Apr 20, 2013

Surprising New Function for Small RNAs in Evolution

An international research team in including Christian Schlötterer and Alistair McGregor of the Vetmeduni Vienna has discovered a completely new mechanism by which evolution can change the appearance of an organism. The researchers found that the number of hairs on flies' legs varies according to the level of activity of a so-called microRNA.

The results, published in the journal Current Biology, shed a completely new light on the molecular mechanisms of evolution.

It has long been known that certain proteins, known as transcription factors, directly control the way in which information is read from DNA. As a result, it is widely believed that changes in genes encoding such proteins underlie the mechanisms responsible for evolutionary adaptation. The idea that small RNA molecules, so-called microRNAs, may play an important part in evolutionary changes to animals' appearance is completely new. An international team of researchers, including Christian Schlötterer and Alistair McGregor from the Institute of Population Genetics of the University of Veterinary Medicine, Vienna (Vetmeduni Vienna), has now published a study that describes such an evolutionary mechanism.

Small and large bald patches

Insect bodies are generally covered with a large number of microscopic hairs. This is the case for the legs of many closely related species of the fruit fly genus Drosophila, although the animals have a bald patch on the second pair of legs, intriguingly known as the naked valley. Previous work had shown that the size of this patch is regulated by the gene ultrabithorax (Ubx) and that it differs between species. However, the work at the Vetmeduni Vienna showed that similar differences are shown by individuals from different populations of Drosophila melanogaster.

Their search for the genetic basis of the variation led the researchers to a segment of fruit fly DNA that contained four genes. Three of these genes were known to encode proteins with no role in the development of the hairs. The fourth gene, known as miR-92a, encodes a microRNA. Previous experiments had shown that an increase in activity of the miR-92a gene was associated with a loss of hairs from the animals' wings. By overexpressing the gene in the legs of the fruit flies, the scientists were able to cause hair loss on the animals' legs.

Read more at Science Daily

Alternative Medicine Use by MS Patients Now Mapped

A major Nordic research project involving researchers from the University of Copenhagen has, for the first time ever, mapped the use of alternative treatment among multiple sclerosis patients -- knowledge which is important for patients with chronic disease and the way in which society meets them.

People with multiple sclerosis (MS) often use alternative treatments such as dietary supplements, acupuncture and herbal medicine to facilitate their lives with this chronic disease. This is the result of a new study of how MS patients use both conventional and alternative treatments which has been carried out by researchers from five Nordic countries. The results have been published in two scientific journals, the Scandinavian Journal of Public Health and Autoimmune Diseases.

"What we see is that patients do not usually use alternative treatments for treating symptoms, but as a preventative and strengthening element," says Lasse Skovgaard, industrial PhD candidate from the Faculty of Health and Medical Sciences and the Danish Multiple Sclerosis Society, who has been involved in conducting the questionnaire-based study among 3,800 people with MS in Denmark, Sweden, Norway, Finland and Iceland.

Multiple sclerosis is a chronic disease which attacks the central nervous system, and which can lead to a loss of mobility and sight. Denmark is one of the countries with the highest incidence of the disease worldwide, with approx. 12,500 MS patients. At the same time, the number of MS patients in the West is increasing, posing considerable challenges in respect of treatment, prevention and rehabilitation.

Access to knowledge bank

Together with researchers from the five other Nordic countries, Lasse Skovgaard has spent three years gathering the new data, and he is delighted at what it offers: "Within the field of health research, it is often a question of studying the extent to which a particular type of drug affects a particular symptom. However, it is equally as important to look at how people with a chronic disease, for example, use different treatments to cope with their situation. Here, MS patients offer valuable experience. Their experiences constitute a knowledge bank which we must access and learn from," he says.

Lasse Skovgaard draws attention to the significance of this new knowledge because, if people with chronic disease are better able to manage their lives, it can potentially save society large sums of money.

"There is a lot of talk about 'self-care competence', in other words patients helping themselves to get their lives to function. Here, many people with a chronic disease find they benefit from using alternative treatments, so we should not ignore this possibility," says Lasse Skovgaard.

At the same time, he emphasises that knowing more about why patients choose particular treatments is important in relation to improving patient safety because of the possible risks involved in combining conventional and alternative medicine.

Growing use of alternative treatments

According to the latest Health and Sickness Study from the Danish National Institute of Public Health (NIPH) in 2010, one in four Danes say that they have tried one or more types of alternative treatments within the past twelve months. Among MS patients, the use of alternative medicine has been growing steadily over the past fifteen years. In the researchers' latest study, more than half of the respondents say that they either combine conventional and alternative medicine or only use alternative medicine.

"We cannot ignore the fact that people with chronic disease use alternative treatments to a considerable extent, and that many of them seem to benefit from doing so. It doesn't help to only judge this from a medical point of view or say that alternative treatments are nonsense -- rather, we must try to understand it," says Lasse Skovgaard.

Highly qualified women top the list

The study shows that, among MS patients using alternative treatments, there is a significantly bigger proportion of people with a high level of education compared to those who do not use alternative treatments. There is also a larger proportion of highly paid people and of younger women.

"Some critics are of the opinion that when alternative treatments are so popular, it is because they appeal to naïve people looking for a miraculous cure. But our results indicate that it is primarily the well-educated segment that is subscribing to alternative treatments. And that using alternative treatments is part of a lifestyle choice," says Lasse Skovgaard.

Read more at Science Daily

Apr 19, 2013

Stonehenge Settled 5,000 Years Earlier Than Thought

Excavation near Stonehenge found evidence of a settlement dating back to 7,500 BC, revealing the site was occupied some 5,000 years earlier than previously thought.

Working at Vespasian’s Camp in Amesbury, Wiltshire, less than a mile from the megalithic stones, a team led by archaeologist David Jacques of the Open University unearthed material which contradicted the general belief that no people settled there until as late as 2,500 BC.

Indeed, carbon dating of the material revealed the existence of a semi-permanent settlement which was occupied from 7,500 to 4,700 BC. The dating showed that people were present during every millennium in between.

The team has “found the community who put the first monument up at Stonehenge,” archaeologist Josh Pollard from Southampton University and the Stonehenge Riverside Project, told the BBC.

The researchers believe that the people who settled at Vespasian’s Camp also built the first monument at Stonehenge — large wooden posts erected between the 9th and 7th millennia BC.

The findings, to be broadcast in a documentary on BBC One, shows that Stonehenge wasn’t just abandoned by Mesolithic humans and occupied by Neolithic people thousands of years later. On the contrary, it represents a place where one culture mingled with the other.

