Formation of a magnetar 6.5 billion light years away

Researchers used X-ray images like this one to identify the formation of a magnetar. Different colors represent different levels of X-ray energy detected by the Chandra X-Ray Observatory.

A University of Arkansas researcher is part of a team of astronomers who have identified an outburst of X-ray emission from a galaxy approximately 6.5 billion light years away, which is consistent with the merger of two neutron stars to form a magnetar -- a large neutron star with an extremely powerful magnetic field. Based on this observation, the researchers were able to calculate that mergers like this happen roughly 20 times per year in each region of a billion light years cubed.

The research team, which includes Bret Lehmer, assistant professor of physics at the University of Arkansas, analyzed data from the Chandra X-ray Observatory, NASA's flagship X-ray telescope.

The Chandra Deep Field-South survey includes more than 100 X-ray observations of a single area of the sky over a period of more than 16 years to collect information about galaxies throughout the universe. Lehmer, who has worked with the observatory for 15 years, collaborated with colleagues in China, Chile and the Netherlands, and at Pennsylvania State University and the University of Nevada. The study was published in Nature.

A neutron star is a small, very dense star, averaging around 12 miles in diameter. Neutron stars are formed by the collapse of a star massive enough to produce a supernova, but not massive enough to become a black hole. When two neutron stars merge to become a magnetar, the resulting magnetic field is 10 trillion times stronger than a kitchen magnet.

"Neutron stars are mysterious because the matter in them is so extremely dense and unlike anything reproduceable in a laboratory," Lehmer explained. "We do not yet have a good understanding of the physical state of the matter in neutron stars. Mergers involving neutron stars produce lots of unique data that gives us clues about the nature of neutron stars themselves and what happens when they collide."

A previous discovery of two neutron stars merging, which used gravitational waves and gamma rays to make the observation, gave astronomers new insight into these objects. The research team used this new information to look for patterns in Chandra Observatory's X-ray data that were consistent with what they learned about merging neutron stars.

The researchers found an outburst of X-rays in the data from the Chandra Deep Field-South survey. After ruling out other possible sources of the X-rays, they determined the signals came from the process of two neutron stars forming a magnetar.

"A key piece of evidence is how the signal changed over time," said Lehmer. "It had a bright phase that plateaued and then dropped off in a very specific way. That is exactly what you'd expect from a magnetar that is rapidly losing its magnetic field through radiation."

Read more at Science Daily

Hubble peers at cosmic blue bauble

Messier 3: Containing an incredible half-million stars, this 8-billion-year-old cosmic bauble is one of the largest and brightest globular clusters ever discovered.

Globular clusters are inherently beautiful objects, but the subject of this NASA/ESA Hubble Space Telescope image, Messier 3, is commonly acknowledged to be one of the most beautiful of them all.

Containing an incredible half-million stars, this 8-billion-year-old cosmic bauble is one of the largest and brightest globular clusters ever discovered. However, what makes Messier 3 extra special is its unusually large population of variable stars -- stars that fluctuate in brightness over time. New variable stars continue to be discovered in this sparkling stellar nest to this day, but so far we know of 274, the highest number found in any globular cluster by far. At least 170 of these are of a special variety called RR Lyrae variables, which pulse with a period directly related to their intrinsic brightness. If astronomers know how bright a star truly is based on its mass and classification, and they know how bright it appears to be from our viewpoint here on Earth, they can thus work out its distance from us. For this reason, RR Lyrae stars are known as standard candles -- objects of known luminosity whose distance and position can be used to help us understand more about vast celestial distances and the scale of the cosmos.

Messier 3 also contains a relatively high number of so-called blue stragglers, which are shown quite clearly in this Hubble image. These are blue main sequence stars that appear to be young because they are bluer and more luminous than other stars in the cluster. As all stars in globular clusters are believed to have formed together and thus to be roughly the same age, only a difference in mass can give these stars a different color. A red, old star can appear bluer when it acquires more mass, for instance by stripping it from a nearby star. The extra mass changes it into a bluer star, which makes us think it is younger than it really is.

