Feb 23, 2013

Has Evolution Given Humans Unique Brain Structures?

Humans have at least two functional networks in their cerebral cortex not found in rhesus monkeys. This means that new brain networks were likely added in the course of evolution from primate ancestor to human.

These findings, based on an analysis of functional brain scans, were published in a study by neurophysiologist Wim Vanduffel (KU Leuven and Harvard Medical School) in collaboration with a team of Italian and American researchers.

Our ancestors evolutionarily split from those of rhesus monkeys about 25 million years ago. Since then, brain areas have been added, have disappeared or have changed in function. This raises the question, 'Has evolution given humans unique brain structures?'. Scientists have entertained the idea before but conclusive evidence was lacking. By combining different research methods, we now have a first piece of evidence that could prove that humans have unique cortical brain networks.

Professor Vanduffel explains: "We did functional brain scans in humans and rhesus monkeys at rest and while watching a movie to compare both the place and the function of cortical brain networks. Even at rest, the brain is very active. Different brain areas that are active simultaneously during rest form so-called 'resting state' networks. For the most part, these resting state networks in humans and monkeys are surprisingly similar, but we found two networks unique to humans and one unique network in the monkey."

"When watching a movie, the cortex processes an enormous amount of visual and auditory information. The human-specific resting state networks react to this stimulation in a totally different way than any part of the monkey brain. This means that they also have a different function than any of the resting state networks found in the monkey. In other words, brain structures that are unique in humans are anatomically absent in the monkey and there no other brain structures in the monkey that have an analogous function. Our unique brain areas are primarily located high at the back and at the front of the cortex and are probably related to specific human cognitive abilities, such as human-specific intelligence."

Read more at Science Daily

Newly Found Dino Had Chicken-Sized Young

A newly discovered dinosaur, Yulong mini, was appropriately named, as the remains of its chicken-sized offspring are now among the smallest dinosaurs ever found, according to a new study.

The tiny baby dinosaurs, described in the journal Naturwissenschaften, were oviraptorids, a.k.a. "egg thieves." These non-flying dinosaurs resembled modern birds, except adults of some species could grow to over 26 feet long.

"Yulong looks like chicken with a tail," lead author Junchang Lü told Discovery News. "Its behavior was similar to living birds too. Based on the primitive oviraptors such as Caudipteryx, Yulong should be feathered, although we could not find feathers due to the poor preservation condition."

Lü, of the Chinese Academy of Geological Sciences, and his colleagues analyzed the dinosaur remains, which were unearthed at Henan Province in central China. In addition to Lü, the team included researchers from the Henan Geological Museum as well as Philip Currie from the University of Alberta.

While adult dinosaurs were found in the general region of the excavation, they were not directly with the babies, suggesting that members of this species did not require parental care when young.

It has been widely accepted that oviraptors were carnivores. One earlier specimen, for example, was found with the preserved remains of a lizard in its stomach. The new study, however, challenges that theory.

In terms of the new oviraptor fossils, "based on their hind limb proportions, the pattern is more commonly seen in herbivores than in carnivores, thus indicating that they were herbivores," Lü said.

He did, however, add that the jaw structure of this dinosaur could have handled a few meaty edibles.

"It provided strong bite force when (the dinosaur) ate hard foods such as nuts, mollusks and even eggs," he explained.

Currie, though, described Yulong mini as having a "sedentary lifestyle that did not involve the pursuit of similar-sized prey."

The dinosaur might then have rather passively poked around for food, similar to how some birds today forage.

Yulong mini itself was good eats.

Just as many humans today love chicken, it seems that other dinosaurs enjoyed chowing down on Yulong. Remains of several large carnivorous dinosaurs, including T. rex, were found in the area and likely preyed on the more sedentary dinosaurs, the researchers believe.

Read more at Discovery News

Feb 22, 2013

'Genesis Death Sandwich' Discovered in Bible

Researchers using text-analysis software say they've discovered a new literary device in the first book of the Bible: the "Genesis death sandwich."

The name refers to a familiar rhetorical structure -- sandwiching bad news in between the good. In the case of Genesis, the slices of white bread are themes of life, and the slimy cold cuts in between are mentions of death.

"The structuring of life and death in Genesis appears to be something that hasn't been noticed before," researcher Gordon Rugg, a senior lecturer in Computing and Mathematics at Keele University in the United Kingdom, wrote in a Feb. 21 blog post. "We think it's a standard literary device being used on a larger scale than had been previously realized. No aliens, no secret codes, no conspiracies, but some striking images, and a great name for a band."

For their study, Rugg and his colleagues ran the King James version of the text through software known as the Search Visualizer, which plotted mentions of life in red and death in green on a single gridded page representing the whole book. Their results showed frequent mentions of life in the opening and closing verses of Genesis, while themes of death were clustered in the middle. They say the device is an example of a literary convention known as inclusio, also called bracketing, where one theme frames another.

Rugg acknowledged that it is uncertain whether or not this "death sandwich" convention was applied to the text intentionally. Nonetheless, he says it might have been used to cushion the negative messages of death, or perhaps to put life and death in stark contrast.

"Whether it was a deliberate use of inclusio or a subconscious use is an open question," Rugg wrote. "We don't think that this structure is likely to be a coincidence, given the number of times the two words occur within Genesis, and given that these are themes that have long been recognized as significant within it."

Rugg and his colleagues ran other searches using the software for words not considered significant by scholars, finding no specific patterns in the book of Genesis. However, they did find the word "woman" appears overwhelmingly in the first part of Genesis, while it rarely pops up in the second half, Rugg wrote. Another term, "begat," illustrates something scholars have long recognized -- that the gospels of Matthew, Mark, Luke and John mirror the themes and structures of the Old Testament (which includes Genesis); sure enough, "begat" showed a striking cluster in the first part of Genesis, mirroring what was found in the first part of the gospel of Matthew, Rugg said.

Read more at Discovery News

Hunting Fertilizer to Find Hints of Early Life

In Brazil, a search for fertilizer fodder is also turning into a hunt for ancient life.

Scientists at Nova Scotia-based Acadia University are working with MbAC Fertilizer Corp. to help the Brazilian company find and analyze phosphate deposits — the basis for fertilizer — in a small mining town in central Brazil.

At the same time, the project researchers seek to understand how the tiny plants that deposited the phosphorous helped drive ocean evolution, particularly in the period from 700 million to 740 million years ago — just as multicellular life began evolving on Earth.

"It's kind of like turning a book on its side so you've got the pages horizontal. What we do, and what I train my students to do, is to learn the language. To interpret the rocks," said Peir Pufahl, a chemical and economic sedimentologist at Acadia.

"Mind you, 80 percent of our pages are ripped out and missing," he told OurAmazingPlanet. "We get to piece together the story using the layers of sediment we see accumulated in these ancient oceans."

MbAC and the Acadia researchers together examine aerial maps of the Campos Belos region, looking for rock outcrops, then travel to the sites to perform their work. Many of these sites have never been probed with modern tools, providing a bit of frontier research for the Acadia scientists.

Tidal environments

In a typical day, Pufahl and his students visit the site and examine the layers of rocks in the field. By day's end, they leave the area — often with a long cylinder of rock that they extracted using a special tool. They then perform chemical analyses on how the so-called phosphorous cycle changed over time. [Images: Mining for Signs of Early Life]

Phosphorous typically washes into the water from land deposits, then is eaten by algae. In turn, bigger animals eat the algae.

