Dec 27, 2014

See Six Months of Earth From Space: Timelapse

If you're a fan of epic ultra high definition time-lapse videos from space -- and really who isn't — then you'll be happy to know that Christmas arrived early and Hannukah is right on time. The European Space Agency has stiched together more than five months of astronaut Alexander Gerst's time-lapse photography from the International Space Station (ISS) and made it into a six-minute video.

Gerst spent 166 days in orbit starting in late May on the ISS as one of five flight engineers, all part of the European Space Agency's aptly named mission, Blue Dot. Luckily for us mere mortals, he also had an excellent photographic eye and captured some pretty spectacular views as the ISS hurtled around the planet at 17,200 mph, making more than 15 laps each day.

Lightning from space looks like daubs of electric paint atop of clouds. Large-scale weather patterns including spinning areas of low pressure look just like they do on weather maps. The aurora takes on the appearance of a shimmering green curtain draped around the high latitudes of Earth. And day and night on the horizon of Gerst and his fellow astronaut's view, the crystaline strip of the atmosphere -- the one we're filling with greenhouse gases -- is clearly visible, separating those of us back on planet Earth from the rest of the universe.

But lest you think it's all eye candy and fodder for philosophical musings, there are also a few hidden insights into how the various apparati that ensure the ISS can sustain the astronauts that call it home. Solar panels rotate to catch the most sun and keep all systems up and running. At the 1:35 mark, a robotic arm extends to pluck a Cygnus spacecraft -- one of the commercial spacecraft that help supply the ISS -- out of, well, space. After collecting its payload, the same arm releases it on its homeward journey at the 4:50 mark. It truly looks like science fiction.

So go ahead, ratchet the video up to ultra high definition and enjoy each one of the 12,500 images it took to create it. And let it not go unnoted that the European Space Agency also found some pretty futuristic background music for the video. Hope you're taking notes, NASA.

From Discovery News

Coolest Archaeological Discoveries of 2014

1. Alexander the Great-era tomb at Amphipolis

This mosaic from the tomb depicts the abduction of Persephone.
Thanks to the careful work of archaeologists, we learned more in the past year about Stonehenge's hidden monuments, Richard III's gruesome death and King Tut's mummified erection. From the discovery of an ancient tomb in Greece to the first evidence of Neanderthal art, here are 10 of Live Science's favorite archaeology stories of 2014.

Rarely do archaeological digs attract so much attention in real time. But at Amphipolis, an ancient coastal city in northern Greece, the discovery of a lavish 2,300-year-old tomb has created a national frenzy. In August, state archaeologists broke through the entrance of a huge burial mound that's been billed as the largest of its kind in the Greek world. (Its perimeter measures about 1,600 feet, or 490 meters.)

Excavators found broken sphinxes, two female statues called caryatids, a remarkably intact mosaic floor and some skeletal material, which is awaiting analysis. It's still unclear who was buried inside the tomb, but some have speculated that it could be someone from Alexander the Great's inner circle.

2. Stonehenge's secret monuments

This aerial picture shows patchmarks believed to be "stone holes."
Capping a four-year survey of the landscape around England's Stonehenge, researchers reported that they found signs of at least 17 previously unknown Neolithic shrines. The big announcement -- which was accompanied by TV specials on the BBC and Smithsonian Channel --could change the way historians have thought of Stonehenge.

"Stonehenge is undoubtedly a major ritual monument, which people may have traveled considerable distances to come to, but it isn't just standing there by itself," project leader Vincent Gaffney, an archaeologist at the University of Birmingham, told Live Science in September. "It's part of a much more complex landscape with processional and ritual activities that go around it."

3. A shipwreck under the World Trade Center

Rings in the white oak timbers used to build the ship reveal that the vessel was built around 1773 near Philadelphia.
In the summer of 2010, archaeologists in New York discovered a school-bus-size shipwreck in an unlikely place: the site of the World Trade Center, still under construction after the Sept. 11, 2001, terrorist attacks. This year, tree-ring researchers who were studying the ship's fragile timbers announced that they had uncovered new details about the vessel.

The ship was likely built in 1773, or soon after, in a small shipyard near Philadelphia, according to the study, which was published in the journal Tree-Ring Research. What's more, the ship's timbers may have originated from the same white oak forest where wood was harvested to build Philadelphia's Independence Hall, the researchers said.

4. Richard III's twisted spine, kingly diet and family tree

King Richard III's skeleton, including his skull, shown here, was found during an archaeological excavation in Leicester in 2012.
Once lost to history, the skeleton of Britain's King Richard III was found under a parking lot in 2012, and, since then, the monarch's remains have been a boon for scientists who study centuries-old DNA, diet and disease. Among this year's findings, scientists reported that they found a mitochondrial DNA match between Richard and two of his living relatives, offering further confirmation that the bones really belong to the king. A model of Richard's misshapen spine showed that he suffered from adolescent idiopathic scoliosis.