Jacques started to survey the area after seeing aerial photographs of the site in 1999 as a student.

He noticed it contained a natural spring, which would have attracted animals.

“What we found was the nearest secure watering hole for animals and people, a type of all year round fresh water source,” Jacques told the BBC.

Read more at Discovery News

Did Richard III Get Painful Scoliosis Treatment?

King Richard III may not have been a hunchback as portrayed by Shakespeare, but he did suffer from the spine-curving condition scoliosis, and he may have undergone painful medical treatments to straighten it out, scientists report today (April 19).

Archaeologists announced in February that bones excavated from underneath a parking lot in Leicester, England, belonged to the medieval king. Since this confirmation, examination has continued on the bones and historical records, which have suggested the king was a control freak who had a friendly face.

Previous work showed King Richard III likely developed severe scoliosis, a painful condition, in his teen years.

Now, Mary Ann Lund, of the University of Leicester's School of English, has looked into the types of scoliosis treatments available when Richard III was alive, finding one would have been widely available for those who could afford it, such as the nobility.

Even so, there is no evidence on his bones to support the treatment.

"It wouldn't necessarily be possible to distinguish such signs," Lund told LiveScience. "Richard had idiopathic adolescent onset scoliosis, which means that the cause for it is not apparent, and that it developed after the age of about 10. So he would probably have been treated as an adolescent as well as during his adult life."

"It wouldn't necessarily be possible to distinguish such signs," Lund told LiveScience. "Richard had idiopathic adolescent onset scoliosis, which means that the cause for it is not apparent, and that it developed after the age of about 10. So he would probably have been treated as an adolescent as well as during his adult life."

Traction treatment

Richard III was born in was born in 1452 and ruled England from 1483 to 1485, a reign cut short by his death at the Battle of Bosworth Field, the decisive battle in the English civil war known as the War of the Roses.

At the time, scoliosis was generally thought to be caused by an imbalance in the body's humors. "The theory of the humors would mean that this would be geared towards Richard's individual humoral complexion," Lund wrote in an email. "Given the severity of his scoliosis, it's likely that treatment would have involved more than the topical application of ointments."

Some of the short-term scoliosis treatments available during the late medieval period would have been painful, Lund said. For instance, one such treatment, traction, relied on the same principle as the so-called Rack used in torture, she added.

For this treatment, rope would be tied under the patient's armpits and around his legs; these ropes would then be pulled at either end to stretch the person's spine.

Richard III would have been able to afford traction treatment, Lund said. In addition, his doctors would have been well aware of the method, which was detailed in treatises on medicine and philosophy by 11th-century Persian polymath Avicenna. (Avicenna's work seems to have been influenced by Greek philosopher Hippocrates, Lund said.) These treatises, including Avicenna's theories on using traction in scoliosis treatment, would have been widely read in Medieval Europe, Lund noted.

Avicenna's treatments for back disorders also included massage techniques done in Turkish baths and herbal applications. For longer-term care, patients were likely encouraged to wear a long piece of wood or metal to straighten their spines, Lund said.

"Hippocratic medicine was based on responding carefully to the individual, so without Richard's medical records we can only make conjectures," Lund wrote. Whether the possible treatment worked is also "impossible" to definitively answer, Lund said. "Historical accounts describe him as an active fighter in battle, so he was clearly able to do strenuous physical activity. On the other hand, it seems likely that the condition was painful and would have restricted his lung capacity," Lund wrote.

Finding Richard

After the king's death in battle, he was brought to Leicester and reportedly interred at the church of the Grey Friars, a location long lost to history. Even so, interest in the king led to some far-fetched grave tales about the burial's whereabouts, including one purporting the bones were thrown into the Soar River. "Other fables, equally discredited, claimed that his coffin was used as a horse-trough," Philippa Langley, a Richard III Society member, said in a statement.

Relying on historical records, University of Leicester archaeologists started digging beneath the Leicester City Council parking lot on Aug. 25. They soon found the church and a 17th-century garden marked by paving stones. Records suggest mayor of Leicester Robert Herrick built a mansion and garden on the medieval church site years after the king's death, reportedly placing in the garden a stone pillar inscribed with, "Here lies the body of Richard III sometime King of England."

Shortly thereafter, the team unearthed human remains, including both a female skeleton (possibly an early church founder) and a male skeleton with a spine curved by scoliosis. The male skeleton's skull was cleaved with a blade, and a barbed metal arrowhead was lodged among the vertebrae of the upper back.

Interest in the king has remained strong. Richard III enthusiasts, or Richardians, as they are called, have societies in the United Kingdom and the United States. The discovery of the bones of the medieval king has only swelled their passions.

Read more at Discovery News

Yellowstone's Volcano Bigger Than Thought

Yellowstone's underground volcanic plumbing is bigger and better connected than scientists thought, geologists reported this week at the Seismological Society of America's annual meeting.

"We are getting a much better understanding of the volcanic system of Yellowstone," said Jamie Farrell, a seismology graduate student at the University of Utah. "The magma reservoir is at least 50 percent larger than previously imaged."

Knowing the volume of molten magma beneath Yellowstone is important for estimating the size of future eruptions, Farrell told OurAmazingPlanet.

Supervolcano trail

Geologists believe Yellowstone sits over a hotspot, a plume of superheated rock rising from Earth's mantle. As North America slowly drifted over the hotspot, the Yellowstone plume punched through the continent's crust, leaving a bread-crumb-like trail of calderas created by massive volcanic eruptions along Idaho's Snake River Plain, leading straight to Yellowstone.

The last caldera eruption was 640,000 years ago. Smaller eruptions occurred in between and after the big blasts, most recently about 70,000 years ago.

The magma chamber seen in the new study fed these smaller eruptions and is the source of the park's amazing hydrothermal springs and geysers. It also creates the surface uplift seen in the park, said Bob Smith, a seismologist at the University of Utah and author of a related study presented at the meeting.

The volcanic plume of partly molten rock that feeds the Yellowstone supervolcano. Yellow and red indicate higher conductivity, green and blue indicate lower conductivity. Made by University of Utah geophysicists and computer scientists, this is the first large-scale 'geoelectric' image of the Yellowstone hotspot.

"This crustal magma body is a little dimple that creates the uplift," Smith said. "It's like putting your finger under a rubber membrane and pushing it up and the sides expand."

Clearer picture
A clearer picture of Yellowstone's shallow magma chamber emerged from earthquakes, whose waves change speed when they travel through molten or solid rock. Farrell analyzed nearby earthquakes to build a picture of the magma chamber.

