Jan 26, 2013

Cookiecutter Sharks Tear Flesh Out of Great Whites

Great white shark with bite and scar inflicted by a cookiecutter shark. The arrow shows the scar from a healed gash.

Great white sharks have long been at the top of the marine food chain, but it turns out they are victimized by ravenous cookiecutter sharks, which bite out chunks of great white flesh.

The bites, recently documented in the journal Pacific Science, are like the ultimate sushi. Lone cookiecutters sneak up on their great white victims before taking a big bite. The sneaky predators rotate their bodies, allowing them to remove plugs of flesh. This leaves the great white victim grossly injured, but still alive.

The attack is quite a feat, considering that cookiecutter sharks are just one-tenth the size of great whites.

“In most cases, these little sharks will eat little prey, but with cookiecutter sharks, you have this unique situation of a small shark that will target animals much, much larger than itself, up to 10 times their own size, and that’s pretty unique in the animal kingdom — it’s a very active foraging process,” co-author Yannis Papastamatiou, a marine biologist in the division of ichthyology at the Florida Museum of Natural History on the UF campus, said in a press release.

For the study, the researchers analyzed a bite wound near a great white shark’s mouth. The great white shark was photographed by a diver in a shark cage near Guadalupe Island in the Pacific Ocean.

Cookiecutters inhabit deep tropical waters. Their bites have been found on many animals, including tuna, whales, dolphins, swordfish, elephant seals and even humans.

“When biologists first started noticing the bites on the pelagic fishes and whales, they thought it might be a viral infection because they didn’t know any animal that could bite and leave such a smooth wound,” Papastamatiou said. “And it’s not only animals — they’ve taken chunks of plastic out of submarines and underwater oceanographic equipment, so it’s pretty amazing what they can do.”

This “talent” is made possible by the cookiecutter’s unique teeth. Unlike the teeth of other sharks, those of cookiecutter sharks are connected at the bottom in the lower jaw, allowing them to scoop out the flesh of their victims like a living melon baller.

These sharks have the largest teeth of any shark in relation to the size of their jaws. Cookiecutters are also bioluminescent, meaning they produce their own light on parts of their bodies. Their hunting tactic is to hide and surprise larger fish, taking bites before quickly leaving the scene.

Read more at Discovery News

Secret Painting in Rembrandt Masterpiece Seen

Scientists may be one step closer to revealing a hidden portrait behind a 380-year-old Rembrandt painting.

The masterpiece, "Old Man in Military Costume" by Dutch painter Rembrant Harmenszoon van Rijn, resides at the J. Paul Getty Museum in Los Angeles. Scientists had noticed the painting bears faint traces of another portrait beneath its surface. Researchers had previously probed the painting with infrared, neutron and conventional X-ray methods, but could not see the behind the top coat, largely because Rembrandt used the same paint (with the same chemical composition) for the underpainting and the final version.

New studies with more sophisticated X-ray techniques that can parse through the painting's layers give art historians hope that they may finally get to see who is depicted in the secret image.

"Our experiments demonstrate a possibility of how to reveal much of the hidden picture," Matthias Alfeld from the University of Antwerp said in a statement. "Compared to other techniques, the X-ray investigation we tested is currently the best method to look underneath the original painting."

Read more at Discovery News

Jan 25, 2013

More Than One Brain Behind Einstein's Famous Equation: E=mc2

A new study reveals the contribution of a little known Austrian physicist, Friedrich Hasenöhrl, to uncovering a precursor to Einstein famous equation.

Two American physicists outline the role played by Austrian physicist Friedrich Hasenöhrl in establishing the proportionality between the energy (E) of a quantity of matter with its mass (m) in a cavity filled with radiation. In a paper about to be published in the European Physical Journal H, Stephen Boughn from Haverford College in Pensylvannia and Tony Rothman from Princeton University in New Jersey argue how Hasenöhrl's work, for which he now receives little credit, may have contributed to the famous equation E=mc2.

According to science philosopher Thomas Kuhn, the nature of scientific progress occurs through paradigm shifts, which depend on the cultural and historical circumstances of groups of scientists. Concurring with this idea, the authors believe the notion that mass and energy should be related did not originate solely with Hasenöhrl. Nor did it suddenly emerge in 1905, when Einstein published his paper, as popular mythology would have it.

Given the lack of recognition for Hasenöhrl's contribution, the authors examined the Austrian physicist's original work on blackbody radiation in a cavity with perfectly reflective walls. This study seeks to identify the blackbody's mass changes when the cavity is moving relative to the observer.

They then explored the reason why the Austrian physicist arrived at an energy/mass correlation with the wrong factor, namely at the equation: E = (3/8) mc2. Hasenöhrl's error, they believe, stems from failing to account for the mass lost by the blackbody while radiating.

Read more at Science Daily

Bats Create Tidy Bachelor Pads

Certain bat females and males get on each others nerves so much that they create their own homes where adult members of the opposite sex are not allowed entry.

A paper in the journal PLoS ONE describes such a species, the tiny Daubenton’s bat. A research team studied the bats living along a valley near the River Wharfe in the U.K.

Some of the male bats were found in spotlessly clean “bat bachelor” pads.

Certain female bats, along with their offspring, were found in slightly messier roosts (due to the kids) in less windy locations.

“One possible reason for not finding males … is that the mothers just want to avoid competing with males for food,” project leader John Altringham from the University of Leeds’ School of Biology said in a press release. ”It takes a lot of insects to make the milk needed to feed their young.”

“But it is also possible,” he continued, “that the males choose not to roost with the females. Mothers and pups often have a lot of ectoparasites like ticks and mites. In a warm, crowded nursery, parasites can thrive. Parasites not only make life uncomfortable but can affect a bat’s health. The males that live by themselves are usually very clean in their bachelor pads, so you can understand why they might not want to move in.”

This seems to be a personal choice — not all Daubenton’s bats live in separate housing. Altringham and his team found a “small oasis of cohabitation in Grassington,” a nearby town.

“They have these warm, cuddly males to bunk up with. This way, females use less energy keeping warm and babies grow faster,” Altringham said. “In these marginal conditions, they may just tolerate a few males to keep them warm. Otherwise they kick them out. Why do the males co-habit if they are going to get parasites all over them? Well, that may be down to the usual answer: sex.”

Bats therefore face some of the same challenges that we do, in terms of finding good mates and real estate, and dealing with messy children. And they also have their doting dads, resourceful females and confirmed bachelors.

“At Grassington, most of the fathers of bats born there spent the summer with the females,” Altringham said, adding that females only produce one pup a year.

