Tropical Forests Gulp CO2, Slowing Climate Change

If you’re worried about climate change, the recent news that 2014 was the hottest year on record didn’t help your anxiety. But here’s at least one positive bit of news to ease your mind a little. Researchers have discovered that tropical forests -- in reaction to rising atmospheric levels of carbon dioxide -- may be absorbing far more of the greenhouse gas than previously believed.

A NASA-led study, published in Proceedings of the National Academy of Sciences, estimates that tropical forests annually absorb 1.4 billion metric tons of carbon dioxide out of a total global absorption of 2.5 billion metric tons. That’s more than is absorbed by the boreal forest in Canada, Siberia and other northern regions, the researchers say.

“This is good news, because uptake in boreal forests is already slowing, while tropical forests may continue to take up carbon for many years,”  lead author David Schimel of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., said in a press release.

The planet’s wooded areas have been a big part of slowing the effects of increased human output of carbon dioxide, a process called sequestration. Trees remove CO2 from the atmosphere during photosynthesis, storing some of it in their wood and leaves, and transferring some to the soil through their roots, as this article from the U.S. Forest Service’s website explains. Forests and other vegetation take care of about 30 percent of human carbon emissions. But if that rate of absorption ever slows, the the rise in global temperature would speed up as a consequence.

For the past quarter-century, climate scientists have believed that the northern forests were sequestering more carbon dioxide than the tropical forests, based upon what was then understood about global air flow, and the belief that massive deforestation in tropical areas was causing those forests to emit more carbon than they were storing. But in the mid-2000s, Britton Stephens of the National Center for Atmospheric Research, who is another of the study’s co-authors, studied measurements made by aircraft and concluded that existing climate models were underestimating tropical forests’ carbon absorption. This new study builds upon that view.

From Discovery News

2 New Exoplanets More Like Earth Than Any Others

Astronomers have found eight more worlds properly situated from their parent stars for liquid surface water, a condition which, at least on Earth,  is believed to be key for life to evolve.

The newly found planets include two that are more similar to Earth than any other exoplanets found to date, astronomers said at a press conference Tuesday at the 225th American Astronomical Society meeting in Seattle, Wash.

“Most of these planets have a good chance of being rocky, like Earth,” astronomer Guillermo Torres, with the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., said in a statement.

Torres and colleagues found the planets by analyzing data collected by NASA’s Kepler space telescope. The Earth-cousins include Kepler-438b, located about 470 light-years away, and Kepler-442b, located about 1,100 light-years from Earth. Kepler-438b has a diameter just 12 percent bigger than Earth and Kepler-442b is one-third larger.

The planets orbit so-called red dwarf stars, which are smaller and cooler than the sun.

“We don’t know for sure whether any of the planets in our sample are truly habitable,” said David Kipping, also with CfA. “All we can say is that they’re promising candidates.”

A computer analysis published last year, however, raises questions about whether red dwarf stars make for life-friendly planets.

The study suggests a planet situated relatively close to a red dwarf star would be pummeled by powerful radioactive stellar winds. Theoretically, only planets with a strong magnetic field or thick atmosphere may be capable of hosting life — at least life as it appears on Earth, physicist Ofer Cohen, also with the Harvard-Smithsonian Center for Astrophysics, told Discovery News last year.

The new research is being published in The Astrophysical Journal.

From Discovery News

Hubble's Stunning New View of the 'Pillars of Creation'

Twenty years ago, the Hubble Space Telescope showed the world what has become one of the most famous images of our time. Staring deep into the Eagle Nebula, Hubble demonstrated its sheer imaging power, picking out the vast pillars of gas and dust in a star-making factory. Deep within their dusty cocoons, baby stars are being born, a factor that spawned the apt moniker “Pillars of Creation.”

I was only 15 when these mind-blowing views from Hubble started appearing in newspapers and magazines, and I remember having a huge poster on my wall of the Pillars that I’d often stare at, looking so hard at the details that I would eventually be frustrated by the pixelated resolution of the printed glossy paper. But now, in this brand new Hubble observation of the same portion of the Eagle Nebula, the harder you stare, it seems like the detail goes on forever.

Released today in celebration of Hubble’s 25th year in space, this version of the Pillars is more detailed than ever before, capturing the finer details over a wider view.

Using data collected by the Wide Field Camera 3 that was installed on Hubble in 2009, additional visible light detail has been added. As a bonus, an additional infrared layer has been released separately, producing an eery version of the Pillars of Creation — the cocooned stars that were once obscured by the opaque dust are suddenly visible:

Revisiting this star-forming region isn’t only great for some mind-blowing photos, it also serves a practical purpose. As one would expect, the Pillars are highly dynamic and astronomers can compare the original observations with this modern version 20 years later. Any rapid motion in the clouds and changing brightness in stars can be detected and analyzed, potentially enriching theoretical star formation models.