When those bigger animals die, their bodies sink to the seafloor, and the phosphorous is released into the sand as the animals decay, leaving deposits behind. Over eons, some of these once-underwater areas become dry land.

The scientists have completed only one field season of research, so their investigations have not yet produced any journal papers. But so far, the researchers have figured out the phosphate deposits arose in some sort of tidal flat.

"That's the first step to understand these deposits and the environments in which the phosphate is recycling," Pufahl said.

Pufahl aims to examine the global glaciations and melts that were occurring just before multicellular organisms arose, to see how these sudden climate changes affected the evolution of life.

Finding fodder

Pufahl's working relationship with MbAC arose through serendipity. Four years ago, at the request of the Society of Economic Geologists, he gave a talk on phosphorous in Brazil, where he met company representatives.

Brazil is seeking "mineral independence" in the next 20 years, meaning the country would no longer need to import these life essentials from other nations, Pufahl said. With a population of 200 million people to feed, phosphorous is important because it will let Brazil increase its fertilizer production, leading to more food for its residents.

Read more at Discovery News

Acupuncture for Allergies? Jury's Still Out

Though acupuncture is often used to treat seasonal allergies, there has been limited scientific evidence that it actually works. A new study finds that it does — kind of, maybe, but not really.

The study, led by Dr. Benno Brinkhaus of the Charité-University Medical Center in Berlin, examined the outcomes of 422 patients with seasonal allergic rhinitis (pollen allergies) over an eight-week period. They were randomly assigned to different conditions to evaluate whether acupuncture helps alleviate symptoms compared to the drug cetrizine and fake acupuncture.

Though the study has been widely reported as showing that acupuncture likely works, there are important red flags suggesting that the results may not be all they are cracked up to be.

The Placebo Effect

First, there is strong evidence that much of the improvement in allergy symptoms may simply have been caused by the placebo effect. When a patient is given a treatment and told that it will help them, often it will — even if there’s no active ingredient. A person’s expectation that they will feel better often actually makes them feel better subjectively.

One problem with trying to test acupuncture’s effectiveness apart from the placebo effect lies with the treatment itself. If doctors are testing a drug, they can make pills that look and taste identical, both with and without active ingredients. Because the patient doesn’t know if they are taking a placebo or not, the difference in outcomes can be attributed to the medicine. But in the case of acupuncture, it’s very difficult to fool someone into thinking they’re not being poked with needles.

Statistical Versus Clinical Significance

There’s another, more serious issue. The researchers noted, “We found that acupuncture led to statistically significant improvements in disease-specific quality of life and antihistamine use after eight weeks of treatment compared with sham acupuncture and with alone, but the clinical significance of the findings remains uncertain.”

To see why is this a problem it’s important to understand the difference between statistical and clinical (or practical) significance; they are very different things. Let’s say that in a clinical trial Cold remedy A has been shown statistically to work better on some measure than Cold remedy B. Does that mean that Cold remedy A is better than Cold remedy B?

Not necessarily, because outside of the laboratory and in the real world, people look for practical, not just theoretical or statistical significance. Maybe the average person sneezes 20 times per hour using Cold remedy A but only 18 times per hour using Cold remedy B. So what? If Cold remedy A shortens the duration of a cold by half a day that might be a good reason to choose it — unless it costs twice as much as its competitor, or has significantly more side effects, or any number of other reasons.

Or, to use an example outside of the medical field, let’s say that research is done on the price of food in a certain metropolitan area, and, on average, Supermarket A tends to be about 2 percent cheaper than Supermarket B after prices are compared and calculated. Does that mean that Supermarket A is better or worth shopping at more often? Not necessarily. For example that 2 percent difference is only a statistical average across many products that not every household uses, and may not necessarily reflect the products you regularly buy. Even if it does, the savings may not be worth the effort to save $1 on a $50 purchase. This is especially true if Supermarket A is out of the way: there’s little point in spending $3 in gasoline to drive across town to save $1.50 on groceries — not to mention the extra time and hassle.

Read more at Discovery News

Marvelous Mercury -- In Color

To the human eye, tiny Mercury, the innermost planet of the solar system, may look like Earth’s moon, but appearances can be deceiving.

Instruments aboard NASA’s MESSENGER spacecraft, currently orbiting Mercury, reveal a rich variety of chemicals, minerals and physical features, a new image of the planet shows.

The false-color view depicts variations in the composition of Mercury’s rocks.

"It’s an oddball planet," David Blewett, with the Applied Physics Laboratory at Johns Hopkins University, told reporters at the American Association for the Advancement of Science meeting in Boston last week.

Mercury is the smallest of the solar system’s eight planets (the dwarf planet Pluto is no longer is considered a full-fledged planet), but its most dense. It also sports a global magnetic field like Earth’s, a feature Venus and Mars lack.

In the image, released by NASA on Friday, the giant Caloris impact basin appears near the top, filled with orange-toned volcanic plains. The small orange and tan spots are places where materials have been deposited by volcanic eruptions.

Read more at Discovery News

Feb 21, 2013

Treasure-Filled Warrior's Grave Found in Russia

Hidden in a necropolis situated high in the mountains of the Caucasus in Russia, researchers have discovered the grave of a male warrior laid to rest with gold jewelry, iron chain mail and numerous weapons, including a 36-inch iron sword set between his legs.

That is just one amazing find among a wealth of ancient treasures dating back more than 2,000 years that scientists have uncovered there.

Among their finds are two bronze helmets, discovered on the surface of the necropolis. One helmet (found in fragments and restored) has relief carvings of curled sheep horns while the other has ridges, zigzags and other odd shapes.

Although looters had been through the necropolis before, the warrior's grave appears to have been untouched. The tip of the sword he was buried with points toward his pelvis, and researchers found "a round gold plaque with a polychrome inlay" near the tip, they write in a paper published in the most recent edition of the journal Ancient Civilizations from Scythia to Siberia.

The remains of three horses, a cow and the skull of a wild boar were also found buried near the warrior.

Diagram of Grave

"These animals were particularly valuable among barbarian peoples of the ancient world. It was sign of great importance of the buried person, which was shown by his relatives and his tribe," wrote team member Valentina Mordvintseva, a researcher at the Ukrainian National Academy of Sciences Institute of Archaeology, in an email to LiveScience. The animal bones and pottery remains suggest that a funeral feast was held in his honor.

Without written records it is difficult to say exactly who the warrior was, but rather than ruling a city or town, "he was rather a chief of a people," Mordvintseva said.

The necropolis is located near the town of Mezmay. Grave robbers discovered the site in 2004 and rescue excavations began in 2005.

Iron Axe

Based on the artifacts, researchers believe the warrior's burial dates back around 2,200 years, to a time when Greek culture was popular in west Asia, while the necropolis itself appears to have been in use between the third century B.C. and the beginning of the second century A.D.

Researchers were careful to note that the artifacts cannot be linked to a specific archaeological culture. Mordvintseva points out that "this region is very big, and not sufficiently excavated," particularly in the area where the necropolis is located. "t is situated high in mountains. Perhaps the population of this area trade routes/passes with Caucasian countries -- Georgia, Armenia etc.," Mordvintseva writes in the email.

While the people who used the necropolis were clearly influenced by Greek culture, they maintained their own way of life, said Mordvintseva. "Their material culture shows that they were rather very proud of themselves and kept their culture for centuries."

Read more at Discovery News

Secret Sex Scandal Report Behind Pope Resignation?

