Aug 25, 2012

Hubble Captures a Collection of Ancient Stars

The NASA/ESA Hubble Space Telescope has produced a beautiful image of the globular cluster Messier 56 (also known as M 56 or NGC 6779), which is located about 33,000 light years away from Earth in the constellation of Lyra (The Lyre). The cluster is composed of a large number of stars, tightly bound to each other by gravity.

However, this was not known when Charles Messier first observed it in January 1779. He described Messier 56 as "a nebula without stars," like most globular clusters that he discovered -- his telescope was not powerful enough to individually resolve any of the stars visible here, making it look like a fuzzy ball through his telescope's eyepiece. We clearly see from Hubble's image how the development of technology over the years has helped our understanding of astronomical objects.

Astronomers typically infer important properties of globular clusters by looking at the light of their constituent stars. But they have to be very careful when they observe objects like Messier 56, which is located close to the Galactic plane. This region is crowded by "field-stars," in other words, stars in the Milky Way that happen to lie in the same direction but do not belong to the cluster. These objects can contaminate the light, and hence undermine the conclusions reached by astronomers.

A tool often used by scientists for studying stellar clusters is the color-magnitude (or Hertzsprung-Russell) diagram. This chart compares the brightness and color of stars -- which in turn, tells scientists the surface temperature of a star.

By comparing high quality observations taken with the Hubble Space Telescope with results from the standard theory of stellar evolution, astronomers can characterize the properties of a cluster. In the case of Messier 56, this includes its age, which at 13 billion years is approximately three times the age of the Sun. Furthermore, they have also been able to study the chemical composition of Messier 56. The cluster has relatively few elements heavier than hydrogen and helium, typically a sign of stars that were born early in the Universe's history, before many of the elements in existence today were formed in significant quantities.

Astronomers have found that the majority of clusters with this type of chemical makeup lie along a plane in the Milky Way's halo. This suggests that such clusters were captured from a satellite galaxy, rather than being the oldest members of the Milky Way's globular cluster system as had been previously thought.

This image consists of visible and near-infrared exposures from Hubble's Advanced Camera for Surveys. The field of view is approximately 3.3 by 3.3 arcminutes.

Read more at Science Daily

Neil Armstrong, First Human to Walk on Moon, Dies at 82

Neil Armstrong has died at the age of 82.

As reported by the Associated Press, Armstrong died following “complications resulting from cardiovascular procedures,” according to a statement from his family.

Armstrong was the commander of Apollo 11. On July 20, 1969, together with fellow astronaut Buzz Aldrin, he landed the mission’s Lunar Module on the surface of the moon, and six hours later, he climbed down the ladder of the spacecraft, becoming the first human to walk on another world.

He retired from NASA 41 years ago today, just over two years after his historic mission with Aldrin and Michael Collins, who orbited the moon as the Lunar Module descended to the surface.

Armstrong was born in Wapakoneta, Ohio and first soloed an airplane just a few weeks after his sixteenth birthday. Before being selected as an astronaut, Armstrong was a naval aviator flying F9F Panther fighter jets in the Korean War. After the War, he became a research pilot for the National Advisory Committee for Aeronautics, the predecessor of NASA. While a research pilot, he flew the rocket powered Bell X-1B and the North American X-15 along with a wide variety of jet and propeller aircraft.

During his time in the X-15 program, now under NASA, Armstrong demonstrated his engineering skills working on the hypersonic aircraft’s flight control system as well as the relatively primitive simulator used to develop flight profiles of the first winged aircraft to fly into space.

At the same time, Armstrong was working on the X-15 program, he also worked on the X-20 Dynasoar project, part of the Air Force’s ‘Man in Space Soonest’ program. The veteran test pilot flew a modified Douglas F5D fighter jet (now on display at the Neil Amrstrong Museum in Wapakoneta) on a series of flights to develop launch abort procedures that were to be used for the winged X-20 spacecraft.

Armstrong joined the astronaut core as part of the “new nine” and first flew on Gemini 8. In 1968, the now space flight veteran was selected as commander of Apollo 11, the first mission slated to land on the moon.

After retiring from NASA, Armstrong went on to be a professor of aerospace engineering and served on the board of various companies.

From Wired Science

Aug 24, 2012

Bigger Creatures Live Longer, Travel Farther for a Reason

A long-standing mystery in biology about the longer lifespans of bigger creatures may be explained by the application of a physical law called the Constructal Law.

What this law proposes is that anything that flows -- a river, bloodstream or highway network -- will evolve toward the same basic configuration out of a need to be more efficient. And, as it turns out, that same basic law applies to all bodies in motion, be they animals or tanker trucks, says Adrian Bejan, the J.A. Jones Professor of mechanical engineering at Duke and father of the Constructal Law.

In his latest theory paper, appearing Aug. 24 in the journal Nature Scientific Reports, Bejan argues that there is a universal tendency for larger things, animate and inanimate, to live longer and to travel further.

He starts his argument with an examination of the well-known observation in biology that larger animals tend to live longer. Bejan wanted to see if this general rule might apply to inanimate systems as well and proceeded to mathematically analyze the relationship in rivers, jets of air and vehicles.

He found, as a general rule, that bigger rivers are older and that larger jets of air, such as atmospheric jet streams, last longer. By his calculations, larger vehicles should also last longer, but hard evidence of that is lacking, he says, and there are outliers of course, like Subaru Justys with 300,000 miles.

By being larger and lasting longer, all of these systems also travel farther, he says.

If you look at a moving vehicle or animal simply as a mass in motion, that is, something flowing, "the spreading of the mass of vehicles and animals is completely analogous to the flow of water in river channels," Bejan says. "It is the same design."

Interestingly, if the body size and lifespan of known species of animals are plotted on a curve, it falls on a slope of about ¼. And then, following a different line of inquiry, if you plot the frequency of breathing to body size, that is a slope of - ¼.

When combined, these two insights about animal body size work out to a constant for the number of breaths per lifetime, Bejan says. This gives most creatures about the same number of breaths in their lifetime, but the larger, slower-breathing animals use their breaths up over a longer span of time. "So bigger means a longer lifespan," he said. "I was looking at this enigma about body size and longevity from a point of view that hadn't occurred to biologists," Bejan said.

The Constructal Law governs how big an engine a truck needs and how big a heart a whale needs. "There's no difference between a vehicle and an animal," Bejan said. "Being larger means two things, not one: you live longer and you travel farther."

Read more at Science Daily

Most Mutations Come from Dad

Humans inherit more than three times as many mutations from their fathers as from their mothers, and mutation rates increase with the father's age but not the mother's, researchers have found in the largest study of human genetic mutations to date.

The study, based on the DNA of around 85,000 Icelanders, also calculates the rate of human mutation at high resolution, providing estimates of when human ancestors diverged from nonhuman primates. It is one of two papers published this week by the journal Nature Genetics as well as one published at Nature that shed dramatic new light on human evolution.

"Most mutations come from dad," said David Reich, professor of genetics at Harvard Medical School and a co-leader of the study. In addition to finding 3.3 paternal germline mutations for each maternal mutation, the study also found that the mutation rate in fathers doubles from age 20 to 58 but that there is no association with age in mothers -- a finding that may shed light on conditions, such as autism, that correlate with the father's age.