But for me, staring into the Pillars once more reminds me of my childhood fascination with the birth of stars within a nebula, the very definition of creation occurring only 6,500 light-years from Earth. This is where stars are born, eventually giving birth to systems of alien worlds and, in millions to billions of years time, possibly life.

Se moore at Discovery News

Tomb of Previously Unknown Pharaonic Queen Found

Czech archaeologists have unearthed the tomb of a previously unknown queen believed to have been the wife of Pharaoh Neferefre who ruled 4,500 years ago, officials in Egypt said Sunday.

The tomb was discovered in Abu Sir, an Old Kingdom necropolis southwest of Cairo where there are several pyramids dedicated to pharaohs of the Fifth Dynasty, including Neferefre.

The name of his wife had not been known before the find, Antiquities Minister Mamdouh al-Damaty said in a statement.

He identified her as Khentakawess, saying that for the "first time we have discovered the name of this queen who had been unknown before the discovery of her tomb".

That would make her Khentakawess III, as two previous queens with the same name have already been identified.

Her name and rank had been inscribed on the inner walls of the tomb, probably by the builders, Damaty said.

"This discovery will help us shed light on certain unknown aspects of the Fifth Dynasty, which along with the Fourth Dynasty, witnessed the construction of the first pyramids," he added.

Miroslav Barta, who heads the Czech Institute of Egyptology mission who made the discovery, said the tomb was found in Neferefre's funeral complex.

"This makes us believe that the queen was his wife," Barta said, according to the statement.

An official at the antiquities ministry said the tomb dated from the middle of the Fifth Dynasty (2994-2345 BC).

Archaeologists also found around 30 utensils, 24 made of limestone and four of copper, the statement added.

From Discovery News

Ancient Amulet Discovered with Palindrome Inscription

An ancient, two-sided amulet uncovered in Cyprus contains a 59-letter inscription that reads the same backward as it does forward.

Archaeologists discovered the amulet, which is roughly 1,500 years old, at the ancient city of Nea Paphos in southwest Cyprus.

One side of the amulet has several images, including a bandaged mummy (likely representing the Egyptian god Osiris) lying on a boat and an image of Harpocrates, the god of silence, who is shown sitting on a stool while holding his right hand up to his lips. Strangely, the amulet also displays a mythical dog-headed creature called a cynocephalus, which is shown holding a paw up to its lips, as if mimicking Harpocrates' gesture.

On the other side of the amulet is an inscription, written in Greek, that reads the same backward as it does forward, making it a palindrome. It reads:

ΙΑΕW

ΒΑΦΡΕΝΕΜ

ΟΥΝΟΘΙΛΑΡΙ

ΚΝΙΦΙΑΕΥΕ

ΑΙΦΙΝΚΙΡΑΛ

ΙΘΟΝΥΟΜΕ

ΝΕΡΦΑΒW

ΕΑΙ

This translates to "Iahweh(a god)is the bearer of the secret name, the lion of Re secure in his shrine."

Researchershave found similar palindromes elsewhere in the ancient world writes Joachim Sliwa, a professor at the Institute of Archaeology at Jagiellonian University in Kraków, Poland, in an article recently published in the journal Studies in Ancient Art and Civilization.

Sliwa notes that the scribe made two small mistakes when writing this palindrome, in two instances writing a "ρ" instead of "v."

The amulet was discovered in the summer of 2011 by archaeologists with the Paphos Agora Project. Led by Jagiellonian University professor Ewdoksia Papuci-Wladyka, this team is excavating an ancient agora at Nea Paphos, and uncovered this amulet during their work. Agoras served as gathering places in the ancient world.

Amulets like the one found at Nea Paphos were made to protect their owners from danger and harm, Papuci-Wladyka told Live Science in an email.

Christians and pagans

During the 5th and 6th centuries, Cyprus was part of the Eastern Roman Empire. The Roman Empire had split in two during the 4th century, with Cyprus falling under control of the east. When the Western Roman Empire fell during the 5th century, the Eastern Roman Empire continued to flourish and became what is sometimes called the Byzantine Empire.

By the 5th century, Christianity was the official religion of the Eastern Roman Empire, and as time went on, traditional polytheistic (also called pagan) practices came under tighter restrictions and bans. Nevertheless, some people continued to practice the old beliefs, worshipping the traditional gods.

