Oldest stone tool ever found in Turkey discovered

Scientists have discovered the oldest recorded stone tool ever to be found in Turkey, revealing that humans passed through the gateway from Asia to Europe much earlier than previously thought, approximately 1.2 million years ago.

According to research published in the journalQuaternary Science Reviews, the chance find of a humanly-worked quartzite flake, in ancient deposits of the river Gediz, in western Turkey, provides a major new insight into when and how early humans dispersed out of Africa and Asia.

Researchers from Royal Holloway, University of London, together with an international team from the UK, Turkey and the Netherlands, used high-precision equipment to date the deposits of the ancient river meander, giving the first accurate timeframe for when humans occupied the area.

Professor Danielle Schreve, from the Department of Geography at Royal Holloway, said: "This discovery is critical for establishing the timing and route of early human dispersal into Europe. Our research suggests that the flake is the earliest securely-dated artefact from Turkey ever recorded and was dropped on the floodplain by an early hominin well over a million years ago."

The researchers used high-precision radioisotopic dating and palaeomagnetic measurements from lava flows, which both pre-date and post-date the meander, to establish that early humans were present in the area between approximately 1.24 million and 1.17 million years ago. Previously, the oldest hominin fossils in western Turkey were recovered in 2007 at Koçabas, but the dating of these and other stone tool finds were uncertain.

"The flake was an incredibly exciting find," Professor Schreve said. "I had been studying the sediments in the meander bend and my eye was drawn to a pinkish stone on the surface. When I turned it over for a better look, the features of a humanly-struck artefact were immediately apparent.

"By working together with geologists and dating specialists, we have been able to put a secure chronology to this find and shed new light on the behaviour of our most distant ancestors."

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The above story is based on materials provided by University of Royal Holloway London.

Trial confirms Ebola vaccine candidate safe, equally immunogenic in Africa

Two experimental DNA vaccines to prevent Ebola virus and the closely related Marburg virus are safe, and generated a similar immune response in healthy Ugandan adults as reported in healthy US adults earlier this year. The findings, from the first trial of filovirus vaccines in Africa, are published in The Lancet.

"This is the first study to show comparable safety and immune response of an experimental Ebola vaccine in an African population," says lead author Dr Julie Ledgerwood from the National Institutes of Allergy and Infectious Diseases (NIAID) at the National Institutes of Health, USA. "This is particularly encouraging because those at greatest risk of Ebola live primarily in Africa, and diminished vaccine protection in African populations has been seen for other diseases."

Scientists from the NIAID developed the DNA vaccines that code for Ebola virus proteins from the Zaire and Sudan strains and the Marburg virus protein. The vaccines contain the construction plans for the proteins on the outer surface of the virus. Immune responses against these proteins have shown to be highly protective in non-human primate models.

In this phase 1 trial, the Makerere University Walter Reed Program enrolled 108 healthy adults aged between 18 and 50 from Kampala, Uganda between November, 2009 and April, 2010. Each volunteer was randomly assigned to receive an intramuscular injection of either the Ebola vaccine (30 volunteers), Marburg vaccine (30), both vaccines (30), or placebo (18) at the start of the study, and again 4 weeks and 8 weeks later.

The vaccines given separately and together were safe and stimulated an immune response in the form of neutralising antibodies and T-cells against the virus proteins. Four weeks after the third injection, just over half of the volunteers (57%; 17 of 30) had an antibody response to the Ebola Zaire protein as did 14 of 30 participants who received both the Ebola and Marburg vaccines. However, the antibodies were not long-lasting and returned to undetectable levels within 11 months of vaccination.

Both DNA vaccines were well tolerated in Ugandan adults with similar numbers of local and systemic reactions reported in all groups. Only one serious adverse event (neutropenia; low white blood cell count) was reported in a Marburg vaccine only recipient, but was not thought to be vaccine related.

According to Dr Ledgerwood, "These findings have already formed the basis of a more potent vaccine, delivered using a harmless chimpanzee cold virus, which is undergoing trials in the USA, UK, Mali, and Uganda in response to the ongoing Ebola virus outbreak."

Writing in a linked Comment, Dr Saranya Sridhar from the Jenner Institute at the University of Oxford in the UK says, "[This] study deserves to be the focal point around which the broader question of vaccine development, particularly for Africa, must be addressed. With the uncharitable benefit of hindsight in view of the evolving 2014 Ebola outbreak, we must ask ourselves whether a filovirus vaccine should have been in more advanced clinical development. The international response to the present Ebola outbreak is an exemplar of the speed and purpose with which clinical vaccine development can progress and has set the benchmark against which future vaccine development must be judged. This study is the first step on the aspirational road towards the deployment of filovirus vaccines in Africa and must serve to shake the metaphorical cobwebs that can stall our advance towards this destination."

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The above story is based on materials provided by The Lancet.

New species found in the deepest trench on Earth

Whitman biology professor Paul Yancey and students Anna Downing '16 and Chloe Weinstock '17 have returned from the first detailed study of the Mariana Trench aboard Schmidt Ocean Institute's research vessel Falkor.

The Mariana Trench -- located in the Western Pacific near Guam -- has been the focus of high-profile voyages to conquer Challenger Deep, the deepest place on Earth. This recent expedition to the Trench onboard Research Vessel Falkor targeted multiple depths and found active thriving communities of animals. The expedition set many new records, including the deepest rock samples ever collected and the discovery of new fish species at the greatest depths ever recorded.

This Hadal Ecosystem Studies (HADES) expedition departed from other deep-sea trench research by sampling a broad spectrum of environments using five deep-sea vehicle systems called landers at specifically targeted depths from 5000 to 10,600 meters (16,404 to 34,777 feet). Rather than solely focusing on the deepest point in the Mariana Trench, a concerted effort was made to gain a better understanding of the interplay between life and geologic processes across the entire hadal zone.

Dr. Jeff Drazen, co-chief scientist, expressed the drive behind this method: "Many studies have rushed to the bottom of the trench, but from an ecological view that is very limiting. It's like trying to understand a mountain ecosystem by only looking at its summit."