The study's first author is James Sun, a graduate student in Reich's lab who worked with researchers from deCODE Genetics, a biopharma company based in Reykjavik, Iceland, to analyze about 2,500 short sequences of DNA taken from 85,289 Icelanders in 24,832 father-mother-child trios. The sequences, called microsatellites, vary in the number of times that they repeat, and are known to mutate at a higher rate than average places in the genome.

Reich's team identified 2,058 mutational changes, yielding a rate of mutation that suggests human and chimpanzee ancestral populations diverged between 3.7 million and 6.6 million years ago.

A second team, also based at deCODE Genetics (but not involving HMS researchers), published a paper this week in Nature on a large-scale direct estimate of the rate of single nucleotide substitutions in human genomes (a different type of mutation process), and came to largely consistent findings.

The finding complicates theories drawn from the fossil evidence. The upper bound, 6.6 million years, is less than the published date of Sahelanthropus tchadensis, a fossil that has been interpreted to be a human ancestor since the separation of chimpanzees, but is dated to around 7 million years old. The new study suggests that this fossil may be incorrectly interpreted.

Great Heights

A second study led by HMS researchers, also published in Nature Genetics this week, adds to the picture of human evolution, describing a newly observable form of recent genetic adaptation.

The team led by Joel Hirschhorn, Concordia Professor of Pediatrics and professor of genetics at Boston Children's Hospital and HMS, first asked why closely-related populations can have noticeably different average heights. David Reich also contributed to this study.

They examined genome-wide association data and found that average differences in height across Europe are partly due to genetic factors. They then showed that these genetic differences are the result of an evolutionary process that acts on variation in many genes at once. This type of evolution had been proposed to exist but had not previously been detected in humans.

Although recent human evolution is difficult to observe directly, some of its impact can be inferred by studying the human genome. In recent years, genetic studies have uncovered many examples where recent evolution has left a distinctive signature on the human genome. The clearest "footprints" of evolution have been seen in regions of DNA surrounding mutations that occurred fairly recently (typically in the last several thousand years) and confer an advantageous trait, such as resistance to malaria. Hirschhorn's team observed, for the first time in humans, a different signature of recent evolution: widespread small but consistent changes at many different places in the genome, all affecting the same trait, adult height.

"This paper offers the first proof and clear example of a new kind of human evolution for a specific trait," said Hirschhorn, who is also a senior associate member of the Broad Institute. "We provide a demonstration of how humans have been able to adapt rapidly without needing to wait for new mutations to happen, by drawing instead on the existing genetic diversity within the human population."

Average heights can differ between populations, even populations that are genetically very similar, which suggests that human height might have been evolving differently across these populations. Hirschhorn's team studied variants in the genome that are known to have small but consistent effects on height: people inheriting the "tall" version of these variants are known to be slightly taller on average than people inheriting the "short" versions of the same variants.

The researchers discovered that, in northern Europe, the "tall" versions of these variants are consistently a little more common than they are in southern Europe. The combined effects of the "tall" versions being more common can partly explain why northern Europeans are on average taller than southern Europeans. The researchers then showed that these slight differences have arisen as a result of evolution acting at many variants, and acting differently in northern than in southern Europe.

Read more at Science Daily

Grave of Richard III May Be Under Parking Lot

King Richard III of England had the honor of being memorialized in a William Shakespeare play after his death in battle in 1485. Now, modern-day archaeologists are on the hunt for the medieval king's physical resting place.

The University of Leicester, Leicester City Council and the Richard III Society have joined forces to search for the grave of Richard III, thought to be under a parking lot for city council offices. The team will use ground-penetrating radar to search for the ideal spots to dig.

"This archaeological work offers a golden opportunity to learn more about medieval Leicester as well as about Richard III's last resting place -- and, if he is found, to re-inter his remains with proper solemnity in Leicester Cathedral," Philippa Langley, a Richard III Society member, said in a statement.

Richard III was King of England from 1483 to 1485. He died during the Battle of Bosworth Field during the War of the Roses, an English civil war between the House of Lancaster and the House of York. Richard III was the last English king to die in battle. Shakespeare penned "Richard III," a play about the tragic king, approximately 100 years later.

Regardless of his Shakespeare claim to fame, the king was talked about for his own right. "Richard III is a charismatic figure who attracts tremendous interest, partly because he has been so much maligned in past centuries, and partly because he occupies a pivotal place in English history," Langley said.

"The continuing interest in Richard means that many fables have grown up around his grave." Langley said, adding that some far-fetched tales include that the bones were thrown into the river Soar.

"Other fables, equally discredited, claimed that his coffin was used as a horse-trough," Langley said.

After his death, the king was stripped and brought to Leicester, where he was buried in the church of the Franciscan Friary, known as the Greyfriars. The location of Greyfriars was eventually lost to history.

"The big question for us is determining the whereabouts of the church on the site and also where in the church the body was buried," University of Leicester archaeologist Richard Buckley said in a statement. "Although in many ways finding the remains of the king is a long-shot, it is a challenge we shall undertake enthusiastically. There is certainly potential for the discovery of burials within the area, based on previous discoveries and the postulated position of the church."

Read more at Discovery News

Animals Are as With It as Humans, Scientists Say

An international group of prominent scientists has signed The Cambridge Declaration on Consciousness in which they are proclaiming their support for the idea that animals are conscious and aware to the degree that humans are -- a list of animals that includes all mammals, birds, and even the octopus. But will this make us stop treating these animals in totally inhumane ways?

While it might not sound like much for scientists to declare that many nonhuman animals possess conscious states, it's the open acknowledgement that's the big news here. The body of scientific evidence is increasingly showing that most animals are conscious in the same way that we are, and it's no longer something we can ignore.

 What's also very interesting about the declaration is the group's acknowledgement that consciousness can emerge in those animals that are very much unlike humans, including those that evolved along different evolutionary tracks, namely birds and some encephalopods.

"The absence of a neocortex does not appear to preclude an organism from experiencing affective states," they write. "Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors."

Consequently, say the signatories, the scientific evidence is increasingly indicating that humans are not unique in possessing the neurological substrates that generate consciousness.

 The group consists of cognitive scientists, neuropharmacologists, neurophysiologists, neuroanatomists, and computational neuroscientists -- all of whom were attending the Francis Crick Memorial Conference on Consciousness in Human and Non-Human Animals. The declaration was signed in the presence of Stephen Hawking, and included such signatories as Christof Koch, David Edelman, Edward Boyden, Philip Low, Irene Pepperberg, and many more.

The declaration made the following observations:

  • The field of Consciousness research is rapidly evolving. Abundant new techniques and strategies for human and non-human animal research have been developed. Consequently, more data is becoming readily available, and this calls for a periodic reevaluation of previously held preconceptions in this field. Studies of non-human animals have shown that homologous brain circuits correlated with conscious experience and perception can be selectively facilitated and disrupted to assess whether they are in fact necessary for those experiences. Moreover, in humans, new non-invasive techniques are readily available to survey the correlates of consciousness.
  • The neural substrates of emotions do not appear to be confined to cortical structures. In fact, subcortical neural networks aroused during affective states in humans are also critically important for generating emotional behaviors in animals. Artificial arousal of the same brain regions generates corresponding behavior and feeling states in both humans and non-human animals. Wherever in the brain one evokes instinctual emotional behaviors in non-human animals, many of the ensuing behaviors are consistent with experienced feeling states, including those internal states that are rewarding and punishing. Deep brain stimulation of these systems in humans can also generate similar affective states. Systems associated with affect are concentrated in subcortical regions where neural homologies abound. Young human and nonhuman animals without neocortices retain these brain-mind functions. Furthermore, neural circuits supporting behavioral/electrophysiological states of attentiveness, sleep and decision making appear to have arisen in evolution as early as the invertebrate radiation, being evident in insects and cephalopod mollusks (e.g., octopus).
Read more at Discovery News

Aug 23, 2012

Spacetime: A Smoother Brew Than We Knew

Spacetime may be less like beer and more like sipping whiskey. Or so an intergalactic photo finish would suggest.