Pope Benedict XVI’s abrupt resignation was prompted by a secret report revealing sex and graft scandals inside the Vatican, according to the Italian daily La Repubblica.

“The Pope decided to step down the week before Christmas,” the newspaper wrote.

Relying on an unnamed Vatican source, La Repubblica revealed that on December 17 three cardinals presented the pontiff with the “Relationem,” a 300-page report which investigated allegations brought up last year by the so-called Vatileaks scandal.

Last autumn Benedict’s butler, Paolo Gabriele, was found guilty of having stolen confidential documents from the papal apartment.

Commissioned by Benedict himself, the report was prepared by Cardinals Julian Herranz, Salvatore De Giorgi and Josef Tomko, the former chief of the Vatican’s secret services.

The Relationem, consisting of two red, leatherbound volumes, contained the “exact map of the mischief and the bad fish” inside the Holy See, according to La Repubblica.

“It all revolves around the breach of the sixth and seventh commandments,” the newspaper quoted its source, a man described as being very close to the three authors of the report.

The seventh commandment — “thou shalt not steal” — would refer to the affairs of the Vatican Bank, IOR, which is under investigation for money laundering.

The Relationem would also contain plenty of details on the breaking of the sixth commandment — “thou shall not commit adultery” or “impure actions.”

According to La Repubblica, some high-ranking members of the clergy were blackmailed by laymen with whom they entertain relationships of “worldly nature.”

The Italian newspaper mentioned a gay network which organized sexual encounters in villas and saunas in Rome as well as in the Vatican rooms.

Benedict, who in the past called gay people a “defect of human nature” and gay marriages a “threat to world peace,” admitted last week in his last public Mass that “the face of the church is, at times, disfigured.”

Read more at Discovery News

Flowers Communicate With Electricity

Flowers may be silent, but scientists have just discovered that electric fields allow them to communicate with bumblebees and possibly other species, including humans.

It’s well known that color, shape, pattern and fragrances allow flowers to connect with pollinators, but the new study, published in the journal Science, adds electricity to this already impressive lineup.

“We just now have discovered that electrical potentials, an unavoidable by-product of flying in air for bumblebees and being grounded for the flower, is being exploited to benefit both parties,” co-author Daniel Robert told Discovery News. It’s “another example of the beauty of evolution,” added Robert, a professor in the University of Bristol’s School of Biological Sciences.

He explained that bees have a positive electrical charge because they fly in air, which is full of all kinds of tiny particles, such as dust and charged molecules. Friction from these particles causes bees to lose electrons, leaving bumblebees positively charged.

Flowers, on the other hand, “are electrically connected to ground,” he said. Unlike copper wire, which transfers charges very quickly, plants conduct electricity very slowly and tend to possess a negative charge.

For the study, Robert and his team placed petunia flowers in an area with free-flying foraging bees. The researchers then studied how interactions between the two changed the electric fields and the bees’ behavior.

They determined that when a bee lands on a flower, this generates its own electrical field, and therefore a force. It’s as though a mini spark results when the two connect.

Robert and his colleagues believe “that the bee can sense this electrically induced force.” It appears to improve the bee’s memory of flower rewards, such as pollen and nectar, affecting later foraging.

The flower, in turn, is electrically changed for a short period after the interaction.

“Bees have what has been observed to be flower constancy, (meaning that) once they forage, they tend to keep going to one type of flower, and they keep going until they feel that the rewards are not worth it anymore,” Robert said.

“We think that flowers have their say in that strategy, and inform the bees that the supply will be back soon,” he added. This is “a dynamic interaction.”

This process of flower informing brings together all of the plant’s communication tools. It appears that electricity boosts the power of the other tools, such as color.

“We have demonstrated that when there is an electric field present, even a mild one, bees can learn the difference between two colors faster,” Robert said. “So, like in a commercial advertisement, the main and obvious message can be supported by co-lateral cues that do not necessarily convey information about the product, but are easily associated with it.”

Thomas Seeley, chairman of the Cornell University Department of Neurobiology and Behavior, is intrigued by the possibility that electric fields may facilitate rapid and dynamic communication between flowers and pollinators.

Seeley told DNews that the study "opens a window on a sensory system of the bees that we had no idea existed and no idea was used by bees during foraging."

Read more at Discovery News

Dark Matter Matters -- When You Can't Find It

There is a phantom in the machinery of the universe, and it evades even the best “ghost hunting” physicists.

Known for nearly 80 years, and for lack of a better terminology simply called “dark matter,” it still eludes detection to this day. Even our biggest particle accelerator, the Large Hadron Collider (LHC), apparently hasn’t been able to manufacture it.

Researchers at this week’s meeting of the American Association for the Advancement of Science (AAAS) reported that their Alpha Magnetic Spectrometer (AMS) on the International Space Station may yield new clues as to what dark matter is. This $1.5 billion “bug trap” experiment collects all kinds of exotic high-energy particles from deep space. Any unusual peaks in the count of particles monitored by the AMS might be the result of dark matter behavior. The AMS team are expected to release their results next month.

What’s frustrating is, that whatever it is, dark matter is a lynchpin in modern astrophysics. It is the ghostly link between the infinitely small and infinitely large: particle physics and cosmology.

But unlike ghosts, dark matter is unequivocally real — like the character Griffin in The Invisible Man written in the 1897 by H.G. Wells. People see Griffin’s actions as he actually moves things around but never the body (at least until his death).

Dark matter’s gravitational pull is the glue of the universe, holding together galaxies and clusters of galaxies. Dark matter warps space like a funhouse mirror, stretching images of far-flung galaxies. Dark matter is also imprinted on the acoustic waves frozen in our snapshot of the 380,000 year-old universe, cosmic microwave background radiation.

Therefore, dark matter is not an illusion based on some lack of understanding of gravity, as some have suggested. “If solving dark matter calls for a modified theory of gravity I’ll eat my PowerPoint slides — and my laptop computer!” said astrophysicist Mike Turner, of the University of Chicago.

In fact, “dark” is a misnomer says Harvard University theoretical physicist Lisa Randall because it does not interact with radiation. A dark object still absorbs or reflects a little light. A black cat eating licorice in a coal bin is dark matter.

So, let’s call the glue of the universe invisible matter, with a tip of the hat to 19th century poet Hughes Mearns:

“Yesterday, upon the stair; I met a man who wasn’t there; He wasn’t there again today; I wish, I wish he’d go away…”

Invisible matter particles were presumably cooked up when the newborn universe was a “quark soup,” 1/100,000th of a second after the Big Bang. The seething hot universe was essentially a nuclear reactor for making particles more massive than quarks.

One idea is that invisible matter was born out of a phase transition — like water vapor turning into droplets. It may have decoupled from normal matter to make such hypothetical particles as axions or WIMPs (Weakly Interacting Massive Particles). Normal matter and invisible matter may have transferred properties between each other in the primeval cauldron. Both forms of matter store the same amount of energy in the same volume, so they must have a kinship.

Today there is an ongoing do-loop between theories and experiments for invisible matter. One theory is that invisible matter particles occasionally collide with each other to make specific flavors of cosmic rays, anti-protons or gamma rays. And, all of this must be sorted out from the cacophony of high-energy radiation saturating the universe.

Rather than waiting for Mother Nature, physicists are eagerly trying to home cook their own invisible matter in the LHC. This allows for the invisible matter egg-hunt to be done under controlled conditions.

But, like our Invisible Man, invisible matter particles can only be inferred from the behavior of observable particles created deep in the bowels of the LHC’s building-sized detector arrays.

