian searching for his lost love in the 1932 film "The Mummy." Public "unwrappings" of real mummified human remains performed by both showmen and scientists heightened the fascination, but also helped develop the growing science of Egyptology, says a Missouri University of Science and Technology historian.

Dr. Kathleen Sheppard, an expert in the history of science, particularly archaeology and Egyptology, and an assistant professor of history and political science at Missouri S&T, says that while mummy unwrappings served as public spectacles that objectified exotic artifacts, they were also scientific investigations that sought to reveal medical and historical information about ancient life.

Sheppard wrote about this intersection between science and showmanship in an article titled "Between Spectacle and Science: Margaret Murray and the Tomb of the Two Brothers." It will be published in the December issue of the journalScience in Context.

Sheppard says 20th century Egyptologist Margaret Murray, the first woman to publicly unwrap a mummy, sought to unravel the mysteries of ancient Egypt by exposing mummified human remains. She says Murray's work is culturally significant because it is "poised between spectacle and science, drawing morbid public interest while also producing ground-breaking scientific work that continues to this day."

Public spectacles that displayed mummified remains as objects of curiosity date back to the 16th century, Sheppard says. "These types of spectacles were highly engaging shows in which people were, to a certain degree, educated about different aspects of science both by showmen and scientists."

Many Egyptologists drew a distinction between "Egyptomania," the fascination with all things Egypt, and "Egyptology," the scientific study of Egyptian life, Sheppard says, but Murray had a different goal -- involving the public in scientific inquiry with a goal of correcting popular misconceptions.

"Murray tried to get the public to see that mummies weren't magical, they were just preserved human remains to be studied and learned from," Sheppard says. "In other words, rather than trying to separate the 'mania' from the 'ology,' she wanted to bring reason and understanding to the mania."

Journal Reference:

1.      Kathleen L. Sheppard. Between Spectacle and Science: Margaret Murray and the Tomb of the Two Brothers.Science in Context, 2012; 25 (04): 525 DOI:10.1017/S0269889712000221

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New Device Could Allow Your Heartbeat to Power Pacemaker

An experimental device converted energy from a beating heart to provide enough electricity to power a pacemaker, in a study presented at the American Heart Association's Scientific Sessions 2012.

The findings suggest that patients could power their pacemakers -- eliminating the need for replacements when batteries are spent.

In a preliminary study, researchers tested an energy-harvesting device that uses piezoelectricity -- electrical charge generated from motion. The approach is a promising technological solution for pacemakers, because they require only small amounts of power to operate, said M. Amin Karami, Ph.D., lead author of the study and research fellow in the Department of Aerospace Engineering at the University of Michigan in Ann Arbor.

Piezoelectricity might also power other implantable cardiac devices like defibrillators, which also have minimal energy needs, he said.

Today's pacemakers must be replaced every five to seven years when their batteries run out, which is costly and inconvenient, Karami said.

"Many of the patients are children who live with pacemakers for many years," he said. "You can imagine how many operations they are spared if this new technology is implemented."

Researchers measured heartbeat-induced vibrations in the chest. Then, they used a "shaker" to reproduce the vibrations in the laboratory and connected it to a prototype cardiac energy harvester they developed. Measurements of the prototype's performance, based on sets of 100 simulated heartbeats at various heart rates, showed the energy harvester performed as the scientists had predicted -- generating more than 10 times the power than modern pacemakers require.

The next step will be implanting the energy harvester, which is about half the size of batteries now used in pacemakers, Karami said. Researchers hope to integrate their technology into commercial pacemakers.

Two types of energy harvesters can power a typical pacemaker: linear and nonlinear. Linear harvesters work well only at a specific heart rate, so heart rate changes prevent them from harvesting enough power.

In contrast, a nonlinear harvester -- the type used in the study -- uses magnets to enhance power production and make the harvester less sensitive to heart rate changes. The nonlinear harvester generated enough power from heartbeats ranging from 20 to 600 beats per minute to continuously power a pacemaker.

Devices such as cell phones or microwave ovens would not affect the nonlinear device, Karami said.

Co-authors are David J. Bradley, M.D., and Daniel J. Inman, Ph.D.

The National Institute of Standards and Technology and National Center for Advancing Translational Sciences funded the study.

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Super-Massive Black Hole Inflates Giant Bubble

Like symbiotic species, a galaxy and its central black hole lead intimately connected lives. The details of this relationship still pose many puzzles for astronomers.