Physicist Robert Nemiroff of Michigan Technological University reached this heady conclusion after studying the tracings of three photons of differing wavelengths that were recorded by NASA's Fermi Gamma-ray Space Telescope in May 2009.

The photons originated about 7 billion light years away from Earth in one of three pulses from a gamma-ray burst. They arrived at the orbiting telescope just one millisecond apart, in a virtual tie.

Gamma-ray bursts are short-lived bursts of gamma-ray photons, the most energetic form of light. They can originate far across the universe, and astronomers believe many are caused by giant stars collapsing, often billions of years before Earth was formed.

"Gamma-ray bursts can tell us some very interesting things about the universe," Nemiroff said. In this case, those three photons recorded by the Fermi telescope suggest that spacetime may not be not as bubbly as some scientists think.

Some theories of quantum gravity say that the universe is not smooth but foamy -- made of fundamental units called Planck lengths that are less than a trillionth of a trillionth the diameter of a hydrogen atom. Planck lengths are so small that there's no way to detect them, except via photons like those that make up gamma-ray bursts.

Here's why. The wavelengths of these photons are some of the shortest distances known to science -- so short they should interact with the even smaller Planck length. And if they interact, the photons should be dispersed -- scattered -- on their trek through Planck length-pixelated spacetime.

In particular, they should disperse in different ways if their wavelengths differ, just as a ping pong ball and a softball might take alternate paths down a gravely hillside.

You wouldn't notice the scattering over short distances, but across billions of light years, the Planck lengths should disperse the light. And three photons from the same gamma-ray burst should not have crashed through the Fermi telescope at the same moment.

Read more at Science Daily

More Exoplanets Discovered: 41 New Transiting Planets in Kepler Field of View

Two newly submitted studies verify 41 new transiting planets in 20 star systems. These results may increase the number of Kepler's confirmed planets by more than 50 percent: to 116 planets hosted in 67 systems, over half of which contain more than one planet.

The papers are currently under scientific peer-review.

Nineteen of the newly validated planetary systems have two closely spaced transiting planets and one system has three. Five of the systems are common to both of these independent studies.

The planets range from Earth-size to more than seven times the radius of Earth, but generally orbit so close to their parent stars that they are hot, inhospitable worlds.

The planets were confirmed by analyzing Transit Timing Variations (TTVs). In closely packed systems, the gravitational pull of the planets causes the acceleration or deceleration of a planet along its orbit. These "tugs" cause the orbital period of each planet to change from one orbit to the next. TTV demonstrates that two transiting planet candidates are in the same system and that their masses are planetary in nature.

"These systems, with their large gravitational interactions, give us important clues about how planetary systems form and evolve," said lead researcher Jason Steffen, the Brinson postdoctoral fellow at Fermilab Center for Particle Astrophysics in Batavia, Ill. "This information helps us understand how our own solar system fits into the population of all planetary systems."

The two research teams used data from NASA's Kepler space telescope, which measures dips in the brightness of more than 150,000 stars, to search for transiting planets.

"The sheer volume of planet candidates being identified by Kepler is inspiring teams to look at the planet confirmation and characterization process differently. This TTV confirmation technique can be applied to large numbers of systems relatively quickly and with little or no follow-up observations from the ground," said Natalie Batalha, Kepler mission scientist at NASA's Ames Research Center, Moffett Field, Calif. "Perhaps the bottleneck between identifying planet candidates and confirming them just got a little wider."

Ames Research Center in Moffett Field, Calif., manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory, Pasadena, Calif., managed the Kepler mission's development.

Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

Read more at Science Daily

Gibbons on Helium Trill Like Opera Singers

Gibbons effortlessly use the same techniques as professional opera singers when calling out to other animals, scientists found by listening to the squeaky songs of one of the apes on helium.

The Japanese study provides evidence for an unusual physiological similarity between gibbons and humans.

"The complexity of human speech is unique among primates as it requires varied soft sounds made by the rapid movements of vocal tracts," lead researcher Takeshi Nishimura, from the Primate Research Institute at Kyoto University, said in a statement. "Our speech was thought to have evolved through specific modifications in our vocal anatomy. However, we've shown how the gibbons' distinctive song uses the same vocal mechanics as soprano singers, revealing a fundamental similarity with humans."

Nishimura's team analyzed 20 melodious and loud calls of a captive white-handed gibbon (Hylobates lar) in a normal atmosphere, followed by 37 calls in an environment infused with helium.

Sucking in helium from a balloon gives humans a squeaky, high-pitch-sounding voice, because the gas, which is less dense than air, pushes the resonance frequencies of the vocal tract upwards, but doesn't change the sound at its source. An analysis of the gibbon's squeaky songs suggested that the same is true for these apes. Like humans, the origin of the sound of a gibbon's call, which occurs in the larynx, is separate from the vocal tools used to modify it, the research showed.

What's more, the analysis demonstrated gibbons have expert control over the tuning of their vocal cords and tract when singing -- an ability that is important to the subtleties of human speech and is mastered by soprano singers.

Read more at Discovery News

Vaporizing Planets in the Name of Science

One sure-fire way to grab an audience's attention is to vaporize a planet, amirite? We saw the destruction of Vulcan in Star Trek, the end of Krypton in the Christopher Reeves-era Superman, while the Death Star vaporized Alderaan in Star Wars: A New Hope.

As for Hitchhikers Guide to the Galaxy, Douglas Adams went all in, vaporizing the Earth right off the bat, all because an alien race known as the Vogons want to make way for a hyperspatial express route, leaving poor Arthur to roam about the Milky Way in his bathrobe.

But can you really vaporize a planet? According to the latest computer simulations by a couple of planetary scientists in St. Louis, you betcha! As outlined in their new paper in The Astrophysical Journal, Bruce Fegley and his colleagues (Katharina Lodders and Laura Schaefer) mathematically constructed a couple of model "Super-Earths" and put them through a series of atmospheric simulations.

The object wasn't really to study how to destroy the Earth. Fegley et al were trying to learn more about the kinds of atmospheres most likely to be found on Super-Earths -- i.e., exoplanets with masses that are more than that of Earth but less than that of Neptune, while still being rocky in nature, instead of, say, a gas giant.

Having detailed knowledge of likely chemical compositions could help astronomers who hunt for such planets find them. And one way of gaining that knowledge is to build computer models of Super-Earths and vaporize them.

Most exoplanets within that size range that have been found are gaseous in nature, because they orbit so close to their host stars that any rocky stuff gets melted. (How Stuff Works has an excellent summary of the various techniques astronomers use to hunt for exoplanets.)

For instance, using photometry, astronomers can detect an exoplanet as it transits the host star, because of predictable periodic dimming of a star's brightness as the planet momentarily blocks its light. Astronomers can also determine the chemical composition of said planet's atmosphere because the star's light gets filtered through that atmosphere -- think of it as stellar spectroscopy.

