Feb 27, 2016

The key to mass-producing nanomaterials

Nanoparticles -- tiny particles 100,000 times smaller than the width of a strand of hair -- can be found in everything from drug delivery formulations to pollution controls on cars to HD TV sets. With special properties derived from their tiny size and subsequently increased surface area, they're critical to industry and scientific research.

They're also expensive and tricky to make.

Now, researchers at USC have created a new way to manufacture nanoparticles that will transform the process from a painstaking, batch-by-batch drudgery into a large-scale, automated assembly line.

The method, developed by a team led by Noah Malmstadt of the USC Viterbi School of Engineering and Richard Brutchey of the USC Dornsife College of Letters, Arts and Sciences, was published in Nature Communications on Feb. 23.

Consider, for example, gold nanoparticles. They have been shown to be able to easily penetrate cell membranes without causing any damage -- an unusual feat, given that most penetrations of cell membranes by foreign objects can damage or kill the cell. Their ability to slip through the cell's membrane makes gold nanoparticles ideal delivery devices for medications to healthy cells, or fatal doses of radiation to cancer cells.

However, a single milligram of gold nanoparticles currently costs about $80 (depending on the size of the nanoparticles). That places the price of gold nanoparticles at $80,000 per gram -- while a gram of pure, raw gold goes for about $50.

"It's not the gold that's making it expensive," Malmstadt said. "We can make them, but it's not like we can cheaply make a 50 gallon drum full of them."

Right now, the process of manufacturing a nanoparticle typically involves a technician in a chemistry lab mixing up a batch of chemicals by hand in traditional lab flasks and beakers.

Brutchey and Malmstadt's new technique instead relies on microfluidics -- technology that manipulates tiny droplets of fluid in narrow channels.

"In order to go large scale, we have to go small," Brutchey said. Really small.

The team 3D printed tubes about 250 micrometers in diameter -- which they believe to be the smallest, fully enclosed 3D printed tubes anywhere. For reference, your average-sized speck of dust is 50 micrometers wide.

They then built a parallel network of four of these tubes, side-by-side, and ran a combination of two non-mixing fluids (like oil and water) through them. As the two fluids fought to get out through the openings, they squeezed off tiny droplets. Each of these droplets acted as a micro-scale chemical reactor in which materials were mixed and nanoparticles were generated. Each microfluidic tube can create millions of identical droplets that perform the same reaction.

Read more at Science Daily

Male Nursery-Web Spider Ties Up Partners During Sex

Tying up your lover is one way to introduce a little excitement to the bedroom. But for male nursery-web spiders, bondage during mating can be a matter of life and death. By restraining their partners, male spiders reduce their chances of falling victim to sexual cannibalism, a new study finds.

Nursery-web spiders (Pisaurina mira) are long-limbed hunters that catch and overpower their prey. Though the females' bodies can be a bit larger than males', measuring about 0.5 to 0.7 inches (12 to 17 millimeters) in length, researchers noted that males' legs were longer than females', relative to their body size.

Prior studies described the male spider's unusual mating behavior — wrapping silk around the female's legs before and during copulation — and the scientists wondered if longer legs would help males restrain their hungry mates, leaving the guys more likely to survive cannibalism sparked during the throes of passion.

In some insect and spider species, sex can be a deadly roll of the dice for males, carrying the possibility that their female partners may suddenly identify them as a convenient postcoital snack. While this is understandably not an ideal outcome for males, cannibalizing is "quite beneficial for the female," said Alissa Anderson, who co-authored the study.

Anderson, a behavioral ecologist at the University of Nebraska-Lincoln, told Live Science in an email that to a just-fertilized female with eggs to nourish, her mate's immediate value transforms from sex partner into "resources for her developing offspring" — like a Happy Meal with legs. In another spider species, Anderson and her colleagues explained in the study, when a female consumes the male after mating, it leads to more offspring and increases the little spiders' weight and chances for survival.

And it’s the conflict between these two competing desires — the female’s urgent need for sustenance and the male’s need to not die — that can lead to unusual sexual-survival strategies, Anderson said.

According to the researchers, in one spider species that practices sexual cannibalism, the males will play dead to keep from being eaten. In other species, males sedate the females into unconsciousness, while the males of still other species seek out and mate with females that are busy cannibalizing their earlier sex partners.

Or, like the nursery-web spider, males will bind the females’ legs securely in the pursuit of safer sex.

Silk serves several purposes for nursery-web spiders, though the arachnids don’t spin webs to catch prey. Females build “nursery webs” that hold newly hatched and developing spiderlings, while both males and females produce strands of silk that may be used like lifelines to help the critters swing to safety if they fall or are threatened.

And during mating, the males loop silk strands around the females’ legs. Other spiders may drape their mates with silk, but these nursery-web spiders are the only male spiders that use their silk to physically restrain females, Anderson told Live Science.

To study this, the researchers paired male and female spiders, with some of the males able to spin protective strands and some inhibited from spinning. The males that couldn’t restrain females were able to mate nearly as much as males that could bind their partners. But the unprotected males were also much more likely to be eaten afterward, the researchers reported.

Read more at Discovery News

Feb 26, 2016

Searching for planet 9

Location of a possible ninth planet. Analysis of radio data from the Cassini spacecraft defines forbidden areas (in red) where the perturbations created by the planet are inconsistent with observations, and a likely area (green) where the addition of the planet improves the model prediction, reducing the differences between the calculations and Cassini data. The position of minimum residues is the most likely location for a planet at P9. Scales are in astronomical units (AU).
Using observations from the Cassini spacecraft, a team of French astronomers from the Institut de mécanique céleste et de calcul des éphémérides (Observatoire de Paris / CNRS / UPMC / université Lille 1), and the laboratory GeoAzur (Observatoire de la Côte d'Azur / CNRS / Université de Nice-Sophia Antipolis / IRD) have been able to specify the possible positions of a ninth planet in the Solar System. This research is published on 22nd February 2016 in Astronomy & Astrophysics letters.

The Kuiper Belt Objects, small bodies similar to Pluto beyond Neptune, have a particular distribution that is difficult to explain by pure chance. This is what led Konstantin Batygin and Mike Brown at Caltech (US) to propose, in a paper published January 20,  in The Astronomical Journal, the existence of a ninth planet of 10 Earth masses, whose perturbations on Kuiper Objects could have led to their current distribution. Using numerical simulations, the two scientists determined the possible orbit of this planet. To be able to reproduce the observed distribution of Kuiper Belt Objects, this orbit, with a semi-major axis of 700 AU, must be very eccentric (e = 0.6) and inclined (i = 30°), but no constraint on the current position of the planet is proposed in the study of Batygin and Brown. This does not facilitate the task of observers who need to search in all possible directions in longitude to try and discover this planet.

Since 2003, Agnès Fienga (astronomer at the Observatoire de la Côte d'Azur), Jacques Laskar (CNRS senior researcher ) and their team have been developing the INPOP planetary ephemerides, which calculate the motion of planets in the Solar System with the highest accuracy. In particular, using data from the Cassini spacecraft (NASA / ESA / ASI), the distance between The Earth and Saturn is known with an uncertainty of about 100m. The researchers had the idea to use the INPOP model to test the possibility of adding a ninth planet in the Solar System, as proposed by Batygin and Brown.

In the study published this week, the French team shows that depending on the position of the planet from its perihelion (denoted "true anomaly"), the ninth planet induces perturbations in the orbit of Saturn that can be detected by analyzing the radio data from the Cassini spacecraft, orbiting Saturn since 2004. The researchers were able to compute the effect induced by the ninth planet and to compare the perturbed orbit to the Cassini data. For an angle from perihelion of less than 85 ° or greater than -65 °, the perturbations induced by the ninth planet are inconsistent with the observed Cassini distances. The result is the same for the sector from -130 ° to -100 °. This result allows to exclude half of the directions in longitude, in which the planet cannot be found. On the other hand, it appears that for some directions, the addition of the ninth planet reduces the discrepancies between the model calculated by the astronomers and the observed data, by comparison to a model that does not include this ninth planet. This makes plausible the presence thereof of the ninth planet for an angle from perihelion between 104 ° and 134 °, with a maximum probability for 117 °.