Isotopes locked in Richard's teeth and bones revealed that the king ate (and drank) quite well during his two years at the throne. And, after a much-delayed autopsy, researchers also determined this year that Richard likely died a quick death on the battlefield; they found two wounds on the back of Richard's skull that were likely candidates for the fatal blow.

5. A teenager in a "black hole"

Using photography, videography, three dimensional modeling and minimal sampling, researchers studied the skeleton of a teenage girl without removing it from its watery grave.
At the bottom of an underwater cave called Hoyo Negro (Spanish for "Black Hole") in Mexico's Yucatan Peninsula, divers discovered a near-complete skeleton of a teenage girl. Dubbed "Naia," the girl was found alongside unlikely gravemates: saber-toothed cats, pumas, sloths and bears. Researchers think Naia and the animals likely fell to their deaths 12,000 to 13,000 years ago, before the pit filled with water when the world's glaciers started melting.

Scientists also found that DNA from Naia's remains resembled modern Native American DNA. The discovery, which was reported in May in the journal Science, could help solve the long-standing debate over the identity of the first Americans.

Read more at Discovery News

Dec 26, 2014

Egg and sperm race: Scientists create precursors to human egg and sperm

Scientists at the University of Cambridge working with the Weizmann Institute have created primordial germ cells - cells that will go on to become egg and sperm - using human embryonic stem cells. Although this had already been done using rodent stem cells, the study, published today in the journal Cell, is the first time this has been achieved efficiently using human stem cells.

When an egg cell is fertilised by a sperm, it begins to divide into a cluster of cells known as a blastocyst, the early stage of the embryo. Within this ball of cells, some cells form the inner cell mass - which will develop into the foetus - and some form the outer wall, which becomes the placenta. Cells in the inner cell mass are 'reset' to become stem cells - cells that have the potential to develop into any type of cell within the body. A small number of these cells become primordial germ cells (PGCs) - these have the potential to become germ cells (sperm and egg), which in later life will pass on the offspring's genetic information to its own offspring.

"The creation of primordial germ cells is one of the earliest events during early mammalian development," says Dr Naoko Irie, first author of the paper from the Wellcome Trust/Cancer Research UK Gurdon Institute at the University of Cambridge. "It's a stage we've managed to recreate using stem cells from mice and rats, but until now few researches have done this systematically using human stem cells. It has highlighted important differences between embryo development in humans and rodents that may mean findings in mice and rats may not be directly extrapolated to humans."

Professor Surani at the Gurdon Institute, who led the research, and his colleagues found that a gene known as SOX17 is critical for directing human stem cells to become PGCs (a stage known as 'specification'). This was a surprise as the mouse equivalent of this gene is not involved in the process, suggesting a key difference between mouse and human development. SOX17 had previously been shown to be involved in directing stem cells to become endodermal cells, which then develop into cells including those for the lung, gut and pancreas, but this is the first time it has been seen in PGC specification.

The group showed that PGCs could also be made from reprogrammed adult cells, such as skin cells, which will allow investigations on patient-specific cells to advance knowledge of the human germline, infertility and germ cell tumours. The research also has potential implications for understanding the process of 'epigenetic' inheritance. Scientists have known for some time that our environment - for example, our diet or smoking habits - can affect our genes through a process known as methylation whereby molecules attach themselves to our DNA, acting like dimmer switches to increase or decrease the activity of genes. These methylation patterns can be passed down to the offspring.

Read more at Science Daily

Putting bedbugs to bed forever

The world owes a debt of gratitude to Simon Fraser University biologist Regine Gries. Her arms have provided a blood meal for more than a thousand bedbugs each week for five years while she and her husband, biology professor Gerhard Gries, searched for a way to conquer the global bedbug epidemic.

Working with SFU chemist Robert Britton and a team of students, they have finally found the solution--a set of chemical attractants, or pheromones, that lure the bedbugs into traps, and keep them there.

This month, after a series of successful trials in bedbug-infested apartments in Metro Vancouver, they have published their research, "Bedbug aggregation pheromone finally identified," in Angewandte Chemie, a general chemistry journal.

They're working with Victoria-based Contech Enterprises Inc. to develop the first effective and affordable bait and trap for detecting and monitoring bedbug infestations. They expect it to be commercially available next year.

"The biggest challenge in dealing with bedbugs is to detect the infestation at an early stage," says Gerhard, who holds an NSERC-Industrial Research Chair in Multimodal Animal Communication Ecology.

"This trap will help landlords, tenants, and pest-control professionals determine whether premises have a bedbug problem, so that they can treat it quickly. It will also be useful for monitoring the treatment's effectiveness."

It's a solution the world has been waiting for.

Over the last two decades the common bedbug (Cimex lectularius), once thought eradicated in industrialized countries, has reappeared as a global scourge. These nasty insects are infesting not just low-income housing but also expensive hotels and apartments, and public venues such as stores, movie theatres, libraries and even public transit.