This, in turn, provides clues as to the planet's density, because the gases in the atmosphere likely came about because of vaporized rock. So it would be nice to have tidy simulated models to compare with the measured spectra of actual exoplanets.

One model Super-Earth had a continental crust just like our Earth, dominated by granite, while the other simulated Earth's composition before its crust formed, when it was mostly bulk silicate. (Water is the key ingredient in getting Earth today from that precursor Earth. Without it, our planet's crust would more closely resemble Venus.)

Then they plugged in the likely surface temperatures of observed Super-Earths, ranging from between 270 to 1700 degrees Celsius, just to see what would happen to the atmosphere. "The vapor pressure of the liquid rock increases as you heat it, just as the vapor pressure of water increases as you bring a pot to boil," Fegley explained via press release. "Ultimately this puts all the constituents of rick into the atmosphere."

Read more at Discovery News

Aug 22, 2012

Ancient Fossils Reveal How the Mollusc Got Its Teeth

The radula sounds like something from a horror movie -- a conveyor belt lined with hundreds of rows of interlocking teeth. In fact, radulas are found in the mouths of most molluscs, from the giant squid to the garden snail. Now, a "prototype" radula found in 500-million-year-old fossils studied by University of Toronto graduate student Martin Smith, shows that the earliest radula was not a flesh-rasping terror, but a tool for humbly scooping food from the muddy sea floor.

The Cambrian animals Odontogriphus and Wiwaxia might not have been much to look at -- the former a naked slug, the latter a creeping bottom-dweller covered with spines and scales. Despite the hundreds of fossil specimens collected from the Canadian Rockies by the Royal Ontario Museum, scientists could not agree whether they represented early molluscs, relatives of the earthworm, or an evolutionary dead-end. Smith, a PhD candidate in U of T's Department of Ecology and Evolutionary Biology and author of a study published this week in Proceedings of the Royal Society B, employed a new, non-destructive type of Electron Microscopy to reveal the new details.

"I put the fossils in the microscope, and the mouth parts just leaped out," says Smith, a PhD candidate in U of T's Department of Ecology and Evolutionary Biology. "You could see details you'd never guess were there if you just had a normal microscope."

After examining some 300 fossils, Smith was able not just to reconstruct the mouthparts, but work out how they grew. "The fossils are squashed completely flat, which makes them really hard to reconstruct in 3D," says Smith. "I surrounded myself with micrographs of the mouth parts and lumps of plasticine, and spent weeks trying to come up with a model that made sense of the fossils."

The new observations demonstrated that the mouthparts consisted of two to three rows of 17 similarly-shaped teeth, with a symmetrical central tooth and smaller teeth on the edges. The teeth would have moved round the end of a tongue in the conveyor-belt fashion seen in molluscs today, scooping food -- algae or detritus -- from the muddy sea floor. By establishing how the teeth were arranged, moved, grew, and were replaced, Smith was able to demonstrate that they formed a shorter and squatter forerunner to the modern radula.

Read more at Science Daily

More Sophisticated Wiring, Not Just Bigger Brain, Helped Humans Evolve Beyond Chimps, Geneticists Find

Human and chimp brains look anatomically similar because both evolved from the same ancestor millions of years ago. But where does the chimp brain end and the human brain begin?

A new UCLA study pinpoints uniquely human patterns of gene activity in the brain that could shed light on how we evolved differently than our closest relative. Published Aug. 22 in the advance online edition of Neuron, these genes' identification could improve understanding of human brain diseases like autism and schizophrenia, as well as learning disorders and addictions.

"Scientists usually describe evolution in terms of the human brain growing bigger and adding new regions," explained principal investigator Dr. Daniel Geschwind, Gordon and Virginia MacDonald Distinguished Professor of Human Genetics and a professor of neurology at the David Geffen School of Medicine at UCLA. "Our research suggests that it's not only size, but the rising complexity within brain centers, that led humans to evolve into their own species."

Using post-mortem brain tissue, Geschwind and his colleagues applied next-generation sequencing and other modern methods to study gene activity in humans, chimpanzees and rhesus macaques, a common ancestor for both chimpanzee and humans that allowed the researchers to see where changes emerged between humans and chimpanzees. They zeroed in on three brain regions -- the frontal cortex, hippocampus and striatum.

By tracking gene expression, the process by which genes manufacture the amino acids that make up cellular proteins, the scientists were able to search the genomes for regions where the DNA diverged between the species. What they saw surprised them.

"When we looked at gene expression in the frontal lobe, we saw a striking increase in molecular complexity in the human brain," said Geschwind, who is also a professor of psychiatry at the Semel Institute for Neuroscience and Behavior at UCLA.

While the caudate nucleus remained fairly similar across all three species, the frontal lobe changed dramatically in humans.

"Although all three species share a frontal cortex, our analysis shows that how the human brain regulates molecules and switches genes on and off unfolds in a richer, more elaborate fashion," explained first author Genevieve Konopka, a former postdoctoral researcher in Geschwind's lab who is now the Jon Heighten Scholar in Autism Research at University of Texas Southwestern Medical Center. "We believe that the intricate signaling pathways and enhanced cellular function that arose within the frontal lobe created a bridge to human evolution."

The researchers took their hypothesis one step further by evaluating how the modified genes linked to changes in function.

"The biggest differences occurred in the expression of human genes involved in plasticity -- the ability of the brain to process information and adapt," said Konopka. "This supports the premise that the human brain evolved to enable higher rates of learning."

One gene in particular, CLOCK, behaved very differently in the human brain. Considered the master regulator of Circadian rhythm, CLOCK is disrupted in mood disorders like depression and bipolar syndrome.

"Groups of genes resemble spokes on a wheel -- they circle a hub gene that often acts like a conductor," said Geschwind. "For the first time, we saw CLOCK assuming a starring role that we suspect is unrelated to Circadian rhythm. Its presence offers a potentially interesting clue that it orchestrates another function essential to the human brain."

When comparing the human brain to the non-human primates, the researchers saw more connections among gene networks that featured FOXP1 and FOXP2. Earlier studies have linked these genes to humans' unique ability to produce speech and understand language.

"Connectivity measures how genes interact with other genes, providing a strong indicator of functional changes," said Geschwind. "It makes perfect sense that genes involved in speech and language would be less connected in the non-human primate brains -- and highly connected in the human brain."

The UCLA team's next step will be to expand their comparative search to 10 or more regions of the human, chimpanzee and maque brains.

Read more at Science Daily

Dinosaur Footprint Found at NASA Center

For decades, scientists at NASA's Goddard Space Flight Center in Greenbelt, Md., have been looking into the heavens to better understand our place in the universe, oblivious to a fascinating piece of Earth history literally under their feet.

About 110 million years ago, the land that now sports one of NASA's premiere science centers was home to a four-footed tank of a dinosaur called a nodosaur, one of which left a calling card -- a deep footprint inside ancient mud.

"Space scientists may walk along here, and they're walking exactly where this big, bungling heavy armored dinosaur walked," amateur dinosaur tracker Ray Stanford said in an article published Monday on a NASA website .

The imprint shows the right rear foot of a nodosuar -- a "low-slung, spiny leaf-eater -- apparently moving in haste," said Stanford, noting that the dinosaur's heel did not fully settle in the cretaceous mud.