The findings from this research will help to answer important questions about Earth's largest and least explored habitat, including what organisms live there and how life adapts to these extreme conditions, as well as, how much carbon in the atmosphere reaches the deep sea and if it affects the food chains there.

New species were discovered on this expedition that will provide insight into the physiological adaptations of animals to this high-pressure environment. This research is being conducted in the lab of Whitman College's Professor of Biology Paul Yancey. In the past, Yancey and his students, working on animals from moderate depths, discovered certain organic molecules that protect the cells of deep-sea animals from the effects of high pressure, which distorts proteins such as enzymes. These kinds of protective molecules are also being tested to treat human diseases that are caused by malformed proteins, such as cystic fibrosis. Additionally, his work on protective molecules in fishes predicted that fish would not be able to live below about 8,200 meters (27,060 feet). Prior to this expedition, the deepest documented fish was from 7,700 meters (25,410 feet).

"In this new research, my students Chloe Weinstock '17 and Anna Downing '16 and I want to see if such molecules help animals at the greatest ocean depths -- about 35,000 feet in the Mariana Trench," said Yancey. "In a preliminary analysis of amphipods we got from the Kermadec Trench (33,000 feet deep) last spring, Gemma Wallace '14 and I discovered high levels of a potentially protective molecule, scyllo-inositol, that is coincidentally being tested by medical researchers to treat malformed proteins thought to cause Alzheimer's Disease."

The expedition also broke several records for the deepest living fish either caught or seen on video. Setting the record at 8,143 meters, (26,872 feet) was a completely unknown variety of snailfish, which stunned scientists when it was filmed several times during seafloor experiments. The white translucent fish had broad wing-like fins and an eel-like tail, and slowly glided over the bottom.

Additionally, the deepest rock samples ever obtained from the inner slope of the Trench represent some of the earliest volcanic eruptions of the Mariana Island arc. These rocks can provide significant information on the geology of the trench system.

Wendy Schmidt, co-founder and vice president of Schmidt Ocean Institute, was delighted with the success of the expedition. "Rarely do we get a full perspective of the ocean's unique deep environments. The questions that the scientists will be able to answer following this cruise will pave the way for a better understanding of the deep sea, which is not exempt from human impact."

Falkor is now back in the Mariana Trench conducting research that will complement the previous expedition and continue to explore this unique environment. For the latest findings and updates, check the Schmidt Ocean Institute website at www.schmidtocean.org. Additional information about the HADES program can be found at www.whoi.edu/hades.

NASA Goddard Instrument Makes First Detection of Organic Matter on Mars

The team responsible for the Sample Analysis at Mars (SAM) instrument suite on NASA's Curiosity rover has made the first definitive detection of organic molecules at Mars. Organic molecules are the building blocks of all known forms of terrestrial life, and consist of a wide variety of molecules made primarily of carbon, hydrogen, and oxygen atoms. However, organic molecules can also be made by chemical reactions that don't involve life, and there is not enough evidence to tell if the matter found by the team came from ancient Martian life or from a non-biological process. Examples of non-biological sources include chemical reactions in water at ancient Martian hot springs or delivery of organic material to Mars by interplanetary dust or fragments of asteroids and comets.

The surface of Mars is currently inhospitable to life as we know it, but there is evidence that the Red Planet once had a climate that could have supported life billions of years ago. For example, features resembling dry riverbeds and minerals that only form in the presence of liquid water have been discovered on the Martian surface. The Curiosity rover with its suite of instruments including SAM was sent to Mars in 2011 to discover more about the ancient habitable Martian environment by examining clues in the chemistry of rocks and the atmosphere.

The organic molecules found by the team were in a drilled sample of the Sheepbed mudstone in Gale crater, the landing site for the Curiosity rover. Scientists think the crater was once the site of a lake billions of years ago, and rocks like mudstone formed from sediment in the lake. Moreover, this mudstone was found to contain 20 percent smectite clays. On Earth, such clays are known to provide high surface area and optimal interlayer sites for the concentration and preservation of organic compounds when rapidly deposited under reducing chemical conditions.

While the team can't conclude that there was life at Gale crater, the discovery shows that the ancient environment offered a supply of reduced organic molecules for use as building blocks for life and an energy source for life. Curiosity's earlier analysis of this same mudstone revealed that the environment offered water and chemical elements essential for life and a different chemical energy source.

"We think life began on Earth around 3.8 billion years ago, and our result shows that places on Mars had the same conditions at that time -- liquid water, a warm environment, and organic matter," said Caroline Freissinet of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "So if life emerged on Earth in these conditions, why not on Mars as well?" Freissinet is lead author of a paper on this research submitted to the Journal of Geophysical Research-Planets.

The organic molecules found by the team also have chlorine atoms, and include chlorobenzene and several dichloroalkanes, such as dichloroethane, dichloropropane and dichlorobutane. Chlorobenzene is the most abundant with concentrations between 150 and 300 parts-per-billion. Chlorobenzene is not a naturally occurring compound on Earth. It is used in the manufacturing process for pesticides (insecticide DDT), herbicides, adhesives, paints and rubber. Dichloropropane is used as an industrial solvent to make paint strippers, varnishes and furniture finish removers, and is classified as a carcinogen.

It's possible that these chlorine-containing organic molecules were present as such in the mudstone. However, according to the team, it's more likely that a different suite of precursor organic molecules was in the mudstone, and that the chlorinated organics formed from reactions inside the SAM instrument as the sample was heated for analysis. Perchlorates (a chlorine atom bound to four oxygen atoms) are abundant on the surface of Mars. It's possible that as the sample was heated, chlorine from perchlorate combined with fragments from precursor organic molecules in the mudstone to produce the chlorinated organic molecules detected by SAM.

In 1976, the Gas Chromatograph Mass Spectrometer instrument on NASA's Viking landers detected two simple chlorinated hydrocarbons after heating Martian soils for analysis (chloromethane and dichloromethane). However they were not able to rule out that the compounds were derived from the instrument itself, according to the team. While sources within the SAM instrument also produce chlorinated hydrocarbons, they don't make more than 22 parts-per-billion of chlorobenzene, far below the amounts detected in the mudstone sample, giving the team confidence that organic molecules really are present on Mars.