The underground magma resembles a mutant banana, with a knobby, bulbous end poking up toward the northeast corner of Yellowstone National Park, and the rest of the tubular fruit angling shallowly southwest. It's a single connected chamber, about 37 miles (60 kilometers) long, 18 miles (30 km) wide, and 3 to 7 miles (5 to 12 km) deep.

Previously, researchers had thought the magma beneath Yellowstone was in separate blobs, not a continuous pocket.

Read more at Discovery News

How the Mind Adjusts to Lost Limbs

After an amputation, most patients have a sensation that the limb is still attached and functional. It's known as phantom limb, and it's just one sign that the psychological adjustment to losing a limb can be as challenging as the physical adjustment.

In addition to phantom limb, those who lost legs in Monday's Boston Marathon attack may face post-traumatic stress disorder and grief as they adjust to a new normal.

"I always tell my patients that as hard as it is, it's a new reality, and the choices are to go into a dark room and close the door or confront the world in that new reality," said Dr. Alberto Esquenazi, chairman of Einstein Healthcare Network's Department of Physical Medicine and Rehabilitation and chief medical officer for MossRehab Medical Center in Pennsylvania, who is himself an amputee.

Often, doctors will hear new amputees say their lives are over. When Dr. Terrence Sheehan, Chief Medical Officer at Adventist Rehabilitation Hospital of Maryland and medical director of the Amputee Coalition hears that, he says, "Nope. It's changed, and we're going to help."

The rehab process involves a team of social workers, psychiatrists, physical therapists, occupational therapists, case managers and nurses. Often one of the most powerful visits in that early stage, Sheehan said, is from a new peer: a fellow amputee.

"When someone who has also lost a limb comes in and says, let me show you how to get back to life, that's when they can see what life's going to be," said Sheehan, referring specifically to the Amputee Coalition's peer visitation program.

And while runners may be able to handle the physical challenge of rehab and therapy, sometimes the emotional toll is hardest on people who perceive themselves as strong.

"It can take much longer for them to realize their new reality," Esquenazi said. "You can imagine that for someone who was running the race or had the ability to be there watching, in an instant their life changed. When you're confronted with that kind of life-changing event, it can be very challenging psychologically."

Like those injured in war zones, many people who witnessed the scene at the Boston Marathon may face PTSD.

"The shock is wearing off," Dr. Joseph Shrand of Harvard Medical School said on New England Cable News. "Now the reality is setting in." Symptoms may include anger, fear, sadness, a sense of confusion -- at any time, in any order, he said. That's in addition to the steps of the grieving process that most new amputees go through, Esquenazi said: denial, why me?, blaming others ... and, finally, acceptance.

When they do reach acceptance, patients can usually visualize what their life might be like. Life without a limb can mean a variety of different things to different people. For the elderly, it may be getting to live at home again. For a teenager, it may mean driving to the prom. For a runner, it may mean competing in another marathon. Much more is possible for amputees now than before 1990, Sheehan said.

"Before then, we might have said, OK, you're done with service, or you're done working. You're disabled," he said. "Now it's, get back on the plane, get back to climbing, running, jumping."

To runners, he'd say, "we have the technology to get you back to your sport."

In addition to, or perhaps because of, the advances in prosthetics that allowed Oscar Pistorius, the Blade Runner, to compete in the Olympics, and allows others to run marathons, people's perceptions have changed.

"People are much more comfortable showcasing their apparatus without qualms," Esquenazi said.

Jeff Glasbrenner, who has been an amputee since age 8, was finishing the marathon when the bombs went off.

"I wish I could reach out to the people who lost a leg," he told the New Republic. "I'd love to run a race with them."

Read more at Discovery News

Apr 18, 2013

Dinosaur Egg Study Supports Evolutionary Link Between Birds and Dinosaurs: How Troodon Likely Hatched Its Young

A small, bird-like North American dinosaur incubated its eggs in a similar way to brooding birds -- bolstering the evolutionary link between birds and dinosaurs, researchers at the University of Calgary and Montana State University study have found.

Among the many mysteries paleontologists have tried to uncover is how dinosaurs hatched their young. Was it in eggs completely buried in nest materials, like crocodiles? Or was it in eggs in open or non-covered nests, like brooding birds?

Using egg clutches found in Alberta and Montana, researchers Darla Zelenitsky at the University of Calgary and David Varricchio at Montana State University closely examined the shells of fossil eggs from a small meat-eating dinosaur called Troodon.

In a finding published in the spring issue of Paleobiology, they concluded that this specific dinosaur species, which was known to lay its eggs almost vertically, would have only buried the egg bottoms in mud.

"Based on our calculations, the eggshells of Troodon were very similar to those of brooding birds, which tells us that this dinosaur did not completely bury its eggs in nesting materials like crocodiles do," says study co-author Zelenitsky, assistant professor of geoscience.

"Both the eggs and the surrounding sediments indicate only partial burial; thus an adult would have directly contacted the exposed parts of the eggs during incubation," says lead author Varricchio, associate professor of paleontology.

Varricchio says while the nesting style for Troodon is unusual, "there are similarities with a peculiar nester among birds called the Egyptian Plover that broods its eggs while they're partially buried in sandy substrate of the nest."

Paleontologists have always struggled to answer the question of how dinosaurs incubated their eggs, because of the scarcity of evidence for incubation behaviours.

As dinosaurs' closest living relatives, crocodiles and birds offer some insights.

Scientists know that crocodiles and birds that completely bury their eggs for hatching have eggs with many pores or holes in the eggshell, to allow for respiration.

This is unlike brooding birds which don't bury their eggs; consequently, their eggs have far fewer pores.

The researchers counted and measured the pores in the shells of Troodon eggs to assess how water vapour would have been conducted through the shell compared with eggs from contemporary crocodiles, mound-nesting birds and brooding birds.

They are optimistic their methods can be applied to other dinosaur species' fossil eggs to show how they may have been incubated.

Read more at Science Daily

Scientists Throw New Light On DNA Copying Process

Research led by a scientist at the University of York has thrown new light on the way breakdowns in the DNA copying process inside cells can contribute to cancer and other diseases.

Peter McGlynn, an Anniversary Professor in the University's Department of Biology, led a team of researchers who have discovered that the protein machines that copy DNA in a model organism pause frequently during this copying process, creating the potential for dangerous mutations to develop.

The research, which is published in the Proceedings of the National Academy of Sciences (PNAS), involved scientists at the School of Medical Sciences at the University of Aberdeen, where Professor McGlynn worked previously, the Centre for Genetics and Genomics at the Queen's Medical Centre, University of Nottingham and the Memorial Sloan-Kettering Cancer Center, New York.