Read more at Science Daily

Record 6,250 Manatees Spotted in Florida Waters

The number of manatees in the waters around Florida have reached a new peak of at least 6,250, conservationists said Thursday, a record reflecting years of efforts to protect the marine mammals.

The count is up slightly from the 6,063 spotted last year, the Florida Fish and Wildlife Conservation Commission said in a statement, citing results from surveys conducted by 11 organizations.

Last month, the US Fish and Wildlife Service proposed downgrading the manatee’s status from endangered, a designation given to species on the brink of extinction, to threatened.

Manatees, which are also known as sea cows, have been on the endangered list for more than 40 years due to threats posed by urbanization, water contamination and collisions with boats.

During winter months, manatees head for warmer waters. Their return in the spring affords researchers an ideal opportunity to take stock of their health and their numbers.

The survey is conducted by air and the count represents the minimum number of manatees in the area.

The Florida manatees are part of the estimated

13,000 that also includes those living in the Caribbean and along the coasts of Colombia, Venezuela and Brazil.

Manatees live in shallow waters and must come to the surface to breathe about every 15 minutes. The herbivores can reach four meters (13 feet) long, weigh up to 600 kilos (1,300 pounds) and live about 40 years.

From Discovery News

New Monitor Lizard the Top Predator on Remote Island

Mussau Island, a small, partly volcanic stretch in Papua New Guinea’s St. Matthias chain, has been harboring for up to 2 million years a previously unknown species of blue-tailed monitor lizard.

The new species (Varanus semotus) can grow to well over 3 feet long and has a black body marked with yellow and orange. Its yellow tongue is a feature possessed by only three other monitor lizards in the Pacific. Adult tails take on a bluish or turquoise hue.

The creature is isolated from any other monitor lizard species, separated by several hundred kilometers of water from others of its kind. But, things could be worse. Islands as isolated as Mussau don’t tend to have colonizing, predatory mammals on scene.

That leaves smart, active lizards like V. semotus as the island’s top predator and general scavenger. It will eat other reptiles and their eggs, crabs, and small birds.

The team that discovered the lizard, led by University of Turku, Finland graduate student Valter Weijola, called the animal a ”biogeographical oddity.” Genetic analysis showed the animal to have been isolated on the island for a whopping 1 to 2 million years.

“Isolation is the keyword here,” said Weijola. “It is what has driven speciation and made the South-Pacific region one of the World’s biodiversity hotspots.”

“For anything to arrive on Mussau (from New Guinea or New Britain) it would need to cross 250-350 kilometers of open sea, and this doesn’t happen frequently,” Weijola added. “So, once the ancestor arrived, perhaps in the form of a gravid female, the population must have been completely isolated.”

“These islands are full of unique creatures often restricted in distribution to just one island or island group,” Weijola said. “Yet, we know relatively little about them. Even large species of reptiles and mammals are regularly being discovered, not to mention amphibians and invertebrates. This is what makes it such a biologically valuable and fascinating region.”

Details about the new species have been published by Weijola, Stephen Donnellan, and Christer Lindqvist in the open-access journal ZooKeys.

From Discovery News

Palm-Size Satellites Could Hunt for Alien Worlds

Tiny satellites could hitch a ride into orbit and spot alien worlds from afar, new research suggests.

NASA’s 2,230-pound (1,052 kilogram) Kepler Space Telescope has discovered thousands of potential planets around other stars. Now, some scientists want to go smaller: They propose searching for new worlds using miniaturized satellites that can fit in the palm of your hand.

“We want to be cheaper than sending up a huge satellite, to be able to collect more data in less time for less money,” Ameer Blake, an undergraduate student at Howard University in Washington, D.C., told Space.com. Blake and his adviser, Aki Roberge, a research astrophysicist at NASA Goddard Space Flight Center, studied the possibility of using a smaller instrument known as a cubesat to search for a new planet around the star Beta Pictoris, already known to host at least one world, Beta Pictoris b. He presented the results in January at the American Astronomical Society meeting in Kissimmee, Florida.

“We wanted to know, are there any other planets other than Beta Pictoris b, and if so, where are they?” Blake said.

Small but powerful

In 2008, scientists used NASA’s Hubble Space Telescope to reveal a giant planet more than 1.5 times the radius of Jupiter orbiting Beta Pictoris. Circling only nine times the Earth-sun distance from its star, just inside what would be the orbit of Saturn in the solar system, Beta Pictoris b is the closest orbiting exoplanet captured by direct imaging, the technique that essentially photographs other worlds. The method is most sensitive to giant planets several times the mass of Jupiter, and faces challenges when it comes to spotting smaller worlds or worlds close to their star.

Blake and Roberge are interested in launching a cubesat into space to search for a new world around the star. The evidence suggests the star’s system sits nearly edge-on as seen from Earth — that is, oriented so we’re looking at the edge of the system rather than from above or below. Researchers have seen a debris disk that stretches to over 1,400 times the Earth-sun distance on both sides of the star, and the known planet’s orbit also agrees with that orientation. This should allow a cubesat to search for other planets using a process called the transit method, which should be able to see worlds inside the orbit of Beta Pictoris b.

Unlike direct imaging, which relies on capturing the light reflected from a planet, the transit method, which is also used by the Kepler telescope, searches for dips in the brightness of the star as a planet moves between it and Earth. Instruments can only detect the transiting planets’ presence if they pass between the star and Earth, so the system must lie within a few degrees of being edge-on to Earth.

Based on their preliminary study, Blake said that a cubesat should be able to spot the most massive gas giants on a short orbit.

“We would definitely be able to see hot Jupiters,” he said, referring to the worlds several times the mass of the solar system’s largest planet in orbits closer than Mercury’s.

“We would like to get as small as maybe Neptune-size planets, but things get more complicated when you get to smaller sizes.”

Stare & collect

Several years ago, planet hunter Sara Seager, of the Massachusetts Institute of Technology, proposed using a fleet of cubesats to survey part of the sky in search of worlds beyond the solar system. Blake said the idea inspired him and his adviser to consider a single instrument targeting only one star. This avoids concerns about focusing or redirecting a suite of satellites.

“This is just, stare at one thing and collect as much information as possible,” Blake said.

Blake said that sending up a single satellite would make a good first step toward an entire fleet. Once the method is proven to work, other satellites could be launched to either discover new worlds or confirm preliminary observations, such as those made by Kepler.

When it comes to discovery, however, the search would need to be limited to stars which already demonstrate that their systems are edge-on to Earth. Researchers can identify such stars by observing massive debris disks around them or targeting stars with directly imaged worlds whose orbits are edge-on.

Cubesats were first introduced in 1999 as compact satellites that university students could construct to perform experiments and test new technologies. They take the standardized shape of a 4 x 4 x 4-inch (10 x 10 x 10 centimeters) cube, which allows them to hitch a ride into space with other, larger launches. Two will be launched in March 2016 to cover the entry, descent, and landing of NASA’s upcoming Mars InSight lander, while other scientists have discussed dropping them off at destinations such as Europa and Enceladus.

Read more at Discovery News

A Year Ago, The Dress Murdered the Idea of Objective Color

A year ago I wrote a story attempting to explain the perceptual science behind why some people looked at a picture of a woman’s dress and saw it as blue while others saw it as white. People really, really cared—not, I now know, because anyone gave a damn what color the dress actually was, but because its color seemed so manifestly obvious that when someone else saw it as something else, it felt like an affront, a threat to one’s self-image. Whoever disagreed with you wasn’t just wrong but, like, nuts, right? We’re all just one screenshot away from turning into a nation of Internet commenters, I guess.

It was a thrill, then, to use a scientific explanation (albeit, I’ll grant you, a speculative one) not to drive a wedge between opposing opinions but to unite them. I talked to some researchers who specialize in color vision, and they told me that the picture of the dress was a sort of optical illusion that worked through color instead of line and form. Owing to a property called color constancy—the brain’s tendency to interpret an object as having a specific color based on experience as opposed to the actual wavelength of light the object is reflecting—the dress could plausibly appear as more than one color. Unlike many optical illusions, though, most people didn’t flip back and forth between two interpretations. Once you saw the dress one way, you tended to keep seeing it that way.