And while these blood-sucking pests were previously not considered a carrier of disease, scientists have recently discovered they can transmit the pathogen that causes Chagas disease, which is prevalent in Central and South America. Yet until now, tools for detecting and monitoring these pests have been expensive and technically challenging to use.

The research was funded with a Natural Sciences and Engineering Research Council of Canada industry grant in partnership with Contech Enterprises Inc.

Backgrounder: The research story--180,000 bedbug bites later

The Gries' began their research eight years ago when Gerhard, who is internationally renowned for his pioneering work in chemical and bioacoustic communication between insects, began searching for pheromones that could lure and trap bedbugs.

Regine worked with him, running all of the lab and field experiments and, just as importantly, enduring 180,000 bedbug bites in order to feed the large bedbug colony required for their research. She became the unintentional "host" because, unlike Gerhard, she is immune to the bites, suffering only a slight rash instead of the ferocious itching and swelling most people suffer.

The Gries' and their students initially found a pheromone blend that attracted bedbugs in lab experiments, but not in bedbug-infested apartments. "We realized that a highly unusual component must be missing--one that we couldn't find using our regular gas chromatographic and mass spectrometric tools," says Gerhard.

That's when they teamed up with Britton, an expert in isolating and solving the structure of natural products, and then synthesizing them in the lab. He used SFU's state-of-the-art NMR spectrometers to study the infinitesimal amounts of chemicals Regine had isolated from shed bedbug skin, looking for the chemical clues as to why the bedbugs find the presence of skin so appealing in a shelter.

It was like looking for a needle in a haystack.

After two years of frustrating false leads, Britton, his students and the Gries duo finally discovered that histamine, a molecule with unusual properties that eluded identification through traditional methods, signals "safe shelter" to bedbugs. Importantly, once in contact with the histamine, the bedbugs stay put whether or not they have recently fed on a human host.

Read more at Science Daily

Dec 24, 2014

Happy Holidays

I Wanted to take the time to wish everybody that reads this blog a merry Christmas and happy holidays.

I've been running this blog for almost five (5) years and it's been a journey. Without you, the readers, I wouldn't post this much as I do, so keep on reading.

Yours truly
Danny Boston

Imagination, Reality Look Different in the Brain

"Turn off your mind, relax, and float down stream..."

Maybe John Lennon was onto something when he wrote those words for the Beatles' song "Tomorrow Never Knows."

It turns out that that reality and imagination flow in different directions in the brain, researchers say. The visual information from real events that the eyes see flows "up" from the brain's occipital lobe to the parietal lobe, but imagined images flow "down" from the parietal to the occipital.

"There seems to be a lot in our brains and animal brains that is directional — that neural signals move in a particular direction, then stop, and start somewhere else," said Dr. Giulio Tononi, a psychiatry professor and neuroscientist at the University of Wisconsin-Madison and one of the study's co-authors. "I think this is really a new theme that had not been explored."

The finding, published in the November issue of the journal NeuroImage, may lead to a better understanding of how the brain processes short-term memories and how memory is connected to imagination, the researchers said.

By "flow," the scientists are referring to the general direction of electrical signaling of neurons in the brain. This direction is oriented against the various lobes of the brain.

The occipital lobe sits in the lower, back part of the brain. Containing the visual cortex, this lobe's primary function is to process visual information. The parietal lobe lies above the occipital lobe, and its primary function is to integrate sensory information, such as vision, but also touch and sound. In doing so, the parietal lobe assembles elementary building bricks from so-called "lower-order" brain regions to create concepts, said Daniela Dentico, a researcher at the University of Wisconsin-Madison and lead author on the report.

A leading theory in image processing "posits that our visual mental images are not stored somewhere in the brain, but get actively reconstructed," Dentico told Live Science. The brain does this, she said, by reversing the order it uses for visual perception. She described this as the "top-down" direction, which starts from the big concept and moves back toward the smaller elements.

"Our study represents the first direct measure of the prevalence of top-down signal flow during imagery," Dentico added.

To determine the flow of neural firing, the Madison researchers, along with scientists at University of Liege in Belgium, asked study participants who were hooked up to an electroencephalography (EEG) machine to watch videos or to imagine fantastical scenes, such as traveling on a magic bicycle. EEG is an established technique that uses sensors on the scalp to measure underlying electrical activity.

Read more at Discovery News

Dec 23, 2014

Series of Earthquakes Threaten Michelangelo's David

More than 250 tremors have been rattling Florence and the Chianti region since Friday, raising concerns over the safety of Michelangelo’s David.

According to Italy’s National Institute of Geophysics and Volcanology, the two major shocks that hit the wine-growing region measured 3.8. and 4.1 on the Richter scale, while several others reached 3.0 to 3.5, scaring people but leaving no one injured.