From Science Daily

One-third of cancer patients use complementary and alternative medicine

A stunning one-third of people with a cancer diagnosis use complementary and alternative medicines such as meditation, yoga, acupuncture, herbal medicine, and supplements.

UT Southwestern Medical Center's Dr. Nina Sanford made the discovery that's now drawing renewed attention to habits she said cancer patients must disclose during treatment. Dr. Sanford is an Assistant Professor of Radiation Oncology who specializes in and treats cancers of the gastrointestinal tract.

Herbal supplements were the most common alternative medicine and chiropractic, or osteopathic manipulation, was the second most common, according to Dr. Sanford's analysis of data from the Centers for Disease Control and Prevention's National Health Interview Survey. Her findings were published in the journal JAMA Oncology.

"Younger patients are more likely to use complementary and alternative medicines and women were more likely to, but I would have thought more people would tell their doctors," Dr. Sanford said, referring to the finding that 29 percent of people who use complementary and alternative medicine did not tell their physicians. Many survey respondents said they did not say anything because their doctors did not ask, or they did not think their doctors needed to know.

Dr. Sanford and other cancer specialists agree this is concerning, especially in the case of herbal supplements.

"You don't know what's in them," Dr. Sanford said. "Some of these supplements are kind of a mishmash of different things. Unless we know what's in them, I would recommend patients avoid using them during radiation because there's likely not data on certain supplements, which could interfere with treatment. With radiation specifically, there is concern that very high levels of antioxidants could make radiation less effective."

Dr. David Gerber, a lung cancer specialist and a Professor of Internal Medicine and Population and Data Sciences at UTSW, said physicians need to know if their patients use herbal supplements because they can completely throw off traditional cancer treatments.

"They may interact with the medicines we're giving them, and through that interaction it could alter the level of the medicine in the patient," he said. "If the levels get too high, then toxicities increase, and if the levels get too low, the efficacy would drop."

Nancy Myers wanted to use supplements during her 2015-2017 cancer treatments, but she ran it by her doctors first.

"I would ask the physician, 'Could I?' and everyone said, 'No, we don't know how that interacts with your conventional medicine,' so I respected that," the 47-year-old mother of four said. Only after treatment did she start taking turmeric, omega-3, vitamin D, and vitamin B6.

"I have plenty of friends in this cancer journey who I've met who take supplements. A lady I met recently takes 75 supplements a day. It takes her two hours to package her supplements every week," she said.

Ms. Myers said every person in her cancer support group uses some kind of alternative medicine. In addition to supplements, she practices meditation and yoga with guidance from a smartphone app.

"It's what we can control. We can't control the whole cancer," she said. "It helps because it takes your mind off just thinking about it."

She said she knows of some people with cancer who use only alternative medicine -- and no traditional medical treatments. Dr. Sanford said this is a dangerous approach that could be fatal. The most famous case of this was Apple founder Steve Jobs, who reportedly used special diets, acupuncture, and other alternatives after receiving a diagnosis of pancreatic cancer. He turned to traditional medicine late in his battle with cancer and died in 2011.

While doctors are highly cautious about the use of herbs and other supplements during treatment, they are much more open to meditation and yoga as practices that can help patients cope with the shock of a cancer diagnosis and the stress of chemotherapy, radiation, and surgery.

"We strongly advise patients to stay active and engage in exercise during treatment," Dr. Sanford said. "A common side effect of radiation is fatigue. I let the patients know that the patients who feel the most fatigue are the ones who are the most sedentary and that those who are doing exercise are the ones who frequently have the most energy."

Belindy Sarembock, 53, of Dallas, said she practiced yoga during her treatments for breast cancer. She started the classes with skepticism and quickly became convinced of the benefits.

"I was one who would have laughed at yoga before breast cancer, but now it just helps me so much," she said. "It's just so relaxing, I just feel so good after I leave. It's just so peaceful. For your body, I can't think of anything better than that."

She said she had neuropathy or nerve damage from chemotherapy, and yoga almost immediately took the pain away.

Read more at Science Daily

Earliest life may have arisen in ponds, not oceans

Did life originate in shallow ponds?