This amulet adds to evidence that people practiced traditional, polytheistic beliefs on Cyprus for an extended time, Papuci-Wladyka said. She notes that a structure called the Villa of Theseus has a mosaic with pagan elements that was likely repaired as late as the 7th century A.D.

It "rather seems that Christian and pagan religions coexisted in Paphos in times of amulet being in use," Papuci-Wladyka told Live Science in an email.

Strange iconography

Despite that coexistence, the amulet has several unusual features that suggest its creator didn't fully understand the mythological characters depicted.

"It must be stated that the depiction is fairly unskilled and schematic. It is iconographically based on Egyptian sources, but these sources were not fully understood by the creator of the amulet," Sliwa wrote in the journal article.

Read more at Discovery News

Hidden World War II Battlefields Reveal Germans' Tactics

Deep in the forests of northwestern Europe, the ghosts of battle from World War II remain. These landscapes preserve troves of bomb craters, trenches and even the remains of supply depots — all of which have not been well studied until now.

These battleground remnants may shed new light on logistical support of German field armies and the impact of Allied bombings, researchers said in a new study.

David Passmore, a geoarchaeologist and lecturer at the University of Toronto, Mississauga, led the study. Passmore specializes in conflict archaeology, the study of battlefields and conflict in human societies.

"Although the history of the Second World War is widely documented and intensely researched, the archaeology of WWII has only recently begun to be formally investigated," Passmore told Live Science.

Forest battle scars

There have been plenty of studies on coastal fortifications, large battlefields and the D-Day landings, but Passmore couldn't find any documentation of conflict in the forests of Europe.

"We realized quite soon there had been very little formal study of WWII landscapes in these forested terrains," he said.

So, Passmore and his colleagues conducted a formal archaeological survey of key WWII battlegrounds from June 1944 through February 1945. In particular, the archaeologists focused on parts of northwestern France; the Ardennes forests of Belgium, Luxembourg and Germany; the Hürtgenwald and Reichswald forests of western Germany; and the woodlands around the Arnhem region of the Netherlands.

They conducted field walks of these areas based on information from academic studies, Internet searches and WWII heritage guidebooks. The researchers found evidence of bomb craters, foxholes and trenches, as well as German logistics depots.

These landscapes "can tell us a great deal," Passmore said. "These things illuminate war diaries and accounts of battlefield history, and provide a far more accurate impression of where troops were fighting, how they were fighting" and so on, he said.

What the Allies knew

The logistics depots provide a picture of exactly where and how the Germans established their support network for armies before the Allied invasion of Normandy, how they developed this network during the invasion and how the depots were overrun, Passmore said.

"We are now interested in investigating what the Allies knew of these depots, and how they went about attacking them with bomber forces," he said. By comparing Allied intelligence records of the suspected locations of German depots to the archaeological evidence, researchers can determine how successful the Allied bombings were.

Read more at Discovery News

Recipe for 'Earth-Like' Alien Worlds Discovered

After carefully measuring the masses of small, rocky exoplanets, astronomers have come to the conclusion that our solar system may not be unique and, by extension, those exoplanets surveyed are likely composed of similar materials as Earth.

Using the High-Accuracy Radial velocity Planet Searcher (HARPS) North instrument on the 3.6-meter Telescopio Nazionale Galileo in the Canary Islands, the researchers, led by Courtney Dressing of the Harvard-Smithsonian Center for Astrophysics (CfA), focused on the slight wobble small exoplanets exert on their host stars.

As an exoplanet orbits its star, the tiny gravitational pull can tug the star slightly off-center. By measuring this ‘wobble’ (through the analysis of the shifting of wavelength of the detected starlight), astronomers are able to determine the mass of that exoplanet. This mode of exoplanet detection is known as the “radial velocity” method. By combining these mass measurements with observations made by NASA’s Kepler Space Telescope, which uses the “transit method” to detect exoplanets and determine their physical size, the density of that exoplanet can be calculated. With this valuable information, scientists can begin to understand what that world is made of.

In a new study presented today (Jan. 5) at the 225th American Astronomical Society meeting in Seattle, Wash., and accepted for publication in the The Astrophysical Journal, Dressing’s team discussed their findings for small worlds that have a lot more in common with Earth than we thought.

“Our strategy for using HARPS-North over the past year has been to focus on planets less than two times the diameter of Earth and to study a few planets really well,” said astronomer David Charbonneau, also of the CfA and head of the HARPS-North Science Team.

One key discovery focused on Kepler-93b, an exoplanet identified by Kepler. It is known to be 1.5 times the size of Earth, but it has an extreme 4.7-day orbit around its host star. Before Dressing’s team began measurements of the distant world, very little was known about its mass and composition. But HARPS-North was able to precisely measure its mass to 4.02 times the mass of Earth. From this information alone, the astronomers could say that this world was a rocky exoplanet.