The SAM instrument suite was built at NASA Goddard with significant elements provided by industry, university, and national and international NASA partners.

For this analysis, the Curiosity rover sample acquisition system drilled into a mudstone and filtered fine particles of it through a sieve, then delivered a portion of the sample to the SAM laboratory. SAM detected the compounds using its Evolved Gas Analysis (EGA) mode by heating the sample up to about 875 degrees Celsius (around 1,600 degrees Fahrenheit) and then monitoring the volatiles released from the sample using a quadrupole mass spectrometer, which identifies molecules by their mass using electric fields. SAM also detected and identified the compounds using its Gas Chromatograph Mass Spectrometer (GCMS) mode. In this mode, volatiles are separated by the amount of time they take to travel through a narrow tube (gas chromatography -- certain molecules interact with the sides of the tube more readily and thus travel more slowly) and then identified by their signature mass fragments in the mass spectrometer.

The first evidence for elevated levels of chlorobenzene and dichloroalkanes released from the mudstone was obtained on Curiosity Sol 290 (May 30, 2013) with the third analysis of the Cumberland sample at Sheepbed. The team spent over a year carefully analyzing the result, including conducting laboratory experiments with instruments and methods similar to SAM, to be sure that SAM could not be producing the amount of organic material detected.

"The search for organics on Mars has been extremely challenging for the team," said Daniel Glavin of NASA Goddard, a co-author on the paper. "First, we need to identify environments in Gale crater that would have enabled the concentration of organics in sediments. Then they need to survive the conversion of sediment to rock, where pore fluids and dissolved substances may oxidize and destroy organics. Organics can then be destroyed during exposure of rocks at the surface of Mars to intense ionizing radiation and oxidants. Finally, to identify any organic compounds that have survived, we have to deal with oxychlorine compounds and possibly other strong oxidants in the sample which will react with and combust organic compounds to carbon dioxide and chlorinated hydrocarbons when the samples are heated by SAM."

As part of Curiosity's plan for exploration, an important strategic goal was to sample rocks that represent different combinations of the variables thought to control organic preservation. "The SAM and Mars Science Laboratory teams have worked very hard to achieve this result," said John Grotzinger of Caltech, Mars Science Laboratory's Project Scientist. "Only by drilling additional rock samples in different locations, and representing different geologic histories were we able to tease out this result. At the time we first saw evidence of these organic molecules in the Cumberland sample it was uncertain if they were derived from Mars, however, additional drilling has not produced the same compounds as might be predicted for contamination, indicating that the carbon in the detected organic molecules is very likely of Martian origin."

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Earth's most abundant mineral finally has a name

An ancient meteorite and high-energy X-rays have helped scientists conclude a half century of effort to find, identify and characterize a mineral that makes up 38 percent of the Earth.

And in doing so, a team of scientists led by Oliver Tschauner, a mineralogist at the University of Las Vegas, clarified the definition of the Earth's most abundant mineral -- a high-density form of magnesium iron silicate, now called Bridgmanite -- and defined estimated constraint ranges for its formation. Their research was performed at the Advanced Photon Source, a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National Laboratory.

The mineral was named after 1964 Nobel laureate and pioneer of high-pressure research Percy Bridgman. The naming does more than fix a vexing gap in scientific lingo; it also will aid our understanding of the deep Earth.

To determine the makeup of the inner layers of the Earth, scientists need to test materials under extreme pressure and temperatures. For decades, scientists have believed a dense perovskite structure makes up 38 percent of the Earth's volume, and that the chemical and physical properties of Bridgmanite have a large influence on how elements and heat flow through the Earth's mantle. But since the mineral failed to survive the trip to the surface, no one has been able to test and prove its existence -- a requirement for getting a name by the International Mineralogical Association.

Shock-compression that occurs in collisions of asteroid bodies in the solar system create the same hostile conditions of the deep Earth -- roughly 2,100 degrees Celsius (3,800 degrees Farenheit) and pressures of about 240,000 times greater than sea-level air pressure. The shock occurs fast enough to inhibit the Bridgmanite breakdown that takes place when it comes under lower pressure, such as the Earth's surface. Part of the debris from these collisions falls on Earth as meteorites, with the Bridgmanite "frozen" within a shock-melt vein. Previous tests on meteorites using transmission electron microscopy caused radiation damage to the samples and incomplete results.

So the team decided to try a new tactic: non-destructive micro-focused X-rays for diffraction analysis and novel fast-readout area-detector techniques. Tschauner and his colleagues from Caltech and the GeoSoilEnviroCARS, a University of Chicago-operated X-ray beamline at the APS at Argonne National Laboratory, took advantage of the X-rays' high energy, which gives them the ability to penetrate the meteorite, and their intense brilliance, which leaves little of the radiation behind to cause damage.

The team examined a section of the highly shocked L-chondrite meteorite Tenham, which crashed in Australia in 1879. The GSECARS beamline was optimal for the study because it is one of the nation's leading locations for conducting high-pressure research.

Bridgmanite grains are rare in the Tenhma meteorite, and they are smaller than 1 micrometer in diameter. Thus the team had to use a strongly focused beam and conduct highly spatially resolved diffraction mapping until an aggregate of Bridgmanite was identified and characterized by structural and compositional analysis.

This first natural specimen of Bridgmanite came with some surprises: It contains an unexpectedly high amount of ferric iron, beyond that of synthetic samples. Natural Bridgmanite also contains much more sodium than most synthetic samples. Thus the crystal chemistry of natural Bridgmanite provides novel crystal chemical insights. This natural sample of Bridgmanite may serve as a complement to experimental studies of deep mantle rocks in the future.

Prior to this study, knowledge about Bridgmanite's properties has only been based on synthetic samples because it only remains stable below 660 kilometers (410 miles) depth at pressures of above 230 kbar (23 GPa). When it is brought out of the inner Earth, the lower pressures transform it back into less dense minerals. Some scientists believe that some inclusions on diamonds are the marks left by Bridgmanite that changed as the diamonds were unearthed.