The project focused on a bacterium called Escherichia coli which is a powerful model for studying the DNA copying process, the study of which has revealed many aspects of DNA metabolism in more complex organisms such as humans.

Professor McGlynn, who was one of 16 Chairs established at York to mark the University's 50th Anniversary, says: "Our work demonstrates that when organisms try to copy their genetic material, the copying machines stall very frequently which is the first step in formation of mutations that, in man, can cause cancers and genetic disease.

"We have analysed what causes most of these breakdowns and how, under normal circumstances, cells repair these broken copying machines. Just as importantly, our work reveals that efficient repair of these breakdowns is very important to avoid corruption of the genetic code."

Read more at Science Daily

No 'Silver Bullet' for Science Standards

America's K-12 teachers are not fully prepared to meet a new set of science standards, a Michigan State University education scholar argues in Science.

Writing in the April 19 issue, Suzanne Wilson said the professional training landscape for teachers is woefully inadequate to handle the Next Generation Science Standards. The voluntary guidelines, unveiled this month by the advocacy group Achieve in collaboration with 26 states, call for more hands-on learning and analysis and cover fewer science topics but in greater depth.

Science in U.S. classrooms already has been de-emphasized in favor of math and reading, Wilson noted, and suddenly the new standards turn up the proverbial Bunsen burner on science teachers.

"Science has been marginalized by the No Child Left Behind Act, so less science has been taught in schools, not more," said Wilson, University Distinguished Professor and chair of the Department of Teacher Education. "And now these standards are coming out that not only call for a renewed focus on science teaching, but the kind of science that many teachers haven't taught and many teachers haven't experienced."

While there is a wealth of teacher training options in the United States, Wilson said, the programs do not accommodate the depth of the new standards.

"When it comes to professional development for science teachers, we simply don't have the knowledge base," Wilson said.

Effective professional development should bolster teachers' content knowledge and their ability to teach students the subject matter and develop the students' critical thinking skills. It should also help teachers reach all students, including English language learners, Wilson said.

Getting to that point will require a major investment to develop the right instructional materials and the tools to support teachers and students in using those materials, she said. That includes harnessing new technologies and social media to make high-quality training available to all teachers.

"We must realign the considerable resources spent on professional development with the demands teachers will face with the new standards," Wilson said.

The process could take years.

"Though some might hope for a silver bullet, education reform that leads to fundamental change, such as that envisioned with the new standards, requires time," Wilson said.

Read more at Science Daily

What Makes Fertilizer Plants So Explosive?

Wednesday night, ammonium nitrate exploded with deadly results at the West Fertilizer Company plant near Waco, Texas.

Ammonium nitrate is a capricious chemical. Fertilizers made with the chemical provide nitrogen to crops, which helps them grow leaves and maintain their green color. However, ammonium nitrate can also break down rapidly and produce a tremendous amount of heat. In other words, it explodes.

When exposed to an intense shock or high heat, ammonium nitrate decomposes quickly into nitrogen, oxygen and water. This chemical reaction is exothermic, meaning it expels heat.

The heat can trigger a chemical chain reaction in which a large amount of ammonium nitrate decomposes at once and produces the lethal explosion of fertilizer plants or bombs.

During fertilizer production, high-pressure tanks keep ammonium nitrate in a liquid state. If those tanks rupture, the liquid becomes a gas and mixes with oxygen in the air. This combination explodes easily.

The exact circumstances of the fire and explosion at the West Fertilizer Company plant remain to be pieced together from the wreckage.

The recent disaster occurred one day after the 66th anniversary of another ammonium nitrate catastrophe in Texas. On April 16, 1947, nearly 600 people died when approximately 2,300 tons of ammonium nitrate exploded in the port of Texas City, southeast of Houston, Texas.

The United States Department of Homeland Security and other government agencies monitor and regulate the sale and transport of ammonium nitrate, since it can easily be made into an explosive. For example, in 1995 a truck bomb detonated diesel fuel that spurred the explosive chemical reaction of ammonium nitrate and massacred 168 people in the Oklahoma City bombing.

Read more at Discovery News

Apr 17, 2013

Oldest European Medieval Cookbook Found

A 12th-century manuscript contains the oldest known European Medieval food recipes, according to new research.

The recipes, which include both food and medical ointment concoctions, were compiled and written in Latin. Someone jotted them down at Durham Cathedral’s monastery in the year 1140.

It was essentially a health book, so the meals were meant to improve a person’s health or to cure certain afflictions. The other earliest known such recipes dated to 1290.

Many of the dishes sound like they would work on a modern restaurant menu. Faith Wallis, an expert in medical history and science based at McGill University, translated a few for Discovery News:

“For “hen in winter’: heat garlic, pepper and sage with water.”

“For ‘tiny little fish’: juice of coriander and garlic, mixed with pepper and garlic.”

For preserved ginger, it should kept in “pure water” and then “sliced lengthwise into very thin slices, and mixed thoroughly with prepared honey that has been cooked down to a sticky thickness and skimmed. It should be rubbed well in the honey with the hands, and left a whole day and night.”

Re – the “hen in winter” dish, Giles Gasper from Durham University’s Institute of Medieval and Early Modern Studies said, “We believe this recipe is simply a seasonal variation, using ingredients available in the colder months and specifying ‘hen’ rather than ‘chicken,’ meaning it was an older bird as it would be by that time of year.”

Gasper added, “The sauces typically feature parsley, sage, pepper, garlic, mustard and coriander, which I suspect may give them a Mediterranean feel when we recreate them. According to the text, one of the recipes comes from the Poitou region of what is now modern central western France. This shows the extent to which international travel and exchange of ideas took place within the medieval period. And what more evocative example of cultural exchange could there be than food?”

Gaspar and colleagues are recreating some of the dishes for a workshop to be held on April 25 at Blackfriars Restaurant in Newcastle, U.K. A lunch the following Saturday will feature the same dishes. The researchers are also putting together a translation of the cookbook under the title “Zinziber” (Latin for ginger).

While much of the food is still tasty to modern palates, not all of the medical cures would work today.

Read more at Discovery News

Could Life Be Older Than Earth Itself?

Applying a maxim from computer science to biology raises the intriguing possibility that life existed before Earth did and may have originated outside our solar system, scientists say.

Moore’s Law is the observation that computers increase exponentially in complexity, at a rate of about double the transistors per integrated circuit every very two years. If you apply Moore’s Law to just the last few years’ rate of computational complexity and work backward, you’ll get back to the 1960s, when the first microchip was, indeed, invented.

Now, two geneticists have applied Moore’s Law to the rate at which life on Earth grows in complexity — and the results suggest organic life first came into existence long before Earth itself.