Despite thousands of years of thinking and hundreds of years of research, scientists are still working out exactly how people see colors. The ineffable combination of photons bouncing off of objects in real space, entering people’s eyes, interacting with the pigments that talk to the optic nerve, converting into neuroelectrical signals, and then pinging around the visual cortex isn’t a solved problem. It’s on the tip of the spear of science, up there with unifying quantum physics and gravity, or figuring out how life first evolved on Earth.

What I didn’t write about last year, though, is the philosophical question of what color is and why we see it the way we do. You think the scientists have problems? Oy. As soon as you tell a philosopher that the subatomic particles that comprise all matter don’t have color as such, because photons don’t really interact with them in any meaningful way, or that the photons that bounce off of matter don’t make it past the back of the eyeball and instead transduce to electrical signals, manifested as images in brain-meat somehow … well, that’s how you blow a philosopher’s mind, my friend.

The big shots all took a crack at color—Aristotle, Aquinas, Galileo, Descartes, Newton, Goethe. Nobody could figure it out. And it’s a big deal because, as M. Chirimuuta writes in Outside Color: Perceptual Science and the Problem of Color in Philosophy (yes, this is going to be one of those kind of articles), “the color question is a single instance of the larger issue concerning the secondary qualities—the ontological status of smells, sounds, tastes, and the tactile qualities. It is assumed, rightly or not, that once we settle on a solution for color, this result will be smoothly translated across to our theories of these other modalities.”

In other words, color is a proxy for understanding the difference between objective reality and the version of it that people perceive with their senses and create in their brains. It’d be good to connect those things.

Well, don’t get your hopes up. As Chirmuuta explains, the way you think about color has a lot to do with the way you think about the universe. If you think that everything we perceive is just an outcome of how our brains convert inputs to neural zaps, you’re an antirealist. The Matrix is just as real as something “real,” if you see what I mean. If, on the other hand, you think it’s obvious that there’s a real world out there, and photons bounce off of things and their wavelengths have an objective meaning apart from perception, you’re a realist. Or maybe you’re a relationist, who thinks of colors “in terms of relations between objects and perceivers.” Color is maybe a “psychobiological” property that lets living things discriminate among objects acutely and reliably.

Is there color, in other words, without a brain to see it? What about animals with different visual systems, like the reptiles, bugs, and birds that can see wavelengths of the spectrum we humans can’t? Infrared and ultraviolet? Those colors are real to them and invisible—nonexistent—to people. But they still exist. Right? What about people who are tetrachromic, whose eyes have four ways of seeing colors instead of the usual three? Or people who are red-green colorblind, who perceive fewer colors than most humans? Just because some people see a given color and others don’t, that doesn’t make the color less real.

And don’t get me started on the shared-metaphor problem of whether your “red” is my “red,” and what those “reds” are “like.” Let’s just agree that when you and I see something with a wavelength of roughly 650 nm, it’s what we both call “red,” and be thankful for the consensual hallucination we construct as language.

Play a game with me. Imagine Earth before anything lived on it. It had water, rocks, and sky … but nobody was looking at it. The entire visible spectrum was there—white clouds, black night sky, green emerald crystals, yellow lightning flashes, red flowing magma. But none of the adjectives mattered in any real sense.

When terrestrial plants learned to pull energy from the broad-spectrum energy output of the sun, they did it by absorbing all the photons except the green ones. I’m simplifying here—quite a lot, actually—but the idea I want to get across is that plants are only accidentally green, a function of how photosynthesis happens, based on the molecular structure of chlorophyll (in roughly the same way that blood’s ability to carry oxygen via a molecule called hemoglobin, based around an iron atom, makes it necessarily, physically red.)

Read more at Wired Science

Feb 25, 2016

First Animal on Earth Was Likely the Sea Sponge

Sea sponges, widely considered the first animals on Earth, now have some extra ammunition to back up that belief.

A molecule present in 640-million-year-old rocks comes from a simple sea sponge, according to genetic analysis done by Massachusetts Institute of Technology (MIT) researchers. The time frame is well before the Cambrian Explosion 540 million years ago, in which most animals groups sprang up and took hold in a relatively short geologic stretch.

That makes the humble sea sponge a likely bearer of the title “first animal on Earth.”

That’s according to findings appearing in a paper just published in the journal Proceedings of the National Academy of Sciences by lead author David Gold and senior author Roger Summons, both from MIT.

True to its name, the Cambrian Explosion produced no shortage of fossils. But very few pre-Cambrian samples exist. That paucity has made it difficult for scientists to determine which animal was first.

The MIT researchers decided to look for the elusive first creature by studying molecular fossils –- trace molecules still present in ancient rocks after the animal that left them has long since decayed into nothingness.

Gold and Summons focused on a particular molecule: 24-isopropylcholestane, or 24-ipc. It had been found, through prior research, in the 640-million-year-old rocks.

They suspected the molecule was from a sea sponge, as some modern sponges are known to produce it. But, the rub was that some forms of algae also make 24-ipc. So they had to prove the molecule came from a sea sponge, while ruling out algae.

The researchers first identified the gene that made the molecule, observing that sea sponges and algae have an extra copy of the gene.

Then, after some evolutionary-tree detective work, they traced the extra-copy genetic behavior back to its oldest evolutionary carrier: the sea sponge. It turned out the sponge had evolved the extra gene copy well before algae, sometime around -- you guessed it -- 640 million years ago.

Read more at Discovery News

Iron Age Skeletons Found Buried With Turtles

Excavations at a site in southeastern Turkey has revealed the more than 2,500-year-old remains of a woman and a child who were buried with several previously slaughtered and butchered turtles.

Most of the turtles belonged to the Euphrates softshell species, known for their aggression.

The unique burial was found at Kavuşan Höyük, a multi-period mound site on the southern bank of the Tigris River, some six miles from the modern town of Bismil in Turkey.

Dated to the late Iron Age, which is known locally as the post-Assyrian period, the pit revealed the skeletons of a 6-7-year-old child and a woman aged between 45 and 55 years.

Lying face down, the infant, whose sex wasn't identified, had the left leg bent at the knee and the right leg fully extended. The right arm lay under the body, while the left was stretched above the shoulder, as if protecting the face.

"A broken iron fibula grave good that was placed next to the skull may indicate that the child was a girl," Rémi Berthon, archaeozoologist at the National Museum of Natural History in Paris, France, Güriz Kozbe, professor of archaeology at the Batman University, Turkey, and colleagues wrote in the latest issue of Antiquity.

Directly beneath the child, was the female skeleton, lying on her back in a semi-flexed position. No evidence of trauma related to a violent death was found in both skeletons.

Since ancient DNA analyses were not performed, the researchers have no information on the relationship between the adult women and the child.

“We know that the child and the woman were buried in a short time range because the woman’s skeleton, found just below the child, has not been disturbed when the child’s body was placed into the grave,” Berthon told Discovery News.

All around the edge of the pit, the archaeologists found numerous remains of turtles. Two carapaces and some scattered skeletal elements were also found in the middle of the grave.

One of the centrally deposited shells belonged to a spur-thighed tortoise (Testudo graeca), 17 remains were of Euphrates soft-shelled turtles (Rafetus euphraticus) and three belonged to Middle Eastern terrapins(Mauremys caspica).

“Although the Middle Eastern terrapin is very common in eastern Turkey, this is the first evidence of its use as a grave good. Finding Euphrates soft-shelled turtles in a burial is unprecedented as well,” Berthon said.

Characterized by an olive-green leathery skin that covers the carapace, the Euphrates softshell turtles are primarily known as having a carnivorous diet, although they also feed on plants and vegetables.

“They are also scavengers and have frequently been observed feeding on the drifting carcasses of various mammals, which can be as large as a horse,” the researchers wrote.

The Euphrates soft-shelled turtles that were placed in the grave were clearly butchered.

“Some anatomical parts are missing, suggesting they were taken away, probably for consumption in the frame of a funerary feasting,” Berthon said.