Minor tremors are continuing at the moment, sparking alarm over the national art treasure, with the focus on Michelangelo’s statue of David. Earlier this year, experts found David at risk of crumbling down under its own weight because of tiny fractures in its ankles.

Italy’s ministry of culture Dario Franceschini announced on Sunday that the 17-foot high statue will be given a special, anti-seismic platform worth $250,000. The support is expected to be ready for use by the end of 2015.

“The recent earthquakes make this project urgent,” Franceschini said in a statement. “A masterpiece like David must not be left to any risk.”

Representing the biblical hero who killed Goliath, the sculpture marked a watershed in Renaissance art and established Michelangelo as the foremost sculptor of his time at the age of 29.

The towering sculpture, acclaimed for its depiction of male physical perfection, was displayed for the first time beside the main doorway of the Piazza della Signoria in Florence on Sept. 8, 1504.

David remained in its original location, at the mercy of the elements, until 1873, when it was moved to its present location in the Galleria dell’Accademia, where it attracts 1.25 million visitors a year.

Indeed, the micro fractures on David’s ankles are the result of a long-lasting, small forward inclination of about 5 degrees during the statue’s time in Piazza della Signoria.

Tests by the National Research Council and Florence University suggested that the 6-ton marble statue would break under its own weight if standing at an inclination higher than 15 degrees.

“There is a real risk that David collapses under an earthquake,” Fernando De Simone, an expert in underground engineering, said.

According to De Simone, the anti-seismic platform will not fully protect the masterpiece from earthquakes.

“It will protect it from vibrations, but could not prevent the ceiling from crumbling over the statue,” De Simone said.

Read more at Discovery News

Antarctic Seals May Navigate by Earth's Magnetic Field

Does Antarctica's Weddell seal come standard with internal navigation capabilities keyed on Earth's magnetic field? That's the working hypothesis of a team of researchers working with the support of the National Science Foundation. If their ideas can be proven, it would mark the first evidence of the capability in a marine mammal.

Randall Davis, from the Department of Marine Biology at Texas A&M University; Terrie Williams, professor of ecology and evolutionary biology at the University of California, Santa Cruz; and Lee Fuiman, associate director of the University of Texas Marine Science Institute, have long studied Weddell seals, their research going back to the 1990s.

The group marveled at the animal's navigating skills. Weddell seals excel at deep diving when they hunt, but like all mammals they need oxygen, so when it's time to come up for air they know exactly how to locate holes in the ice in time to breathe again, before they drown. The researchers observed the seals finding holes in the ice with incredible precision.

How did the seals know how far from holes they could swim before they needed to turn around and head for the surface? Plans are underway to learn the answer.

As their notion of a magnetic-field-based navigation system is at this point a hypothesis, the team plans to spend the next three years observing a group of seals that will be rigged with video and data recording gear. The animals will be set loose in three areas of McMurdo Sound. Their release points in the sound will correspond with places where the scientists have in great detail mapped the magnetic field.

The team will track the seals' behavior when they encounter different magnetic fields. Once they marry the seals' dive data with the magnetic locations, they hope to have a more definitive understanding of whether or not the creatures are employing the magnetic field to hunt, navigate, and, in effect, survive.

From Discovery News

TV Medical Show Claims Not Backed by Science

Most people know that they can’t believe everything they see on TV, though many assume that talk shows featuring well-known medical doctors are giving them valid health information.

However a new article in the British Medical Journal examining the medical advice given on TV talk shows finds that many of the claims are unproven or unsubstantiated. The researchers examined 40 randomly-selected episodes for each of the two most popular medical shows, The Dr. Oz Show and The Doctors, to examine and rate their content. From those episodes they randomly selected 80 of the stronger recommendations from each show and researched what evidence was available in the published, peer-reviewed literature to support those recommendations.

The results are sobering for anyone who heeds advice from these shows:
“We could find at least a case study or better evidence to support 54% of the 160 recommendations (80 from each show). For recommendations in The Dr Oz Show, evidence supported 46%, contradicted 15%, and was not found for 39%. For recommendations in The Doctors, evidence supported 63%, contradicted 14%, and was not found for 24%.”

Dr. Oz and the Magic Beans

Perhaps the most famous example of the sort of problems that the study describes emerged in 2012 when celebrity TV doctor Mehmet Oz endorsed green coffee bean extract as a “magic weight-loss cure” on his show. Oz was reprimanded by Sen. Claire McCaskill, D-Mo., on Capitol Hill for promoting dubious and discredited supplements and treatments. Dr. Oz acknowledged of the products he features and promotes on his show: “I recognize that oftentimes they don’t have the scientific muster to present as fact.”

The example of coffee bean extract was raised: “Green coffee bean extract, which Dr. Mehmet Oz promoted on his show as a ‘magic weight-loss cure,’ had one scientific study backing up the extract’s purported effects … When asked specifically about the green coffee bean extract, Oz cited a study that found people who took the supplements did lose weight. However, that study was funded by the product’s manufacturer,” according to

Scientific consensus, of course, cannot be built on a single study, no matter how well designed. For doctors to determine that a drug or therapy should be used by patients — it is safe and effective, its benefits can be demonstrated beyond placebo and outweigh its side effects, and so on — dozens of studies should be consulted.