Staff Scientist Alexei Sharov of the National Institute on Aging in Baltimore, and Theoretical Biologist Richard Gordon of the Gulf Specimen Marine Laboratory in Florida, took Moore’s Law, replaced the transistors with nucleotides — the building blocks of DNA and RNA — and the circuits with genetic material, and did the math.

The results suggest life first appeared about 10 billion years ago, far older than the Earth’s projected age of 4.5 billion years.

So even if it’s mathematically possible for life to have existed before Earth did, is it physically possible? Again, Sharov and Gordon said yes, it is. As our solar system was forming, pre-existing bacterialike organisms, or even simple nucleotides from an older part of the galaxy, could have reached Earth by hitching an interstellar ride on comets, asteroids or other inorganic space debris — a theoretical process called panspermia.

The scientists’ calculations are not scientific proof that life predates Earth — there’s no way of knowing for sure that organic complexity increased at a steady rate at any point in the universe’s history. Call it a thought exercise or an essay, rather than a theory, Sharov said.

“There are lots of hypothetical elements to (our argument)… but to make a wider view, you need some hypothetical elements,” Sharov told TechNewsDaily.

Sharov and Gordon’s idea raises other intriguing possibilities. For one, “life before Earth” debunks the long-held science-fiction trope of the scientifically advanced alien species. If genetic complexity progresses at a steady rate, then the social and scientific development of any other alien life form in the Milky Way galaxy would be roughly equivalent to those of humans.

Sharov and Gordon’s study draws a theoretical and practical parallel between the origin of life and the relationship between life and knowledge. Human evolution doesn’t just occur in the genome; it occurs epigenetically, or within the mind, as technology, language and cultural memory all become more complex. “The functional complexity of organisms (is) encoded partially in the heritable genome and partially in the perishable mind," they explain in the paper.

By applying Moore’s Law — a theory originally devised to explain technological development — to life, the geneticists aren’t simplifying evolution; they’re acknowledging its extraordinary complexity, they say.

Read more at Discovery News

Hobbit Humans Had Big Brains

Hobbit humans, the tiny folks who lived on the remote Indonesian island of Flores until about 12,000 years ago, had bigger brains than previously thought, according to a new paper that strengthens the theory that hobbits evolved from own own ancestor, Homo erectus.

Homo erectus, in turn, is thought to have evolved into our own species in Africa. The new study, published in the latest Proceedings of the Royal Society B, reveals how location and environment could mean the difference between an individual who looked like us, and someone who wound up a hobbit.

"They were extremely short (about 3'6"), much shorter than any healthy living humans," co-author Yousuke Kaifu told Discovery News. "Their legs were short relative to their arms and feet, (features that) some researchers think were primitive."

Kaifu, a senior researcher at the National Museum of Nature and Science in Tokyo, conducted the study with lead author Daisuke Kubo and Reiko Kono.

The three used high-resolution micro-CT scanning to study the brain regions of hobbit human skulls. The scans found that the brains measured 426 cc, as opposed to earlier estimates of around 400 cc. The former is still not huge by modern standards, and was about the same size as a chimpanzee's brain.

Nevertheless, the difference means it was possible for a Homo erectus population to have evolved such brains. The prior estimate ruled that out, since there is only so much shrinkage that could have taken place.

The researchers believe H. erectus, living on the mainland, either intentionally or unintentionally -- such as due to a storm -- made it to the isolated island of Flores.

The hobbits' "unique evolution suggests they did not go out of the island once they got there," Kaifu said.

He explained that "a popular theory is that big mammals tend to reduce and small mammals tend to increase their body sizes on an isolated island because of energetic demands."

Elephants, for example, tend to get smaller, since without many carnivores, they have no need to maintain such big, bulky bodies. Remains suggest that the hobbits hunted primitive elephants called Stegodon.

In contrast to the pygmy elephants, a type of stork and lizard evolved larger bodies on Flores, probably because predators were few and food was plentiful.

Known distribution of Homo erectus extends all the way from Africa to parts of Europe and Asia. Thus far, it looks like they could not survive the extreme cold of the North, but they did reach at least the one isolated island.

"So there are chances that they were also present on other near-shore islands of that region, such as Sulawesi and possibly the Philippines," Kaifu said.

Yet another likely regional population of Homo erectus, called "Peking man," inhabited the Asian continent, but it is still unclear if they evolved into more advanced humans or even interbred with Homo sapiens arriving from Africa. DNA analysis of what are known as Denisovans from Melanesia, Australia and the Philippines suggest that some interbreeding did indeed take place.

As for the hobbit human's contribution to the mix, much hinges on the brain size, given how that either strengthens or weakens the possible relationship to Homo erectus.

Dean Falk, whose team previously estimated the brain to be smaller, told Discovery News that the new measurement is “the most precise estimate available to date because it has been calculated with improved methods and great care." Falk, a Florida State University professor of anthropology, hopes that the "thoughtful and thorough analysis" will move "the discussion forward" about H. floresiensis.

William Jungers, professor and chairman of Stony Brook University Medical Center's Department of Anatomical Sciences, said, "this is the normal brain of a very small and now extinct human relative that evolved in isolation for at least a million years on Flores Island."

Read more at Discovery News

Big Bang? This Is What It Really Sounds Like

In the beginning, there was a righteous bass.

So says physicist John Cramer, who has not only found evidence of the sound created during the Big Bang, but has also created a simulation of the low, deep noise emitted as the universe came into being.

After the Big Bang, the universe expanded so rapidly that matter itself resonated to create a deep bass noise, and sound waves themselves became stretched and warped. "As the early universe expanded, sound waves propagated through the dense medium that closed back on itself, so that the hypersphere of the universe rang like a bell," Cramer, a professor of physics at the University of Washington, explained.

The effect would have been similar to that of a magnitude-9 earthquake that caused the entire planet to actually ring, Cramer said. However, in this case, the ringing covered the entire universe.

That sound is long gone, of course, but it left its imprint on the cosmic microwave background, which is a thermal echo of the energy released during the Big Bang.

Listen to Cramer's Big Bang simulation here.

In 2003, NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) satellite gave scientists an unprecedented picture of the cosmic microwave background. In an article for science-fiction magazine Analog Science Fiction and Fact, Cramer wrote how this thermal data could be extrapolated into wavelengths of sound.

In other words, the universe's cosmic microwave background is kind of like a recording of the Big Bang's phat beat.

Two years after Cramer published his findings, the mother of an 11-year-old elementary school student wrote to Cramer, asking if there was an actual recording of the sound that her son could use for his school science-fair project. Cramer responded that there wasn't — but there could be.