The team's results were published in the November 28 issue of the journalScience as "Discovery of bridgmanite, the most abundant mineral in Earth, in a shocked meteorite," by O. Tschauner at University of Nevada in Las Vegas, N.V.; C. Ma; J.R. Beckett; G.R. Rossman at California Institute of Technology in Pasadena, Calif.; C. Prescher; V.B. Prakapenka at University of Chicago in Chicago, IL.

This research was funded by the U.S. Department of Energy, NASA, and NSF.

Poor semen quality linked to hypertension, other health problems, study finds

A study of more than 9,000 men with fertility problems has revealed a correlation between the number of different defects in a man's semen and the like

lihood that the man has other health problems.

The study, conducted by investigators at the Stanford University School of Medicine, also links poor semen quality to a higher chance of having various specific health conditions, such as hypertension, and more generally to skin and endocrine disorders.

The findings, published online Dec. 10 in Fertility and Sterility, may spur more-comprehensive approaches to treating male infertility. They also point to the wisdom of performing complete physical examinations of men experiencing reproductive difficulties.

"About 15 percent of all couples have fertility issues, and in half of those cases the male partner has semen deficiencies," said the study's lead author, Michael Eisenberg, MD, assistant professor of urology and director of male reproductive medicine and surgery at Stanford. "We should be paying more attention to these millions of men. Infertility is a warning: Problems with reproduction may mean problems with overall health."

A study Eisenberg co-authored a few years ago showed that infertile men had higher rates of overall mortality, as well as mortality linked to heart problems, in the years following an infertility evaluation. "But here, we're already spotting signs of trouble in young men in their 30s," he said.

Analyzing medical records

In the new study, Eisenberg and his colleagues analyzed the medical records of 9,387 men, mostly between 30 and 50 years old, who had been evaluated at Stanford Hospital & Clinics (now Stanford Health Care) between 1994 and 2011 to determine the cause of their infertility. The men had routinely provided semen samples, which the researchers assessed for characteristics including volume, concentration and motility. In about half of all the male infertility cases, the problem was abnormal semen; in the rest, the fault lay elsewhere. So, using the database, the investigators were able to compare the overall health status of men who had semen defects to that of the men who didn't.

With a median age of 38, this was a fairly young group of men. However, 44 percent of all the men had some additional health problem besides the fertility problem that brought them to the clinic. In particular, the investigators found a substantial link between poor semen quality and specific diseases of the circulatory system, notably hypertension, vascular disease and heart disease. "To the best of my knowledge, there's never been a study showing this association before," said Eisenberg. "There are a lot of men who have hypertension, so understanding that correlation is of huge interest to us."

In addition, as the number of different kinds of defects in a man's semen rose, so did his likelihood of having a skin disease or endocrine disorder. When looking at the severity of all health problems, the scientists observed a statistically significant connection between the number of different ways in which a man's semen was deficient and the likelihood of his having a substantial health problem.

Health, semen quality 'strongly correlated'

The study wasn't designed to determine precisely how connections between semen deficiencies and seemingly unrelated disorders, such as cardiovascular or endocrine disease, come about. But, Eisenberg noted, some 15 percent of all genes in the human genome are connected fairly directly to reproduction, and most of these genes also have diverse functions in other bodily systems. He also noted that it may not be a disease itself, but the treatment for the disease, that's actually responsible for reproductive malfunction. He said he is exploring this possibility now.

As we treat men's infertility, we should also assess their overall health.

"A man's health is strongly correlated with his semen quality," he said. "Given the high incidence of infertility, we need to take a broader view. As we treat men's infertility, we should also assess their overall health. That visit to a fertility clinic represents a big opportunity to improve their treatment for other conditions, which we now suspect could actually help resolve the infertility they came in for in the first place."

The senior author of the study is Mark Cullen, MD, professor of medicine at Stanford. Other Stanford co-authors are professor of reproductive endocrinology and fertility Barry Behr, PhD; former professor of obstetrics and gynecology Renee Reijo Pera, PhD; and statistical programmer Shufeng Li.

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Warmer Pacific Ocean could release millions of tons of seafloor methane

Off the West Coast of the United States, methane gas is trapped in frozen layers below the seafloor. New research from the University of Washington shows that water at intermediate depths is warming enough to cause these carbon deposits to melt, releasing methane into the sediments and surrounding water.

Researchers found that water off the coast of Washington is gradually warming at a depth of 500 meters, about a third of a mile down. That is the same depth where methane transforms from a solid to a gas. The research suggests that ocean warming could be triggering the release of a powerful greenhouse gas.

"We calculate that methane equivalent in volume to the Deepwater Horizon oil spill is released every year off the Washington coast," said Evan Solomon, a UW assistant professor of oceanography. He is co-author of a paper to appear in Geophysical Research Letters.

While scientists believe that global warming will release methane from gas hydrates worldwide, most of the current focus has been on deposits in the Arctic. This paper estimates that from 1970 to 2013, some 4 million metric tons of methane has been released from hydrate decomposition off Washington. That's an amount each year equal to the methane from natural gas released in the 2010 Deepwater Horizon blowout off the coast of Louisiana, and 500 times the rate at which methane is naturally released from the seafloor.

"Methane hydrates are a very large and fragile reservoir of carbon that can be released if temperatures change," Solomon said. "I was skeptical at first, but when we looked at the amounts, it's significant."

Methane is the main component of natural gas. At cold temperatures and high ocean pressure, it combines with water into a crystal called methane hydrate. The Pacific Northwest has unusually large deposits of methane hydrates because of its biologically productive waters and strong geologic activity. But coastlines around the world hold deposits that could be similarly vulnerable to warming.

"This is one of the first studies to look at the lower-latitude margin," Solomon said. "We're showing that intermediate-depth warming could be enhancing methane release."

Co-author Una Miller, a UW oceanography undergraduate, first collected thousands of historic temperature measurements in a region off the Washington coast as part of a separate research project in the lab of co-author Paul Johnson, a UW professor of oceanography. The data revealed the unexpected sub-surface ocean warming signal.

"Even though the data was raw and pretty messy, we could see a trend," Miller said. "It just popped out."