The tortoise and terrapins, meanwhile, were seemingly neither butchered nor consumed during the funerary rites.

“Only their empty carapaces were used as grave goods,” the researchers noted.

Chelonians had a strong symbolic value in the ancient Near East and were strongly connected with afterlife.

“We call them psychopomp animals, responsible for escorting newly deceased souls to the afterlife, Berthon said. “The ritual evidenced in the burial probably attests to the peculiar social status of the deceased."

Read more at Discovery News

Rare Charles Darwin Letter Will Be Sold at Auction

A rare handwritten letter by famed naturalist Charles Darwin to a British marine biologist will be auctioned off Thursday, in which he details plans to release a corrected version of the book “The Origin of Species.”

In the letter, Darwin also expresses excitement about the work of the marine biologist George Charles Wallich on brittle starfish but also wonders about his findings on basaltic pebbles. He also thanks Wallich for sending his book “Notes on the Presence of Animal at Vast Depth in the Sea” and asks about Wallich’s observations regarding shell deposits, which are important “for me in relation to some few passages in my Book.”

“This signed letter concerning deep ocean discoveries shows Darwin’s interest in biological life and geology at the ocean bottom and his meticulous efforts at clarifying the findings of Wallich,” Nate Sanders, owner of Nate D. Sanders Auctions, said in a statement. “Darwin’s attention to details demonstrates why he was such a superb naturalist.”

It is the latest of several Darwin letters to be auctioned off. In September, a Darwin letter in which he stated he did not believe in God was sold for $197,000 at Bonhams New York. That was three times the previous record of $59,142 for a four-page letter that Darwin had penned to his niece.

A month later, Bonhams sold a letter from Darwin on the sex life of barnacles for $25,000.

This letter was written on Dec. 12, 1860, about a year after the publication of “The Origin of Species.” The book is considered the foundation of evolutionary biology and introduced the idea that species evolved over generations through the process of natural selection.

Read more at Discovery News

Warming Slowdown Was Real, Scientists Say

A global warming slowdown has come and gone, but an academic brouhaha continues to boil over the nitty gritty details of what once was a great scientific mystery.

On Wednesday, a group of prominent scientists published a commentary faulting colleagues who have published papers downplaying or dismissing the significance of a 13-year slowdown in warming rates at the planet’s surface.

“We shouldn’t sweep the early 2000s warming slowdown under the rug,” said Penn State meteorology professor Michael Mann, one of 11 authors of the commentary published in Nature Climate Change.

Temperature measurements taken at the surface of the planet from 2001 to 2014 revealed a lull in the rate of global warming, sometimes called the “warming hiatus,” before spiking upward again. Then 2014 was the hottest year on record until the record was easily beaten in 2015.

Until 2009, scientists had little explanation for the phenomenon. By 2014, though, it was known that the slowdown was caused primarily by a phase in a slow-moving Pacific Ocean cycle, with fierce trade winds driving more heat than normal into ocean depths.

The slowdown at the planet’s surface coincided with a rise in temperatures in ocean depths, worsening sea-level rise.

“The temporary slowdown in no way implies that human-caused warming has ceased or slowed down,” Mann said. “It was temporarily masked by natural factors.”

Several recent papers have called into question whether the surface warming slowdown was significant. Some of the disagreements boil down to semantics; others relate to interpretations of data.

Wednesday’s commentary lauded the advances in climate science that helped solve the mystery of the slowdown, while rebuking other scientists whose research has concluded that the slowdown was insignificant or unimportant.

“Given the intense political and public scrutiny that global climate change now receives, it has been imperative for scientists to provide a timely explanation of the warming slowdown,” wrote the 11 scientists, who are based in Canada, England, Australia and the U.S. “Despite recently voiced concerns, we believe this has largely been accomplished.”

One of the studies singled out in the commentary was produced by National Oceanic and Atmospheric Administration scientists led by Thomas Karl, who directs the agency’s National Climatic Data Center.

Karl’s team believes some historical records of ocean temperatures are flawed, and they corrected them accordingly.  The result of that analysis led them to conclude in a paper published last year in Science that warming during the early 2000s was “far more similar” to the longer-term trends “than previously estimated.”

That surprise finding prompted Rep. Lamar Smith, a Republican from Texas who is chairman of the House Committee on Science, Space and Technology, to aggressively push for access to the government scientist’s emails, part of an investigation that others have characterized as a witch hunt.

Smith has argued that the NOAA study was “expedited to fit” the Obama Administration’s “aggressive” climate policies — a claim the agency strongly denies.

Karl on Wednesday stood by his work, saying “there is no disagreement” that temperatures and warming rates vary between decades. “We showed that one could not claim that the long-term warming trend was significantly different from the shorter period,” he said.

Wednesday’s commentary was a reminder that opposition to NOAA’s findings is not just from politicians and fossil fuel groups, but from researchers who are convinced that the warming slowdown was real — and worthy of a public conversation.

The new commentary included new analysis of temperature data that showed what the authors described as a “mismatch” between early-century rates of warming and rates projected by model simulations.

“We’re presenting results to support previous findings of reduced rates of surface warming,” said John Fyfe, a Canadian government climate scientist who coordinated publication of the commentary. “That essentially refutes the Karl et al. paper.”

Fyfe said he had “no doubt” that the commentary would be misused by climate science deniers, but that he had no hesitations about publishing it. “I don’t think we should be in the business of pandering to the climate deniers.”

Two other teams of scientists whose papers were critiqued in the commentary downplayed any differences in opinion, pointing to the consensus that global warming and natural variability both affected early-century surface temperatures.

“Their perspective is very much in line with our previously published work,” said Noah Diffenbaugh, one of four Stanford researchers who wrote a paper published last year in Climatic Change provocatively titled “Debunking the climate hiatus.” “Global warming has resulted in a long-term trend superimposed on natural climate variability.”

Another paper criticized in the commentary was published last year by the Bulletin of the American Meteorological Society. In it, three scientists led by University of Bristol cognitive psychology professor Stephan Lewandowsky concluded that “there is no evidence that identifies the recent period” of warming as “unique or particularly unusual.”

That paper argued against the use of the term “global warming hiatus,” or “pause,” which is sometimes used to describe the recent global warming slowdown.

Read more at Discovery News

Human Teeth Likely Shrank Due to Tool Use

Wisdom teeth may have shrunk during human evolution as part of changes that started with human tool use, according to a new study.

The research behind this finding could lead to a new way of figuring out how closely related fossil species are to modern humans, scientists added.

Although modern humans are the only surviving members of the human family tree, other species once lived on Earth. However, deducing the relationships between modern humans and these extinct hominins — humans and related species dating back to the split from the chimpanzee lineage — is difficult because fossils of ancient hominins are rare.

Teeth are the hominin fossils most often found because they are the hardest parts of the human body. “Teeth are central to how a fossil ancestor lived, and can tell us about which species they belonged to, how they are related to other species, what they ate, and how quickly or slowly they developed during childhood,” said lead study author Alistair Evans, an evolutionary biologist at Monash University in Melbourne, Australia.

Hominin teeth have shrunk in size throughout evolution, a trend perhaps most clearly seen with the wisdom teeth located at the back of the mouth, the researchers said. In modern humans, wisdom teeth are often very small or do not even develop, while in many other hominin species they were huge, with chewing surfaces two to four times larger than those of their modern human counterparts.

Previous research suggested this profound shrinking in modern human wisdom tooth size was due to the advent of cooking or other changes in diet unique to modern humans. However, Evans and his colleagues now suggest this shift may have begun much earlier in human evolution.

The scientists analyzed tooth size in modern humans and fossil hominins. They found that hominin teeth fell into two major groups. One group was composed of the genus Homo, which includes both modern humans and extinct human relatives. The other group was made up of early hominins preceding Homo, such as the australopiths, the first primates to walk on two feet.

In australopiths and other early hominins, the scientists found that teeth tended to get bigger toward the back of the mouth, with proportions that stayed constant regardless of the overall size of the teeth. However, in the genus Homo, the smaller all the teeth were, the smaller the teeth were toward the back of the mouth.