To recreate the Big Bang's sound, Cramer converted WMAP’s wavelength data into sound using a computational program called Mathematica.

The resulting sound is low, creaky, and almost unassuming.

Read more at Discovery News

Apr 16, 2013

Sharks Dive By the Moon

The moon and water temperature affect the diving behaviour of sharks, researchers reported Tuesday, in a discovery that could help prevent fishermen from catching the marine predators inadvertently.

A team from the University of Western Australia's Oceans Institute and the government-run Australian Institute of Marine Science spent nearly three years monitoring grey reef sharks off Palau in the Pacific.

They tagged 39 sharks -- common on coral reefs throughout the Indo-Pacific region -- and used acoustic telemetry to follow them, finding they stayed in deep water on full moon nights but rose to the shallows with the new moon.

Similar patterns have previously been recorded in species such as swordfish, yellowfin and big eye tuna, suggesting the reef shark behaviour was related to feeding.

The study also said it may be an anti-predator response where reef sharks seek to avoid increased light nearer the surface that may aid the hunting abilities of larger sharks.

"We also found that the diving behaviour of grey reef sharks was related to water temperature," said lead researcher Gabriel Vianna.

The sharks, mostly adult females, dived to an average depth of 35 metres (114 feet) in winter when deeper water was colder and 60 metres in spring when temperatures warmed up.

In summer, when the warmer layer of surface water expanded, the sharks tended to move in a broader range of depths.

The authors said that because sharks were cold-blooded, they may prefer warmer waters to conserve energy.

The research, published in the science journal PLOS ONE, also found that the time of day could affect how deeply sharks dive.

"We were surprised to see sharks going progressively deeper during the morning and the exact inverse pattern in the afternoon, gradually rising towards the surface," Vianna said.

"This matches how light changes on the reef during the day. To our knowledge, this is the first time such patterns have been observed in detail for reef sharks."

Read more at Discovery News

Mayan Calendar End Date Confirmed

Carbon-dating of a structural beam from a Guatemalan temple confirms that the Mayan Long Count calendar did end on December 2012, leaving no room for further doomsday prophecies and miscalculations claims.

The Long Count is a complex system of bars and dots that consists of five time units: Bak’tun (144,000 days); K’atun (7,200 days), Tun (360 days), Winal (20 days) and K’in (one day).

The days are counted from a mythological starting point.

The Long Count proliferated to more than 40 different centers across the Mayan lowlands between 600–900 A.D. and was used to anchor major historical events in time.

However, those historic events comprising royal successions, rituals, victories and defeats, could not be precisely ordered by date as scholars were unable to set the date of the mythical starting point.

Indeed, the Long Count system fell into disuse before European contact in the 16th century, moreover the Spanish colonizers destroyed any evidence that could have helped correlate the Maya and European calendars.

“Many solutions to the problem have been proposed, employing a variety of historical and astronomical data,” an international team of researchers led by Douglas J. Kennett, professor of environmental archaeology at Pennsylvania State University, wrote in the journal Scientific Reports.

However, “correlation constants can vary up to 1,000 years and remain controversial,” they said.

To place the Long Count dates into the European calendar in order to understand when things happened in the Maya world relative to historic events elsewhere, Kennett’s team turned to an elaborately carved wooden beam from a temple in the ancient Maya city of Tikal.

The carvings depict Tikal’s king, known as Jasaw Chan K’awiil. A related text describes his defeat of King Yich’aak K’ahk’ , known as “Claw of Fire,” from a rival kingdom at Calakmul.

Using a combination of high-resolution accelerator mass spectrometry carbon-14 dates and a statistical model of tree growth rates estimated from changing calcium concentrations, the researchers established that the lintel was carved sometime around 658-696 A.D.

The estimate closely matches the most popular method in use, the Goodman-Martinez-Thompson (GMT) correlation, initially put forth by Joseph Goodman in 1905 and subsequently modified by others.

According to the GMT estimate, the K’awiil’s victory occurred around 695-712 A.D. The date was determined in the 1950s by carbon dating on two other wooden beams from Tikal.

Kennett and colleagues believe the discrepancy between the two dates can be explained by the fact that the beam was taken from a tree called the sapotilla whose hard wood would have required years to carve.

The date of the Mayan battle would work like a Rosetta stone for the chronology of the ancient civilization.

“Anything that has a Mayan date on it, we can be more certain about what the European date is,” Kennett told U.S. News & World Report.

Read more at Discovery News

Saturn's System May Contain 'Born Again' Moons

The Saturnian system, with its majestic rings, icy moons, and mysteriously veiled Titan, is the gemstone of the solar system. Ironically the system is full of clues that it was born, or rather reborn, out of a violent demolition derby less than 4 billion years ago.

A clue is the giant moon Titan, larger that the planet Mercury. Every month NASA’s prolific Cassini orbiter unveils more details about this orange hued moon that make it look intriguingly earthlike. Just last week scientist reported seeing a cap of ice clouds forming over the moon’s south pole as a harbinger of the approaching southern hemisphere winter.

With its massive nitrogen atmosphere, hydrocarbon seas, ice continents, tropical methane rain, and cryovolcanoes, Titan has been dubbed “Earth II.” What are the odds that potentially habitable Titan-sized worlds exist around the estimated billions of gas giant planets in our galaxy? And, why doesn’t Jupiter have such a massive moon?

Adding to the mystery is that Saturn’s family icy moons, once dismissed as dead snowballs, look geologically young and active. The moon Enceladus is spewing water geysers from a subsurface ocean that could be an abode for life.

The moons are small enough that they should have been blasted apart in a “baptism by fire” period called the Late Heavy Bombardment (LHB) 4 billion years ago. This tore up Earth’s moon with massive impacts, and blasted out giant impact basins on Mercury and Mars, and presumably Venus and Earth.

The LHB was triggered by final gravitational shuffle of the giant planets. They first moved inward and then outward under a gravitational tug-of-war. The giants shifting orbits forced asteroids and comets onto destructive high-speed eccentric orbits.

Erik Asphaug of Arizona State University and co-authors have tied Saturn observations together to propose that the planet shuffle lead to a major makeover of Saturn’s satellite system. Their research was published in the journal Icarus.

Computer modeling by Asphaug suggest that Saturn started out with several primordial moons that were the size of Jupiter’s four major satellites (first discovered in 1609 by Galileo Galilei). The theory is that during the LHB their orbits were disrupted and they collided to merge and form Titan in place of Jupiter’s Galilean-style system. Perhaps not coincidentally, Titan is similar in mass to all of the Galilean satellites put together. “The original physics a satellite formation may have been the same around Jupiter and Saturn,” Asphaug writes.