Primitive ponds may have provided a suitable environment for brewing up Earth's first life forms, more so than oceans, a new MIT study finds.

Researchers report that shallow bodies of water, on the order of 10 centimeters deep, could have held high concentrations of what many scientists believe to be a key ingredient for jump-starting life on Earth: nitrogen.

In shallow ponds, nitrogen, in the form of nitrogenous oxides, would have had a good chance of accumulating enough to react with other compounds and give rise to the first living organisms. In much deeper oceans, nitrogen would have had a harder time establishing a significant, life-catalyzing presence, the researchers say.

"Our overall message is, if you think the origin of life required fixed nitrogen, as many people do, then it's tough to have the origin of life happen in the ocean," says lead author Sukrit Ranjan, a postdoc in MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS). "It's much easier to have that happen in a pond."

Ranjan and his colleagues have published their results today in the journal Geochemistry, Geophysics, Geosystems. The paper's co-authors are Andrew Babbin, the Doherty Assistant Professor in Ocean Utilization in EAPS, along with Zoe Todd and Dimitar Sasselov of Harvard University, and Paul Rimmer at Cambridge University.

Breaking a bond

If primitive life indeed sprang from a key reaction involving nitrogen, there are two ways in which scientists believe this could have happened. The first hypothesis involves the deep ocean, where nitrogen, in the form of nitrogenous oxides, could have reacted with carbon dioxide bubbling forth from hydrothermal vents, to form life's first molecular building blocks.

The second nitrogen-based hypothesis for the origin of life involves RNA -- ribonucleic acid, a molecule that today helps encode our genetic information. In its primitive form, RNA was likely a free-floating molecule. When in contact with nitrogenous oxides, some scientists believe, RNA could have been chemically induced to form the first molecular chains of life. This process of RNA formation could have occurred in either the oceans or in shallow lakes and ponds.

Nitrogenous oxides were likely deposited in bodies of water, including oceans and ponds, as remnants of the breakdown of nitrogen in Earth's atmosphere. Atmospheric nitrogen consists of two nitrogen molecules, linked via a strong triple bond, that can only be broken by an extremely energetic event -- namely, lightning.

"Lightning is like a really intense bomb going off," Ranjan says. "It produces enough energy that it breaks that triple bond in our atmospheric nitrogen gas, to produce nitrogenous oxides that can then rain down into water bodies."

Scientists believe that there could have been enough lightning crackling through the early atmosphere to produce an abundance of nitrogenous oxides to fuel the origin of life in the ocean. Ranjan says scientists have assumed that this supply of lightning-generated nitrogenous oxides was relatively stable once the compounds entered the oceans.

However, in this new study, he identifies two significant "sinks," or effects that could have destroyed a significant portion of nitrogenous oxides, particularly in the oceans. He and his colleagues looked through the scientific literature and found that nitrogenous oxides in water can be broken down via interactions with the sun's ultraviolet light, and also with dissolved iron sloughed off from primitive oceanic rocks.

Ranjan says both ultraviolet light and dissolved iron could have destroyed a significant portion of nitrogenous oxides in the ocean, sending the compounds back into the atmosphere as gaseous nitrogen.

"We showed that if you include these two new sinks that people hadn't thought about before, that suppresses the concentrations of nitrogenous oxides in the ocean by a factor of 1,000, relative to what people calculated before," Ranjan says.

"Building a cathedral"

In the ocean, ultraviolet light and dissolved iron would have made nitrogenous oxides far less available for synthesizing living organisms. In shallow ponds, however, life would have had a better chance to take hold. That's mainly because ponds have much less volume over which compounds can be diluted. As a result, nitrogenous oxides would have built up to much higher concentrations in ponds. Any "sinks," such as UV light and dissolved iron, would have had less of an effect on the compound's overall concentrations.

Ranjan says the more shallow the pond, the greater the chance nitrogenous oxides would have had to interact with other molecules, and particularly RNA, to catalyze the first living organisms.

"These ponds could have been from 10 to 100 centimeters deep, with a surface area of tens of square meters or larger," Ranjan says. "They would have been similar to Don Juan Pond in Antarctica today, which has a summer seasonal depth of about 10 centimeters."