Head-on collisions of clusters of protons accelerated to near the speed of light yield cascades of subatomic particles meticulously recorded by concentric rings of detectors. The subatomic shrapnel from the collision is inventoried by massive data processing. A deficit in the tally could mean that an invisible matter particle was created and promptly zipped through all the layered detectors without a trace.

But is evidence of absence really absence of something tangible? The same effect could be caused by an escaping neutrino (which in fact may account for some fraction of invisible matter) or simply bad data. Or maybe there is an unintended observer bias when looking at the data.

What’s more, only a fraction of the collision data deemed “most interesting” can be stored and the rest is thrown away. “I stay awake every night worrying we might be throwing out the baby with the bathwater,” said U.C. Santa Barbra physicist Claudio Campagnari.

And, can some conclusions be gleaned about invisible matter from a null result?

Read more at Discovery News

3-D View of a Quasar with a Galactic Lens

I get excited when I see astronomers using novel techniques to study more distant and more difficult problems in astronomy. In this case, we have a galaxy cluster acting as a lens and some high-resolution spectroscopy to get a 3-dimensional view of a quasar.

A typical quasar is dominated by a point of light coming from the very center of the distant galaxy, specifically from the accretion disk around a supermassive black hole that is pulling matter into it. That bright central quasar can often act as a background light for probing what is in front of that quasar along our line of sight, including the structures within the very same galaxy.

For this study, a group led by Toru Misawa looks at the broad absorption line features in the spectra of one such quasar, J1029+2623. Such features are not uncommon in quasar spectra as they are a result of some outflow of material away from the accretion disk. Yes, there are things falling in AND things flowing away from the black hole; it’s a very turbulent place. In fact, these outflows are key to transporting angular momentum away from the black hole so that more material can fall in. They also can have the side effect of shutting down star formation in other parts of the galaxy. So, they are quite important to understanding the whole evolution of a quasar.

However, typically, a quasar only allows one, piercing line of sight through the outflow region. J1029+2623 is different because it is being lensed by a whole galaxy cluster that lies somewhere in front of it along our line of sight. So there are three different images of the quasar widely separated apart. This means, as the diagram above shows, you get several different lines of sight through the outflow and can begin to discern its shape and properties.

The astronomers confirmed this by doing high resolution spectroscopy of quasar with the 8.2-meter Subaru Telescope in Hawaii. The shape of the broad absorption lines were different from each lensed image of the quasar. They narrowed this down to being caused by two scenarios: either they were seeing different parts of the outflow cloud of material, or they were seeing changes over a large size scale over a short period of time, since the lensed images take slightly different paths to get to us. Further observations have been scheduled on the telescope to further distinguish between the two possibilities.

Although this method had been tried before, this is the most widely separated quasar lens known, so this had the best chance of succeeding. That means there probably won’t be many more examples that can be studied, so what astronomers learn here from continued observations will serve as just one model to try with other quasars.

It is now thought that many galaxies went through an active stage at some point in their evolution that affected what galaxies will look like today. Also, it has already been theorized that most active galaxies, in all their myriad manifestations, are generally the same type of object, though some differences exist that make one “unification” model too simple to explain every known active galaxy.

Read more at Discovery News

Feb 20, 2013

Secrets of Human Speech Uncovered

A team of researchers at UC San Francisco has uncovered the neurological basis of speech motor control, the complex coordinated activity of tiny brain regions that controls our lips, jaw, tongue and larynx as we speak.

Described this week in the journal Nature, the work has potential implications for developing computer-brain interfaces for artificial speech communication and for the treatment of speech disorders. It also sheds light on an ability that is unique to humans among living creatures but poorly understood.

"Speaking is so fundamental to who we are as humans -- nearly all of us learn to speak," said senior author Edward Chang, MD, a neurosurgeon at the UCSF Epilepsy Center and a faculty member in the UCSF Center for Integrative Neuroscience. "But it's probably the most complex motor activity we do."

The complexity comes from the fact that spoken words require the coordinated efforts of numerous "articulators" in the vocal tract -- the lips, tongue, jaw and larynx -- but scientists have not understood how the movements of these distinct articulators are precisely coordinated in the brain.

To understand how speech articulation works, Chang and his colleagues recorded electrical activity directly from the brains of three people undergoing brain surgery at UCSF, and used this information to determine the spatial organization of the "speech sensorimotor cortex," which controls the lips, tongue, jaw, larynx as a person speaks. This gave them a map of which parts of the brain control which parts of the vocal tract.

They then applied a sophisticated new method called "state-space" analysis to observe the complex spatial and temporal patterns of neural activity in the speech sensorimotor cortex that play out as someone speaks. This revealed a surprising sophistication in how the brain's speech sensorimotor cortex works.

They found that this cortical area has a hierarchical and cyclical structure that exerts a split-second, symphony-like control over the tongue, jaw, larynx and lips.

"These properties may reflect cortical strategies to greatly simplify the complex coordination of articulators in fluent speech," said Kristofer Bouchard, PhD, a postdoctoral fellow in the Chang lab who was the first author on the paper.

In the same way that a symphony relies upon all the players to coordinate their plucks, beats or blows to make music, speaking demands well-timed action of several various brain regions within the speech sensorimotor cortex.

Brain Mapping in Epilepsy Surgery

The patients involved in the study were all at UCSF undergoing surgery for severe, untreatable epilepsy. Brain surgery is a powerful way to halt epilepsy in its tracks, potentially completely stopping seizures overnight, and its success is directly related to the accuracy with which a medical team can map the brain, identifying the exact pieces of tissue responsible for an individual's seizures and removing them.

The UCSF Comprehensive Epilepsy Center is a leader in the use of advanced intracranial monitoring to map out elusive seizure-causing brain regions. The mapping is done by surgically implanting an electrode array under the skull on the brain's outer surface or cortex and recording the brain's activity in order to pinpoint the parts of the brain responsible for disabling seizures. In a second surgery a few weeks later, the electrodes are removed and the unhealthy brain tissue that causes the seizures is removed.

This setting also permits a rare opportunity to ask basic questions about how the human brain works, such as how it controls speaking. The neurological basis of speech motor control has remained unknown until now because scientists cannot study speech mechanisms in animals and because non-invasive imaging methods lack the ability to resolve the very rapid time course of articulator movements, which change in hundredths of seconds.

But surgical brain mapping can record neural activity directly and faster than other noninvasive methods, showing changes in electrical activity on the order of a few milliseconds.

Prior to this work, the majority of what scientists knew about this brain region was based on studies from the 1940's, which used electrical stimulation of single spots on the brain, causing a twitch in muscles of the face or throat. This approach using focal stimulation, however, could never evoke a meaningful speech sound.

Chang and colleagues used an entirely different approach to studying the brain activity during natural speaking brain using the implanted electrodes arrays. The patients read from a list of English syllables -- like bah, dee, goo. The researchers recorded the electrical activity within their speech-motor cortex and showed how distinct brain patterning accounts for different vowels and consonants in our speech.

Read more at Science Daily

Dinosaurs May Not Have Had Fleas After All

Paleontologists used to think that dinosaurs had fleas and other parasites, but now a new study concludes that the insects were actually aquatic or amphibious flies.

The study, published in the journal Nature, focuses on enigmatic Jurassic insects called strashilids. The same team that originally speculated about the fleas has revised its original theory.