The four decades of data show deeper water has, perhaps surprisingly, been warming the most due to climate change.

"A lot of the earlier studies focused on the surface because most of the data is there," said co-author Susan Hautala, a UW associate professor of oceanography. "This depth turns out to be a sweet spot for detecting this trend." The reason, she added, is that it lies below water nearer the surface that is influenced by long-term atmospheric cycles.

The warming water probably comes from the Sea of Okhotsk, between Russia and Japan, where surface water becomes very dense and then spreads east across the Pacific. The Sea of Okhotsk is known to have warmed over the past 50 years, and other studies have shown that the water takes a decade or two to cross the Pacific and reach the Washington coast.

"We began the collaboration when we realized this is also the most sensitive depth for methane hydrate deposits," Hautala said. She believes the same ocean currents could be warming intermediate-depth waters from Northern California to Alaska, where frozen methane deposits are also known to exist.

Warming water causes the frozen edge of methane hydrate to move into deeper water. On land, as the air temperature warms on a frozen hillside, the snowline moves uphill. In a warming ocean, the boundary between frozen and gaseous methane would move deeper and farther offshore. Calculations in the paper show that since 1970 the Washington boundary has moved about 1 kilometer -- a little more than a half-mile -- farther offshore. By 2100, the boundary for solid methane would move another 1 to 3 kilometers out to sea.

Estimates for the future amount of gas released from hydrate dissociation this century are as high as 0.4 million metric tons per year off the Washington coast, or about quadruple the amount of methane from the Deepwater Horizon blowout each year.

Still unknown is where any released methane gas would end up. It could be consumed by bacteria in the seafloor sediment or in the water, where it could cause seawater in that area to become more acidic and oxygen-deprived. Some methane might also rise to the surface, where it would release into the atmosphere as a greenhouse gas, compounding the effects of climate change.

Researchers now hope to verify the calculations with new measurements. For the past few years, curious fishermen have sent UW oceanographers sonar images showing mysterious columns of bubbles. Solomon and Johnson just returned from a cruise to check out some of those sites at depths where Solomon believes they could be caused by warming water.

"Those images the fishermen sent were 100 percent accurate," Johnson said. "Without them we would have been shooting in the dark."

Johnson and Solomon are analyzing data from that cruise to pinpoint what's triggering this seepage, and the fate of any released methane. The recent sightings of methane bubbles rising to the sea surface, the authors note, suggests that at least some of the seafloor gas may reach the surface and vent to the atmosphere.

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The above story is based on materials provided by University of Washington

Research finds clue to why females live longer than males

A study from the University of Exeter has found that male flies die earlier than their female counterparts when forced to evolve with the pressures of mate competition and juvenile survival. The results could help researchers understand the mechanisms involved in aging.

The research, published in the journal Functional Ecology, used populations of the fly Drosophila simulans that had evolved under different selection regimes. The study shows that mate competition (sexual selection), along with survival (natural selection), is tougher on male ageing than it is on females reducing their lifespan by about a third.

Some species, like the flies in this study, age quickly over a number of days while others - including some trees and whales - age slowly across centuries.

Professor David Hosken from Biosciences at the University of Exeter said: “We found dramatic differences in the effects of sexual and natural selection on male and female flies. These results could help explain the sex differences in lifespan seen in many species, including humans, and the diverse patterns of ageing we observe in nature.”

The flies were subjected to elevated or relaxed sexual and natural selection and left to evolve in these conditions. To elevate sexual selection groups of males were housed with single females. A stressful temperature was used to elevate natural selection.

Males court females by singing, dancing and smelling good but their efforts come at considerable cost and this cost is amplified when they also have to cope with stressful temperatures.

The results of the study showed that under relaxed sexual and natural selection, male and female flies had very similar lifespans - around 35 days. However males that evolved under elevated sexual selection and elevated natural selection had a much shorter lifespan - just 24 days - and died seven days earlier than females under the same conditions. 

Both sexual selection and natural selection were found to affect lifespan but their effects were greatest on males. The findings show that the sexes can respond differently to the same selection regimes.  

The study was funded

The Journey to Mars-NASA's Orion Flight Test

In the not-too-distant future, astronauts destined to be the first people to walk on Mars will leave Earth aboard an Orion spacecraft. Carried aloft by the tremendous power of a Space Launch System rocket, our explorers will begin their Journey to Mars from NASA's Kennedy Space Center in Florida, carrying the spirit of humanity with them to the Red Planet.

The first future human mission to Mars and those that follow will require the ingenuity and dedication of an entire generation. It's a journey worth the risks. We take the next step on that journey this Thursday, Dec. 4, with the uncrewed, first flight test of Orion. (Follow along on the Orion Blog, or see the full schedule of events and launch viewing opportunities).

Orion is the first spacecraft built for astronauts destined for deep space since the storied Apollo missions of the 1960s and 70s. It is designed to go farther than humans have ever traveled, well beyond the moon, pushing the boundaries of spaceflight to new heights.

Orion will open the space between Earth and Mars for exploration by astronauts. This proving ground will be invaluable for testing capabilities future human Mars missions will need. The area around our moon, in particular, called cis-lunar space, is a rich environment for testing human exploration needs, like advanced spacewalking suits, navigating using gravity, and protecting astronauts from radiation and extreme temperatures.

One of Orion's early missions in the 2020s will send astronauts to explore an asteroid, which will be placed in a stable orbit around the moon using a robotic spacecraft. This Asteroid Redirect Mission will test new technologies, like Solar Electric Propulsion, which will help us send heavy cargo to Mars in advance of human missions. Astronauts aboard Orion will return to Earth with samples of the asteroid, having tested a number of collection tools and techniques we'll use in future human missions to Mars or its moons.

Astronauts will board Orion for a first crewed flight in 2021. Many of Orion's systems needed for that flight and others will be tested on Thursday with the first uncrewed flight test.

Orion’s flight test is designed to test many of the riskiest elements of leaving Earth and returning home in the spacecraft. It will evaluate several key separations events, including the jettison of the launch abort system that will be capable of carrying astronauts on future missions to safety if a problem were to arise on the launch pad or during ascent to space, and the separation of the Orion crew module from its service module ahead of its reentry though Earth’s atmosphere.