This smashup also left behind Saturn’s family of oddball major icy satellites that that would have been formed after the LHB. The moons’ chemical diversity and geology tell what parts of the larger parent moons they came from, say the researchers. The idea is that denser moons like Enceladus, with its silicate core under a water ocean, came from deep inside the parent body. Low density, purely ice moons like Tethys could have come from a water-ammonia mantle of the lost Galilean sized satellites.

The model predicts that the icy moons should have had their own rings and subsatellites that decayed and crashed onto the moons. This could explain the puzzling equatorial bulge on walnut-shaped Iapetus (pictured right) where a shattered moon might have literally rained out of the sky.

Read more at Discovery News

Proton Mass Mystery Could Mean New Physics

The size of a proton, long thought to be well-understood, may remain a mystery for a while longer, according to physicists.

Speaking on Saturday (April 13) at the April meeting of the American Physical Society, researchers said they need more data to understand why new measurements of proton size don't match old ones.

"The discrepancy is rather severe," said Randolf Pohl, a scientist at the Max Planck Institute of Quantum Optics. The question, Pohl and his colleagues said, is whether the explanation is a boring one -- someone messed up the measurements -- or something that will generate new physics theories.

The Incredible Shrinking Proton

The proton is a positively charged particle in the nucleus of atoms, the building blocks of everything. Years of measurements pegged the proton at 0.8768 femtometers in radius (a femtometer is a millionth of a billionth of a meter).

But a new method used in 2009 found a different measurement: 0.84087 femtometers, a 4 percent difference in radius.

The previous measurements had used electrons, negatively charged particles that circle the nucleus in a cloud, to determine proton radius. To make the measurement with electrons, researchers can do one of two things. First, they can fire electrons at protons to measure how the electrons are deflected. This electron-scattering method provides insight into the size of the positively charged proton.

An alternative is to try to make the electron move. Electrons zing around the nucleus of an atom, where protons reside, at different levels called orbitals. They can jump from orbital to orbital by increasing or decreasing their energy, which electrons do by losing or gaining an elementary particle of light called a photon. The amount of energy it takes to budge an electron from orbital to orbital tells physicists how much pull the proton has, and thus the proton's size.

Pohl and his colleagues didn't use electrons at all in their measurements of the proton. Instead, they turned to another negatively charged particle called the muon. The muon is 200 times heavier than an electron, so it orbits the proton 200 times closer. This heft makes it easier for scientists to predict which orbital a muon resides in and thus a much more sensitive measure of proton size.

"The muon is closer to the proton and it has a better view," Pohl said.

Possible Explanations

These sensitive muon measurements are the ones that gave the smaller-than-expected result for the proton radius, a totally unexpected discovery, Pohl said. Now, physicists are racing to explain the discrepancies.

One possibility is that the measurements are simply wrong. Pohl said this "boring explanation" is the most probable, but not all physicists agree.

"I would say it's not the experimental side," said Massachusetts Institute of Technology physicist Jan Bernauer.

The electron-based measurements have been repeated many times and are well-understood, Bernauer said, and muon experiments have the advantage that if they're done wrong, they don't provide results at all.

If experimental error turns out not to be the culprit, there may be some calculation issue, "so we actually know everything that goes on but we are just not calculating it quite right," Bernauer told reporters.

Most exciting of all, the discrepancy could reveal some new physics not explained by the dominant physics theory, the Standard Model. Perhaps there is something unknown about how muons and electrons interact with other particles, said John Arrington, a physicist at Argonne National Laboratory in Illinois.

One possibility is that photons aren't the only particles that carry forces between particles — perhaps an unknown particle is in the mix, causing the proton-measurement discrepancies.

Next Steps

To find out what's going on, physicists are launching a new set of experiments across multiple laboratories. One major line of research involves testing electron-scattering experiments to be sure they've been done correctly and that all the facets are understood, Arrington said.

Another goal is to repeat the scattering experiments, but instead of shooting electrons at protons they'll shoot muons at protons. This project, the Muon Scattering Experiment, or MuSE, is set to take place at the Paul Scherrer Institute in Switzerland. The facilities there will allow researchers to simultaneously measure electron- and muon-scattering in one experiment.

Read more at Discovery News

Apr 15, 2013

Fish Prone to Melanoma Get DNA Decoded

Scientists at Washington University School of Medicine in St. Louis and elsewhere have decoded the genome of the platyfish, a cousin of the guppy and a popular choice for home aquariums.

Among scientists, the fish are meticulously studied for their tendency to develop melanoma and for other attributes more common to mammals, like courting prospective mates and giving birth to live young.

Known scientifically as Xiphophorus maculatus, platyfish sport a variety of spectacular colors -- brilliant oranges, yellows and a lovely iridescent silver -- and myriad striped and speckled patterns. And when melanomas develop, they are easy to spot, even to an untrained eye.

"In platyfish, melanomas typically develop as black splotches along the tail and fins," says senior author Wesley Warren, PhD, a geneticist at Washington University's Genome Institute. "These fish are an ideal model for exploring the many unknowns of cancer, including how, when and where it develops in the body as well as its severity."

Scientists at Washington University, the University of Würzburg in Germany and Texas State University led an international team involved in sequencing and analyzing the platyfish genome. Their findings are available online in Nature Genetics.

"Now that we have the genome in hand, we can tease apart the way genes interact with one another to cause melanoma," says co-lead author Manfred Schartl, PhD, of the University of Würzburg in Germany. "Just as in human melanoma, genes that play a role in pigment cells also influence the development of melanoma in platyfish."

The platyfish genome includes some 20,000 genes, roughly the same number found in the human genome. But unlike humans and other mammals, the chromosomes of the platyfish, like those in other fish, have remained remarkably intact over some 200 million years of evolution.

"It's very much a mystery as to why these chromosomes are so structurally similar among fish species over long time periods of evolution because they live in vastly different aquatic environments," says Warren.

The platyfish is a prolific breeder. But while most fish lay eggs, platyfish females give birth to live young, often in broods of more than 100.

Comparing the genes of platyfish to those in mice and other mammals that give birth to their young, the scientists found a number of altered genes in the fish involved in live-bearing birth.

"Surprisingly, we found that the platyfish retain some yolk-related genes typically found in fish that lay eggs to produce their offspring, and genes involved in placenta function and egg fertilization displayed unique molecular changes," says co-lead author Ron Walter, PhD, of Texas State University.