The space agency isn't disclosing the exact location of the print, which is about the size of a dinner plate.

"The agency considers the footprint and its location sensitive, but unclassified," Goddard facilities manager Alan Binstock said in the NASA article.

NASA will consult with state officials and paleontologists to come up with a plan for documenting and preserving the print, he added.

Stanford, who is credited with discovering the nodosaur from a fossilized hatchling found near the University of Maryland in College Park, also found several smaller footprints -- three-toed, flesh-eating therapods -- at the Goddard site.

Read more at Discovery News

Caribbean Islands Heading for the Atlantic

Sometimes even a Caribbean island wants to get away from it all. For the past 50 million years, the isles of the Caribbean, including Puerto Rico, Hispaniola, Barbados and many smaller islands, have been very slowly moving east towards the Atlantic. The tectonic plate beneath the islands is easing away from its neighbor, the South American plate.

The gooey molten rock in the Earth's interior, or mantle, is slowly shoving the Caribbean east, according to University of Southern California earth scientists. The molten rock pushes against the South American continent, but South America sits on tectonic plate that is roughly three times thicker than average. When the unstoppable magma force, meets the immovable South American object, it is the Caribbean plate that gets shoved aside by the re-channeled molten rock.

"We're studying the Caribbean, but our models are run for the entire globe," lead author of the study published in Nature Geoscience, Meghan S. Miller, said in a press release. "We can look at similar features in Japan, Southern California and the Mediterranean, anywhere we have instruments to record earthquakes."

To understand the forces acting on the Caribbean, Miller and her colleagues used earthquake measurements to give clues to the make-up of the Earth's interior. They fed those measurements into a computer and created 176 models of the tectonic forces churning within the Earth.

Read more at Discovery News

Aug 21, 2012

Homeopathy Takes Some Hits

The Food and Drug Administration (FDA) recently uncovered significant violations at one of the world's largest manufacturers of homeopathic products. It is only the latest in a long line of blows to the homeopathy industry, both in Europe and the United States.

For example a major medical insurance company in the U.K. recently stopped paying for homeopathic treatment, citing no evidence that homeopathy is effective.

Homeopathy was invented around 1796 by a doctor named Samuel Hahnemann. He believed (contrary to the principles of physics) that homeopathic medicines become more effective the more they are diluted.

Homeopathic solutions are often so literally watered-down that they don't contain a single molecule of the original medicine or substance: the patient is drinking nothing but water. Homeopathic medicines have not been shown to work better than placebos, yet many people use and endorse homeopathy.

In 2009 the British Science and Technology Select Committee conducted a comprehensive study into whether homeopathy has any scientific validity. The report was devastating:"homeopathy is not efficacious, and explanations for why homeopathy would work are scientifically implausible."

Even professional homeopathic practitioners admitted that basic claims made about homeopathy have never been tested nor proven.

Homeopathic products from A Nelson & Co., a British company that manufactures many products including Nelson's line of pain relievers, digestion aids, emotional aids, energy, acne products and Bach Rescue Remedies sold in America were inspected by the Food and Drug Administration and the conclusions are alarming.

FDA Homeopathy Investigation

In a July 26, 2012, warning letter the FDA informed Nelson's that:

During the inspection, the [FDA] investigator observed glass fragments present during the manufacture... Your firm failed to implement adequate measures to prevent glass contamination and had no documentation to demonstrate that appropriate line clearance and cleaning is conducted following occurrences of glass breakage, which has been a recurring problem.

While the presence of glass in any drug or food is alarming, what should be of bigger concern is that because the manufacturer's dispensing machine was broken, one in six bottles in a sample batch of the homeopathic preparation was never even filled with the product they were selling -- yet not a single homeopathic practitioner or patient noticed!

The investigator also observed for Batch #36659 that one out of every six bottles did not receive the dose of active homeopathic drug solution due to the wobbling and vibration of the bottle assembly during filling of the active ingredient. The active ingredient was instead seen dripping down the outside of the vial assembly. Your firm lacked controls to ensure that the active ingredient is delivered to every bottle.

Imagine if an error was made in the manufacturing of an important life-saving drug, and one out of six pills had no active ingredient at all: Doctors and patients would quickly realize that there was something terribly wrong. But because most homeopathic medications literally have no active ingredient in the first place, any pain relief is attributable to the placebo effect. It makes perfect sense that no one would notice that there was no active ingredient in the preparation, since there's no active ingredient in the medicine even when the bottles are correctly and properly filled.

Skirting Drug Regulations

Most manufacturers of homeopathic preparations sold in the United States try to get around the law requiring that they prove their products are safe and effective. One method is to include a legal warning on the packaging that any statements about what the product does be followed in fine print with the disclaimer: "This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease."

By explicitly referring to alternative medicines and homeopathic preparations as dietary supplements instead of drugs, manufacturers avoid any legal obligation to prove that what they sell works. In addition to the other problems, the FDA found that Nelson's had made claims about their products that would classify them as drugs:

Your product labeling documents the intended uses of your products including, but not limited to the following: Arnica: "Homeopathy, such as the homeopathic remedy Rhus tox and Arnica, has been traditionally used to help relieve the symptoms of rheumatoid and osteoarthritis." Arnileve: "Apply Arnileve Arnica Cream liberally to the affected area in order to reduce inflammation and hasten recovery time." Based on the above labeling and claims, these products are drugs...because they are intended for use in the diagnosis, cure, mitigation, treatment, or prevention of disease in man, and...because they are intended to affect the structure or any function of the body.

In one strange effort to avoid scrutiny from public health officials, a leading manufacturer of homeopathic remedies is considering marketing their (supposedly efficacious) homeopathic pills and preparations as candy. Any "medication" which can simply and accurately be re-labeled as "confectionary" is no medication at all.

Read more at Discovery News

Roman Curses Appear on Ancient Tablet

An ancient Roman lead scroll unearthed in England three years ago has turned out to be a curse intended to cause misfortune to more than a dozen people, according to new research.

Found in East Farleigh, U.K., in the filling of a 3rd to 4th Century AD building that may have originally been a temple, the scroll was made of a 2.3- by 3.9-inch inscribed lead tablet.

Popular in the Greek and Roman world, these sorts of "black magic" curses called upon gods to torment specific victims.

Rolled up to conceal their inscriptions, the tablets were either nailed to the wall of a temple or buried in places considered to be close to the underworld, such as graves, springs or wells.

The scroll, unearthed in the Kent village had been carefully rolled up and buried, most likely in the third century AD, similar to other curse tablets found throughout Europe.

The researchers tried to read the fragile scroll without unrolling it by using a technique called neutron computed tomography imaging at the Paul Scherrer Institute in Switzerland, but "the resolution was not sufficient to discern any writing on it," said the Maidstone Area Archaeological Group, which made the finding.

As the curse tablet, or defixio, was unrolled, the inscribed letters became visible under a scanning electron microscope.

Roger Tomlin, lecturer in late Roman history at Wolfson College, Oxford, and an authority on Roman inscriptions, was finally able to decode the inscribed text.

"The tablet is not necessarily complete, but what there is consists of two columns of personal names," Tomlin told Discovery News.

He deciphered the Latin names Sacratus, Constitutus, Memorianus, Constant[...] and the Celtic names (Atr)ectus and Atidenus. Eight other names are incomplete.

Interestingly, the scribe wrote a few of the names backward or upside down.