“There seems to be a key difference between the two groups of hominins — perhaps one of the things that defines our genus Homo,” Evans said in a statement.

This change in how teeth developed between genus Homo and earlier hominins may have occurred due to the advent of advanced tool use in the genus Homo, Evans said.

“It’s always been presumed that sometime in early Homo, we started using more advanced tools,” Evans told Live Science. “Tool use meant we didn’t need as big teeth and jaws as earlier hominins. This may then have increased evolutionary pressure to spend less energy developing teeth, making our teeth smaller.”

In modern humans, tooth-size reduction has reached the point where wisdom teeth are increasingly failing to develop, Evans said. “The advent of cooking made food easier to eat, meaning we didn’t need big teeth as much,” Evans said.

Prior work suggested there was a lot of variation in how teeth evolved in hominins. “Now we’re seeing some very simple, clear patterns in hominin tooth evolution instead,” Evans said. [Infographic: Human Origins – How Hominids Evolved]

These patterns could help researchers decide whether ancient hominins were members of genus Homo or not, Evans said.

“It’s been suggested a number of times over the past 20 years that maybe Homo habilis, often considered the earliest member of Homo, should be considered an australopith instead,” Evans said. “We found Homo habilis tooth proportions followed the australopith rule and not the Homo rule, which supports the argument that Homo habilis should be reclassified to something like Australopithecus habilis.”

This new work builds on previous experiments with mice that suggested teeth could influence each other during development. In this “inhibitory cascade model,” teeth that develop early can inhibit the size of teeth that develop later. These new findings suggest this mechanism underlying tooth size in mice and most mammals is seen in hominins as well, Evans said.

These findings suggest that by knowing the size of a single hominin tooth and the group to which it belongs, scientists could infer the size of the hominin’s remaining teeth with considerable accuracy. “Sometimes we find only a few teeth in a fossil,” Evans said. “With our new insight, we can reliably estimate how big the missing teeth were.”

Read more at Discovery News

Feb 24, 2016

Mystery Ocean Hum May be Migration Signal, or Fish Farting

Vast communities of migrating deep-sea marine life are the culprits behind a mysterious, low-frequency humming sound in the ocean, made as the creatures swim to and from the surface at feeding time.

The discovery, made by University of California, San Diego assistant research biologist Simone Baumann-Pickering, answers a long-standing question. The source of the hum has for years vexed marine biologists, as NPR reports. They knew the sound wasn't consistent with whale calls or other marine mammals, such as dolphins, communicating.

Now, thanks to high-sensitivity undersea audio recordings, Baumann-Pickering says it's animals such as fish, jellies, shrimp, and squid living in what’s known as the ocean’s mesopelagic zone – a range 200 to 1000 meters (660 to 3300 feet) below the surface – that are behind the sound.

Creatures in the mesopelagic neighborhood live deep down, in a dark world where the sun barely shines and there’s not exactly a bounty of food. So each night, with the safety of darkness, they venture up to the surface where food is more plentiful.

And when they head up top (or back down) the hum -- about 3 to 6 decibels louder than ocean background noise -- kicks in.

“It’s not that loud,” Baumann-Pickering said in a statement. “It sounds like a buzzing or humming, and that goes on for an hour to two hours, depending on the day.” (Check out a sound clip of the humming here.)

The purpose behind the sound is still an open question. Baumann-Pickering said it could be a signal to the entire group to head up to the surface or back down.

While it’s neat to think that such communication could be happening among the animals, there could also be a less high-minded reason for the hum. It turns out the creatures might just be passing gas, as their swim bladders regulate their buoyancy.

“It’s known that some fish are considered to be farting,” Baumann-Pickering told NPR, “that they emit gas as they change depths in the water column.”

Read more at Discovery News

Beaten-Up Dinosaur Lived Through Intense Pain

A carnivorous dinosaur from Arizona suffered from “record-breaking pain,” according to a new study that looked at the animal’s remains.

The dinosaur, Dilophosaurus wetherilli, lived about 193 million years ago and shows evidence of having survived the largest number of broken forelimb bones in any known meat-eating dino. The findings are published in the journal PLOS ONE.

“It is not possible to determine with certainty the number of traumatic events that this plethora of pathological features represents,” co-authors Phil Senter of Fayetteville State University and Sara Juengst of Appalachian State University wrote. “It is possible that the entire array of fractures and punctures is the result of a single, high-energy encounter.”

For example, the authors say the dinosaur’s fractures may have occurred when the animal was smashed into a tree or rock face during a fight. It also had puncture wounds that may have been inflicted by its foe’s claws during the same encounter. The authors say it’s at least certain the animal survived its traumatic encounter since they could detect a high level of healing at its wound sites.

Senter and Juengst analyzed the remains of the dinosaur, which once measured about 20 feet long and weighed around 1100 pounds. The fossils were found in the Arizona’s Kayenta Formation that is spread across the Colorado Plateau.

The researchers believe signs of healing indicate the dinosaur “survived for months and possibly years after its ailments began, but its right third finger was permanently deformed and lacked the capability” of flexing.

Some of the deformities might have been due to a condition known as “developmental osteodysplasia,” which afflicts some modern birds. This is an abnormality in the way that bone develops. The affliction, combined with one or more traumatic events, could explain what happened to the victim.

The scientists suspect that life was incredibly challenging for the dinosaur, after the bone problems occurred.

Read more at Discovery News

Dodo Birds Not So Dumb After All

Dodos weren’t as dumb as their reputation suggests. New research finds that these extinct, flightless birds were likely as smart as modern pigeons, and had a better sense of smell.

Dodos (Raphus cucullatus) had gone extinct by 1662, less than 100 years after their island home of Mauritius became a destination for Dutch explorers. The birds, unfamiliar with humans, were initially fearless. This made them easy pickings for hunters and also cemented their reputation as dullards.

A new computed tomography (CT) scan of a rare, intact dodo skull reveals that these birds had brain-to-body sizes that are similar to those of modern pigeons.

“It’s not impressively large or impressively small — it’s exactly the size you would predict it to be for its body size,” study researcher Eugenia Gold of Stony Brook University said in a statement, referring to the dodo’s brain. “So if you take brain size as a proxy for intelligence, dodos probably had a similar intelligence level to pigeons.”

And pigeons aren’t that dumb. Studies find that they’re capable of recognizing and remembering human faces. They’re also very trainable and have mathematical abilities similar to those of rhesus monkeys.

Gold, an anatomist, was interested in learning more about the dodo’s ecology, as this bird is mostly known through the contemporaneous accounts of the sailors and settlers who brought about the animal’s demise. A few living dodos were brought back to Europe, she and her colleagues wrote today (Feb. 23) in the Zoological Journal of the Linnean Society. But those animals were kept confined and fed human food, making them fat. Wild dodos may not have looked like the portly birds seen in European illustrations.

Gold and her colleagues conducted a CT scan of the dodo skull, which was at the Natural History Museum, London. They also scanned the skull of the dodo’s closest relative, the Rodrigues solitaire (Pezophaps solitaria). This flightless bird lived on the Indian Ocean island of Rodrigues and went extinct in the 1700s, due to overhunting and other human activities. Using the scans, the researchers then reconstructed virtual “casts” of the bird brains.

Read more at Discovery News

Gravitational Wave Black Holes Born From One Star?

The pair of black holes the set off the first detection of gravitational waves through space may have been spawned by the death of a single, massive star.

“It’s the cosmic equivalent of a pregnant woman carrying twins,” astrophysicist Avi Loeb, with the Harvard-Smithsonian Center for Astrophysics, said in a statement.

Scientists believe that when a massive star explodes, its core collapses into a black hole, which is a region so dense with matter that not even photons of light can escape from the gravitational warping of space and time.

Scientists detected a gamma ray flash on Sept. 14, 2015, just a fraction of a second after the Laser Interferometer Gravitational-wave Observatory (LIGO) picked up the first signals of gravitational waves, caused in this case by the merger of two black holes.

Gravitational waves are similar to electromagnetic radiation, such as radio, visible, light and X-rays, except that it is space itself that is waving.