That may not seem like a significant body of water, but he says that's precisely the point: In environments any deeper or larger, nitrogenous oxides would simply have been too diluted, precluding any participation in origin-of-life chemistry. Other groups have estimated that, around 3.9 billion years ago, just before the first signs of life appeared on Earth, there may have been about 500 square kilometers of shallow ponds and lakes worldwide.

"That's utterly tiny, compared to the amount of lake area we have today," Ranjan says. "However, relative to the amount of surface area prebiotic chemists postulate is required to get life started, it's quite adequate."

The debate over whether life originated in ponds versus oceans is not quite resolved, but Ranjan says the new study provides one convincing piece of evidence for the former.

Read more at Science Daily

World's fastest hydrogen sensor could pave the way for clean hydrogen energy

Fast and accurate sensors will be crucial in a sustainable society where hydrogen is an energy carrier. Hydrogen gas is produced by water that is split with the help of electricity from wind power or solar energy. The sensors are needed both when the hydrogen is produced and when it is used, for example in cars powered by a fuel cell. In order to avoid the formation of flammable and explosive gas when hydrogen is mixed with air, the hydrogen sensors need to be able to quickly detect leaks.

Hydrogen is a clean and renewable energy carrier that can power vehicles, with water as the only emission. Unfortunately, hydrogen gas is highly flammable when mixed with air, so very efficient and effective sensors are needed. Now, researchers from Chalmers University of Technology, Sweden, present the first hydrogen sensors ever to meet the future performance targets for use in hydrogen powered vehicles.

The researchers' ground-breaking results were recently published in the scientific journal Nature Materials. The discovery is an optical nanosensor encapsulated in a plastic material. The sensor works based on an optical phenomenon -- a plasmon -- which occurs when metal nanoparticles are illuminated and capture visible light. The sensor simply changes colour when the amount of hydrogen in the environment changes.

The plastic around the tiny sensor is not just for protection, but functions as a key component. It increases the sensor's response time by accelerating the uptake of the hydrogen gas molecules into the metal particles where they can be detected. At the same time, the plastic acts as an effective barrier to the environment, preventing any other molecules from entering and deactivating the sensor. The sensor can therefore work both highly efficiently and undisturbed, enabling it to meet the rigorous demands of the automotive industry -- to be capable of detecting 0.1 percent hydrogen in the air in less than a second.

"We have not only developed the world's fastest hydrogen sensor, but also a sensor that is stable over time and does not deactivate. Unlike today's hydrogen sensors, our solution does not need to be recalibrated as often, as it is protected by the plastic," says Ferry Nugroho, a researcher at the Department of Physics at Chalmers.

It was during his time as a PhD student that Ferry Nugroho and his supervisor Christoph Langhammer realised that they were on to something big. After reading a scientific article stating that no one had yet succeeded in achieving the strict response time requirements imposed on hydrogen sensors for future hydrogen cars, they tested their own sensor. They realised that they were only one second from the target -- without even trying to optimise it. The plastic, originally intended primarily as a barrier, did the job better than they could have imagined, by also making the sensor faster. The discovery led to an intense period of experimental and theoretical work.

"In that situation, there was no stopping us. We wanted to find the ultimate combination of nanoparticles and plastic, understand how they worked together and what made it so fast. Our hard work yielded results. Within just a few months, we achieved the required response time as well as the basic theoretical understanding of what facilitates it," says Ferry Nugroho.

Detecting hydrogen is challenging in many ways. The gas is invisible and odourless, but volatile and extremely flammable. It requires only four percent hydrogen in the air to produce oxyhydrogen gas, sometimes known as knallgas, which ignites at the smallest spark. In order for hydrogen cars and the associated infrastructure of the future to be sufficiently safe, it must therefore be possible to detect extremely small amounts of hydrogen in the air. The sensors need to be quick enough that leaks can be rapidly detected before a fire occurs.

"It feels great to be presenting a sensor that can hopefully be a part of a major breakthrough for hydrogen-powered vehicles. The interest we see in the fuel cell industry is inspiring," says Christoph Langhammer, Professor at Chalmers Department of Physics.