Any single clinical study, or even handful of studies, may be wrong for any number of reasons ranging from poor research design to faulty statistical analysis. The fact that the single study demonstrating the efficacy of green coffee bean extract in weight loss was funded by its manufacturer does not, by itself, discredit its results. Many perfectly valid studies are paid for by companies with a financial interest in the results. But it does mean that any potential conflicts should be noted — which they were not.

Read more at Discovery News

Could Dwarf Planet Ceres Support Alien Life?

A NASA probe is about to get the first up-close look at a potentially habitable alien world.

In March 2015, NASA's Dawn spacecraft will arrive in orbit around the dwarf planet Ceres, the largest object in the main asteroid belt between Mars and Jupiter. Ceres is a relatively warm and wet body that deserves to be mentioned in the same breath as the Jovian moon Europa and the Saturn satellite Enceladus, both of which may be capable of supporting life as we know it, some researchers say.

"I don't think Ceres is less interesting in terms of astrobiology than other potentially habitable worlds," Jian-Yang Li, of the Planetary Science Institute in Tucson, Arizona, said Thursday (Dec. 18) during a talk here at the annual fall meeting of the American Geophysical Union.

Life as we know it requires three main ingredients, Li said: liquid water, an energy source and certain chemical building blocks (namely, carbon, hydrogen, nitrogren, oxygen, phosphorus and sulfur).

The dwarf planet Ceres — which is about 590 miles (950 kilometers) wide — is thought to have a lot of water, based on its low overall density (2.09 grams per cubic centimeter; compared to 5.5 g/cubic cm for Earth). Ceres is likely a differentiated body with a rocky core and a mantle comprised of water ice, researchers say, and water-bearing minerals have been detected on its surface.

Indeed, water appears to make up about 40 percent of Ceres' volume, Li said.

"Ceres is actually the largest water reservoir in the inner solar system other than the Earth," he said. However, it's unclear at the moment how much, if any, of this water is liquid, he added.

As far as energy goes, Ceres has access to a decent amount via solar heating, since the dwarf planet lies just 2.8 astronomical units (AU) from the sun, Li said. (One AU is the distance between Earth and the sun — about 93 million miles, or 150 million km). Europa and Enceladus are much farther away from our star — 5.2 and 9 AU, respectively.

Both Europa and Enceladus possess stores of internal heat, which is generated by tidal forces. This heat keeps the ice-covered moons' subsurface oceans of liquid water from freezing up, and also drives the eruption of water-vapor plumes on Enceladus (and probably Europa as well; researchers announced last year that NASA's Hubble Space Telescope spotted water vapor erupting from the Jupiter moon in December 2012).

Intriguingly, scientists announced the discovery of water-vapor emission from Ceres — which may also possess a subsurface ocean — earlier this year.

Ceres' plumes may or may not be evidence of internal heat, Li said. For example, they may result when water ice near Ceres' surface is heated by sunlight and warms enough to sublimate into space.

"Right now, we just don't know much about the outgassing on Ceres," Li said.

Dawn should help bring Ceres into much clearer focus when it reaches the dwarf planet this spring. The spacecraft, which orbited the huge asteroid Vesta from July 2011 through September 2012, will map Ceres' surface in detail and beam home a great deal of information about the body's geology and thermal conditions before the scheduled end of its prime mission in July 2015.

Read more at Discovery News

Dec 22, 2014

Orangutan in Argentina Zoo Wins Right to Freedom

A female orangutan got cleared to leave a Buenos Aires zoo she has called home for 20 years, after a court ruled she was entitled to more desirable living conditions, lawyers said Sunday.

The 29-year-old orangutan, named Sandra, has been living in a zoo enclosure for two decades, which animal rights lawyers said was against her comfort.

Argentina's Association of Professional Lawyers for Animal Rights (AFADA) filed a "habeas corpus" writ -- a form of legal redress against unlawful imprisonment -- arguing she was "suffering an unwarranted confinement."

The lawyers said that while Sandra was not identical to humans biologically, she is in fact like humans emotionally, and would be happier living in a semi-wild habitat.

"She has lived in captivity for 20 years and the point of today's measure is for her to overcome having been held in captivity and depression, for her to be in semi-free conditions in a sanctuary," AFADA lawyer Andres Gil Dominguez told TN television.

If the ruling is not appealed, she could be moved to a semi-wild sanctuary in Brazil.

Lawyers had argued that under Argentine law, Sandra should be considered closer to a "person" than a "thing."

"If humanity's development centers on on our broadening reasoning, than Sandra is subject to law," Dominguez said.

"It's a very basic recognition."