This false colour image shows the galaxy M87. Optical light is shown in white/blue (SDSS), the radio emission in yellow/orange (LOFAR). At the centre, the radio emission has a very high surface brightness, showing where the jet powered by the supermassive black hole is located. (Credit: Francesco de Gasperin, on behalf of the LOFAR collaboration)

 Some black holes actively accrete matter. Part of this material do not fall into the black hole but is ejected in a narrow stream of particles, traveling at nearly the speed of light. When the stream slows down, it creates a tenuous bubble that can engulf the entire galaxy. Invisible to optical telescopes, the bubble is very prominent at low radio frequencies. The new International LOFAR Telescope - designed and built by ASTRON in an international collaboration - is ideally suited to detect this low frequency emission.

Astronomers have produced one of the best images ever of such a bubble, using LOFAR to detect frequencies from 20 to 160 MHz. "The result is of great importance", says Francesco de Gasperin, lead author of the study that is being published in the journal Astronomy & Astrophysics. "It shows the enormous potential of LOFAR, and provides compelling evidence of the close ties between black hole, host galaxy, and their surroundings."

The image was made during the test-phase of LOFAR, and targeted the giant elliptical galaxy Messier 87, at the centre of a galaxy cluster in the constellation of Virgo. This galaxy is 2000 times more massive than our Milky Way and hosts in its centre one of the most massive black holes discovered so far, with a mass six billion times that of our Sun. Every few minutes this black hole swallows an amount of matter similar to that of the whole Earth, converting part of it into radiation and a larger part into powerful jets of ultra-fast particles, which are responsible for the observed radio emission.

“This is the first time such high-quality images are possible at these low frequencies", says professor Heino Falcke, chairman of the board of the ILT and co-author of the study. "This was a challenging observation - we did not expect to get such fantastic results so early in the commissioning phase of LOFAR."

To determine the age of the bubble, the authors added radio observations at different frequencies from the Very Large Array in New Mexico (USA), and the Effelsberg 100-meter radio telescope near Bonn (Germany). The team found that this bubble is surprisingly young, just about 40 million years, which is a mere instant on cosmic time scales. The low frequency observation does not reveal any relic emission outside the well-confined bubble boundaries, this means that the bubble is not just a relic of an activity that happened long ago but is constantly refilled with fresh particles ejected by the central black hole.

"What is particularly fascinating", says Andrea Merloni from the Max-Planck Institute of Extraterrestrial Physics in Garching, who supervised de Gasperin's doctoral work, "is that the results also provide clues on the violent matter-to-energy conversion that occurs very close to the black hole. In this case the black hole is particularly efficient in accelerating the jet, and much less effective in producing visible emission."

Francesco de Gasperin performed the study as part of his PhD work at the Max Planck Institute for Astrophysics and at the Excellence Cluster Universe. De Gasperin is now a postdoctoral researcher at the University of Hamburg.

Journal Reference:

1.      F. de Gasperin, E. Orrú, M. Murgia, A. Merloni, H. Falcke, R. Beck, R. Beswick, L. Bîrzan, A. Bonafede, M. Brüggen, G. Brunetti, K. Chyży, J. Conway, J. H. Croston, T. Enßlin, C. Ferrari, G. Heald, S. Heidenreich, N. Jackson, G. Macario, J. McKean, G. Miley, R. Morganti, A. Offringa, R. Pizzo, D. Rafferty, H. Röttgering, A. Shulevski, M. Steinmetz, C. Tasse, S. van der Tol, W. van Driel, R. J. van Weeren, J. E. van Zwieten, A. Alexov, J. Anderson, A. Asgekar, M. Avruch, M. Bell, M. R. Bell, M. Bentum, G. Bernardi, P. Best, F. Breitling, J. W. Broderick, A. Butcher, B. Ciardi, R. J. Dettmar, J. Eisloeffel, W. Frieswijk, H. Gankema, M. Garrett, M. Gerbers, J. M. Griessmeier, A. W. Gunst, T. E. Hassall, J. Hessels, M. Hoeft, A. Horneffer, A. Karastergiou, J. Köhler, Y. Koopman, M. Kuniyoshi, G. Kuper, P. Maat, G. Mann, M. Mevius, D. D. Mulcahy, H. Munk, R. Nijboer, J. Noordam, H. Paas, M. Pandey, V. N. Pandey, A. Polatidis, W. Reich, A. P. Schoenmakers, J. Sluman, O. Smirnov, C. Sobey, B. Stappers, J. Swinbank, M. Tagger, Y. Tang, I. van Bemmel, W. van Cappellen, A. P. van Duin, M. van Haarlem, J. van Leeuwen, R. Vermeulen, C. Vocks, S. White, M. Wise, O. Wucknitz, P. Zarka. M 87 at metre wavelengths: the LOFAR picture.Astronomy & Astrophysics, 2012; 547: A56 DOI:10.1051/0004-6361/201220209

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