Although the aim is primarily to use hydrogen as an energy carrier, the sensor also presents other possibilities. Highly efficient hydrogen sensors are needed in the electricity network industry, the chemical and nuclear power industry, and can also help improve medical diagnostics.

"The amount of hydrogen gas in our breath can provide answers to, for example, inflammations and food intolerances. We hope that our results can be used on a broad front. This is so much more than a scientific publication," says Christoph Langhammer.

Read more at Science Daily

Ice Ages occur when tropical islands and continents collide

Some 445 million years ago, the Eastern US (extreme left) sat in the tropics, where an island arc-continental collision created the Appalachian Mountains. That collision uplifted rocks that absorbed carbon dioxide, resulting in an ice age that lasted millions of years.

University of California scientists think they know why Earth's generally warm and balmy climate over the past billion years has occasionally been interrupted by cold snaps that enshroud the poles with ice and occasionally turn the planet into a snowball.

The key trigger, they say, is mountain formation in the tropics as continental land masses collide with volcanic island arcs, such as the Aleutian Islands chain in Alaska.

Earth's climate is, to a large degree, driven by the amount of carbon dioxide in the atmosphere, which traps heat and warms the planet. While fossil fuel burning since the Industrial Revolution has driven CO2 levels to heights not seen in 3 million years, CO2 levels have been even higher in Earth's past, coinciding with warm periods when no major ice sheets existed.

In fact, Earth's default climate seems to be warm and balmy. Periods with no glaciers dominated for three-quarters of the past 1 billion years.

Yet, half a dozen ice ages chilled Earth during that time, two of them severe enough to turn the planet into a Snowball Earth with ice covering much of the surface. What caused these frigid interludes?

In a study appearing in this week's edition of the journal Science, the team concludes that when volcanic arcs collide with continents in the tropics -- an inevitable consequence of the planet's constantly moving tectonic plates -- they trigger global cooling, resulting in a glacial climate with extensive ice caps.

Such a collision is going on now as parts of the Indonesian archipelago are pushed upward into mountains on the northern margin of Australia. The result is that there are mountains containing rocks known as ophiolites that have a high capacity to remove carbon from the atmosphere. Over geologic time periods, there is a balancing act between the CO2 emitted from volcanoes and CO2 consumed through chemical reactions with rocks. Rocks with abundant calcium and magnesium, such as ophiolites, are the most efficient at consuming CO2. When these elements are liberated from rocks, they combine with CO2 and make their way to the ocean, where they form limestone, locking CO2 into rock, where it remains for millions of years.

"Earth has a long-running carbon sequestration program," said UC Berkeley's Nicholas Swanson-Hysell, an assistant professor of earth and planetary science who designed the study with Francis Macdonald, a professor in the Department of Earth Science at UC Santa Barbara. "We know that these processes keep Earth's climate in balance, but determining what causes shifts between non-glacial and glacial climates on million-year timescales is a long-standing puzzle."

Unfortunately for Earth's future, the geologic processes that consume CO2 are slow and unable to contend with the massive CO2 emissions that result from the burning of oil, coal and natural gas. Over millennia, Earth's natural carbon sequestration program will restore balance, Swanson-Hysell said, but this will be a long wait for modern civilization, which has been so successful in Earth's current, cooler climate.

The Appalachians came with a major freeze

In 2017, Swanson-Hysell and Macdonald proposed that a major ice age 445 million years ago was triggered by a collision similar to that occurring today in Indonesia. That collision took place during the first phase of Appalachian mountain-building, when the present-day eastern U.S. was located in the tropics. In the warm and wet tropics, the weathering reactions that ultimately sequester carbon are even more efficient, which resulted in less CO2 in the atmosphere and a cooler planet for millions of years. The UC researchers' work built on a similar proposal by Macdonald and Oliver Jagoutz of MIT that such processes were important for cooling over the past 90 million years.

The new study strengthens the link between such tropical collisions and global climate and was conducted by Swanson-Hysell, Macdonald and Jagoutz, along with UC Berkeley graduate student Yuem Park and Lorraine Lisiecki of UC Santa Barbara.