Then, the astronomers measured the densities of “all ten known exoplanets with a diameter less than 2.7 times Earth’s,” according to a CfA press release, and found that five of those worlds with diameters less than 1.6 times that of Earth showed a very tight relationship between mass and size. Most interestingly, both Earth and Venus, when added to the analysis, fitted neatly into the same correlation.

Read more at Discovery News

How To Gauge the Age of a Star? It's all in the Spin

Keeping accurate time and determining age are two crucial, constant goals in science. In the 1700s the proof and construction of an elegant, precise maritime clock opened up much safer and more efficient ocean exploration and provided a way forward for more accurate mapping on Earth. Before then, mariners and astronomers alike were both, literally, at sea.

Likewise, until now, determining the age of stars has been equivalent only to saying that a person is young or old, and our guesses of someone’s age are typically off by as much as 15 percent. But by building on the work of others (as it goes in science) and carefully working out for over a decade how to construct a “clock” to measure the ages of stars, Sydney Barnes, of the Leibniz-Institut fuer Astophysik Potsdam (AIP), Germany, derived an elegant and extraordinary method he named “gyrochronology” to derive a star’s age from its spin rate and its mass.

Barnes named his method from the Greek “gyros” which equals rotation, “chronos” which means time and “logos” for study.

“We here develop an improved way of using a rotating star as a clock, set it using the sun and demonstrate that it keeps time well,” wrote Barnes in 2007 (PDF), but his work on this groundbreaking theory goes back to 2000.

Now, in a new study published in the journal Nature and announced today at the 225th American Astronomical Society meeting in Seattle, Barnes and his colleagues have measured more than 20 sun-like stars believed to have identical ages, all belonging to a single a star cluster, and by showing that gyrochronology gives an age of 2.5 billion years for all of them to within 10 percent, have essentially proven the method beyond reasonable doubt.

“In fact, the uncertainty on the gyro-age of the cluster as a whole is two percent, which means that the new clock is now more precise than the ones used to set it,” said Barnes.

The study’s team, led by Soren Meibom, of the Harvard-Smithsonian Center for Astrophysics, in Cambridge, Mass., used NASA’s Kepler Space Telescope to measure the tiny variations of starlight over days or weeks that are caused as dark spots on the surfaces of the stars are alternately revealed and hidden by the rotation.

These space telescope measurements represent the culmination of a hard slog for over a decade by Meibom, Barnes and the other co-authors using ground-based telescopes to acquire and analyze the required support observations, to develop the theoretical framework adequately and to measure and interpret other appropriate clusters for possible deviations.

Among other crucial things, this work ensures that all the stars measured are indeed cluster members and that their interpretation resides securely within a framework that works for all other current knowledge about rotating stars.

“We have found that the relationship between mass, rotation rate and age is now defined well enough by observations -- and is sufficiently supported by the theory -- that it is possible to obtain the ages of non-cluster stars to within 10 percent,” said Barnes.

In the scientific race of the 1770s to determine longitude at sea, John Harrison designed and constructed a maritime clock that pinpointed longitude to within one half of a degree. Similarly, using the mathematical clock of gyrochronology, combined with state-of-the-art measurements from the Kepler Space Telescope and hard work from ground-based ones, this science team has made a quantum leap in accurately determining ages of stars.

“Now we can look at a random cool star on the sky and use the best gyrochronology models to get its age,” said Meibom.

“This means that precise ages can be derived for large numbers of cool field stars in our galaxy,” added Barnes.

Gyrochronology ushers in a new era in astronomy and astrophysics by enabling a better understanding of the chronologies of astronomical phenomena and how our galaxy was assembled over time. It could also help in selecting which planets to target in the search for ‘exo-life.’

But, like the stars it measures, gyrochronology is interesting a priori. An outline history of how this fundamental method was derived is also an unknown but compelling story. To this author it is a modern day history rather like the scientific journey towards accurately determining longitude at sea.

“After my academic training on the East Coast, I was lucky enough to be able to go out West for postdoctoral work,” recalled Barnes. “There I spent two years mostly relearning how to do science empirically by hiking Grand Canyon and wandering among the trees of the American Southwest, including those that inspired the founders of dendrochronology.” Dendrochronology is a branch of science concerned with determining the ages of trees by studying tree rings.

“In 2000 (published in 2001) in Madison, Wisconsin, where Soren and I became friends, I was examining the rotation rates of exoplanet host stars and realized that the overwhelming majority were not defined by the presence of planets,” Barnes recalled.