Read more at Discovery News

Giant Squid: Still a Deep Mystery

The recent unprecedented video footage of a giant squid filmed in its deep ocean habitat has renewed interest in the enormous -- and yet still mysterious -- species.

It's believed that giant squid (genus Architeuthis) can grow up to 55 feet long. The individual captured on video via a small submarine located in the North Pacific Ocean was about 30 feet long and silver and gold in color, marine biologist Edie Widder, who helped to shoot the footage, said. Her colleague Tsunemi Kubodera added that the squid was missing its two longest tentacles.

Cephalopod experts are intrigued by the world record footage.

"It was really thrilling to see the press releases concerning the filming of a living giant squid with a manned submersible," William Gilly, a professor of biology at Stanford University and the Hopkins Marine Station, told Discovery News.

Gilly previously examined a 7-foot-long giant squid that weighed 300 pounds. It was found floating dead in Monterey Bay, Calif.

"It was missing the tentacles and its stomach had been removed through a hole in its body," he said. "Something strange must like to eat those parts, I guess!"

He also noted that the color-changing system, which functions using organelles called chromatophores that contain pigment and reflect light, was present very deep inside the giant squid's body cavity. In smaller species, this system is arranged only on the body’s outer surface.

In recent months, researchers have also learned more about giant squid eyes. The diameter of these eyes measures two to three times that of any other animal.

Read more at Discovery News

People in the US Still Die from Black Death

The United States is one of the many countries around the world that technically still suffers from what was once called the Black Death. Although we're not keeling over like medieval peasants, there are regular cases of bubonic plague that spring up every year in the American southwest. Occasionally, they lead to deaths. More often, they lead to people scratching their heads as they read the newspaper and wondering aloud, "How do we still have the plague?" It's all San Francisco's fault.

The city was ringing in the year 1900 and things looked bright. San Francisco was both a local hub of industry and a port to ships coming in from the far east. Each of those ships had to pass a health inspection before they docked, of course, but both the passengers and the local businesses pressured the health inspectors to get it out of the way as quickly as possible. They did this even after cases of plague, and mini-epidemics, broke out in China, and then in Hawaii.

It was not a surprise to health officials when the first case of plague was reported in Chinatown, but they were surprised by the opposition they faced in even saying the word "plague." Over the next few years, state and local organizations worked against federal health officials, fearing that any reports of plague would damage trade and tourism. When the 1906 earthquake hit, and the rats took over the rubble of the city, the deaths came so fast and thick that there was no denying it anymore. Still, it took years of work before the plague was quelled. By that time, it had started showing up in local squirrels.

Bubonic plague is not a virus, but a bacterial infection. Yersinia pestis lives in fleas, which leave traces of it in the area that they bite. It works its way into the body and multiplies, traveling through the lymphatic system. The swellings that appear at the groin and under the armpits are the painfully swollen lymph nodes. Bobonic plague kills within four days, at which point the fleas desert the body and go to the next victim, taking their bacteria with them.

An infected flea doesn't necessarily mean an infected host. Different fleas have different eating techniques, different hosts scratch (driving the bacteria into the wound) or don't scratch, and not all hosts act as ideal carriers for the bacteria. But plague in the wildlife won't stay in the wildlife for long.

Read more at Discovery News

Jan 24, 2013

Biggest Dinos Had Tennis Ball-Sized Brains

An advanced member of the largest group of dinosaurs ever to walk the Earth still had a relatively puny brain, researchers say.

The scientists analyzed the skull of 70-million-year-old fossils of the giant dinosaur Ampelosaurus, discovered in 2007 in Cuenca, Spain, in the course of the construction of a high-speed rail track connecting Madrid with Valencia. The reptile was a sauropod, long-necked, long-tailed herbivores that were the largest creatures ever to stride the Earth. More specifically, Ampelosaurus was a kind of sauropod known as a titanosaur, many if not all of which had armorlike scales covering their bodies.

Sauropod skulls are typically fragile, and few have survived intact enough for scientists to learn much about their brains. By scanning the interior of the skull via CT imaging, the researchers developed a 3-D reconstruction of Ampelosaurus' brain, which was not much bigger than a tennis ball.

"This saurian may have reached 15 meters (49 feet) in length; nonetheless its brain was not in excess of 8 centimeters (3 inches)," study researcher Fabien Knoll, a paleontologist at Spain's National Museum of Natural Sciences, said in a statement.

The first sauropods appeared about 160 million years earlier than this fossil.

"We don't see much expansion of brain size in this group of animals as they go through time, unlike a lot of mammalian and bird groups, where you see increases in brain size over time," researcher Lawrence Witmer, an anatomist and paleontologist at Ohio University, told LiveScience. "They apparently hit on something and stuck with it -- expansion of brain size over time wasn't a major focus of theirs."

For years, scientists have wondered how the largest land animals ever lived with such tiny brains. "Maybe we should flip that question on their end -- maybe we shouldn't ask how they could function with tiny brains, but what are many modern animals doing with such ridiculously large brains. Cows may be triple-Einsteins compared to most dinosaurs, but why?" Witmer said.

"Part of the inner ear is associated with hearing, so the fact it had a small inner ear means it probably wasn't all that good at hearing airborne sounds," Witmer said. "It probably used a kind of hearing we don't think much about, which depends on sounds transmitted through the ground."

The inner ear is also responsible for balance and equilibrium, Witmer said.

"Given what we know about its inner ear, Ampelosaurus probably didn't put a real premium on rapid, quick jerky eye or head movements, which makes sense — these are relatively large, slow-moving, plant-eating animals," he said.

Read more at Discovery News

Roman Marker Used to Measure Earth Found

Italian researchers have unearthed a marble benchmark which was once used to measure the shape of Earth in the 19th century.

Called Benchmark B, the marker was found near the town of Frattocchie along one of the earliest Roman roads which links the Eternal City to the southern city of Brindisi.

Placed there by Father Angelo Secchi (1818-1878), a pioneer of astrophysics, the marker consisted of a small travertine slab with a metallic plate in the middle. The plate featured a hole at its center.

“The hole was the terminal point of the geodetic baseline which run in the ancient Appian Way near Rome, between the tomb of Cecilia Metella, a daughter of a Roman consul, and a tower near Frattocchie,” Tullio Aebischer, a cartographical consultant at the department of mathematics and physics of Roma Tre University, told Discovery News.

Geodesy is a science that deals with the size and shape of the Earth and the determination of exact positions on its surface. Essentially the figure of the Earth is abstracted from its topographical features — and a baseline is the fundamental requirement for computing the triangulation of a region.