Loeb believes that that gamma ray burst may be a clue that the black holes seen by LIGO were twins, born out of the destruction of a single star.

He theorizes that if the star was spinning very fast, the core may have been stretched into a dumbbell shape, and then separated into two sections, each forming a black hole.

“In order to power both the gravitational wave event and the gamma-ray burst, the twin black holes must have been born close together, with an initial separation of order the size of the Earth, and merged within minutes. The newly formed single black hole then fed on the in-falling matter, consuming up to a sun’s worth of material every second and powering jets of matter that blasted outward to create the burst,” the Harvard-Smithsonian Center for Astrophysics said in a statement.

NASA’s Fermi Gamma-ray Space Telescope discovered the gamma burst just 0.4 seconds after the LIGO gravitational waves’ detection, the center said. Both events came from the same general area of the sky.

Read more at Discovery News

Stunning Survey Reveals Our Mesmerizing Milky Way

They say a picture is worth a thousand words, but this picture is worth tens of billions of stars.

And that’s what we are seeing here; this is the plane of our galaxy, seen through the eyes of a powerful telescope called the Atacama Pathfinder EXperiment telescope (APEX), located high on the Chajnantor Plateau in Chile’s Atacama region and managed by the European Southern Observatory (ESO).

The mosaic of images represents the completion of the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) project that imaged the entirety of the Milky Way’s plane seen edge-on from APEX’s Southern Hemisphere location. It is the first galactic survey in sub-millimeter wavelengths — a region of the electromagnetic spectrum between infrared and radio waves — and because of the telescope’s awesome 12-meter wide aperture, astronomers can reveal far more detail in these observations than even space-based telescopes.

Sub-millimeter wavelengths are important to astronomers as they are generated by gas and dust only a few tens of degrees above absolute zero. Seeing our galaxy in these wavelengths can help us better understand the distribution of interstellar gas clouds that ultimately provide fuel for baby stars.

“ATLASGAL provides exciting insights into where the next generation of high-mass stars and clusters form,” said Timea Csengeri from the Max Planck Institute for Radio Astronomy (MPIfR), Bonn, Germany, in an ESO news release. “By combining these with observations from Planck, we can now obtain a link to the large-scale structures of giant molecular clouds.”

In a selection of release images, ATLASGAL is compared with data from the European Planck space observatory, surveys in visible light and views from NASA’s Spitzer Space Telescope, which sees the universe in infrared.

From Discovery News

Feb 23, 2016

Rattlesnake Colony Planned for Uninhabited Island

Conservationists in Massachusetts plan to establish a population of native venomous timber rattlesnakes on an uninhabited island, according to the state’s Division of Fisheries and Wildlife (MassWildlife).

Locals are so alarmed by the idea that officials are holding a public meeting on Tuesday to present their case and address concerns.

“Not only has the timber rattlesnake declined in Massachusetts and throughout New England, it is now completely extirpated from Maine and Rhode Island,” according to the MassWildlife statement. “Humans are the greatest threat to (the) timber rattlesnake. In Massachusetts, the timber rattlesnake has lived continuously since long before European settlement, and has persisted in the face of sometimes intense persecution, but its decline over the past 30 years has been more severe than (at) any other time in history.”

Tom French, assistant director of MassWildlife’s Natural Heritage and Endangered Species program, and his colleagues propose to establish a small group of the rattlesnakes on Mount Zion, which is a large island closed to public access at the Quabbin Reservoir located in central Massachusetts. The reservoir is owned and managed by the Department of Conservation and Recreation’s Division of Water Supply Protection.

The plan is to raise juvenile snakes from Massachusetts in captivity by the Roger Williams Zoo in Providence, R.I. After about two years they grow to a size that deters predators, and the young snakes would then be released on the island. French and his team say that only between one and 10 of the timber rattlesnakes would be released in any given year.

To ease worried minds, they reminded that “in the southern Appalachians, a healthy rattlesnake population may be as high as 150 individuals, however here in Massachusetts, our populations are generally much smaller.”

Many locals, however, are not eagerly embracing the plan just yet. Peter Mallett, president of the Millers River Fishermen’s Association, was asked by the Boston Globe, “What could go wrong?” He replied: “Well, they swim.”

MassWildlife countered with this explanation: “While rattlesnakes are perfectly good swimmers, their survival depends on access to unusually deep hibernation sites, usually in a rock talus or boulder field below a ledge, or a deep fissure in bedrock. These special habitats are scarce on our landscape. Any snake that leaves the island whether by water or over the causeway will not be able to find a suitable hibernation site and if unable to return will die over the winter.”

Read more at Discovery News

Earliest Ancestor of Biggest Bird Ever ID'd

The first in a line of birds that would culminate with the world’s biggest bird ever has been discovered in Australia.

Researchers from Flinders University and the University of New South Wales have just published a study in the Journal of Vertebrate Paleontology detailing their findings on the flightless, 551-pound Dromornis murrayi, now the earliest known species in the genus Dromornis -- prehistoric birds that stood up to 10 feet tall and could weigh more than half a ton.

Believe it or not, even at that weight D. murrayi was the baby of the Dromornis line.

“Originally, it was the smallest, at a pretty hefty 250 kilograms [551 pounds],” said the study’s lead author Trevor Worthy. “But by eight million years ago it had evolved into D. stirtoni, which averaged a whopping 450 kilograms [992 pounds], with some individuals reaching 650 kilograms [1,433 pounds] — the largest birds the world has known.”

The new bird D. murrayi lived during the late Oligocene to early Miocene. Its Dromornis genus belonged to the Dromornithidae family of huge birds also known as "Mihirungs."

“Mihirungs were giant flightless birds only found in Australia and are known only from fossils,” explained Worthy. “The largest stood two meters [6.6 feet] high at its back and reached well over three meters [9.8 feet] at the head."

“They survived until the Pleistocene period when Genyornis newtoni, the last species, died out, probably about 50,000 years ago,” he added.

“The very large and distinctive bones of this new ‘Big Bird’ are quite common in the Riversleigh [northwest Queensland, Australia] fossil deposits, and are easily spotted by scientists and visitors to the site,” said study co-author Suzanne Hand, of the University of New South Wales.

The researchers realized the new bird was an ancestor of the hulking D. stirtoni after poring over skull, sternum, and breast bones as well as bones from the leg and foot of the giant bird.

“We even had some tiny bones of the wing, which showed this gigantic bird had already, by 26 million years ago, essentially lost its wings,” said Worthy.

From Discovery News

Volkswagen-Size Armored Mammal Is Armadillo Ancestor

A new genetic analysis of the glyptodont, an ancient armored creature the size of a Volkswagen Beetle, reveals that it’s closely related to the modern-day armadillo.

Glyptodonts roamed the Earth for millions of years until they went extinct during the last ice age, about 10,000 years ago. The animal’s clublike armored tail, enormous size and remarkable bony shell have captivated many since Charles Darwin collected the first known specimens in the early 1830s. Though the glyptodont looked like a giant armadillo, scientists weren’t sure how it fit into the armadillo family tree until now, the researchers said.

“The data sheds light on the familial relations of an enigmatic creature that has fascinated many but was always shrouded in mystery,” study researcher Hendrik Poinar, an evolutionary geneticist and physical anthropologist, said in a statement. “Was the glyptodont a gigantic armadillo or weird offshoot with a fused bony exoskeleton?”

Glyptodonts are part of the mammal group Xenarthra, which includes anteaters, tree sloths, extinct ground sloths, extinct pampatheres (a small armadillolike creature) and armadillos, but its relationship to these animals had eluded scientists.

Now, a genetic analysis shows that the glyptodont is nestled deeply within the armadillo family and should be treated like a close relative, the researchers said.

“Glyptodonts, in fact, represent an extinct lineage that likely originated about 35 million years ago within the armadillo ,” said Poinar, who is director of the McMaster Ancient DNA Center at McMaster University in Canada.

Poinar worked with an international team of scientists to collect glyptodont specimens; they used ancient DNA-extraction techniques on one specimen — an approximately 12,000-year-old bony shell of a Doedicurus, one of the largest glyptodonts on record.