Experts speculated that this was probably intended to invoke "sympathetic magic" and make life especially difficult for the named and shamed individuals.

However, the motive of the curse and the curse itself remain a mystery.

"No god is named. Indeed, we cannot be sure that we have the beginning of the text," Tomlin said.

Overall, more than 200 curse tablets have been found in Britain. The largest collection was found in the thermal spring at Bath, -- about 100 tablets -- and are displayed in the Roman Baths Museum.

The second-largest collection is from the Roman temple at Uley, and some are displayed in the British Museum.

Most curses related to thefts and called upon a god to fulfill the malevolent wishes detailed in the inscriptions.

One of the tablets from Bath, for example, prayed that its victim should "become as liquid as water," while another on display at the British Museum cursed "Tretia Maria and her life and mind and memory and liver and lungs mixed up together, and her words, thoughts and memory."

According to the Maidstone Area archaeologists, it is reasonable to assume that the names listed were of people who lived at the site.

Read more at Discovery News

Dying Star Devours Its Own Planet

In the second episode of the Doctor Who rebooted series -- starring Christopher Eccleston as the ninth doctor -- the regenerated Time Lord takes his new "companion," Rose, far into the future. Specifically, he takes her to the year five billion, to join a bevy of various alien leaders on board a space station, parked near the sun. They are there for a momentous occasion: the sun is about to expand into a red giant, and in the process, destroy the Earth.

Science fiction? Well, yes, at least when it comes to the whole time travel and alien space station bit. But as far as the fate of the sun -- and with it, the fate of our pretty blue planet -- that's firmly in the realm of science fact.

Astronomers have just announced the first observational evidence of an aging star destroying its own planet in the Astrophysical Journal.

The sun's energy comes from the nuclear reactions taking place in its core, specifically the conversion of hydrogen into helium. But that energy is not infinite. Eventually all the hydrogen will be converted into helium -- in fact, as this article at Universe Today points out, that process speeds up, little by little, with a corresponding slight increase in the sun's brightness, or heat:

In 1.1 billion years from now, the Sun will be 10 percent brighter than it is today. This extra energy will cause a moist greenhouse effect in the beginning, similar to the runaway warming on Venus. But then the Earth’s atmosphere will dry out as the water vapor is lost to space, never to return.
In 3.5 billion years from now, the Sun will be 40 percent brighter than it is today. It will be so hot that the oceans will boil and that water vapor will be lost to space as well. The ice caps will permanently melt, and snow will be ancient history; life will be unable to survive anywhere on the surface of the Earth. The Earth will resemble dry hot Venus.

When all the hydrogen is turned into helium -- roughly 6 billion years from now -- the sun will no longer generate sufficient energy to counteract the pull of gravity. The core will contract inward, heating up the interior to sufficient temperatures to fuse helium into carbon. This spells doom for Earth, and all of its inhabitants, assuming any managed to survive that hot, dry Venus stage.

As this new phase begins, the sun will puff outward and turn into a red giant, expanding its outer layers as the core collapses. Those outer layers will engulf the nearest planets, including Earth, which will plunge into the core and be vaporized.

The sun's own lifetime will continue, however, until it ultimately cools into a white dwarf star.

In a trillion years, that remnant of our our sun will reach thermal equilibrium with the rest of the cosmos (just a few degrees above absolute zero).

That puffing-out stage, into a red giant, is what the Doctor Who episode depicts. And now an international team of astronomers has found evidence of a similar event when they studied a red giant star called BD+48 740.

They used spectroscopic analysis to determine the chemical composition of this star system, and found huge amounts of lithium. It's a rare element, despite being one of the oldest (dating back to the Big Bang, 14 billion years ago), because it is usually destroyed by stars. So why is it so abundant here?

Alexander Wolszczan (Penn State University) and his colleagues propose in their paper that the lithium was created when a planet-sized massive object spiraled into BD+48 740, heating up sufficiently while it was being "digested" to trigger the production of lithium.

It's not just the spectroscopic evidence that points to the destruction of a planet. The team found another massive planet (larger than Jupiter) orbiting the star, with an equally rare highly elliptical orbit. This could also be caused by the destruction of a massive planet by the host star. That event would produce a burst of energy sufficient to toss the second massive planet into such a strange orbit.

"Catching a planet in the act of being devoured by a star is an almost improbable feat to accomplish, because of the comparative swiftness of the process," co-author Eva Villaver (Universidad Autonoma de Madrid) said via press release. But astronomers can infer this happened by looking at stellar chemistry and orbits of other planets in the system.

Read more at Discovery News

LHC Smashes Highest Man-Made Temperature Record

Just a couple of short months ago, we reported that Brookhaven National Laboratory's Relativistic Heavy Ion Collider had made the Guinness World Records for achieving the "Highest Manmade Temperature" -- a whopping 4 trillion degrees Celsius, 250,000 times hotter than the center of the sun.

That was the work of the lab's PHENIX collaboration, designed to study the formation and characteristics of the quark-gluon plasma (QGP), a state of matter believed to have existed for ten-millionths of a second after the universe's birth.

Even then, we noted that another experiment at the Large Hadron Collider (LHC), called ALICE (A Large Ion Collider Experiment), was nipping at the record's heels. The latest results from the LHC were just announced at the 2012 Quark Matter conference last week, and sure enough, the record has been beaten -- actually, smashed.

Physicists want to know more about the QGP in order to further probe the extreme conditions that existed in the earliest moments of the cosmos. In those first fractions of a second, the universe was so hot that no nuclei could exist. Instead, there was the QGP, made of quarks and gluons (the massless particles that "carry" the force between quarks).

But making this exotic plasma in a laboratory requires enormous energies. Here's a short video detailing how Brookhaven's RHIC achieves them:

ALICE uses lead ions instead of gold ones to create a QGP. The LHC, with its much-higher energies, had no problem beating PHENIX's temperatures by some 38 percent, boosting the record for the hottest manmade material from around 4 trillion degrees Celsius to an eye-popping 5.5 trillion degrees Celsius (that's nearly 10 trillion degrees Fahrenheit).

As impressive as this achievement might be, smashing Guinness records really isn't the point. Unlike ATLAS and CMS, which are focused on hunting for the Higgs boson, ALICE is focused on studying the QCP and other conditions in the primordial universe.

The scientists on ALICE presented a bunch of new results at the conference, most notably concerning charmed particles -- those that contain either a charm or anti-charm quark. Charm quarks are 100 times heavier than the more common up and down quarks that make up normal matter.

The heavier the particle, the more energy it takes to create it within a particle accelerator, and the more quickly it decays into lighter particles. This also makes it more difficult to study such a particle's properties. It's just not around long enough to get a good look, so to speak.

Enter the QGP, which serves to slow down charm quarks as they pass through it; in fact, the ALICE scientists reported that the quarks actually seem to be dragged along by the plasma's current. (Yes, the QGP has a flow.)

And sometimes, they found, those charm and anti-charm quarks recombine to form something called "charmonium." This notion dates back to the 1980s, when such an end product was proposed as a direct signature, or indicator, that a QGP had formed. It was first confirmed in 2000 at CERN's Super Proton Synchrotron.

Read more at Discovery News

More Evidence for Russian Quasicrystal Meteorite

Earlier this year, we told you about an unusual type of rock known as a quasicrystal, found deep in the Russian mountains in 2010 -- the first known naturally occurring quasicrystal. And the most likely origin of that rock was a meteorite from outer space.