In order to determine the extension of the “triangle,” it is necessary to know the exact distance between two points: A, the starting point, and B, the ending point.

In this way, networks of triangulation can be spread over entire countries and continents.

While Benchmark A, the starting point of the baseline, was found in 1999 in front of the Cecilia Metella mausoleum, nothing was known of the Benchmark B’s whereabouts.

“We found it after a long archival research and a georadar survey. The discovery will allow us to precisely verify the ancient measurements with modern GPS technologies,” Aebischer said.

“The measurements along the Appian Way were part of surveys which began in the middle of the 18th century and spread all over Italy, in Europe, especially in France and Lapland, and in South America. The aim was to measure the shape of the Earth,” Aebischer said.

In 1735 the Académie Française proposed the verification of Isaac Newton’s theory about the shape of the planet Earth. Newton (1642-1727) predicted the Earth to be an oblate ellipsoid, thus several scientific expeditions were carried in the attempt to assess the length of one degree of a meridian measured at different latitudes.

In 1750 Pope Benedictus XIV commissioned the measurement of the length of the meridian arc stretching from Rome to Rimini and passing through St. Peter’s dome.

To do so and to produce a geodetic triangulation of the Papal States, the Jesuits Christopher Maire (1697-1767) and Roger Boscovich (1711-1787) measured a baseline between the tomb of Cecilia Metella and an anonymous ruin near the town of Frattocchie.

“The area was chosen because of its smooth and straight ground. In addition, in a geodetical baseline, the markers A and B must be visible from the other points of the triangulation. Here we had a mausoleum and a ruined tower,” Aebischer said.

Maire and Boscovich’s results were heavily criticized by the French engineers in the beginning of the 19th century, and a long scientific dispute began.

The quarrel was started by Secchi a century after the publication of the Jesuits’ results. The astronomer re-measured the Boscovich geodetical base between November 1854 and April 1855.

The baseline measures 12,043.14 meters (39,511.61 feet) .

Read more at Discovery News

Why We Love The Manatee Nebula

Okay, I know what this story has some of you thinking. What are those astronomers up to again? Naming things… renaming things… isn’t it all just silly? Well yes, and no. I think the “Manatee Nebula” is silly in all the right ways.

Why do I love this story? Well first, it’s the telescope that took the image. This exquisite, gorgeous image was constructed with data from the newly revamped Jansky Very Large Array. This iconic set of 27 dishes arranged in a Y-formation in the New Mexico desert got a brand new life with major upgrades put in place over the last few years.

Oh sure, at first glance it looks like the same telescope. But if you look deeper, you’ll see all new receivers (collectors of radio light) that span a much broader range of wavelengths than the previous iteration. This opens the JVLA to a broader set of spectral features and makes it much more sensitive to faint radiation. More sensitivity means more science. Add to that a whole new fiber optic data transfer system and a brand new massive supercomputer at the back end, and you have some rather giddy astronomers.

Then, there is the nebula itself. Formerly known as W50, it is home to a strange phenomenon known as a microquasar. You may remember that a quasar is what is seen when a supermassive black hole in the center of a galaxy is feeding off of the material around it. Well a microquasar is similar, except that it is powered by a stellar-mass black hole that formed in the death of a massive star in a supernova explosion. These are some pretty powerful forces at work that create the microquasar, its jets, and the bubble of a nebula that has been blown out around it.

I also love that this story allows two different branches of science to come together and say, “Look at how awesome the universe is!” In one story, you can read about astrophysical phenomena and the giant, peaceful creatures that inhabit the Florida coasts. In fact, the newly named nebula was unveiled at the Manatee Festival at the site where many manatees come to rest in the winter.

Finally, I love this story because of the people involved. The suggestion for the name came from a remark made by Heidi Winter, the Executive Assistant to the Director of the National Radio Astronomy Observatory. She is also one of the sweetest people I have ever known and had an enthusiasm for astronomy that was simply infectious. The idea was picked up on by Tania Burchell, Public Information Officer for the observatory and also one of the coolest people I know.

Tania spent a year working with manatees as a Park Ranger and makes an excellent case for why this nebula and those gentle giants are really so similar. For example, sadly, manatees are often injured and scarred by boat propellers, whereas the Manatee Nebula has been twisted up and scarred by the action of the microquasar jets. When else has an astrophysical object raised awareness for a distressing problem in the natural world on Earth?

Read more at Discovery News

Betelgeuse to Rip Through Interstellar 'Wall'

The famous Betelgeuse is a star in serious trouble. Not only is it rapidly approaching the end of its life, it’s also speeding toward a honking huge interstellar wall! Fortunately, this wall is made of dust, so it probably rates quite low on the red supergiant’s list of concerns.

This spectacular observation was captured by the European space telescope Herschel, which is sensitive to infrared light. Betelgeuse was the target, but as can be seen to the left of the image, an apparently vertical glowing structure can be seen (a high-resolution image can be downloaded here). Astronomers have calculated that the star’s bow shock will “impact” the wall in about 5,000 years time — the star itself will hit around 12,500 years later.

It was originally believed that the structure may be material that was flung from the dying star earlier, but analysis has shown that it is in fact stationary and did not originate from Betelgeuse. The structure may therefore be dust trapped in the interstellar magnetic field of our galaxy or the outer edge of a nearby stellar cloud illuminated by Betelgeuse’s light.

In addition to the glowing dusty wall is the incredible bow shock generated by Betelgeuse’s stellar winds, buffeting against the interstellar medium as the star powers through space at 30 km/s (19 miles per second). Our sun also has a bow shock that curves around the sun in its direction of travel, but Betelgeuse’s bow shock is inevitably more dramatic as its stellar winds are ferocious.

Betelgeuse is a massive star — around 1,000 times bigger and 100,000 times brighter than the sun — and is therefore predicted to end its life as a supernova. The red supergiant phase is violent; strong winds strip the outermost layers of the star, blasting them into space. Observations have even shown that the star’s shape is irregular, a sure sign that Betelgeuse is, quite literally, falling apart.

Read more at Discovery News

Jan 23, 2013

Researchers Make DNA Data Storage a Reality: Every Film and TV Program Ever Created -- In a Teacup

Researchers at the EMBL-European Bioinformatics Institute (EMBL-EBI) have created a way to store data in the form of DNA – a material that lasts for tens of thousands of years. The new method, published January 23 in the journal Nature, makes it possible to store at least 100 million hours of high-definition video in about a cup of DNA.