An analysis of the specimen, found in Argentina, allowed them to extract and sequence the mitochondrial DNA (genetic data passed down through the maternal line). Then, they compared it with the mitochondrial DNA of other living mammals in the Xenarthra group.

“Ancient DNA has the potential to solve a number of questions such as phylogenetic position — or the evolutionary relationship — of extinct mammals, but it is often extremely difficult to obtain usable DNA from fossil specimens,” Poinar said. “In this particular case, we used a technical trick to fish out DNA fragments and reconstruct the mitochondrial genome.”

Read more at Discovery News

Seas Are Rising at Fastest Pace in 2,800 Years

The world’s oceans are rising at a faster rate than any time in the past 2,800 years, and might even have fallen without the influence of human-driven climate change, researchers say.

Sea levels rose globally by about 5.5 inches (14 centimeters) from 1900 to 2000, said the study led by Rutgers University, published in Proceedings of the National Academy of Sciences.

In the absence of global warming, the change in sea level would have been far less — ranging between a 1.2 inch (3 centimeters) drop in the last century, to a rise of about 2.8 inches (7 centimeters).

“The 20th century rise was extraordinary in the context of the last three millennia — and the rise over the last two decades has been even faster,” said lead author Robert Kopp, an associate professor in Rutgers University’s Department of Earth and Planetary Sciences.

The study also predicted that global sea level will rise by 1.7 to 4.3 feet (50 to 130 centimeters) in the 21st century if the world continues to rely heavily upon fossil fuels.

Even if fossil fuels were phased out, the seas would likely mount between 0.8 and two feet by century’s end, it said.

Average global temperature today is about 1.8 degrees Fahrenheit (one degree Celsius) higher than it was in the late 19th century.

The Rutgers-led study — with co-authors from Harvard University, the Woods Hole Oceanographic Institution and the Potsdam Institute for Climate Impact Research in Germany — was based on a database that included records from 24 locations around the world, and 66 tide-gauge records from the last 300 years.

Scientists say the planet is incredibly sensitive to small changes in temperature, with today’s average climate about 1.8 degrees Fahrenheit (one degree Celsius) warmer than it was in the 19th century.

“During the past millennia sea-level has never risen nearly as fast as during the last century,” said co-author Stefan Rahmstorf, co-Chair of the Potsdam-Institute for Climate Impact Research’s (PIK) research domain Earth System Analysis.

Read more at Discovery News

Pluto Moon Charon 'Bursting' With Frozen Ocean?

Charon, to begin bursting at the seams, much like Marvel's green superhero the Hulk.

A newly released image of Charon from NASA's New Horizons spacecraft suggests that some of the fractures on that moon's surface may be the result of a once-liquid ocean beneath the surface freezing over time. That may have resulted in the signs of expansion on Charon's surface that NASA scientists compared to "Bruce Banner tearing his shirt as he becomes the Incredible Hulk."

The largest of Pluto's five moons, Charon is about 750 miles (1,200 kilometers) in diameter, about half as wide as Pluto. Because the center of mass of the Pluto-Charon system lies beyond Pluto's surface, the two are frequently regarded as a twin planet system.

When New Horizons passed by Charon in July 2015, the probe discovered a network of tectonic faults on the moon in the form of ridges, scarps and valleys. The extensive system of chasms is one of the longest in the solar system, stretching at least 1,100 miles (1,800 km) long and 4.5 miles (7.5 km) deep. By comparison, Arizona's Grand Canyon is only 277 miles (446 km) long and just over a mile (1.6 km) deep.

The new image shows a color-coded topography of Serenity Chasma captured by the Long-Range Reconnaissance Imager (LORRI) on New Horizons. Measurements of the feature's shapes reveals that Charon's water-ice layer was once at least partially liquid before freezing solid.

Scientists have said that Charon may have housed a layer of liquid water, the same material that makes up Charon's surface. The decay of radioactive elements, combined with the internal heat produced by Charon's formation, could have caused the deeper water-ice to melt. As the moon cooled over time, the ocean would have frozen and expanded. Like with an overly full plastic cup of water left in the freezer, the surface was pushed outward, with tearing resulting in the detailed system of chasms, scientists said.

It's also thought that Pluto once hosted a liquid ocean, though the younger surface of the dwarf planet suggests that this ocean took longer to freeze than Charon's.

From Discovery News

Feb 22, 2016

Giant Dinosaur Had 2 Tumors on Its Tailbone

It’s fairly common to discover dinosaur remains scratched with ancient claw or bite marks, but finding fossils with signs of tumors is rare.

And now scientists have found not one but two different types of tumor on the same bone — the vertebra of a titanosaur, a gigantic long-necked, long-tailed paleo beast, a new study finds.

“Finding any disease in fossils is rare,” said the study’s lead researcher, Fernando Barbosa, a doctoral student of geology at the Federal University of Rio de Janeiro in Brazil. “Cancer still is most rare because the majority of them do not leave signals in bones.”

The finding is the first known case of a tumor in a dinosaur that isn’t a duck-billed dinosaur, or hadrosaur, the researchers said.

The 7-inch-long (17 centimeters) fossilized vertebra, discovered in 2012 in Brazil’s southern São Paulo state, belongs to a species in the Titanosauridae family, “the most abundant Cretaceous dinosaur family of South America,” the researchers wrote in the study.

However, the 90-million-year-old bone had an unusual appearance — a “small bony button-shaped protuberance,” the researchers wrote in the study. Curious, Barbosa and his colleagues decided to investigate the weird bump, which measured just 0.3 by 0.3 inches (8.6 by 7.5 millimeters).

They found evidence of two tumors, both benign, Barbosa said. One is an osteoma, a bone overgrowth, which the researchers confirmed with a computer tomography (CT) scan and an examination of the fossil’s structure.

The other, a hemangioma, is a harmless vascular tumor.

“We were very lucky finding this because we didn’t have any evidence of the hemangioma,” Barbosa told Live Science in an email. “It was diagnosed by [the CT scan], which was only possible because we were investigating the radiological appearance of the osteoma.”

The tumors, though examples of abnormal cell growth, should not be called cancer, he said. Usually, only harmful tumors are called cancer, and these tumors were benign, Barbosa said. Furthermore, because of the tumors’ location and likely small sizes, the dinosaur probably didn’t notice them, the researchers said.

It’s not the first ancient animal to have an osteoma, the researchers said. The oldest known case of osteoma dates to the early Carboniferous (a period spanning 359.2 million to 299 million years ago) in the North American fish Phanerosteon mirabile. The mosasaur Platecarpus, a marine reptile, also had an osteoma, as did a crocodile, Leidyosuchus formidabilis, which lived during the Paleocene, a period spanning between 65 million and 56 million years ago.

Read more at Discovery News

30-Million-Year-Old Fossilized Flowers May Be Toxic

Delicate, though possibly deadly, flowers trapped in amber for some 30 million years have been discovered, scientists report.

The fossilized plants are asterids, which make up about one-third of the world’s flowering plants. About 80,000 species fall under this taxonomic clade, including coffee trees, tomato plants, mint, basil and tobacco. Despite the ubiquity of asterids today, no fossilized examples of the plants have been found until now, the researchers say.

The two flower specimens, which have been named Strychnos electri, belong to the same genus as poisonous plants that have been used to make lethal, paralyzing substances like strychnine and curare.

“Species of the genus Strychnos are almost all toxic in some way,” George Poinar Jr., an amber expert at Oregon State University, said in a statement. “Each plant has its own alkaloids with varying effects. Some are more toxic than others, and it may be that they were successful because their poisons offered some defense against herbivores.”

Scientists have identified about 200 species of Strychnosplants. One of the most famous representatives of this genus might be Strychnos nux-vomica, from which strychnine is derived. Strychnine has been used in rat poison, but it has also cropped up as a weapon in Agatha Christie novels, and Norman Bates used the poison to kill his mother in Alfred Hitchcock’s “Psycho.” Strychnine poisoning was even proposed as a possible cause of Alexander the Great’s death.