Sandra was born in a German zoo in 1986 and moved to Argentina in 1994.

Read more at Discovery News

Global Warming Blamed for Pacific Coral Bleaching

The Marshall Islands is experiencing its worst-ever coral bleaching as global warming threatens reefs across the entire northern Pacific, scientists said Monday.

Marine researchers said an El Nino weather pattern had been developing in recent months, raising ocean temperatures and stressing delicate coral reefs.

"The worst coral bleaching event ever recorded for the Marshall Islands has been occurring since mid-September," Karl Fellenius, a Majuro-based marine scientist with the University of Hawaii told AFP.

C. Mark Eakin, manager of the US National Oceanic and Atmospheric Administration's Coral Reef Watch programme, said recent observations showed the problem was widespread across the vast waters of the northern Pacific.

"Major bleaching was seen in Guam and the Commonwealth of the Northern Marianas Islands, the northwestern Hawaiian Islands (NWHI), the Marshall Islands, and Kiribati," he said.

"Thermal stress levels set new record highs in CNMI and the NWHI and we saw the first widespread bleaching event in the main Hawaiian Islands."

Fellenius said coral bleaching was a naturally occurring phenomenon but not on the scale currently being seen.

"While bleaching can occur on very hot days in pools of water with little circulation (such as) very low tides on reef flats, it has become a global problem due to greenhouse gas emissions causing elevated temperatures under climate change."

He said sea surface temperatures had been on average half to a full degree Celsius higher than normal for months, adding: "This does not seem like a lot but it makes a big difference to corals."

Fellenius said the last major bleaching event was in 1997, when an exceptionally strong El Nino system affected about a quarter of the world's coral reefs.

He said indications were that the latest episode had affected up to 75 percent of smaller corals and 25 percent of the larger varieties at some sites in the Marshalls.

He said the bleached coral was becoming covered with algae, hindering its chances of recovery.

Read more at Disocvery News

NASA's Black Hole X-Ray Hunter Could Solve Solar Mystery

What’s the sun got in common with distant black holes? Well, at first glance, not a lot. But as this psychedelic solar portrait shows, there is one trait that the sun and black holes do have in common — the emission of high-energy X-rays.

Now NASA’s Nuclear Spectroscopic Telescope Array, or NuSTAR, has turned its gaze from distant black holes and focused on our sun, producing the most sensitive measurement of high-energy solar X-rays ever achieved.

Long before NuSTAR was even launched in 2012, solar physicist David Smith, of the University of California, Santa Cruz, approached the NASA NuSTAR mission team to request that the space telescope spend some of its observing time looking toward our nearest star.

Shifting focus from the high-energy X-rays generated by supermassive black holes in the centers of galaxies millions of light-years away to the sun may seem strange, but only NuSTAR has the capability of sensing the faint high-energy X-ray flashes generated by small-scale solar flares — known as nanoflares — deep inside the sun’s atmosphere, or corona.

“At first I thought the whole idea was crazy,” said NuSTAR principal investigator Fiona Harrison of the California Institute of Technology in Pasadena, Calif. “Why would we have the most sensitive high energy X-ray telescope ever built, designed to peer deep into the universe, look at something in our own back yard?”

Staring at the sun is as an unhealthy proposition for space telescopes as it is for the human eye. NASA’s Chandra X-ray space telescope, for example, would be blinded if it turned its gaze toward the sun as our nearest star generates a broad spectrum of low-energy to high-energy X-rays — Chandra is sensitive to all X-rays. But NuSTAR is unique in that it only detects the highest energy X-rays (blocking out low-energy X-rays) that are generated by powerful relativistic processes surrounding black holes.

And it is high-energy X-rays, which the sun very weakly radiates, that Smith is interested in. But why?

Solar physicists and space weather forecasters have been puzzled for decades as to why the sun’s corona is so hot. On comparison with the sun’s ‘surface’ — the photosphere — which has a temperature of a few thousand degrees Fahrenheit, the corona is (on average) 1.8 million degrees Fahrenheit (1 million Kelvin). That doesn’t make sense in our everyday experience; it would be like the air surrounding a light bulb being hotter than the bulb’s glass, a situation that completely violates basic thermodynamic laws — normally it gets cooler the further you step away from a heat source, not hotter!

So in an effort to explain this mysterious coronal heating phenomenon, solar physicists have arrived at two key theories that have some observational evidence. Magnetohydrodynamic waves — basically waves that travel from the sun’s interior and through the magnetized corona — are thought to resonate with the energetic coronal plasma, causing a heating effect. Another theory suggests that tiny ‘reconnection’ events in the magnetic field of the corona cause rapid heating of the coronal plasma, generating nanoflares. If these nanoflares occur throughout the corona, perhaps they act as sparks that maintain coronal heating to millions of degrees.

Nanoflares are predicted to generate high-energy X-rays, but they have so far proven illusive as we haven’t had the instrumentation to filter out all the noise.