“Rather, their periods, like those of all the other cool stars, changed very simply with only two variables: stellar age and stellar mass. Two additional years of work resulted in my 2003 paper naming and describing gyrochronology.”

Since no one seemed to appreciate that such ages would actually be better than others, he published another paper in 2007, proving that such ages would also be precise.

Read more at Discovery News

Plant genetic advance could lead to more efficient conversion of plant biomass to biofuels

Plant geneticists including Sam Hazen at the University of Massachusetts Amherst and Siobhan Brady at the University of California, Davis, have sorted out the gene regulatory networks that control cell wall thickening by the synthesis of the three polymers, cellulose, hemicellulose and lignin.

The authors say that the most rigid of the polymers, lignin, represents "a major impediment" to extracting sugars from plant biomass that can be used to make biofuels. Their genetic advance is expected to "serve as a foundation for understanding the regulation of a complex, integral plant component" and as a map for how future researchers might manipulate the polymer-forming processes to improve the efficiency of biofuel production.

The three key components, found in plant tissues known as xylem, provide plants with mechanical strength and waterproof cells that transport water. Working in the model plant Arabidopsis thaliana, Hazen, Brady and colleagues explored how a large number of interconnected transcription factors regulate xylem and cell wall thickening. Results appeared in an early online edition Dec. 24 in Nature.

An invited commentary in the journal on the significance of this discovery points out that "understanding how the relative proportions of these biopolymers are controlled in plant tissue would open up opportunities to redesign plants for biofuel use."Hazen, Brady and colleagues'study identified hundreds of new regulators and offers "considerable insight," the authors say, "into the developmental regulation of xylem cell differentiation."

Specifically, using a systems approach to identify protein-DNA interactions, they screened more than 460 transcription factors expressed in root xylem to explore their ability to bind the promoters of about 50 genes known to be involved in processes that produce cell-wall components. Hazen says, "This revealed a highly interconnected network of more than 240 genes and more than 600 protein-DNA interactions that we had not known about before."

They also found that each cell-wall gene in the xylem regulatory network is bound by an average of five different transcription factors from 35 distinct families of regulatory proteins. Further, many of the transcription factors form a surprisingly large number of feed-forward loops that co-regulate target genes.

In other words, rather than a series of on-off switches that leads to an ultimate action like making cellulose, most of the proteins including regulators of cell cycle and differentiation bind directly to cellulose genes and to other transcription regulators. This gives plants a huge number of possible combinations for responding and adapting to environmental stress such as salt or drought, the authors point out.

Read more at Science Daily

Disco Clam Freezes Prey With Toxic Snot

The disco clam, so named because light flashes from its mirrored “lips,” turns out to be the disco ball from hell. New research has found that the clam’s impressive light show attracts prey, which may be rendered immobile by noxious, acidic mucus produced by the busy bivalve.

The unusual findings, reported at the 2015 annual conference of the Society of Integrative and Comparative Biology in West Palm Beach, Fla., solve the mystery as to why the disco clam (Ctenoides ales) puts on such a flashy light show.

At first it was thought that the clam might be trying to woo mates, but that sentiment might have been felt more by researcher Lindsey Dougherty of UC Berkeley. She was thrilled when she first encountered the unique clams in a dark, underwater cave during a dive in Indonesia.

“It was on that trip I first saw the disco clam, and immediately fell in love,” reminisced Dougherty in a press release.

She and her collaborators, Professor Roy Caldwell and undergraduate Alexandria Neibergall, brought some of the clams back to a lab to investigate why and how the clam’s flash.

First, the researchers determined that the flashes are caused by specialized tissues that form a double layer that is reflective to light on one side, but absorbent on the other.

When the tissue along the lip margins of the clam’s mantle is rapidly rolled and unfurled, the reflecting light gives the appearance of flashing. These tissues are so reflective that they can even flash using the low levels of blue light found in the caves. Disco clams are the only species of bivalve to have evolved structural coloration of this kind, according to the researchers.

The team next examined the structure and proteins in the clam’s tiny eyes using a powerful microscope. The researchers concluded the clam’s vision is too poor to allow it to observe displays by other clams. Since the clams aren’t visually attracted to each other, the wooing theory around the light show was tossed out.

The scientists then investigated what would happen if a predator threatened the disco clam.

“In this case, the false predator was just a styrofoam lid,” Dougherty said. “But it turns out a styrofoam lid is indeed pretty scary to the clams, because their flash rate almost doubled from just under 2 Hz to just under 4 Hz.”

Read more at Discovery News