Curare —which contains the toxin tubocurarine, extracted from the plant Strychnos toxifera — has a storied history as well. Hunters in South America used the poison to make paralyzing blow darts (witnessed as early as the 16th century by the English explorer Sir Walter Raleigh). More recently, safe doses of the poison have been used in medicine as a muscle relaxer.

Read more at Discovery News

Apollo 10 Astronauts Heard Odd 'Music' on Far Side of Moon

The astronauts who flew the dress rehearsal for the first lunar landing reported hearing mysterious “outer space-type music” while flying behind the moon in May 1969.

The case of the odd, unexplained whistling noise is uncovered during an upcoming episode of the Science Channel series, “NASA’s Unexplained Files.” The episode focuses on a strange event experienced by the crew members of Apollo 10, a mission which flew to the moon, entered lunar orbit and got within 5,000 feet of the moon’s surface in preparation for Apollo 11’s historic flight two months later.

The Apollo 10 astronauts – Tom Stafford, John Young and Eugene Cernan – can be heard on recordings from the flight talking about the strange sound, and whether to tell NASA about it.

“It sounds like, you know, outer space-type music,” one of the astronauts says.

“Shall we tell about it?” an astronaut asks.

“I don’t know,” another replies. “We ought to think about it.”

There’s no record of the astronauts discussing the noise with NASA or with the public. It’s unclear if the astronauts ever heard the noise on subsequent passes on the far side of the moon or if other astronauts on subsequent missions heard the sound. Young eventually flew back to the moon and walked on it as the commander of Apollo 16. Cernan commanded the Apollo 17 mission and was the last man to walk on the moon. Stafford flew in space again, but never journeyed back to the moon.

The May 1969 tapes were recorded while Stafford, Young and Cernan were on the far side of the moon, out of radio communication with Earth. The whistling sound lasted nearly the entire hour the astronauts were out of touch. Later, the recordings were sent back to Mission Control where they were transcribed, archived and classified, per protocol.

The conversation was eventually unearthed in 2008.

Some technicians have speculated the sound may have originated from interference from VHF radios on the command module and lunar module interacting with each other, according to researcher and author Andrew Chaikin.

Read more at Discovery News

Mars 2030: Explore Your Own Virtual Red Planet

Catching a flight to Mars won’t be possible for most of us until human trips to the Red Planet become affordable, routine and heck, even possible. NASA is currently hoping to send astronauts to Mars in the 2030s, although some experts recently warned Congress that the agency’s budget may not be able to support that goal.

In any case, NASA is sticking to the 2030s timeline for now, and one way it is promoting it is by letting you stroll on the Red Planet in virtual reality. Through a partnership with VR developer Fusion (whose parent companies are Disney-ABC and Univision) and the Massachusetts Institute of Technology (MIT), a new game called “Mars 2030″ will premiere at South By Southwest in March and be available to the public later this year.

“NASA has provided us information to achieve the highest level of regard for scientific accuracy through direct contact with various teams working on the many facets of such a complex mission,” said Julian Reyes, Fusion virtual reality producer and designer, in an e-mail to Discovery News.

“We’ve visited JSC (Johnson Space Center) and Langley Research Center on multiple occasions and had several interviews with scientists dedicated to studying the planet. Our goal is to stay within the bounds of scientific accuracy while still driven by a compelling story that engages the players.”

Fusion first got interested in Mars 2030 after reading about a now-famous “Mars One” 2014 feasibility study written by MIT students. Mars One is a privately funded initiative to send humans on a one-way trip to the Red Planet, and is now selecting astronauts for preliminary training while simultaneously trying to raise funds for the journey. While Mars One says the hardware will be capable of keeping humans alive indefinitely, the study cited limitations with their version such as needing frequent resupplies, which will only grow as a colony naturally expands in size.

Fusion contacted lead author Sydney Do (a Ph.D. student at MIT) after the study was publicized. To do the study, Do explained to Discovery News in an e-mail, the students created a simulation of a Mars outpost based on statements and claims by Mars One. Following the activities of four people on Mars, the students then created the systems needed for consumables (gases and water) to keep the crew alive, and the spare parts needed to support these systems. This information then gave them information on what a surface habitat system would need.

“The Mars 2030 experience essentially incorporates insights like these into a more realistic visual environment,” said Do, who describes himself as an occasional gamer. “You could say that our research does the back-end work — it determines how much of what resource or technology is needed based on a crew activity profile designed to meet some mission objective, while the Mars 2030 experience visualizes this information and builds a story around it using the state of the art in game development.”

Do acted as a technical advisor for Fusion, providing information on aspects of Mars such as surface habitats, life support, food, crew activities in the habitat and outside, maintenance and in-situ resource utilization. He even took into account planetary protection protocols to, for example, suggest sterilized robots explore an area before a human went there and threatened any possible microbes.

Read more at Discovery News

Feb 21, 2016

3D-Print Your Own Homo Naledi Skull

Ever felt like cranking up your 3D printer and making fossil recreations suitable for living room décor?

Now you can, thanks to a free website under the auspices of Duke University that allows registered users to peruse a library of some 9,000 digital scans of fossils uploaded to the site from scientists at more than 70 institutions.

The site, MorphoSource, was created by Duke assistant professor Doug Boyer, and the university calls it the “largest and most open digital fossil repository of its kind.” Just this month it announced the addition of more than 400 skulls and other bones from 59 species of apes, lemurs, and monkeys.

The site boasts among its digitized goodies a fossil superstar: Homo naledi, the ancient human that made headlines worldwide when it was found in a South African cave in 2015. MorphoSource made available to site visitors more than 80 scans of bones from the famous fossil find. Including, yes, a skull.

While many institutions have made moves to digitize their fossil collections, MorphoSource says it is one of the only ones that has put all of the images under one roof.

“We’re essentially taking bones out of museum catacombs and putting them online,” Boyer said in a press release.

The site offers image files representing bones from more than 500 extinct species. Visitors can rotate the images, zoom in/out on them and run them through a 3D printer.

Among the other scans on the site are Megalodon teeth, vertebrae from the largest snake ever known (Titanoboa), and the bones of a foot-plus-long devil frog.

“Paleoanthropology has been relying on digital data more and more,” Boyer said. “Before we released this dataset, only a dozen labs around the world had digital samples that large at their fingertips. Overnight we leveled the playing field in a significant way.”

From Discovery News

Record 18,300 Apply for NASA Astronaut Training

More than 18,300 people have applied for 14 or fewer spots in NASA's next astronaut class, shattering the 1978 record of 8,000 applicants.

(In 1978, it had been nine years since the previous chance to apply to be an astronaut, and the space shuttle had recently been announced. Plus, it was the first official call for female applicants.)

The prospective astronauts all submitted their applications between Dec.14 and when the application period closed yesterday (Feb. 18) — and the total number is close to triple the applicants for NASA's most recent astronaut class, in 2012. (At the time, the 2012 application pool was the second largest ever at more than 6,300.)

"It's not at all surprising to me that so many Americans from diverse backgrounds want to personally contribute to blazing the trail on our journey to Mars," NASA Administrator Charles Bolden said in a statement. "A few exceptionally talented men and women will become the astronauts chosen in this group who will once again launch to space from U.S. soil on American-made spacecraft."

Bolden himself is a former astronaut, selected as one of a class of 19 in 1980.

Over the next 18 months, NASA's astronaut-selection board will narrow the applicants down, and the top applicants will interview at Johnson Space Center in Houston — ultimately, NASA will select a final set of eight to 14 astronaut candidates to begin training.

The training process will take about two years, and will include "training on spacecraft systems, spacewalking skills and teamwork, Russian language and other requisite skills," NASA officials said in the statement.

Ultimately, those who make it through the training will be assigned to either the International Space Station, NASA's Orion spacecraft, the Boeing CST-100 Starliner or the SpaceX Crew Dragon. Orion, currently in development to launch in the early 2020s on the new Space Launch System megarocket, will be able to support a crew of four for up to 21 days — habitat modules will be added for longer journeys, such as visiting Mars or deep space. Both the Starliner and Crew Dragon are in development aided by NASA's commercial crew program to bring four astronauts to the space station at a time.

Read more at Discovery News