Orion’s heat shield also will be tested to examine how the spacecraft endures its high speed return from deep space. The heat shield will experience temperatures near 4,000 degrees Fahrenheit during Thursday’s test, and will come back at about 80 percent of the speed the spacecraft would endure returning from the vicinity of the moon.

Other elements will also be put to the test, including how Orion’s computers handle the radiation environment in the Van Allen Belt, the spacecraft’s attitude control and guidance and how its 11 parachutes slow the crew module to just about 20 mph ahead of its splashdown in the Pacific Ocean.

Teams also will evaluate the procedures and tools used to recover Orion from the ocean after it touches down about 600 miles southwest of San Diego and is transported back to shore. 

Testing these capabilities now will help ensure that Orion will be the next generation spacecraft for missions in the 2020s that will put Mars within the reach of astronauts in the 2030s. 

As development continues on Orion, astronauts aboard the International Space Station are helping us learn how to protect the human body for longer durations, which missions to Mars will require. Researchers operating increasingly advanced rovers and spacecraft on and around Mars are revealing the planet's history while characterizing its environment to better prepare for human explorers. Here on Earth, the U.S. spaceflight industry is building and testing next generation technologies NASA will need to send astronauts to Mars and return them safely.

The Journey to Mars is humanity's Next Giant Leap

 into our solar system. The Orion spacecraft and its first flight test will help make it possible.

Marvels of Engineering—Roman Aqueducts

OF ALL the feats of ancient engineering, Roman aqueducts are among the most remarkable. “With such an array of indispensable structures carrying so many waters, compare, if you will, the idle Pyramids or the useless, though famous, works of the Greeks!” wrote Sextus Julius Frontinus (35–c. 103 C.E.), Roman governor and water commissioner. *

Why the Need for Aqueducts?

Ancient cities were usually built near an abundant water supply, and Rome was no exception. Originally, the Tiber River and nearby springs and wells provided sufficient water. From the fourth century B.C.E. on, however, Rome grew rapidly, as did its need for water.

Since few people had running water in their homes, the Romans built hundreds of private and public baths. The first public bath in the city of Rome was fed by the Aqua Virgo, dedicated in 19 B.C.E. The builder of this aqueduct, Marcus Agrippa, a close friend of Caesar Augustus, poured much of his vast fortune into overhauling and extending Rome’s water-supply system.

Baths also became social venues, larger ones even having gardens and libraries. After leaving the baths, aqueduct water, which could not be shut off, flowed into the sewers, constantly flushing them of refuse, including waste from the latrines attached to the baths.

Construction and Maintenance

When you hear the words “Roman aqueduct,” do you think of lofty arches running to distant horizons? In fact, arches formed less than 20 percent of those conduits, the larger portion of which lay underground. This more economical design not only protected aqueducts against erosion but also minimized their impact on fields and neighborhoods. For example, the Aqua Marcia, completed  in 140 B.C.E., was about 57 miles (92 km) long but comprised just 7 miles or so (11 km) of arches.

Before building an aqueduct, engineers assessed the quality of a potential water source by examining the clarity, rate of flow, and taste of the water. They also took note of the physical condition of the locals who drank it. Once a site was approved, surveyors calculated the right path and gradient for the conduit, as well as its channel size and length. Slaves evidently provided manpower. Aqueducts could take years to complete, making them costly—especially if arches were needed.

Moreover, aqueducts had to be maintained and protected. To care for them, the city of Rome at one time employed about 700 people. Provisions for maintenance were also incorporated into the design. For instance, underground sections of the aqueducts were made accessible by means of manholes and shafts. When major repairs were needed, engineers could temporarily divert the water away from a damaged section.

Rome’s Urban Aqueducts

By the early third century C.E., 11 major aqueducts served the city of Rome. The first, the Aqua Appia, built in 312 B.C.E. and just over ten miles (16 km) long, ran almost entirely underground. Still preserved in part is the Aqua Claudia, which was some 43 miles (69 km) long with about 6 miles (10 km) of arches, a number of which stood 90 feet (27 m) high!

How much water did the city’s aqueducts carry? A lot! The Aqua Marcia, mentioned earlier, daily channeled about 6.7 million cubic feet (190,000 cu m) of water into Rome. Once the water reached urban areas—gravity being the driving force—it flowed into distribution tanks and then into branches, which channeled the water to other distribution tanks or to locations for water use. Some estimate that Rome’s water distribution system grew to the point that it could have daily supplied more than 265 gallons (1,000 L) of water for each inhabitant.

As the Roman Empire grew, “the aqueducts went wherever Rome went,” says the bookRoman Aqueducts & Water Supply. Travelers in Asia Minor, France, Spain, and North Africa can still gaze in awe at these ancient marvels of engineering.

Invisible shield found thousands of miles above Earth blocks 'killer electrons'

A The barrier to the particle motion was discovered in the Van Allen radiation belts, two doughnut-shaped rings above Earth that are filled with high-energy electrons and protons, said Distinguished Professor Daniel Baker, director of CU-Boulder's Laboratory for Atmospheric and Space Physics (LASP). Held in place by Earth's magnetic field, the Van Allen radiation belts periodically swell and shrink in response to incoming energy disturbances from the sun.

team led by the University of Colorado Boulder has discovered an invisible shield some 7,200 miles above Earth that blocks so-called "killer electrons," which whip around the planet at near-light speed and have been known to threaten astronauts, fry satellites and degrade space systems during intense solar storms.

As the first significant discovery of the space age, the Van Allen radiation belts were detected in 1958 by Professor James Van Allen and his team at the University of Iowa and were found to be composed of an inner and outer belt extending up to 25,000 miles above Earth's surface. In 2013, Baker -- who received his doctorate under Van Allen -- led a team that used the twin Van Allen Probes launched by NASA in 2012 to discover a third, transient "storage ring" between the inner and outer Van Allen radiation belts that seems to come and go with the intensity of space weather.

The latest mystery revolves around an "extremely sharp" boundary at the inner edge of the outer belt at roughly 7,200 miles in altitude that appears to block the ultrafast electrons from breeching the shield and moving deeper towards Earth's atmosphere.