Diying Huang of the Nanjing Institute of Geology and Palaeontology and colleagues first thought that strashilids were huge fleas. You might have seen eye-catching headlines mentioning how the “fleas” were an inch long.

Closer investigation of the Jurassic insects finds that they weren’t parasites. Previously, their pincer-like legs were thought to help the insects cling to hosts. Huang and the other researchers, however, propose that they were used for grasping mates during copulation. This theory gets a boost from fossils showing the insects having sex.

Here’s a pic of one such couple, fossilized in the act:

In addition to this rather voyeuristic discovery, the researchers noticed that males possessed abdominal respiratory gills. These point to a life in the water.

Read more at Discovery News

'Living' Molecules Found in Ancient Fossils

“Living” molecules, meaning intact cellular structures that haven’t fossilized, were recently retrieved from 350-million-year-old remains of aquatic sea creatures uncovered in Ohio, Indiana, and Iowa, according to a study that will appear in the March issue of the journal Geology.

The animals- crinoids- were spindly and had feathered arms. Their relatives today are called by the plant-like name “sea lily.”

The retrieved molecules are quinones, which function as pigments or toxins (to help ward off predators) and are still found in modern sea lilies. The molecules aren’t DNA, unfortunately, but they can reveal other things about past life, such as the color of long gone animals.

“There are lots of fragmented biological molecules — we call them biomarkers — scattered in the rock everywhere,” William Ausich, professor in the School of Earth Sciences at Ohio State and co-author of the paper, said in a press release. “They’re the remains of ancient plant and animal life, all broken up and mixed together. But this is the oldest example where anyone has found biomarkers inside a particular complete fossil. We can say with confidence that these organic molecules came from the individual animals whose remains we tested.”

The ultra ancient crinoids appear to have been buried alive in storms during the Carboniferous Period. At that time, North America was covered with vast inland seas. The skeletal remains of the buried-alive crinoids filled with minerals over time, but some of the pores containing organic molecules were miraculously sealed intact.

This finding helps to negate the prior belief that complex organic molecules cannot survive fossilization.

Lead author Christina O’Malley, from Ohio State too, began the study when she noticed something strange about crinoids that had perished side by side and became preserved in the same piece of rock. She observed that the various species were preserved in different colors.

In one rock sample used in the study, one crinoid species appears a light bluish-gray, while another appears dark gray and yet another more of a creamy white. All stand out from the color of the rock they were buried in. The researchers have since found similar fossil deposits from around the Midwest.

“People noticed the color differences 100 years ago, but no one ever investigated it,” O’Malley said. “The analytical tools were not available to do this kind of work as they are today.”

She and her team employed a high tech machine called a gas chromatograph mass spectrometer to vaporize a liquid mixture that contained small bits of the ground up fossils. Computer software identified some of the resulting molecules as quinones.

The researchers next compared these molecules with ones from living sea lilies. As the scientists suspected, quinone-like molecules occur in both living sea lilies and their fossilized ancestors.

While “mummified” dinosaurs have yielded 66-million-year-old organic material, this level of preservation is exceedingly rare. And consider that these prehistoric sea lilies lived long before the first dinosaurs.

Crinoids tend to preserve really well because, like modern sand dollars, they possess a skin on top of their hard shells, which consist of stacked calcite rings. Calcite is a mineral made up of calcium carbonate. It is stable over geologic time, so organic matter may be protected by it when sealed whole.

“We think that rock fills in the skeleton according to how the crystals are oriented,” Ausich said. “So it’s possible to find large crystals filled in such a way that they have organic matter still trapped inside.”

Read more at Discovery News

Mini-Mercury: Tiniest Exoplanet Discovered

Astronomers have discovered the smallest planet beyond the solar system: a mini-Mercury that is hellishly hot, probably rocky and lacking atmosphere and water.

The planet, known as Kepler-37b, is one of a trio of planets orbiting a yellow star similar to the sun that is located about 210 light-years away in the constellation Lyra.

The planet circles its parent star every 13 days. Mercury’s orbit, by comparison, is 88 days. Sibling planets Kepler-37c, which is slightly smaller than Venus, and Kepler-37d, about twice the size of Earth, have orbital periods of 21 and 40 days respectively. The whole system would fit within the orbit of Mercury.

"We're really finding there is a great diversity in planetary systems," Thomas Barclay, with NASA's Ames Research Center in Mountain View, Calif., told Discovery News.

"When we first found exoplanets, they were all much larger than anything we have in the inner solar system. We didn't know of anything that was smaller, so we didn't know about the architecture of other star systems at the low range. This is the first time we’ve been able to probe the smallest range, smaller than anything we have in our solar system,” Barclay said.

Kepler-37 is a sun-like star, though slightly smaller and cooler than our sun, a G-type star. Its innermost planet, Kepler-37b, which is about the size of Earth's moon, is estimated to have a surface temperature of about 800 degrees Fahrenheit.

“This particular one is nowhere near habitable. It’s 10 times closer to its star than we are,” astronomer Eric Ford, with the University of Florida in Gainesville, told Discovery News.

The planets were found with NASA’s Kepler space telescope, launched in 2009 to look for Earth-sized planets positioned in so-called habitable zones where liquid water, believed to be necessary for life, can exist on their surfaces.

The telescope monitors about 150,000 sun-like stars for minute changes in the amount of light coming from the stars. The observations are then analyzed to see if the dips are caused by orbiting planets passing in front of the stars, relative to the telescope’s point of view.

Read more at Discovery News

Feb 19, 2013

Fear, Anger or Pain: Why Do Babies Cry?

Spanish researchers have studied adults' accuracy in the recognition of the emotion causing babies to cry. Eye movement and the dynamic of the cry play a key role in recognition.

It is not easy to know why a newborn cries, especially amongst first-time parents. Although the main reasons are hunger, pain, anger and fear, adults cannot easily recognise which emotion is the cause of the tears.

"Crying is a baby's principal means of communicating its negative emotions and in the majority of cases the only way they have to express them," as explained by Mariano Chóliz, researcher at the University of Valencia.

Chóliz participates in a study along with experts from the University of Murcia and the National University of Distance Education (UNED) which describes the differences in the weeping pattern in a sample of 20 babies between 3 and 18 months caused by the three characteristic emotions: fear, anger and pain.

In addition, the team observed the accuracy of adults in recognising the emotion that causes the babies to cry, analysing the affective reaction of observers before the sobbing.

According to the results published recently in the Spanish Journal of Psychology, the main differences manifest in eye activity and the dynamics of the cry.

"When babies cry because of anger or fear, they keep their eyes open but keep them closed when crying in pain," states the researcher.

As for the dynamic of the cry, both the gestures and the intensity of the cry gradually increase if the baby is angry. On the contrary, the cry is as intense as can be in the case of pain and fear.

The adults do not properly identify which emotion is causing the cry, especially in the case of anger and fear.

Nonetheless, "although the observers cannot recognise the cause properly, when babies cry because they are in pain, this causes a more intense affective reaction than when they cry because of angry or fear," outlines Chóliz.

For the experts, the fact that pain is the most easily recognisable emotion can have an adaptive explanation, since crying is a warning of a potentially serious threat to health or survival and thus requires the carer to respond urgently.

Anger, fear and pain

When a baby cries, facial muscle activity is characterised by lots of tension in the forehead, eyebrows or lips, opening of the mouth and raised cheeks. The researchers observed different patterns between the three negative emotions.

As Chóliz notices, when angry the majority of babies keep their eyes half-closed, either looking in apparently no direction or in a fixed and prominent manner. Their mouth is either open or half-open and the intensity of their cry increases progressively.