There is a lot of digital information in the world – about three zettabytes’ worth (that’s 3000 billion billion bytes) – and the constant influx of new digital content poses a real challenge for archivists. Hard disks are expensive and require a constant supply of electricity, while even the best ‘no-power’ archiving materials such as magnetic tape degrade within a decade. This is a growing problem in the life sciences, where massive volumes of data – including DNA sequences – make up the fabric of the scientific record.

"We already know that DNA is a robust way to store information because we can extract it from bones of woolly mammoths, which date back tens of thousands of years, and make sense of it,” explains Nick Goldman of EMBL-EBI. “It’s also incredibly small, dense and does not need any power for storage, so shipping and keeping it is easy.”

Reading DNA is fairly straightforward, but writing it has until now been a major hurdle to making DNA storage a reality. There are two challenges: first, using current methods it is only possible to manufacture DNA in short strings. Secondly, both writing and reading DNA are prone to errors, particularly when the same DNA letter is repeated. Nick Goldman and co-author Ewan Birney, Associate Director of EMBL-EBI, set out to create a code that overcomes both problems.

“We knew we needed to make a code using only short strings of DNA, and to do it in such a way that creating a run of the same letter would be impossible. So we figured, let’s break up the code into lots of overlapping fragments going in both directions, with indexing information showing where each fragment belongs in the overall code, and make a coding scheme that doesn't allow repeats. That way, you would have to have the same error on four different fragments for it to fail – and that would be very rare," says Ewan Birney.

The new method requires synthesising DNA from the encoded information: enter Agilent Technologies, Inc, a California-based company that volunteered its services. Ewan Birney and Nick Goldman sent them encoded versions of: an .mp3 of Martin Luther King’s speech, “I Have a Dream”; a .jpg photo of EMBL-EBI; a .pdf of Watson and Crick’s seminal paper, “Molecular structure of nucleic acids”; a .txt file of all of Shakespeare's sonnets; and a file that describes the encoding.

“We downloaded the files from the Web and used them to synthesise hundreds of thousands of pieces of DNA – the result looks like a tiny piece of dust,” explains Emily Leproust of Agilent. Agilent mailed the sample to EMBL-EBI, where the researchers were able to sequence the DNA and decode the files without errors.

“We’ve created a code that's error tolerant using a molecular form we know will last in the right conditions for 10 000 years, or possibly longer,” says Nick Goldman. “As long as someone knows what the code is, you will be able to read it back if you have a machine that can read DNA.”

Read more at Science Daily

Thousands of Microbes Cross Pacific Ocean to US

Not all bacteria are hardy enough to survive the harsh conditions present in the upper atmosphere. However, the ones that can survive are capable of some serious long-range transport. In a paper to be published in the February 2013 issue of Applied and Environmental Microbiology, scientists identified more than 2,800 bacterial species that were deposited onto Mt. Bachelor, Oregon during two trans-Pacific dust plume events in 2011. The dust is thought to have originated somewhere near China, Korea or Japan.

Each year strong winds blowing over arid lands in Asia pick up and deposit up to 70 million tons (64 teragrams) of aerosols onto the continent of North America. These aerosols are composed of particles of dust, debris and microorganisms. The aerosols are often transported during dust plumes events that can take as little as 7 to 10 days to cross the Pacific Ocean.

Scientists took samples of two trans-Pacific dust plume events from the top of Mt. Bachelor in Oregon during the spring of 2011. They extracted DNA from the samples and sequenced it to determine what types of microorganisms were present in the dust plumes. They found over 2,800 different bacterial species (or operational taxonomic units) at the peak of the plume events.

Many of the microorganisms present in the samples can also be found in background air samples, the scientists say. The scientists think that the trans-Pacific dust plume events were noteworthy because of the elevated amounts of microorganisms they were depositing onto Mt. Bachelor. A few species of marine archaea were found only during plume events, and these species have never been seen before at high altitudes.

David Smith, lead author of the study and graduate of the doctoral program in astrobiology at the University of Washington, commented on the findings in a news release.

"The long-range transport and surprising level of species richness in the upper atmosphere overturns traditional paradigms in aerobiology," Smith said. "It’s a small world. Global wind circulation can move Earth’s smallest types of life to just about anywhere."

Smith says that future research aimed at understanding how bacteria can survive at high altitudes could be invaluable to the fields of biotechnology and medicine.

Funding for the research was provided by the National Science Foundation, the National Geographic Society, NASA’s Astrobiology Institute and the University of Washington.

Read more at Discovery News

Neanderthal Baby Momma Ad Denied

Yesterday, DNews ran the article, Surrogate Mother Wanted for Neanderthal Baby. In it, we told you that Harvard professor of genetics, George Church, proposed finding an “extremely adventurous female human” to serve as a surrogate mother for a cloned Neanderthal baby. Since that article ran, Church has come out saying that’s not what he meant, exactly. He blames the misinterpretation on the poor translation of an interview with him that appeared in the German magazine, Der Spiegel.

“I’m certainly not advocating it,” Church told the Boston Herald. “I’m saying, if it is technically possible someday, we need to start talking about it today.”

A paragraph from his book, Regenesis: How Synthetic Biology Will Reinvent Nature and Ourselves,” clarifies his idea. Church explains that genetic engineering gives researchers a way to start with an intact genome of an animal and change it to the genome of another animal. You could start with an elephant’s genome, for example, and change it into that of a mammoth’s.

“The same technique would work for the Neanderthal,” he writes, “except that you’d start with a stem cell genome from a human adult and gradually reverseengineer it into the Neanderthal genome or a reasonably close equivalent. These stem cells can produce tissues and organs. If society becomes comfortable with cloning and sees value in true human diversity, then the whole Neanderthal creature itself could be cloned by a surrogate mother chimp or an extremely adventurous female human.”

And then today on a radio interview with WBUR’s Tom Ashbrook, Church explained it more. Ashbrook also interviewed Arthur Caplan, head of the division of bioethics at New York University and Jay Keasling, director of the Synthetic Biology Engineering Research Center.

Tom asks, What would the potential benefit be?

“It’s very hard to anticipate the what the benefits are of the Apollo Moon shot are, for example. We didn’t precisely describe GPS navigation in the streets,” Church says.

“We may be limited, chauvinistic in the way we think about things,” he says.

Read more at Discovery News

Magnetic 'Braids' May Cook the Sun's Corona

Scientists have long puzzled over why the surface of the sun is cooler than its corona, the outer hazy atmosphere visible during a solar eclipse. Now thanks to a five-minute observation by a small, but very high-resolution ultraviolet telescope they have some answers.