Now physicist Paul Steinhardt is back with new evidence that his theory about the origin of that Russian quasicrystal is correct, and that meteorite responsible for its transport likely hit Earth around 15,000 years ago, during the last glacial period.

Those findings just appeared in the journal Reports on Progress in Physics, published by the Institute of Physics in England. It's one of the most colorful material physics papers I've read in recent memory, complete with candid photos of scientists in the field.

Quasicrystals are an unusual type of material first described in the 1980s by Israeli scientist Daniel Schechtman. A quasicrystal has a strange atomic structure that gives it unique properties, falling somewhere between a true crystal and glass.

Schechtman found them quite by accident, while on sabbatical in the US. He was working with rapidly cooled alloys of aluminum and manganese, and noticed an unusual pattern in the electron diffraction pattens they produced.

Schechtman was famously ridiculed for his ideas when he first proposed them, but eventually it appeared in Physical Review Letters. That paper is now one of the ten most cited articles in the history of the journal, sparking a revolution in crystallography and snagging Schechtman the 2011 Nobel Prize in Chemistry.

Most quasicrystals to date -- over a hundred different varieties -- have been created under carefully controlled conditions in the laboratory. Man made quasicrystals are now used in non-stick frying pans, ball bearings, and razor blades.

But the original theory predicted that quasicrystals should occur naturally, and be as robust and stable as regular crystals. Steinhardt started searching for this elusive object back in 1984 in major museum collections, but came up empty. He resumed the search more than 10 years later, and this time he succeeded.

In 2007, Steinhardt and his cohorts pored over a collection of rocks belonging to Luca Bindi of the University of Florence. One of those specimens,found in the Koryak Mountains, exhibited a quasicrystalline pattern.

A mass spectroscopy analysis revealed unusual ratios of oxygen atoms and their isotopes, matching the ratios typically found inside a certain type of meteorite known as a carbonaceous chondrite. The samples also contained silica, suggesting it had formed under high pressure conditions.

Steinhardt and his colleagues hypothesized that the most likely scenario is that the quasicrystal found in the Koryak Mountains fell to Earth inside a meteorite, outlined in their paper published in the Jan. 2 issue of the Proceedings of the National Academy of Science.

But in order to definitively prove this hypothesis, Steinhardt had to verify that the sample was, indeed, from that region. The paper merely states that the year-long forensic investigation had "more twists and turns than can be recounted here," while the press release offers tantalizing hints that those twists and turns involved "secret diaries, smugglers, gold prospectors and bears." (I hereby offer to buy Steinhardt a drink, just to hear his swashbuckling tale of adventure in the way such tales were meant to be told.)

The man who found the sample back in 1979 turned out to be one Valery Kryachko, who was panning for platinum along the clay bed of a tributary of the Khatyrka River. He failed to find platinum but did bring back "a few rocks with metallic phases," according to the paper. The quasicrystal sample was among them.

So, where there's one naturally occurring quasicrystal, might there be more? Steinhardt knew this would require an expedition to the place where the original rock was found. Never mind funding, guides, and all the practical details involved in pulling off such an explanation. "Only one person in the world knew the precise spot where the original sample was discovered in 1979, and travel to the autonomous okrug of Chukotka is restricted," the authors wrote.

But succeed they did, setting off last July with a team of ten scientists, two drivers and cook, crawling across the tundra and into the Koryak Mountains on a pair of slow-moving tractor vehicles. It took four days just to get there, and the effort seems to have been worth the trek.

Steinhardt and his colleagues collected more samples, which contained more naturally occurring quasicrystals. They were also able to verify that the local terrestrial environment didn't have the kind of extreme conditions that would have been necessary to produce such quasicrystals, significantly bolstering Steinhardt's case that they arrived here via meteorite. Based on sediment samples, the researchers peg the likely date of that impact at around 15,000 years ago.

Read more at Discovery News

Aug 20, 2012

Why Aren't There More Stars?

Boston University undergraduate researcher Rob Marchwinski and his colleagues in BU’s Astronomy Department may have found the answer to a universal question: Why aren’t there more stars?

A possible answer to that question presented itself to Marchwinski while he, graduate student Michael Pavel and Professor of Astronomy Dan Clemens used new data from the Galactic Plane Infrared Polarization Survey (GPIPS) to create the first complete map of magnetic field strength in a large, interstellar gas cloud. (The GPIPS is being conducted by BU astronomers on the 1.8-meter Perkins telescope, which is shared by Boston University and Lowell Observatory in Flagstaff, Arizona.)

Stars form when large clouds of interstellar gas and dust nucleate or form centers, eventually consolidating into dense cores, which in tum collapse under the force of gravity. While the steps in the star formation process have become better understood in recent years, the rate at which new stars form has remained something of a mystery. Indeed, most models predict there should be up to ten times more stars forming than are observed. What is preventing stars from forming at faster rates?

Working with more than 3000 infrared polarization measurements—out of the roughly one million gathered by the GPIPS—Marchwinski was able to identify the very weak magnetic field present in a gas cloud located about 6000 light-years away in the constellation Aquila. The huge cloud, spanning an area of 30 by 120 light-years, contains more than 17,000 times the mass of the Sun in diffuse gas and dust. However, despite its enormous size, the BU researchers have measured an average magnetic field strength of just over five micro-Gauss—about one hundred thousand times weaker than the magnetic field on Earth.

They also found seven dense cores within the cloud, with average masses of one hundred times that of the Sun. These cores, which eventually will develop into new stars, are also sites of somewhat stronger magnetic field strengths that are just strong enough to prevent gravitational collapse. "It is surprising that magnetic fields as weak as these can disrupt star formation, but it seems to be the case in this cloud," said Marchwinski.

Read more at Science Daily

Big Bang Theory Challenged by Big Chill

The start of the Universe should be modeled not as a Big Bang but more like water freezing into ice, according to a team of theoretical physicists at the University of Melbourne and RMIT University.

They have suggested that by investigating the cracks and crevices common to all crystals -- including ice -- our understanding of the nature of the Universe could be revolutionized.

Lead researcher on the project, James Quach said current theorizing is the latest in a long quest by humans to understand the origins and nature of the Universe.

"Ancient Greek philosophers wondered what matter was made of: was it made of a continuous substance or was it made of individual atoms?" he said. "With very powerful microscopes, we now know that matter is made of atoms."

"Thousands of years later, Albert Einstein assumed that space and time were continuous and flowed smoothly, but we now believe that this assumption may not be valid at very small scales.

"A new theory, known as Quantum Graphity, suggests that space may be made up of indivisible building blocks, like tiny atoms. These indivisible blocks can be thought about as similar to pixels that make up an image on a screen. The challenge has been that these building blocks of space are very small, and so impossible to see directly."

However James Quach and his colleagues believe they may have figured out a way to see them indirectly.

"Think of the early universe as being like a liquid," he said. "Then as the universe cools, it 'crystallizes' into the three spatial and one time dimension that we see today. Theorized this way, as the Universe cools, we would expect that cracks should form, similar to the way cracks are formed when water freezes into ice."

RMIT University research team member Associate Professor Andrew Greentree said some of these defects might be visible.

"Light and other particles would bend or reflect off such defects, and therefore in theory we should be able to detect these effects," he said.

The team has calculated some of these effects and if their predictions are experimentally verified, the question as to whether space is smooth or constructed out of tiny indivisible parts will be solved once and for all.