In the case of fear, the eyes remain open almost all the time. Furthermore, at times the infants have a penetrating look and move their head backwards. Their cry seems to be explosive after a gradual increase in tension.

Read more at Science Daily

How Seals Sleep With Only Half Their Brain at a Time

A new study led by an international team of biologists has identified some of the brain chemicals that allow seals to sleep with half of their brain at a time.

The study was published this month in the Journal of Neuroscience and was headed by scientists at UCLA and the University of Toronto. It identified the chemical cues that allow the seal brain to remain half awake and asleep. Findings from this study may explain the biological mechanisms that enable the brain to remain alert during waking hours and go off-line during sleep.

"Seals do something biologically amazing -- they sleep with half their brain at a time. The left side of their brain can sleep while the right side stays awake. Seals sleep this way while they're in water, but they sleep like humans while on land. Our research may explain how this unique biological phenomenon happens" said Professor John Peever of the University of Toronto.

The study's first author, University of Toronto PhD student Jennifer Lapierre, made this discovery by measuring how different chemicals change in the sleeping and waking sides of the brain. She found that acetylcholine -- an important brain chemical -- was at low levels on the sleeping side of the brain but at high levels on the waking side. This finding suggests that acetylcholine may drive brain alertness on the side that is awake.

But, the study also showed that another important brain chemical -- serotonin -- was present at the equal levels on both sides of the brain whether the seals were awake or asleep. This was a surprising finding because scientist long thought that serotonin was a chemical that causes brain arousal.

These findings have possible human health implications because "about 40% of North Americans suffer from sleep problems and understanding which brain chemicals function to keep us awake or asleep is a major scientific advance. It could help solve the mystery of how and why we sleep" says the study's senior author Jerome Siegel of UCLA's Brain Research Institute.

From Science Daily

Our Ancestors Had Much Better Teeth

Mesolithic hunter-gatherers living on a meat-dominated, grain-free diet had much healthier mouths that we have today, with almost no cavities and gum disease-associated bacteria, a genetic study of ancient dental plaque has revealed.

The international team of researchers, led by a group at the Australian Center for Ancient DNA, University of Adelaide, publish their findings in today's Nature Genetics.

The researchers extracted DNA from dental plaque from 34 prehistoric northern European human skeletons, and traced the changes in the nature of oral bacteria from the last hunter-gatherers to Neolithic and medieval farmers and modern individuals.

"Dental plaque represents the only easily accessible source of preserved human bacteria," said lead author Dr. Christina Adler, now associate lecturer in dentistry at the University of Sydney.

The researchers found that the composition of bacteria changed with the introduction of farming and again 150 years ago, during the Industrial Revolution.

In contrast to the hunter-gatherer and early agriculturist diet, a modern diet full of refined carbohydrates and sugars has given us mouths dominated by cavity-causing bacteria.

"What we found was that the early (hunter-gatherer) groups really had a lot lower frequencies of any of the disease-associated bacteria compared to what you see today (and) that the number of species per person's mouth, or the diversity, was much higher in the past," said Adler.

"If they've got more (bacterial) diversity, that means that those people's mouths were more resilient to stresses, and probably less likely to develop disease."

However, while the researchers noted that bacteria associated with dental cavities such as S. mutans became dominant around the time of the Industrial Revolution, the frequency of bacteria associated with periodontal diseases such as gingivitis has not changed much since farming began.

This may have implications for the notion that gum disease and associated bacteria are a significant contributor to the recent increase in conditions such as cardiovascular disease and atherosclerotic plaques, said co-author Professor Alan Cooper, director of the Australian Center for Ancient DNA.

"It has been suggested that the presence of this permanent inflammation state along the gums was promoting an immune inflammatory response, which in turn leads to cardiovascular disease," said Cooper.

"The idea was that a recent increase in the bacteria P. gingivalis (which causes gingivitis), was associated with the recent increases in cardiovascular disease; however, we could show that this particular species has been fairly stable throughout the farming period."

Read more at Discovery News

Higgs Boson Discovery = Cosmic Doomsday?

If calculations of the newly discovered Higgs boson particle are correct, one day, tens of billions of years from now, the universe will disappear at the speed of light, replaced by a strange, alternative dimension, one theoretical physicist calls “boring.”

Scientists last year announced they had discovered what appeared to be the long-sought subatomic particle that accounts for how matter gets its mass.

Analysis is ongoing to fully characterize the particle, known as the Higgs boson, and its related daughter, grand-daughter and cousin particles, all of which are needed to assure scientists that they’ve truly found what was once pure theory.

“It sounds too easy -- a particle with no spin and no charge. Like you made it up and yet there it is,” theoretical physicist Joseph Lykken, with the Fermi National Accelerator Laboratory in Batavia, Ill., told Discovery News.

So far, scientists have found nothing to indicate that the particle discovered last year at Europe’s Large Hadron Collider, or LHC, is not the Higgs boson with a mass of about 126 billion electron volts. It turns out that’s a critical number when it comes to the fate of the universe.

“If you use all the physics that we know now and you do what you think is a straightforward calculation, it’s bad news,” said Lykken, who also serves on the LHC science team.

“It may be that the universe we live in is inherently unstable and at some point billions of years from now it’s all going to get wiped out. This has to do with the Higgs energy field itself,” Lykken added, referring to an invisible field of energy that is believed to exist throughout the universe.

The calculation requires knowing the mass of the Higgs to one percent, as well as the precise mass of other related subatomic particles.

"It's right along the critical line,” said physicist Christopher Hill, also with Fermi.

“That could either be a cosmic coincidence, or it could be that there's some physics that's causing that,” Hill said.

Any life forms still around when the universe ends won’t have to worry about what’s coming -- it will unfold at light speed.

“You won’t actually see it because it will come at you at the speed of light and that’s it, so don’t worry. We know the universe is pretty stable because it’s been around for 13.5 billion years, so even before we did this calculation we knew that.

“This calculation tells you that many tens of billions of years from now there’ll be a catastrophe,” Lykken said.

Read more at Discovery News

Feb 18, 2013

Living Organisms Need Antifreeze to Survive in the Cold

If you thought antifreeze was only something that was necessary to keep your car from freezing up in the winter, think again. Plants and animals living in cold climates have natural antifreeze proteins (AFPs) which prevent ice growth and crystallization of organic fluid matter. Without such antifreeze, living matter would suffer from frost damage and even death.

Production of such antifreeze proteins is one of the major evolutionary routes taken by a variety of organisms, including fish, insects, bacteria, plants and fungi. Understanding how this mechanism works is not only significant in itself, but also has important implications for improving the world's food and medicinal production, believe researchers from Israel, Canada and the US who investigated how the process works.

Working on unraveling the AFP enigma were scientists from the lab of Dr. Ido Braslavsky of the Hebrew University of Jerusalem and from Ohio University in the US, in collaboration with Prof. Peter L. Davies from Queens University (Ontario, Canada) and Prof. Alex Groisman from the University of California (San Diego, CA).

Despite half a century of research, the mechanism underlying the activity of the natural antifreeze proteins is still unclear. One of the debates in the academic community regards the chemistry and physics behind the interactions of antifreeze proteins and ice. In particular, there is an ongoing argument over whether the binding of the proteins to ice is reversible and whether continued presence of these proteins in solution is necessary for prevention of ice growth.