“NuSTAR will give us a unique look at the sun, from the deepest to the highest parts of its atmosphere,” said Smith, who is also a member of the NuSTAR team. “NuSTAR will be exquisitely sensitive to the faintest X-ray activity happening in the solar atmosphere, and that includes possible nanoflares.”

Read more at Discovery News

Dust Devils' Powerful Updrafts Could Drive Mars Climate

Mars’ atmosphere is often viewed as frigid and unchanging, but in studies of the red planet’s aeolian processes, nothing could be further from the truth — particularly where Martian dust devils are concerned.

Aeolian, or wind-blown, processes dominate the Martian landscape; from space, aeolian features such as vast dune fields have fascinated planetary scientists. But another dominant atmospheric phenomenon studied by robotic missions in Mars orbit and on the ground is the dust devil, which often leaves its mark as dark curved paths in the dust.

Scientists are now beginning to understand how these swirling dusty vortexes are able to beef-up to the size of tornadoes we find on Earth and how they could impact the Martian climate.

“To start a dust devil on Mars you need convection, a strong updraft,” said atmospheric science graduate Bryce Williams, of the University of Alabama in Huntsville (UAH), at the American Geophysical Union’s fall meeting in San Francisco last week.

Dust devils, on Earth, are minor meteorological curiosities when the landscape is heated by sunlight. As the surface warms the air above it, the heat rises through the cooler upper layers. This convection can start to form a swirling vortex a couple of hundred meters high during an otherwise windless day. But their Mars cousins can dwarf their terrestrial counterparts, often becoming long-lived features reaching up to 12 miles high.

Now, Williams and supervisor Udaysankar Nair have been able to show how these fascinating funnels of air and dust are able to become super-sized.

“We looked at the ratio between convection and surface turbulence to find the sweet spot where there is enough updraft to overcome the low level wind and turbulence,” said Williams. “And on Mars, where we think the process that creates a vortex is more easily disrupted by frictional dissipation — turbulence and wind at the surface — you need twice as much convective updraft as you do on Earth.”

This conclusion was reached after studying meteorological data from Australian dust devils and comparing that with observations by NASA’s Viking Lander mission. The researchers were able to create a 1-dimensional “planetary boundary layer model” that could identify the ideal conditions for dust devil formation in the Martian atmosphere and, as it turned out, for a dust devil to form on Mars, more powerful convection currents were needed at the surface layers.

This study is much more than just a curiosity about Martian dust devils, however. Considering the Martian atmosphere is, on average, less than one percent the pressure of Earth’s atmosphere (at sea level), dust has a significant impact on the planet’s climate. As dust devils provide a mechanism for kicking substantial quantities of dust into Mars’ atmosphere, they could act as a global climate control of sorts.

Read more at Discovery News

Dec 21, 2014

New, tighter timeline confirms ancient volcanism aligned with dinosaurs' extinction

A definitive geological timeline shows that a series of massive volcanic explosions 66 million years ago spewed enormous amounts of climate-altering gases into the atmosphere immediately before and during the extinction event that claimed Earth's non-avian dinosaurs, according to new research from Princeton University.

A primeval volcanic range in western India known as the Deccan Traps, which were once three times larger than France, began its main phase of eruptions roughly 250,000 years before the Cretaceous-Paleogene, or K-Pg, extinction event, the researchers report in the journal Science. For the next 750,000 years, the volcanoes unleashed more than 1.1 million cubic kilometers (264,000 cubic miles) of lava. The main phase of eruptions comprised about 80-90 percent of the total volume of the Deccan Traps' lava flow and followed a substantially weaker first phase that began about 1 million years earlier.

The results support the idea that the Deccan Traps played a role in the K-Pg extinction, and challenge the dominant theory that a meteorite impact near present-day Chicxulub, Mexico, was the sole cause of the extinction. The researchers suggest that the Deccan Traps eruptions and the Chicxulub impact need to be considered together when studying and modeling the K-Pg extinction event.

The Deccan Traps' part in the K-Pg extinction is consistent with the rest of Earth history, explained lead author Blair Schoene, a Princeton assistant professor of geosciences who specializes in geochronology. Four of the five largest extinction events in the last 500 million years coincided with large volcanic eruptions similar to the Deccan Traps. The K-Pg extinction is the only one that coincides with an asteroid impact, he said.

"The precedent is there in Earth history that significant climate change and biotic turnover can result from massive volcanic eruptions, and therefore the effect of the Deccan Traps on late-Cretaceous ecosystems should be considered," Schoene said.

The researchers used a precise rock-dating technique to narrow significantly the timeline for the start of the main eruption, which until now was only known to have occurred within 1 million years of the K-Pg extinction, Schoene said. The Princeton group will return to India in January to collect more samples with the purpose of further constraining eruption rates during the 750,000-year volcanic episode.