While humans are known for their higher-level thinking and behaviors, platyfish and other fish have evolved their own set of complex behaviors, like courting, schooling and avoiding predators that far exceed the abilities of amphibians, reptiles and other lower vertebrates. Looking through the platyfish genome, the researchers found a number of gene copies linked to cognition in humans and other mammals that could underlie these behaviors.

Read more at Science Daily

Hermit Arrests Shed Light On Extreme Solitude

Two of the country's most notorious survivalists -- the Hermit of North Pond in Maine, and The Mountain Man of Utah, were found and arrested in the last few weeks. And a case of a missing family, the McStay family of southern California, was effectively closed when investigators said the family appears to have gone to Mexico voluntarily.

So is it still possible to "disappear" in 2013?

"Is it more difficult? Yes," said Jim Biesterfeld, a former U.S. army counter-intelligence special agent who teaches private investigations at California State University-Fullerton Jim Biesterfeld. "Impossible? Not even."

For someone to hide away from society, he said, at least two things are essential: self-sufficiency, and desire.

"There are not that many people who want to stay hidden for that long" in solitude," Biesterfeld said. "Most people try to establish new identities."

That's why it's unusual for two cases of solitary survivalists to have been solved in such close succession.

Christopher Knight, 47, also known as The North Pond Hermit, appears to be one of those few who truly wanted to live on his own.

For 27 years, Knight avoided making a campfire for fear of drawing attention to himself. He stole what he needed to survive from campgrounds; in fact, everything he had was stolen except his eyeglasses. If there's not much reason to be found, as in Knight's case, costly police investigations are unlikely. But, eventually, Knight's thefts of food and survival supplies prompted local law enforcement to get involved.

It would take a possible federal criminal violation in addition to a disappearance, such as a fugitive or kidnapping situation, for the FBI to become involved, said FBI special agent Kathy Wright.

"The FBI requires an authorized law enforcement purpose to conduct an investigation," she said. "The mere fact that an adult disappears, is not, on its own, a violation of law."

In the end, a surveillance camera set up specifically to catch Knight triggered an alarm when he entered a campground kitchen looking for food, and Knight was arrested.

While technology -- such as thermal imaging that detects people by tracking body heat -- is helpful in pinpointing a location once a general area is mapped out, investigators haven't abandoned old-fashioned methods. In the case of Troy James Knapp, also known as The Mountain Man in Utah, it was snowshoe tracks that eventually gave him away.

Biesterfeld relies on the old adage of investigators and journalists: Keep It Simple, Stupid. Find out everything you can about the person.

"What was he like as a kid? Did he have mental health issues? Had he ever talked about it before?" Biesterfeld said. "In most cases, people crave human contact. The rare few who do not are the Maine guy and the unabomber" -- and, it appears, Utah's Mountain Man.

"He says, 'I don't hate people. I just don't like living with them,'" the Huffington Post quotes him telling Sevier County Sheriff Nathan Sheriff Curtis.

Read more at Discovery News

Dinosaur Swam a Strong Doggy-Paddle

Claw marks on a 100-million-year-old riverbed in China reveal how some dinosaurs doggy-paddled over long distances, scientists say.

"What we have are scratches left by the tips of a two-legged dinosaur's feet," study researcher Scott Persons, of the University of Alberta, said in a statement. "The dinosaur's claw marks show it was swimming along in this river and just its tippy toes were touching bottom."

Stretching over a distance of 50 feet (15 meters), the markings show that the dinosaur had a coordinated, left-right, left-right swimming style, Persons said. The researchers believe the scratches belong to a carnivorous theropod -- a type of dinosaur that walked on two legs -- that stood roughly 3 feet (1 meter) at the hip.

While it's tough to determine the identity of the swimming dinosaur from these marks alone, Persons suspects it could have been an early tyrannosaur or a Sinocalliopteryx, predators known to have roamed this prehistoric landscape in China.

The paddle-scratches were found in a dried-up river in China's Szechuan Province, which Persons described as a "dinosaur super-highway," full of the footprints of other Cretaceous-era theropods and long-necked, four-legged sauropods.

The research was detailed April 8 in journal Chinese Science Bulletin.

It's not the first time dinosaur paddle prints have turned up in the fossil record. In 2007, paleontologists found S-shaped prints on the bottom of what was a lake in the Cameros Basin in Spain 125 million years ago. The unusual tracks indicate the animal's body was floating in about 10 feet (3.2 m) of water when it scratched the lakebed, researchers said at the time.

Read more at Discovery News

Taste of Beer Triggers Good Feelings in Brain

The taste of beer, without its alcoholic effects, may be enough to trigger the release of the pleasure chemical dopamine in the brain, a study finds.

To see how the taste of beer affects the brain, researchers gave a group of men tiny tastes of beer, and as the men sipped the beer, the researchers scanned the men’s brains. After a taste of beer, the men's brains showed a notable release of dopamine, a brain chemical associated with the pleasurable experience of consuming alcohol and other drugs. The effect was even greater among men who had a family history of alcoholism.

The findings are not surprising, scientists say, but having a way to assess predisposition to alcohol abuse could be useful.

"We believe this is the first experiment in humans to show that the taste of an alcoholic drink alone, without any intoxicating effect from the alcohol, can elicit this dopamine activity in the brain's reward centers," the study's senior author, neuroscientist David Kareken of the Indiana University School of Medicine, said in a statement. The findings were detailed online today (April 15) in the journal Neuropsychopharmacology.

Dopamine, a brain chemical widely associated with pleasure, has long been linked to the consumption of alcohol and other drugs. Sensory cues — such as tastes, smells or the sight of a bar — can elicit cravings to drink and cause relapses in recovering alcoholics. Dopamine may be critically involved in such cravings, scientists believe.

In the study, researchers gave 49 male volunteers a tiny taste (half an ounce, or 15 milliliters) of their favorite beer over the course of 15 minutes — enough to taste the beer but not enough to cause a change in blood-alcohol level or intoxication. At other times, the volunteers were given a sports drink or water, for comparison.

To study the effect of beer's taste on dopamine receptors, the researchers scanned the volunteers' brains using Positron Emission Tomography, which uses the radiation emitted by a radioactive chemical to produce a 3D image of the brain.

The scans revealed higher increases in dopamine after the men tasted beer compared with tasting the sports drink or water — suggesting that the taste of alcohol is enough to prompt a pleasurable response in the brain. The men also reported higher beer cravings after tasting beer than water or the sports drink.

Furthermore, the men who had a family history of alcoholism showed an even greater spike in dopamine levels after they tasted the beer, so the dopamine response may be a heritable risk factor for alcoholism.

Read more at Discovery News