In the current research, the Berkeley/Santa Barbara/MIT team used state-of-the-art models of Earth's paleogeography to reconstruct the position of such mountain-building events over the last half-billion years. They found that all three major ice ages over this time had been preceded by volcanic arc-continent collisions in the tropics, and that no collisions outside the tropics triggered an ice age.

"While we thought this process was important, the relationship between such environments in the tropics and glacial climate was clearer than we expected," said Swanson-Hysell.

The team's theory also explains why ice ages come to an end. As such collisions grind to a halt and less rock is exposed, or as the rocks drift out of the tropical rain belt, carbon sequestration becomes less efficient, CO2 levels rise as volcanic outgassing continues and Earth once again warms into a non-glacial climate.

Read more at Science Daily

Yukon warmest it has been in 13,600 years

A peat plateau on the Dempster Highway with standing pools with bright green algal mats and a spectacular backdrop featuring the boreal forest.

A study from U of T Mississauga uses new research techniques to reveal alarming information about climate change in Canada's north. A study published in Nature Communications confirms that recent climate warming in the central Yukon region has surpassed the warmest temperatures experienced in the previous 13,600 years, a finding that could have important implications in the context of current global warming trends.

Paleoclimatologist and lead author Trevor Porter studies climate indicators such as water isotopes, tree rings and plant waxes for signs of climate patterns in the Holocene, a period of time that spans the past 11,700 years. In glaciated regions, paleoclimate research often relies on water isotopes measured from ice core samples taken from glaciers, but in the central Yukon where glaciers have long since receded, researchers must rely on other indicators such as plant pollen and small winged insects known as midges preserved in layers of lake sediment. Pollen and midges act as proxies for ancient temperatures but sometimes offer conflicting information.

In a first for the field, Porter and his colleagues used radiocarbon dating and water isotopes preserved in permafrost beneath a central Yukon peatland to reconstruct summer temperatures over the last 13,600 years. Each summer, new peat moss accumulates at the surface, and the top of permafrost, which lies at a constant depth of 58 cm below ground, adjusts to the new surface. It simultaneously preserves precipitation that filtered through the ground and froze at the top of permafrost during previous summers. "Each centimeter of permafrost holds roughly 20 to 30 years of precipitation, which settles into well-blended layers of information," Porter says. "Water isotope records from ice cores are one of the most valued climate proxies but can only be developed in glaciated regions. This project demonstrates that we can develop ice core-like records in non-glaciated permafrost regions. This type of permafrost offers a unique archive for water isotopes that could be used to advance our understanding of Holocene climate change in other northern regions, which would be a major benefit to the climate science community."

The results of the permafrost analysis confirms information provided by previous midge studies, and shows that early Holocene summers in the central Yukon were mostly warmer than the typical Holocene summer. The study further concludes that industrial-era warming has led to current summer temperatures that are unprecedented in the Holocene context, and exceeds all previous maximum temperatures by nearly 2°C.

"When compared with climate reconstructions from other northern areas, our data confirm that this region has been warming at an exceptional rate," Porter says. "We know, based on recent historical climate data, that this area has warmed up more than other high-latitude regions. This

region has experienced warming of just over 2ºC over the past century, which is above the global average and above the average of the Arctic region in general."

"Summer warming has major implications for permafrost landscapes. When temperatures go up, ice-rich permafrost can thaw, become unstable, and previously frozen soil carbon can be released to the atmosphere as carbon dioxide by microbes," Porter says, noting that the region experienced a deep thaw of permafrost roughly 9,000 years ago. "Deep permafrost thaw events did occur in this region in the early Holocene, a time we now know was relatively warm compared to the Holocene average but not nearly as warm as today. This implies that ice-rich permafrost in this region is currently vulnerable to similar thaw events."

"We're seeing the evidence right now that climate warming is destabilizing permafrost in northern Canada and releasing greenhouse gases," he says "This is potentially the new normal and, if it accelerates in the near future, it threatens to further amplify global climate change."