Even before the July 2012 launch of the High-resolution Coronal Imager, nicknamed Hi-C, scientists suspected that magnetic fields on the sun were responsible for ramping up its energy, resulting in a flaring corona that can reach 7 million degrees Fahrenheit, compared to a visible solar surface temperature of about 10,000 degrees.

Hi-C, which was launched aboard a suborbital rocket to study the sun without interference from Earth's atmosphere, revealed interwoven magnetic fields braided like hair. When the braids relaxed, they released energy.

"I had no idea we would see structures like that in the corona. Seeing these braids was very new to me," astrophysicist Jonathan Cirtain with NASA's Marshall Space Flight Center in Huntsville, Ala., told Discovery News.

"Magnetic braiding" is believed to happen when small bundles of magnetic fields become wrapped around each other due to plasma moving around on the sun's surface.

Follow-up observations are needed to learn if the braiding phenomenon is widespread and how important is it to coronal heating.

"Are twisted-up field lines just all over the place? Do they only happen near 'inversion layers,' where you go from a positive net flux out from the sun's surface to negative net flux into the surface? How prevalent is this structure to the overall sun and how important is it to heating the sun's atmosphere? I think that's the next step that we will take," Cirtain said.

"You are not going to solve a problem with five minutes of data," added space scientist and physicist Peter Cargill, with Imperial College London, who isn't associated with this research.

"A rocket flight like this is primarily designed to demonstrate new technology. You hope to get some good science, as they have done, and to point the way toward what to look for when such an instrument flies on a spacecraft," Cargill wrote in an email to Discovery News.

Hi-C had the precision to see the equivalent of something the size of a dime from 10 miles away, allowing astronomers to observe details in extreme ultraviolet light of structures on the sun that were about 100 miles in diameter -- five times better than the resolution of the next-best instrument, the Atmospheric Imaging Assembly aboard NASA's ongoing Solar Dynamics Observatory mission.

The observation was tricky and short. Cirtain said he remotely operated the telescope during flight to home in on a particularly active region of the sun to photograph. The telescope, which was launched from the White Sands Missile Range in New Mexico, then parachuted back to the desert so its onboard data could be recovered and analyzed.

Read more at Discovery News

Jan 22, 2013

Hubble Focuses On the 'Great Attractor'

A busy patch of space has been captured in an image from the NASA/ESA Hubble Space Telescope. Scattered with many nearby stars, the field also has numerous galaxies in the background.

Located on the border of Triangulum Australe (The Southern Triangle) and Norma (The Carpenter's Square), this field covers part of the Norma Cluster (Abell 3627) as well as a dense area of our own galaxy, the Milky Way.

The Norma Cluster is the closest massive galaxy cluster to the Milky Way, and lies about 220 million light-years away. The enormous mass concentrated here, and the consequent gravitational attraction, mean that this region of space is known to astronomers as the Great Attractor, and it dominates our region of the Universe.

The largest galaxy visible in this image is ESO 137-002, a spiral galaxy seen edge on. In this image from Hubble, we see large regions of dust across the galaxy's bulge. What we do not see here is the tail of glowing X-rays that has been observed extending out of the galaxy -- but which is invisible to an optical telescope like Hubble.

Observing the Great Attractor is difficult at optical wavelengths. The plane of the Milky Way -- responsible for the numerous bright stars in this image -- both outshines (with stars) and obscures (with dust) many of the objects behind it. There are some tricks for seeing through this -- infrared or radio observations, for instance -- but the region behind the center of the Milky Way, where the dust is thickest, remains an almost complete mystery to astronomers.

Read more at Science Daily

Brain Structure of Infants Predicts Language Skills at One Year

Using a brain-imaging technique that examines the entire infant brain, researchers have found that the anatomy of certain brain areas – the hippocampus and cerebellum – can predict children's language abilities at 1 year of age.

The University of Washington study is the first to associate these brain structures with future language skills. The results are published in the January issue of the journal Brain and Language.

"The brain of the baby holds an infinite number of secrets just waiting to be uncovered, and these discoveries will show us why infants learn languages like sponges, far surpassing our skills as adults," said co-author Patricia Kuhl, co-director of the UW's Institute for Learning & Brain Sciences.

Children's language skills soar after they reach their first birthdays, but little is known about how infants' early brain development seeds that path. Identifying which brain areas are related to early language learning could provide a first glimpse of development going awry, allowing for treatments to begin earlier.

"Infancy may be the most important phase of postnatal brain development in humans," said Dilara Deniz Can, lead author and a UW postdoctoral researcher. "Our results showing brain structures linked to later language ability in typically developing infants is a first step toward examining links to brain and behavior in young children with linguistic, psychological and social delays."

In the study, the researchers used magnetic resonance imaging to measure the brain structure of a mix of 19 boys and girls at 7 months of age. The researchers used a measurement called voxel-based morphometry to determine the concentration of gray matter, consisting of nerve cells, and of white matter, which make up the network of connections throughout the brain.

The study is the first to relate the outcomes of this whole-brain imaging technique to predict future ability in infants. The whole-brain approach freed the researchers from having to select a few brain regions for study ahead of time, ones scientists might have expected to be involved based on adult data.

Five months later, when the children were about 1 year old they returned to the lab for a language test. This test included measures of the children's babbling, recognition of familiar names and words, and their ability to produce different types of sounds.

"At this age, children typically don't say many words," Deniz Can said. "So we rely on babbling and the ability to comprehend language as a sign of early language mastery."

Infants with a greater concentration of gray and white matter in the cerebellum and the hippocampus showed greater language ability at age 1. This is the first study to identify a relationship between language and the cerebellum and hippocampus in infants. Neither brain area is well-known for its role in language: the cerebellum is typically linked to motor learning, while the hippocampus is commonly recognized as a memory processor.

"Looking at the whole brain produced a surprising result and scientists live for surprises. It wasn't the language areas of the infant brain that predicted their future linguistic skills, but instead brain areas linked to motor abilities and memory processing," Kuhl said. "Infants have to listen and memorize the sound patterns used by the people in their culture, and then coax their own mouths and tongues to make these sounds in order join the social conversation and get a response from their parents."

The findings could reflect infants' abilities to master the motor planning for speech and to develop the memory requirements for keeping the sound patterns in mind.

Read more at Science Daily

Toothy Tumor Found in 1,600-Year-Old Roman Corpse

In a necropolis in Spain, archaeologists have found the remains of a Roman woman who died in her 30s with a calcified tumor in her pelvis, a bone and four deformed teeth embedded within it.