"It's almost like theses electrons are running into a glass wall in space," said Baker, the study's lead author. "Somewhat like the shields created by force fields on Star Trek that were used to repel alien weapons, we are seeing an invisible shield blocking these electrons. It's an extremely puzzling phenomenon."

A paper on the subject was published in the Nov. 27 issue of Nature.

The team originally thought the highly charged electrons, which are looping around Earth at more than 100,000 miles per second, would slowly drift downward into the upper atmosphere and gradually be wiped out by interactions with air molecules. But the impenetrable barrier seen by the twin Van Allen belt spacecraft stops the electrons before they get that far, said Baker.

The group looked at a number of scenarios that could create and maintain such a barrier. The team wondered if it might have to do with Earth's magnetic field lines, which trap and control protons and electrons, bouncing them between Earth's poles like beads on a string. The also looked at whether radio signals from human transmitters on Earth could be scattering the charged electrons at the barrier, preventing their downward motion. Neither explanation held scientific water, Baker said.

"Nature abhors strong gradients and generally finds ways to smooth them out, so we would expect some of the relativistic electrons to move inward and some outward," said Baker. "It's not obvious how the slow, gradual processes that should be involved in motion of these particles can conspire to create such a sharp, persistent boundary at this location in space."

Another scenario is that the giant cloud of cold, electrically charged gas called the plasmasphere, which begins about 600 miles above Earth and stretches thousands of miles into the outer Van Allen belt, is scattering the electrons at the boundary with low frequency, electromagnetic waves that create a plasmapheric "hiss," said Baker. The hiss sounds like white noise when played over a speaker, he said.

While Baker said plasmaspheric hiss may play a role in the puzzling space barrier, he believes there is more to the story. "I think the key here is to keep observing the region in exquisite detail, which we can do because of the powerful instruments on the Van Allen probes. If the sun really blasts Earth's magnetosphere with a coronal mass ejection (CME), I suspect it will breach the shield for a period of time," said Baker, also a faculty member in the astrophysical and planetary sciences department.

"It's like looking at the phenomenon with new eyes, with a new set of instrumentation, which give us the detail to say, 'Yes, there is this hard, fast boundary,'" said John Foster, associate director of MIT's Haystack Observatory and a study co-author.

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The above story is based on materials provided by University of Colorado at Bould.

Gravity may have saved the universe after the Big Bang, say researchers

New research by a team of European physicists could explain why the universe did not collapse immediately after the Big Bang.

Studies of the Higgs particle -- discovered at CERN in 2012 and responsible for giving mass to all particles -- have suggested that the production of Higgs particles during the accelerating expansion of the very early universe (inflation) should have led to instability and collapse.

Scientists have been trying to find out why this didn't happen, leading to theories that there must be some new physics that will help explain the origins of the universe that has not yet been discovered. Physicists from Imperial College London, and the Universities of Copenhagen and Helsinki, however, believe there is a simpler explanation.

In a new study in Physical Review Letters, the team describe how the spacetime curvature -- in effect, gravity -- provided the stability needed for the universe to survive expansion in that early period. The team investigated the interaction between the Higgs particles and gravity, taking into account how it would vary with energy.

They show that even a small interaction would have been enough to stabilise the universe against decay.

"The Standard Model of particle physics, which scientists use to explain elementary particles and their interactions, has so far not provided an answer to why the universe did not collapse following the Big Bang," explains Professor Arttu Rajantie, from the Department of Physics at Imperial College London.

"Our research investigates the last unknown parameter in the Standard Model -- the interaction between the Higgs particle and gravity. This parameter cannot be measured in particle accelerator experiments, but it has a big effect on the Higgs instability during inflation. Even a relatively small value is enough to explain the survival of the universe without any new physics!"

The team plan to continue their research using cosmological observations to look at this interaction in more detail and explain what effect it would have had on the development of the early universe. In particular, they will use data from current and future European Space Agency missions measuring cosmic microwave background radiation and gravitational waves.

"Our aim is to measure the interaction between gravity and the Higgs field using cosmological data," says Professor Rajantie. "If we are able to do that, we will have supplied the last unknown number in the Standard Model of particle physics and be closer to answering fundamental questions about how we are all here."

The research is funded by the Science and Technology Facilities Council, along with the Villum Foundation, in Denmark, and the Academy of Finland.

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The above story is based on materials provided by Imperial College London. 

Why lizards have bird breath

Whether birds are breathing in or out, air flows in a one-directional loop through their lungs. This pattern was unexpected and for decades biologists assumed it was unique to birds, a special adaptation driven by the intense energy demands of flight.

But that view is wrong, according to University of Utah scientists who now have shown that bird-like breathing also developed in green iguanas -- reptiles not known for high-capacity aerobic fitness. The finding bolsters the case that unidirectional bird-like flow evolved long before the first birds, arising nearly 300 million years ago in a common ancestor of lizards, snakes, crocodiles and dinosaurs including birds.

"We thought we understood how these lungs work, but in fact most of us were completely wrong," says Colleen Farmer, an associate professor of biology at the U and lead author of the new study published today in Proceedings of the National Academy of Sciences. "People have made a lot of assumptions about how lungs work in animals such as reptiles and crocodiles but they never actually measured flow," she says.

In humans and other mammals, lungs have airways with a tree-like branching structure. A main trunk in each lung splits into branches and twigs. Air flows in and out in a tidal fashion. Oxygen and carbon dioxide pass to and from blood in tiny air sacs, called alveoli, at the tips of the smallest airway branches.

In bird lungs, air loops in one direction through a series of tubes lined with blood vessels for gas exchange. Aerodynamic forces act like valves to sustain the one-way flow through cycles of inhalation and exhalation.

"For years, people thought that the design evolved to meet the energetic demands of flight," Farmer says. "That's all wrong. Iguanas don't fly."

Alligators also have a bird-like pattern of airflow. Farmer and Kent Sanders, a radiologist at the U, revealed that in a 2010 study. It was the first evidence that one-directional lung ventilation might be an innovation pre-dating the origin of birds. Earlier this year, Farmer along with Emma Schachner and Robert Cieri at the U, and James Butler of Harvard University reported that monitor lizards have one-directional airflow through their lungs, too.