Read more at Science Daily

Archaeologists identify first prehistoric figurative cave art in Balkans

Digital tracing of Bison featured in rock art.

An international team, led by an archaeologist from the University of Southampton and the University of Bordeaux, has revealed the first example of Palaeolithic figurative cave art found in the Balkan Peninsula.

Dr Aitor Ruiz-Redondo worked with researchers from the universities of Cantabria (Spain), Newfoundland (Canada), Zagreb (Croatia) and the Archaeological Museum of Istria (Croatia) to study the paintings, which could be up to 34,000 years old.

The cave art was first discovered in 2010 in Romualdova Pe?ina ('Romuald's cave') at Istria in Croatia, when Darko Komšo, Director of the Archaeological Museum of Istria, noticed the existence of the remains of a red colour in a deep part of the cave.

Following his discovery, the team led by Dr Ruiz-Redondo and funded by the French State and the Archaeological Museum of Istria, with the support of Natura Histrica, undertook a detailed analysis of the paintings and their archaeological context.

This led to the identification of several figurative paintings, including a bison, an ibex and two possible anthropomorphic figures, confirming the Palaeolithic age of the artworks. Furthermore, an excavation made in the ground below these paintings led to the discovery of a number of Palaeolithic age remains; a flint tool, an ochre crayon and several fragments of charcoal.

Radiocarbon dating of these objects show an estimated age of around 17,000 years and other indirect data suggest the paintings date to an even earlier period -- at around 34,000-31,000 years ago. Further research will be conducted in order to establish the precise age of the rock art.

Findings are published in the journal Antiquity.

This discovery expands the so far sparse register of Palaeolithic art in south east Europe. It makes Romualdova Pe?ina the first site where figurative Palaeolithic rock art has been discovered in this area. Together with Badanj in Bosnia and Herzegovina, the two are the only examples of rock art from the Palaeolithic period in the Balkans.

Dr Aitor Ruiz-Redondo, a British Academy-funded Newton International Fellow at the University of Southampton and postdoctoral researcher at the University of Bordeaux, said: "The importance of this finding is remarkable and sheds a new light on the understanding of Palaeolithic art in the territory of Croatia and the Balkan Peninsula, as well as its relationship with simultaneous phenomena throughout Europe."

Read more at Science Daily

Unusual phenomenon in clouds triggers lightning flash

The lightning seen here starts out deep inside the cloud where scientists continue to study its first moments. In their study, UNH researchers observed a possible new way that lightning forms called "fast negative breakdown."

In a first-of-its-kind observation, researchers from the University of New Hampshire Space Science Center have documented a unique event that occurs in clouds before a lightning flash happens. Their observation, called "fast negative breakdown," documents a new possible way for lightning to form and is the opposite of the current scientific view of how air carries electricity in thunderstorms.

"This is the first time fast negative breakdown has ever been observed, so it's very exciting," said Ningyu Liu, professor of physics. "Despite over 250 years of research, how lightning begins is still a mystery. The process was totally unexpected and gives us more insight into how lightning starts and spreads."

Their finding, published in the journal Nature Communications, is another step toward answering the question of how lightning begins. Recently, the problem of lightning initiation seemed to be solved with the discovery of "fast positive breakdown" of air, which matched the theory long held by lightning researchers. Fast positive breakdown involves the downward development of a pathway in the cloud, moving from the positive charge at the top of the cloud to the negative charge in the middle of the cloud. The pathway forms at one-fifth the speed of light and can trigger lightning. However, the newly reported observation of fast negative breakdown shows that an upward pathway -- going in the opposite direction and just as fast -- can be created in a thundercloud, indicating there's another way to start electricity in the air. Ultimately, this provides scientists with a new view of what's possible inside a storm cloud.

"These findings indicate that lightning creation within a cloud might be more bidirectional than we originally thought," said Julia Tilles, a doctoral candidate in the UNH Space Science Center.

In collaboration with a lightning research team from New Mexico Institute of Mining and Technology, the researchers documented fast negative breakdown in a Florida lightning storm at Kennedy Space Center using radio waves originating deep inside the storm clouds. An array of ground-based antennas picked up the radio waves, which then allowed researchers to create a highly detailed image of the radio sources and identify this unusual phenomenon.