Two of the teeth are still attached to the wall of the tumor researchers say.

The woman, who died some 1,600 years ago, had a condition known today as an ovarian teratoma which, as its name indicates, occurs in the ovaries . The word Teratoma comes from the Greek words "teras" and "onkoma" which translate to "monster" and "swelling," respectively. The tumor is about 1.7 inches (44 millimeters) in diameter at its largest point.

"Ovarian teratomas are bizarre, but benign tumors," writes lead researcher Núria Armentano, of the ANTROPÒLEGS.LAB company and the Universitat Autònoma de Barcelona, in an email to LiveScience.

The tumors come from germ cells, which form human eggs and can create hair, teeth and bone, among other structures.

This is the first time scientists have found this type of teratoma in the ancient world.

"his is an extraordinary case, not only for its antiquity, but also its identification in the archeological record," writes the research team in a paper published recently in the International Journal of Paleopathology.

The woman lived at a time of decline for the Roman Empire, with new groups (popularly known as the "barbarians") moving into Roman territory, eventually taking over Spain and other areas.

Who was she?

Archaeologists found the woman buried in a necropolis near Lleida in the Catalonia region of Spain. They only found a few artefacts buried with her: tiles known as tegulae that had been put over her body to form a gabled roof.

"Tegulae graves were the most common Roman burials. She was not an important or rich person. She had a low socio-economic status," Armentano explained.

The researchers note in their paper that while it's possible the woman never experienced symptoms, it's also possible that, despite the tumor being benign, it ultimately killed her.

Read more at Discovery News

Surrogate Mother Wanted for Neanderthal Baby

This may go down as one of the oddest job postings in history: A respected Harvard professor of genetics has proposed finding an "extremely adventurous female human" to serve as surrogate mother for a cloned Neanderthal baby.

Besides saying that the cloning of a live Neanderthal baby would be possible in our lifetime, Dr. George Church told Der Spiegel magazine that using stem cells to create a Neanderthal could have significant benefits to society. "The first thing you have to do is to sequence the Neanderthal genome, and that has actually been done," Church said.

Scientists completed the first sequence of the Neanderthal genome in 2010, finding genetic evidence suggesting ancestors of modern humans successfully interbred with Neanderthals, at least occasionally. More recent research has suggested Neanderthal DNA makes up 1 percent to 4 percent of the genomes of modern Eurasians.

This may go down as one of the oddest job postings in history: A respected Harvard professor of genetics has proposed finding an "extremely adventurous female human" to serve as surrogate mother for a cloned Neanderthal baby.

Besides saying that the cloning of a live Neanderthal baby would be possible in our lifetime, Dr. George Church told Der Spiegel magazine that using stem cells to create a Neanderthal could have significant benefits to society. "The first thing you have to do is to sequence the Neanderthal genome, and that has actually been done," Church said.

Scientists completed the first sequence of the Neanderthal genome in 2010, finding genetic evidence suggesting ancestors of modern humans successfully interbred with Neanderthals, at least occasionally. More recent research has suggested Neanderthal DNA makes up 1 percent to 4 percent of the genomes of modern Eurasians.

Read more at Discovery News

Jan 21, 2013

Scientists Describe a 'New' Type of Volcanic Eruption

Scientists based in the UK and New Zealand have described a "new" type of volcanic eruption.

Volcanic eruptions are commonly categorised as either explosive or effusive. But now, in research published this month in Nature Geoscience, researchers at Victoria University, Wellington and the National Oceanography Centre in Southampton have uncovered a previously undocumented type of eruption in underwater volcanoes -- by looking at tiny original bubble spaces trapped in volcanic rock.

Inside volcanoes, gases are dissolved in the molten magma as a function of the very high pressures and chemistry of the magma. In the same way that gases dissolved in carbonated drinks bubble up when you take the lid off, when magma is erupted as lava, the pressure is relieved and the gases exsolve to form small gas bubbles or so-called "vesicles." In explosive eruptions these vesicles expand so quickly they fragment the magma, violently ejecting lava, which cools and degasses to form solidified pumice that can be sufficiently light to float on water.

In air pumice is obviously associated with violent, explosive eruptions. Consequently underwater volcanoes flanked by highly vesicular pumice have, to date, also been interpreted as having erupted explosively.

But the results of this study indicate that there is a third eruptive style unique to underwater volcanoes, which is neither effusive nor explosive.

"By documenting the shape and density of bubbles in pumices generated by an underwater caldera volcano in the southwest Pacific Ocean -- the Macauley volcano -- we found large differences in the number and shape of "bubbles" in the same pebble-sized samples, different to anything previously documented," said Professor Ian Wright of the National Oceanography Centre, who co-authored the paper.

"This range of bubble densities distinct in these pumice samples indicates that the lava erupting from the caldera was neither vigorous enough for an explosive eruption, nor gentle enough for an effusive flow."

The study proposes that rather than exploding in the neck of the volcano, the formation and expansion of bubbles in the magma created a buoyant foam, which rose to the seafloor and then buoyantly detached from the volcano as molten pumice balloons but with chilled margins. During its ascent to the sea surface, the vesicles within the molten interior would have continued to expand as the pressure -- this time from the weight of the seawater -- reduced.

"These processes explain the unique bubble structure seen in the samples analysed, which could have only occurred with an intermediate eruption style and in an underwater setting," said Professor Wright.

"We conclude that the presence of widespread deposits of pumice on underwater volcanoes does not necessarily indicate large-scale explosive volcanism."

The authors proposed that this style of eruption be named Tangaroan, the Maori god of the sea, and name of the research vessel used to collect the samples.

Read more at Science Daily

New Evidence Indicates Auroras Occur Outside Our Solar System

University of Leicester planetary scientists have found new evidence suggesting auroras – similar to Earth’s Aurora Borealis - occur on bodies outside our solar system.

Auroras occur on several planets within our solar system, and the brightest - on Jupiter – are 100 times brighter than those on Earth. However, no auroras have yet been observed beyond Neptune.

A new study led by University of Leicester lecturer Dr Jonathan Nichols has shown that processes strikingly similar to those which power Jupiter’s auroras could be responsible for radio emissions detected from a number of objects outside our solar system.

In addition, the radio emissions are powerful enough to be detectable across interstellar distances – meaning that auroras could provide an effective way of observing new objects outside our solar system.

Auroras occur when charged particles in an object’s magnetosphere collide with atoms in its upper atmosphere, causing them to glow.  However, before hitting the atmosphere, these particles also emit radio waves into space.