The challenge in unraveling these questions stems from a variety of technical problems associated with the growth and tracking of tiny ice crystals in an environment that mimics the surroundings of the antifreeze proteins in nature.

The Hebrew University researchers studied the antifreeze protein of the yellow mealworm. This protein is a hyperactive AFP with a potency to arrest ice growth that is hundreds of times greater than the potency of fish and plant AFPs.

In their study, published in the American journal PNAS (Proceedings of the National Academy of Sciences), the international team of researchers biochemically created a fluorescent marker version of the AFP that allowed for direct observation under a microscope lens. They injected this protein into custom-designed microfluidic devices with minute diameter channels.

The microfluidic devices were placed in cooling units engineered with a temperature control at the level of a few thousandth of a degree, so that ice crystals of 20 to 50 micrometers could be grown and melted controllably, all under microscopic observation.

Using their specialized system, the researchers were able to show that ice grown and incubated in an antifreeze solution remains coated with protein and therefore protected. They further showed that the AFPs bind ice directly and strongly enough so as to prevent the ice from growth even after there is no longer any further presence of protein in the solution.

The significance of the findings published in this study is not only on the scientific level but also practical. For example, fish AFPs are already used in low-fat ice cream to prevent ice recrystallization, thereby maintaining a soft, creamy texture. These proteins could be used in other frozen foods for maintaining the desired texture without additional fats, say the researchers.

In medicine, AFPs can be used to improve the quality of sperm, ovules and embryos stored in a frozen state, and for cold or cyropreservation of organs (freezing at extremely low temperatures) for transplantation. They can also be used in cryosurgery and in agriculture.

Read more at Science Daily

Water On the Moon: It's Been There All Along

Traces of water have been detected within the crystalline structure of mineral samples from the lunar highland upper crust obtained during the Apollo missions, according to a University of Michigan researcher and his colleagues.

The lunar highlands are thought to represent the original crust, crystallized from a magma ocean on a mostly molten early moon. The new findings indicate that the early moon was wet and that water there was not substantially lost during the moon's formation.

The results seem to contradict the predominant lunar formation theory -- that the moon was formed from debris generated during a giant impact between Earth and another planetary body, approximately the size of Mars, according to U-M's Youxue Zhang and his colleagues.

"Because these are some of the oldest rocks from the moon, the water is inferred to have been in the moon when it formed," Zhang said. "That is somewhat difficult to explain with the current popular moon-formation model, in which the moon formed by collecting the hot ejecta as the result of a super-giant impact of a martian-size body with the proto-Earth.

"Under that model, the hot ejecta should have been degassed almost completely, eliminating all water."

A paper titled "Water in lunar anorthosites and evidence for a wet early moon" was published online Feb. 17 in the journal Nature Geoscience. The first author is Hejiu Hui, postdoctoral research associate of civil and environmental engineering and earth sciences at the University of Notre Dame. Hui received a doctorate at U-M under Zhang, a professor in the Department of Earth and Environmental Sciences and one of three co-authors of the Nature Geoscience paper.

Over the last five years, spacecraft observations and new lab measurements of Apollo lunar samples have overturned the long-held belief that the moon is bone-dry.

In 2008, laboratory measurement of Apollo lunar samples by ion microprobe detected indigenous hydrogen, inferred to be the water-related chemical species hydroxyl, in lunar volcanic glasses. In 2009, NASA's Lunar Crater Observation and Sensing satellite, known as LCROSS, slammed into a permanently shadowed lunar crater and ejected a plume of material that was surprisingly rich in water ice.

Hydroxyls have also been detected in other volcanic rocks and in the lunar regolith, the layer of fine powder and rock fragments that coats the lunar surface. Hydroxyls, which consist of one atom of hydrogen and one of oxygen, were also detected in the lunar anorthosite study reported in Nature Geoscience.

In the latest work, Fourier-transform infrared spectroscopy was used to analyze the water content in grains of plagioclase feldspar from lunar anorthosites, highland rocks composed of more than 90 percent plagioclase. The bright-colored highlands rocks are thought to have formed early in the moon's history when plagioclase crystallized from a magma ocean and floated to the surface.

The infrared spectroscopy work, which was conducted at Zhang's U-M lab and co-author Anne Peslier's lab, detected about 6 parts per million of water in the lunar anorthosites.

"The surprise discovery of this work is that in lunar rocks, even in nominally water-free minerals such as plagioclase feldspar, the water content can be detected," said Zhang, the James R. O'Neil Collegiate Professor of Geological Sciences.

"It's not 'liquid' water that was measured during these studies but hydroxyl groups distributed within the mineral grain," said Notre Dame's Hui. "We are able to detect those hydroxyl groups in the crystalline structure of the Apollo samples."

The hydroxyl groups the team detected are evidence that the lunar interior contained significant water during the moon's early molten state, before the crust solidified, and may have played a key role in the development of lunar basalts.

"The presence of water," said Hui, "could imply a more prolonged solidification of the lunar magma ocean than the once-popular anhydrous moon scenario suggests."

The researchers analyzed grains from ferroan anorthosites 15415 and 60015, as well as troctolite 76535. Ferroan anorthosite 15415 is one the best known rocks of the Apollo collection and is popularly called the Genesis Rock because the astronauts thought they had a piece of the moon's primordial crust. It was collected on the rim of Apur Crater during the Apollo 15 mission.

Rock 60015 is highly shocked ferroan anorthosite collected near the lunar module during the Apollo 16 mission. Troctolite 76535 is a coarse-grained plutonic rock collected during the Apollo 17 mission.

Read more at Science Daily

New Whale Species Unearthed in California Highway Dig

Chalk yet another fossil find up to roadcut science. Thanks to a highway-widening project in California’s Laguna Canyon, scientists have identified several new species of early toothed baleen whales. Paleontologist Meredith Rivin of the John D. Cooper Archaeological and Paleontological Center in Fullerton, California, presented the finds Feb. 17 at the annual meeting of the American Association for the Advancement of Science.

“In California, you need a paleontologist and an archaeologist on-site” during such projects, Rivin says. That was fortuitous: The Laguna Canyon outcrop, excavated between 2000 and 2005, turned out to be a treasure trove containing hundreds of marine mammals that lived 17 million to 19 million years ago. It included 30 cetacean skulls as well as an abundance of other ocean dwellers such as sharks, says Rivin, who studies the fossil record of toothed baleen whales. Among those finds, she says, were four newly identified species of toothed baleen whale—a type of whale that scientists thought had gone extinct 5 million years earlier.

Whales, the general term for the order Cetacea, comprise two suborders: Odontoceti, or toothed whales, which includes echolocators like dolphins, porpoises, and killer whales; and Mysticeti, or baleen whales, the filter-feeding giants of the deep such as blue whales and humpback whales.The two suborders share a common ancestor.

Mysticeti comes from the Greek for mustache, a reference to the baleen that hangs down from their jaw. But the earliest baleen whales actually had teeth (although they’re still called mysticetes). Those toothy remnants still appear in modern fin whale fetuses, which start to develop teeth in the womb that are later reabsorbed before the enamel actually forms.

The four new toothed baleen whale species were also four huge surprises, Rivin says. The new fossils date to 17 to 19 million years ago, or the early-mid Miocene epoch, making them the youngest known toothed whales. Three of the fossils belong to the genus Morawanocetus, which is familiar to paleontologists studying whale fossils from Japan, but hadn’t been seen before in California. These three, along with the fourth new species, which is of a different genus, represent the last known occurrence of aetiocetes, a family of mysticetes that coexisted with early baleen whales. Thus, they aren’t ancestral to any of the living whales, but they could represent transitional steps on the way tothe toothless mysticetes.