Researchers continue to develop images from the data and hope to learn more about how often fast negative breakdown events occur and what fraction of them can initiate an actual lightning flash.

From Science Daily

Ancient 'Texas Serengeti' had elephant-like animals, rhinos, alligators and more

Fossilized skull parts from ancient elephant relatives in the collections of the Jackson School Museum of Earth History. The skull of a shovel-jawed gomphothere (pictured on bottom) collected by Great Depression-era fossil hunters is still wrapped in its field jacket.

During the Great Depression, some unemployed Texans were put to work as fossil hunters. The workers retrieved tens of thousands of specimens that have been studied in small bits and pieces while stored in the state collections of The University of Texas at Austin for the past 80 years.

Now, decades after they were first collected, a UT researcher has studied and identified an extensive collection of fossils from dig sites near Beeville, Texas, and found that the fauna make up a veritable "Texas Serengeti" -- with specimens including elephant-like animals, rhinos, alligators, antelopes, camels, 12 types of horses and several species of carnivores. In total, the fossil trove contains nearly 4,000 specimens representing 50 animal species, all of which roamed the Texas Gulf Coast 11 million to 12 million years ago.

A paper describing these fossils, their collection history and geologic setting was published April 11 in the journal Palaeontologia Electronica.

"It's the most representative collection of life from this time period of Earth history along the Texas Coastal Plain," said Steven May, the research associate at the UT Jackson School of Geosciences who studied the fossils and authored the paper.

In addition to shedding light on the inhabitants of an ancient Texas ecosystem, the collection is also valuable because of its fossil firsts. They include a new genus of gomphothere, an extinct relative of elephants with a shovel-like lower jaw, and the oldest fossils of the American alligator and an extinct relative of modern dogs.

The fossils came into the university's collection as part of the State-Wide Paleontologic-Mineralogic Survey that was funded by the Works Progress Administration (WPA), a federal agency that provided work to millions of Americans during the Great Depression. From 1939 to 1941, the agency partnered with the UT Bureau of Economic Geology, which supervised the work and organized field units for collecting fossils and minerals across the state.

Despite lasting only three years, the survey found and excavated thousands of fossils from across Texas including four dig sites in Bee and Live Oak counties, with the majority of their finds housed in what is now the Texas Vertebrate Paleontology Collections at the Jackson School Museum of Earth History. Over the years, a number of scientific papers have been published on select groups of WPA specimens. But May's paper is the first to study the entire fauna.

This extensive collection of fossils is helping to fill in gaps about the state's ancient environment, said Matthew Brown, the director of the museum's vertebrate paleontology collections.

The emphasis on big mammals is due in large part to the collection practices of the fossil hunters, most of whom were not formally trained in paleontology. Large tusks, teeth and skulls were easier to spot -- and more exciting to find -- than bones left by small species.

"They collected the big, obvious stuff," May said. "But that doesn't fully represent the incredible diversity of the Miocene environment along the Texas Coastal Plain."

In order to account for gaps in the collection, May tracked down the original dig sites so he could screen for tiny fossils such as rodent teeth. One of the sites was on a ranch near Beeville owned by John Blackburn. Using aerial photography and notes from the WPA program stored in the university's archives, May and the research team were able to track down the exact spot of an original dig site.

"We're thrilled to be a part of something that was started in 1939," Blackburn said. "It's been a privilege to work with UT and the team involved, and we hope that the project can help bring additional research opportunities."

Scores of WPA-era fossils in the UT collections are still secured in plaster field jackets, waiting to be unpacked for future research projects. Lab managers Deborah Wagner and Kenneth Bader are supervising their preparation, which includes teaching UT students fossil prep skills so they can pick up where the WPA workers left off.

Wagner said that the advantage of unpacking fossils decades later is that they are able to apply modern research techniques that scientists from past eras wouldn't have dreamed possible.

"We are able to preserve more detailed anatomy and answer questions that require higher resolution data," she said.

Read more at Science Daily