The study which recently appeared in the Astrophysical Journal, shows that this phenomenon is not limited to our solar system.

It shows that the radio emissions from a number of ultracool dwarfs may be caused in a very similar, but significantly more powerful, way to Jupiter’s auroras.

Dr Nichols, a Lecturer and Research Fellow in the University of Leicester’s Department of Physics and Astronomy, said: “We have recently shown that beefed-up versions of the auroral processes on Jupiter are able to account for the radio emissions observed from certain "ultracool dwarfs" - bodies which comprise the very lowest mass stars - and "brown dwarfs" - 'failed stars' which lie in between planets and stars in terms of mass.

“These results strongly suggest that auroras do occur on bodies outside our solar system, and the auroral radio emissions are powerful enough  - one hundred thousand times brighter than Jupiter's - to be detectable across interstellar distances.”

The paper, which also involved researchers at the Center for Space Physics, Boston University, USA, could have major implications for the detection of planets and objects outside our solar system which could not be discovered with other methods.

What’s more, the radio emission could provide us with key information about the length of the planet’s day, the strength of its magnetic field, how the planet interacts with its parent star and even whether it has any moons.

Read more at Science Daily

Did an 8th Century Gamma Ray Burst Irradiate Earth?

A nearby short duration gamma-ray burst may be the cause of an intense blast of high-energy radiation that hit the Earth in the 8th century, according to new research led by astronomers Valeri Hambaryan and Ralph Neuhӓuser.

The two scientists, based at the Astrophysics Institute of the University of Jena in Germany, publish their results in the journal Monthly Notices of the Royal Astronomical Society.

In 2012 scientist Fusa Miyake announced the detection of high levels of the isotope Carbon-14 and Beryllium-10 in tree rings formed in 775 CE, suggesting that a burst of radiation struck the Earth in the year 774 or 775. Carbon-14 and Beryllium-10 form when radiation from space collides with nitrogen atoms, which then decay to these heavier forms of carbon and beryllium. The earlier research ruled out the nearby explosion of a massive star (a supernova) as nothing was recorded in observations at the time and no remnant has been found.

Prof. Miyake also considered whether a solar flare could have been responsible, but these are not powerful enough to cause the observed excess of carbon-14. Large flares are likely to be accompanied by ejections of material from the Sun’s corona, leading to vivid displays of the northern and southern lights (aurorae), but again no historical records suggest these took place.

Following this announcement, researchers pointed to an entry in the Anglo-Saxon Chronicle that describes a ‘red crucifix’ seen after sunset and suggested this might be a supernova. But this dates from 776, too late to account for the carbon-14 data and still does not explain why no remnant has been detected.

Drs. Hambaryan and Neuhӓuser have another explanation, consistent with both the carbon-14 measurements and the absence of any recorded events in the sky. They suggest that two compact stellar remnants, i.e. black holes, neutron stars or white dwarfs, collided and merged together. When this happens, some energy is released in the form of gamma rays, the most energetic part of the electromagnetic spectrum that includes visible light.

In these mergers, the burst of gamma rays is intense but short, typically lasting less than two seconds. These events are seen in other galaxies many times each year but, in contrast to long duration bursts, without any corresponding visible light. If this is the explanation for the 774 / 775 radiation burst, then the merging stars could not be closer than about 3000 light years, or it would have led to the extinction of some terrestrial life. Based on the carbon-14 measurements, Hambaryan and Neuhӓuser believe the gamma ray burst originated in a system between 3000 and 12000 light years from the Sun.

If they are right, then this would explain why no records exist of a supernova or auroral display. Other work suggests that some visible light is emitted during short gamma-ray bursts that could be seen in a relatively nearby event. This might only be seen for a few days and be easily missed, but nonetheless it may be worthwhile for historians to look again through contemporary texts.

Astronomers could also look for the merged object, a 1200 year old black hole or neutron star 3000-12000 light years from the Sun but without the characteristic gas and dust of a supernova remnant.

Read more at Science Daily

Human-Tiger Conflict: Are the Risks Overestimated?

A new study finds a complex web of factors increases perceived risk of tiger attack in the Sundarbans of Bangladesh.

Wildlife conservationists are well aware of the potential conflicts that exist between the endangered species they seek to protect and the human populations which inhabit areas where the animals live. Carnivores, such as tigers, pose a risk to humans and their livestock and can be killed because of this potential risk. Previous research has found that killing of animals can be motivated as much by social and psychological factors, such as perception of danger, as by any actual real risk posed by a species.

A new study published in the Springer journal Human Ecology has identified several key factors which may contribute to perceptions of risk from tigers in a conservation area in Bangladesh. The study, by Chloe Inskip and her colleagues from the Durrell Institute of Conservation and Ecology in Kent, UK, and WildTeam, Bangladesh, is the first to use participatory risk mapping (PRM) and in-depth interviews to explore the wider socio-economic context of human-tiger conflict.

The survey was carried out around the Sundarbans mangrove forests of south-western Bangladesh, home to one of the world's largest remaining tiger populations. Although there are no human inhabitants of the Sundarbans, eight sub-districts with a total population of around 1.7 million people lie directly adjacent to the forest boundary. Records indicate that approximately 30-50 people are killed annually by tigers in the area.

The researchers held 54 semi-structured interviews in six villages which border the Sundarbans forest, followed by 385 questionnaires in a further ten border villages. Of all the issues related to lives and livelihood, tigers were the most commonly reported problem. Other issues recorded were largely poverty-related including low incomes, dependence on natural resources, poor infrastructure and services and a lack of clean water together with soil erosion and weather. Inskip and her colleagues identified the fact that these issues had a direct impact on villagers' perceptions of risk from tigers. The respondents' perceived susceptibility to and their ability to mitigate human-tiger conflict was influenced largely by their poverty related-problems.

The authors suggest that any actions taken to improve these socio-economic issues will also reduce the perceived level of risk from tigers and help to reduce the rate at which tigers are killed. For conservationists, this would mean a shift from traditional models of conflict reduction to holistic models which also incorporate situation-specific actions to reduce risk perceptions. In many poor, rural communities in conservation areas such as the Sundarbans, risk perception reduction is likely to be tied strongly to poverty alleviation.

Read more at Science Daily

Jan 20, 2013

'Quadruple Helix' DNA Discovered in Human Cells

In 1953, Cambridge researchers Watson and Crick published a paper describing the interweaving 'double helix' DNA structure -- the chemical code for all life.