Those discoveries left open the possibility that crocs and monitor lizards evolved their bird-like lungs independently, that is, their evolution converged on a design similar to birds. The finding of bird-like lungs in yet another group of reptiles builds a stronger case for an origin in the remote past in a common ancestor.

To make the discovery, Farmer and co-authors Cieri, Schachner and Brent Craven of Pennsylvania State University had to find a way to visualize air moving through iguana lungs. In one set of experiments, they used a surgical scope to look inside the lungs of live iguanas as the lizards inhaled harmless smoke from a theatrical fog machine. They also used probes that measure air speed and volume in dissected lungs. Working from 3-D X-ray imaging of the contours of iguana lungs, Craven made a computer model simulating airflow. The model's predictions closely matched the patterns observed in real lungs. "It was dead-on with the directions of flow we observed," Farmer says.

The revelations make clear that scientists have much to learn about the physiology of lungs in species other than mammals. Textbooks generally assert that air moving in and out of lungs flows down a pressure gradient from a point of higher pressure to one of lower pressure, but Farmer says her group's findings show that in iguana lungs "that's not what's going on at all." The shapes and angles of the lung airways point jets of air that create one-directional flow.

The mechanics aren't fully known yet, but Farmer says a better understanding could inspire new ways to design devices that circulate or filter blood or other fluids without using mechanical valves. "The geometry of these lungs, it is so weird," Farmer says, "I don't think any engineer would dream that up."

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The above story is based on materials provided by University of Utah.

Scientists Discover Why Mosquitos Love Human Blood

A chemical vapour exuded from human skin became the key reason why mosquitoes turned from feeding on animals to sucking the blood of people, a study has found.

Sulcatone is an important ingredient in the distinctive human odour, and mosquitoes learnt to recognise it many thousands of years ago as a sign that they were near a source of food, scientists have discovered.

Researchers found that the present-day black-bodied mosquitoes that feed on the furry skin of forest animals do not show any preference for sulcatone, but the brown mosquitoes living in and around villages in Africa are highly attracted to the scent.

“We knew that these mosquitoes had evolved to love the way we smell,” said Leslie Vosshall of Rockefeller University in New York, who led the study published in the journal Nature.

“It was a really good evolutionary move. We provide the ideal lifestyle for mosquitoes. We always have water around for them to breed in, we are hairless and we live in large groups,” Professor Vosshall said.

The scientists identified a group of 14 genes in the mosquito genome that are strongly linked to their love of humans and one odour receptor in particular – called Or4 – stood out as being highly active in the human-preferring mosquitoes.

They linked the Or4 receptor with one of many compounds collected from human skin that form part of the natural scent of people. This was the key that locked the mosquito to the smell of its new human host.

Controlling genes with your thoughts

It sounds like something from the scene in Star Wars where Master Yoda instructs the young Luke Skywalker to use the force to release his stricken X-Wing from the swamp: Marc Folcher and other researchers from the group led by Martin Fussenegger, Professor of Biotechnology and Bioengineering at the Department of Biosystems (D-BSSE) in Basel, have developed a novel gene regulation method that enables thought-specific brainwaves to control the conversion of genes into proteins – called gene expression in technical terms.

“For the first time, we have been able to tap into human brainwaves, transfer them wirelessly to a gene network and regulate the expression of a gene depending on the type of thought. Being able to control gene expression via the power of thought is a dream that we’ve been chasing for over a decade,” says Fussenegger.

A source of inspiration for the new thought-controlled gene regulation system was the game Mindflex, where the player wears a special headset with a sensor on the forehead that records brainwaves. The registered electroencephalogram (EEG) is then transferred into the playing environment. The EEG controls a fan that enables a small ball to be thought-guided through an obstacle course.

Wireless transmission to implant

The system, which the Basel-based bioengineers recently presented in the journal Nature Communications, also makes use of an EEG headset. The recorded brainwaves are analysed and wirelessly transmitted via Bluetooth to a controller, which in turn controls a field generator that generates an electromagnetic field; this supplies an implant with an induction current.

 

This diagram shows how the implant takes thoughts, interprets them, and transforms them into electricity to light up a near-infrared LED. (Illustration: Folcher M et al. Nature Communications 2014)

A light then literally goes on in the implant: an integrated LED lamp that emits light in the near-infrared range turns on and illuminates a culture chamber containing genetically modified cells. When the near-infrared light illuminates the cells, they start to produce the desired protein.

Thoughts control protein quantity

The implant was initially tested in cell cultures and mice, and controlled by the thoughts of various test subjects. The researchers used SEAP for the tests, an easy-to-detect human model protein which diffuses from the culture chamber of the implant into the mouse’s bloodstream.

To regulate the quantity of released protein, the test subjects were categorised according to three states of mind: bio-feedback, meditation and concentration. Test subjects who played Minecraft on the computer, i.e. who were concentrating, induced average SEAP values in the bloodstream of the mice. When completely relaxed (meditation), the researchers recorded very high SEAP values in the test animals. For bio-feedback, the test subjects observed the LED light of the implant in the body of the mouse and were able to consciously switch the LED light on or off via the visual feedback. This in turn was reflected by the varying amounts of SEAP in the bloodstream of the mice.

New light-sensitive gene construct

“Controlling genes in this way is completely new and is unique in its simplicity,” explains Fussenegger. The light-sensitive optogenetic module that reacts to near-infrared light is a particular advancement. The light shines on a modified light-sensitive protein within the gene-modified cells and triggers an artificial signal cascade, resulting in the production of SEAP. Near-infrared light was used because it is generally not harmful to human cells, can penetrate deep into the tissue and enables the function of the implant to be visually tracked.

The system functions efficiently and effectively in the human-cell culture and human-mouse system. Fussenegger hopes that a thought-controlled implant could one day help to combat neurological diseases, such as chronic headaches, back pain and epilepsy, by detecting specific brainwaves at an early stage and triggering and controlling the creation of certain agents in the implant at exactly the right time.