Schoene and his co-authors gauged the age of petrified lava flows known as basalt by comparing the existing ratio of uranium to lead given the known rate at which uranium decays over time. The uranium and lead were found in tiny grains -- less than a half-millimeter in size -- of the mineral zircon. Zircon is widely considered Earth's best "time capsule" because it contains a lot of uranium and no lead when it crystallizes, but it is scarce in basalts that cooled quickly. The researchers took the unusual approach of looking for zircon in volcanic ash that had been trapped between lava flows, as well as within thick basalt flows where lava would have cooled more slowly.

The zircon dated from these layers showed that 80-90 percent of the Deccan Traps eruptions occurred in less than a million years, and began very shortly -- in geological terms -- before the K-Pg extinction. To produce useful models for events such as the K-Pg extinction, scientists want to know the sequence of events to within tens of thousands of years or better, not millions, Schoene said. Margins of millions of years are akin to "a history book with events that have no dates and are not written in chronological order," he said.

"We need to know which events happened first and how long before other events, such as when did the Deccan eruptions happen in relation to the K-Pg extinction," Schoene said. "We're now able to place a higher resolution timeframe on these eruptions and are one step closer to finding out what the individual effects of the Deccan Traps eruptions were relative to the Chicxulub meteorite."

Vincent Courtillot, a geophysicist and professor at Paris University Diderot, said that the paper is important and "provides a significant improvement on the absolute dating of the Deccan Traps." Courtillot, who is familiar with the Princeton work but had no role in it, led a team that reported in the Journal of Geophysical Research in 2009 that Deccan volcanism occurred in three phases, the second and largest of which coincides with the K-Pg mass extinction. Numerous other papers from his research groups are considered essential to the development of the Deccan Traps hypothesis. (The Princeton researchers also plan to test the three-phases hypothesis, Schoene said. Their data already suggests that the second and third phase might be a single period of eruptions bridged by smaller, "pulse" eruptions, he said.)

The latest work builds on the long-time work by co-author Gerta Keller, a Princeton professor of geosciences, to establish the Deccan Traps as a main cause of the K-Pg extinction. Virginia Tech geologist Dewey McLean first championed the theory 30 years ago and Keller has since become a prominent voice among a large group of scientists who advocate the idea. In 2011, Keller published two papers that together proposed a one-two punch of Deccan volcanism and meteorite strikes that ended life for more than half of Earth's plants and animals.

Existing models of the environmental effects of the Deccan eruptions used timelines two to three times longer than what the researchers found, which underestimated the eruptions' ecological fallout, Keller explained. The amount of carbon dioxide and sulfur dioxide the volcanoes poured out would have produced, respectively, a long-term warming and short-term cooling of the oceans and land, and resulted in highly acidic bodies of water, she said.

Read more at Science Daily

Top 10 Winter Holiday Myths


 With Thanksgiving and Hanukkah behind us and Christmas and New Year's Day still ahead, the holiday season is in full swing.

Given the mix of stories and superstitions that constitute holiday preparations and celebrations, seasonal myths can carry over year to year along with the traditions themselves. Consider those myths debunked.

Holiday Travel

Anyone flying home for the holidays last week probably saw a familiar sight at the airport: frantic passengers, long lines at the security screening and a cramped seat on a plane. The day before Thanksgiving certainly does feel like the busiest air travel time of the year.

Except it's not. In fact, some years it's not even in the top 10. In 2006, it was the 36th busiest and 55th in 2007.

The busiest travel days of the year aren't anywhere near the winter holiday season, but rather take place in the summer, on Friday in June, July and August.

Savory Dreams

 If you're still recovering from that food-induced coma you received on Thanksgiving, don't blame the tryptophan in your turkey. Despite the widespread belief that the amino acid triggers sleepiness, it's actually not the turkey's fault for causing drowsiness after a Thanksgiving meal.

Rather, it's the massive amount of carbohydrates and often alcohol that lead to that inevitable post-meal nap.

Traditional Thanksgiving?

Despite celebrating in what we believed the fashion of the Pilgrims at Plymouth, Thanksgiving today in no way resembles similar occasions that would have been held in the 17th century. Such events weren't organized or ritualized, according to a religious scholar at Davidson University.

When clergy did find occasion to call together parishioners to give thanks to God, Puritans didn't spend all day feasting, but rather sitting in church.

Our modern conception of Thanksgiving can be credited to a 19th-century magazine editor named Sarah Hale, who saw the holiday as a means of uniting Americans during a time of increasing factionalism.

In the Dark

Seasonal affective disorder (SAD) can lead to the winter blues, affecting some 5 percent of Americans. But the dark days of winter aren't as big a driver of depression in others, despite the lack of light being cited as a leading cause. Stress, sickness and other sources are more likely to blame.

Suicide Spike

Suicides don't spike during the holiday season, a grim myth with no statistical support. According to the Centers for Disease Control and Prevention, the suicide rate is at its lowest in December. It's actually at its highest in the spring and fall.

Read more at Discovery News