Now, in the year of that scientific landmark's 60th Anniversary, Cambridge researchers have published a paper proving that four-stranded 'quadruple helix' DNA structures -- known as G-quadruplexes -- also exist within the human genome. They form in regions of DNA that are rich in the building block guanine, usually abbreviated to 'G'.

The findings mark the culmination of over 10 years investigation by scientists to show these complex structures in vivo -- in living human cells -- working from the hypothetical, through computational modelling to synthetic lab experiments and finally the identification in human cancer cells using fluorescent biomarkers.

The research, published January 20 in Nature Chemistry and funded by Cancer Research UK, goes on to show clear links between concentrations of four-stranded quadruplexes and the process of DNA replication, which is pivotal to cell division and production.

By targeting quadruplexes with synthetic molecules that trap and contain these DNA structures -- preventing cells from replicating their DNA and consequently blocking cell division -- scientists believe it may be possible to halt the runaway cell proliferation at the root of cancer.

"We are seeing links between trapping the quadruplexes with molecules and the ability to stop cells dividing, which is hugely exciting," said Professor Shankar Balasubramanian from the University of Cambridge's Department of Chemistry and Cambridge Research Institute, whose group produced the research.

"The research indicates that quadruplexes are more likely to occur in genes of cells that are rapidly dividing, such as cancer cells. For us, it strongly supports a new paradigm to be investigated -- using these four-stranded structures as targets for personalised treatments in the future."

Physical studies over the last couple of decades had shown that quadruplex DNA can form in vitro -- in the 'test tube', but the structure was considered to be a curiosity rather than a feature found in nature. The researchers now know for the first time that they actually form in the DNA of human cells.

"This research further highlights the potential for exploiting these unusual DNA structures to beat cancer -- the next part of this pipeline is to figure out how to target them in tumour cells," said Dr Julie Sharp, senior science information manager at Cancer Research UK.

"It's been sixty years since its structure was solved but work like this shows us that the story of DNA continues to twist and turn."

The study published January 20 was led by Giulia Biffi, a researcher in Balasubramaninan's lab at the Cambridge Research Institute.

By building on previous research, Biffi was able to generate antibody proteins that detect and bind to areas in a human genome rich in quadruplex-structured DNA, proving their existence in living human cells.

Using fluorescence to mark the antibodies, the researchers could then identify 'hot spots' for the occurrence of four-stranded DNA -- both where in the genome and, critically, at what stage of cell division.

While quadruplex DNA is found fairly consistently throughout the genome of human cells and their division cycles, a marked increase was shown when the fluorescent staining grew more intense during the 's-phase' -- the point in a cell cycle where DNA replicates before the cell divides.

Cancers are usually driven by genes called oncogenes that have mutated to increase DNA replication -- causing cell proliferation to spiral out of control, and leading to tumour growth.

The increased DNA replication rate in oncogenes leads to an intensity in the quadruplex structures. This means that potentially damaging cellular activity can be targeted with synthetic molecules or other forms of treatments.

"We have found that by trapping the quadruplex DNA with synthetic molecules we can sequester and stabilise them, providing important insights into how we might grind cell division to a halt," said Balasubramanian.

"There is a lot we don't know yet. One thought is that these quadruplex structures might be a bit of a nuisance during DNA replication -- like knots or tangles that form.

"Did they evolve for a function? It's a philosophical question as to whether they are there by design or not -- but they exist and nature has to deal with them. Maybe by targeting them we are contributing to the disruption they cause."

The study showed that if an inhibitor is used to block DNA replication, quadruplex levels go down -- proving the idea that DNA is dynamic, with structures constantly being formed and unformed.

The researchers also previously found that an overactive gene with higher levels of Quadruplex DNA is more vulnerable to external interference.

"The data supports the idea that certain cancer genes can be usefully interfered with by small molecules designed to bind specific DNA sequences," said Balasubramanian.

"Many current cancer treatments attack DNA, but it's not clear what the rules are. We don't even know where in the genome some of them react -- it can be a scattergun approach.

Read more at Science Daily

Nearby Universe's 'Cosmic Fog' Measured

Researchers from the Laboratoire Leprince-Ringuet (CNRS/École Polytechnique) have carried out the first measurement of the intensity of the diffuse extragalactic background light in the nearby Universe, a fog of photons that has filled the Universe ever since its formation. Using some of the brightest gamma-ray sources in the southern hemisphere, the study was carried out using measurements performed by the HESS (1) telescope array, located in Namibia and involving CNRS and CEA. The study is complementary to that recently carried out by the Fermi-LAT (2) space observatory. These findings provide new insight into the size of the Universe observable in gamma rays and shed light on the formation of stars and the evolution of galaxies.

They feature on the cover of the 16 January 2013 issue of the journal Astronomy & Astrophysics online.

The light emitted by all the objects in the Universe (stars, galaxies, etc) ever since its birth fills intergalactic space with an 'ocean' of photons known as the 'diffuse extragalactic background light'. The ambient luminosity of our own Galaxy makes it impossible to directly measure this fossil record of the light emitted in the Universe. To get around this problem, astrophysicists make use of gamma rays (3) (whose energy is more than 500 billion times greater than that of visible light), which provide an alternative, indirect method of measuring this light.

A beam of gamma rays emitted by a distant galaxy located several hundred million light years away is attenuated on its way to Earth due to interactions with diffuse light. More specifically, when a gamma-ray photon enters into contact with a diffuse photon it may 'disappear', giving rise to an electron and its antiparticle, a positron, which reduces the intensity of the beam. The thicker the fog of diffuse photons, the greater the attenuation, and the smaller the size of the Universe observable in gamma rays. Finally, absorption by Earth's atmosphere of the remaining radiation gives rise to a shower of subatomic particles, which generates a flash of light that can be detected from the ground by HESS, a mainly French-German telescope array. HESS detects very-high-energy gamma rays (in the region of a thousand billion eV), while those with lower energy are directly detected by the Large Area Telescope (LAT) on the Fermi Gamma-Ray Space Telescope.

In this study, the researchers focused on distinctive galaxies called blazars (4), which are several billion light years away. By using HESS to measure the gamma-ray spectra emitted by relatively close blazars, they evaluated the effect of the interaction of highly energetic gamma rays with the diffuse extragalactic background light within a sphere of a three billion light year radius. The Fermi-LAT collaboration did the same for the more distant Universe, from 5 to 10 billion light years away. These measurements made it possible to estimate, for the first time with a precision of around 20%, the intensity of the starlight contained within the Universe at wavelengths ranging from the near infrared to the ultraviolet, including visible wavelengths.

Read more at Science Daily