Read more at Science Daily

Tiny Green Bug May Be First Photosynthetic Animal

Pea aphids may have an unprecedented ability to harvest sunlight, and use the energy for metabolic purposes. It would make it the only species of animal known to have photosynthesis-like powers.

It comes down to carotenoids, which are a type of pigment used in animals for crucial functions like vision, bone growth and vitamin production. All known animals obtain these by eating the plants, algae and fungi that naturally synthesize the orange-red compounds.

Back in 2010, University of Arizona biologists researcher Nancy Moran and Tyler Jarvik discovered that pea aphids can make their own carotenoids, like a plant. “What happened is a fungal gene got into an aphid and was copied,”said Moran in a press release.

Entomologist Alain Robichon, of the Sophia Agrobiotech Institute in France, wanted to find out why the insects make such metabolically expensive chemicals.

Carotenoids are responsible for aphid body color, and the researchers found that insects changed color depending on environmental conditions. In optimal environments, aphids make a medium amount of carotenoids and come out orange. In the cold, the insects have a high level of carotenoids and are green. In areas with limited resources, aphids are almost devoid of the pigment and are born white.

The team then measured the aphids’ levels of adenosine triphosphate (ATP) — a way to measure energy transfer in living organisms — and received striking results. Green aphids make significantly more ATP than white ones, and orange aphids made more ATP while exposed to sunlight than when kept in the dark.

The researchers also crushed the orange aphids and purified their carotenoids, to demonstrate that it was these extracts that could absorb light and pass this energy on. This all suggests that the synthesized pigments may contribute to a system of photo-induced electron transfer, where the aphids can harness energy from the sunlight.

Read more at Wired Science

Hook-Legged Spider Found in Oregon Cave

A group of cave explorers and scientists have made a rare discovery:  an entirely new taxonomic family of spider in the caves of southern Oregon.

Only two other spider families (the taxonomic group above both genus and species) have been found since 1990, and this is the first newly discovered, native one uncovered in North America since 1890, said California Academy of Sciences researcher Charles Griswold, lead author of the study that described the species.

So far, the family consists only of the one species described, which the researchers named Trogloraptor marchingtoni. The species is named after Neil Marchington, a member of the Western Cave Conservancy, who first discovered the spider. The genus name, Trogloraptor, means "cave robber."

It's an apt name for a spider with unique hooks, or claws, on its legs, which the researchers believe are used to snatch flying insects, like midges, out of the air. With its legs outstretched, the spider measures up to 3 inches (8 centimeters) long.

"They're biggish," Griswold said. "But when you're in a cave and it's dark and there's only the beam of your head lamp, they look much bigger. It's quite astonishing to see them hanging from a few threads."

Griswold and his colleagues think that the newly discovered spiders hang from the underside of caves on simple webs, waiting to snatch a meal with their astonishing sicklelike legs. The few specimens Griswold and his graduate student Tracy Audisio have reared in the lab, though, haven't eaten anything. "It seems very shy," Griswold told OurAmazingPlanet.

The spider also has poisonous glands, although there's no evidence that it is dangerous to humans.

Griswold said this discovery could help explain why there are legends about giant spiders living in caves in this region. And perhaps there are other similar species yet to be found; many caves, especially in the western United States, remain little studied.

Finding a new family like this is an historic moment for the field. "It is just as fascinating to arachnologists as the discovery of a new dinosaur is to paleontologists," said spider expert Norman Platnick at the American Museum of Natural History. Platnick was not involved in the discovery or description of the new species.

Another unusual thing about the spider is that it has two rows of teeth, or serrula. "I don't recall seeing any other spiders with that kind of serrula," Platnick told OurAmazingPlanet.

Currently, there are only 111 recognized spider families. New families get added in one of two ways. The more common way is by studying a group that has already been described, and discovering that its relationships are not what had been previously thought, Platnick said. Less common is a case like Trogloraptor, where a new family is established when the animal is first described, he said.

Read more at Discovery News

Skull Resets Human Migration Clock

Newfound pieces of human skull from "the Cave of the Monkeys" in Laos are the earliest skeletal evidence yet that humans once had an ancient, rapid migration to Asia.

Anatomically modern humans first arose about 200,000 years ago in Africa. When and how our lineage then dispersed out of Africa has long proven controversial.

Archaeological evidence and genetic data suggest that modern humans rapidly migrated out of Africa and into Southeast Asia by at least 60,000 years ago. However, complicating this notion is the notable absence of fossil evidence for modern human occupation in mainland Southeast Asia, likely because those bones do not survive well in the warm, tropical region.

Now a partial skull from Tam Pa Ling, "the Cave of the Monkeys" in northern Laos helps fill in this mysterious gap in the fossil record.

"Most surprising is the fact that we found anything at all," researcher Laura Lynn Shackelford, a paleoanthropologist at the University of Illinois, told LiveScience. "Most people didn't think we'd find anything in these caves, or even in the region where we're working in mainland Southeast Asia. But we're stubborn, gone where no one's really looked before, or at least in almost a century."

Rough terrain, persistent scientists

The fossils were discovered in 2009 in the limestone cave, which is located at the top of the Pa Hang Mountain 3,840 feet (1,170 meters) above sea level.

"The cave is surrounded by lots of papaya and banana trees, so a troop of monkeys likes to come and forage there, therefore its name," Shackelford said.

There were many challenges working in this area.

"It's incredibly difficult to access the site — it's only 150 miles (240 kilometers) from the capital, but it takes us two days to drive there because of the rough terrain," Shackelford said. "We have to hike up the side of a cliff, do a bit of rock-climbing to get to the mouth of the cave, and then going in, we have to go 60 meters (200 ft) down a slope of wet clay. We also have to carry a generator and lights with us to see in the cave. We have to push pigs out of the way to get through the jungle — there are just pigs wandering around there."

"Every bit of clay has to be removed and taken back up by hand, trowel and bucket, so work is incredibly slow," she added. "We only go in the dry season in the winter, so we don't really have to deal with insects and snakes — well, we did have snakes fall into the pit while excavating. And in the cave, we've had more than our fair share of spiders and bats."

Oldest bones of modern humans

No artifacts were found at the site, nor were signs of human occupation.

"We think this fossil was outside with other fauna and flora, and during the rainy season, rain washed it into the cave," Shackelford said. "In subsequent seasons, more sediment washed into the cave and covered it."

The shape of the bone and teeth is distinctly anatomically modern human, not like those of an extinct lineage such as the Neanderthals. A variety of dating techniques of the sediments surrounding the fossils suggests they are at least 46,000 to 51,000 years old, and direct dating of the bone suggests a maximum age of about 63,000 years. This makes these fossils the earliest skeletal evidence for anatomically modern humans east of the Middle East.

These findings "change the thinking regarding modern human migration routes into Asia, that there were more routes of dispersal than previously thought," Shackelford said.

"The typical thinking was that once modern humans hugged the coastline to go from India to Southeast Asia, they went southward into Indonesia and Australasia (the region comprising Australia, New Zealand and neighboring Pacific islands)," she explained. "We think they absolutely did that, but we're also suggesting other populations probably went north or northeast toward China, and some went through the mountains into mainland Southeast Asia, taking advantage of river systems. Beforehand, no one thought they would have gone into the mountains of Laos, Vietnam and Thailand."

Read more at Discovery News