The fourth new species—dubbed “Willy”—has its own surprises, Rivin says. Although modern baleen whales are giants, that’s a fairly recent development (in the last 10 million years). But Willy was considerably bigger than the three Morawanocetus fossils. Its teeth were also surprisingly worn—and based on the pattern of wear as well as the other fossils found in the Laguna Canyon deposit, Rivin says, that may be because Willy’s favorite diet may have been sharks. Modern offshore killer whales, who also enjoy a meal of sharks, tend to have similar patterns of wear in their teeth due to the sharks’ rough skin.

The new fossils are a potentially exciting find, says paleobiologist Nick Pyenson of the Smithsonian Institution’s National Museum of Natural History. Although it’s not yet clear what Rivin’s team has got and what the fossils will reveal about early baleen whale evolution, he says, “I’ll be excited to see what they come up with.” Pyenson himself is no stranger to roadcut science and the rush to preserve fossils on the brink of destruction: In 2011, he managed, within a week, to collect three-dimensional images of numerous whale fossils found by workers widening a highway running through Chile’s Atacama Desert.

Read more at Wired Science

Dark Matter Hunter Results Coming in March

Scientists are preparing to release the first round of results from a key experiment aboard the International Space Station that has been sampling a soup of high-energy particles in space.

The Alpha Magnetic Spectrometer particle detector was installed on the station during the next-to-last space shuttle mission in May 2011. Since then, the $2 billion instrument, a collaboration of  60 research institutes in 16 countries, has been amassing a proverbial mountain of data, including a headcount of 7.7 billion electrons and positrons (the antimatter counterpart to electrons).

In the overall numbers of particles interests scientists less than the ratio between the two. The idea is to determine if there are more antimatter particles than matter, and, if so, at exactly what energy level the disparity occurs.

“The smoking gun that we’re looking for in the positron-to-electron ratio is a rise and then a dramatic fall. That’s  the key signature that would come from the dark matter annihilating the halo,” said Michael Turner, director of the Kavli Institute for Cosmological Physics at the University of Chicago.

The halo Turner is referring to is the halo of the Milky Way galaxy, the region beyond the central disk of stars and dust. If current theoretical models are correct, there’s a massively massive pool of dark matter — perhaps as big as 1 million light-years across — that envelopes the visible galaxy, which is about 100,000 light-years in diameter.

Behind the AMS numbers is an 80-year-old mystery about why our galaxy — and the universe for that matter — hangs together because despite the apparent plethora of stars, galaxies and gas, there is simply far too little of it to gravitationally bind it together.

Physicists estimate that visible (i.e. detectable) matter accounts for a mere 4 percent of the universe’s contents. Dark matter, which is not dark as in “black” but dark as in undetectable with electromagnetic radiation, comprises about another 24 percent. The rest is an even more exotic and less-known force called dark energy.

One idea about dark matter is that even though we can’t, by definition, detect it directly, we can scout for its footprints.

“It’s really not interacting a lot. The hope is it interacts a little bit,” Lisa Randall, a theoretical physicist at Harvard University, said at the American Association for the Advancement of Sciences meeting in Boston.

Read more at Discovery News

Feb 17, 2013

Evolution Helped Turn Hairless Skin Into a Canvas for Self-Expression

Hairless skin first evolved in humans as a way to keep cool -- and then turned into a canvas to help them look cool, according to a Penn State anthropologist.

About 1.5 to 2 million years ago, early humans, who were regularly on the move as hunters and scavengers, evolved into nearly hairless creatures to more efficiently sweat away excess body heat, said Nina Jablonski, Distinguished Professor of Anthropology. Later, humans began to decorate skin to increase attractiveness to the opposite sex and to express, among other things, group identity.

"We can make a visual impact and present a completely different impression than we can with regular, undecorated skin," said Jablonski, who reports on her research  on Feb. 16 at the annual meeting of the American Association for the Advancement of Science in Boston.

Over the millennia, people turned their skin into canvases of self-expression in different ways, including permanent methods, such as tattooing and branding, as well as temporary ones, including cosmetics and body painting, according to the researcher.

Jablonski said both males and females use forms of skin decoration to become more attractive to the opposite sex. Women, for example, may use makeup to increase the size of their eyes, a cue that is considered attractive in most cultures. Males in some cultures also use skin decoration as a way to bring out facial features to appeal to women, or to look more menacing and warrior-like.

"We can paint a great design on our bodies and use those designs to send all sorts of messages or express group memberships," said Jablonski.

While parents may still fret that their children are choosing tattoo designs frivolously, Jablonski said people have traditionally put considerable time and thought into the tattoos.

"Usually it is something with deep meaning," Jablonski said. "When I talk to people about their tattoos they, tell me they've spent months or years choosing a design that is incredibly meaningful and salient to them."

Prior to the evolution of mostly naked skin, humans were furry creatures, not unlike chimpanzees are now, Jablonski said. Skin decoration would not be possible if humans were still covered with fur.

Studying skin is difficult because it can be preserved only for a few thousand years, unlike bones and fossils, which last millions of years.

Jablonski said that she and other researchers based their estimate on when humans evolved hairless skin on the study of the fossil record and an examination of the molecular history of genes that code proteins that help produce skin pigmentation.

"We find a lot of evidence of when humans began to lose hair based on molecular genetics," said Jablonski.

Humans are the only primates that are essentially hairless, although aquatic mammals, like whales and dolphins, have no hair. Prior to the idea that humans evolved hairlessness as a mechanism to cope with body heat, some researchers believed that hairlessness resulted from evolution from a common aquatic ancestor, Jablonski said. However, the theory, often referred to as the aquatic ape theory, does not match the genetic, fossil and environmental evidence, she said.

Read more at Science Daily

Cotton Candy Cloud Hides Baby Black Hole

What looks like the explosion of a cotton candy Death Star (run by evil space clowns, perhaps?) is actually the remains of a star’s death. This colorful cloud is a supernova remnant, seen in infrared, radio and X-ray light and at its center may hide one of the galaxy’s youngest black holes.

Located 26,000 light-years away in the northern constellation Aquila, W49B is a snapshot of the shock waves from a star that went supernova an estimated 1,000 years ago (not including the time it took for its light to reach us). Several observation methods and instruments were used to create the technicolor image above – X-rays from NASA’s Chandra X-ray Observatory shown in blue and green, radio data from the National Science Foundation’s Very Large Array in pink, and infrared and optical data from the Palomar Observatory in orange and yellow — but put all together, one feature becomes glaringly obvious.

This thing is a mess.

Typically, supernova remnants have a roughly circular or shell-like shape, generally seen as a ring of bright material surrounding the dense burnt-out core of a star. The ring is bright because it’s composed of interstellar gas and dust that’s being violently ionized by the spreading force of the supernova. Ionized material gives off many forms of radiation, detectable in various wavelengths by observatories on the ground, as well as in space.

W49B isn’t a ring, though. It’s a sloppy barrel shape that indicates an uneven, asymmetrical eruption, hinting that the original star didn’t go peacefully into this good night.

And as for the star? It’s nowhere to be found — which is in itself strange. Supernova remnants usually have some form of neutron star at their centers, the wildly-spinning, ultra-dense cores of dead massive stars. But even after searching for one, scientists have found no such object at the center of W49B. This could mean that there’s a very different sort of stellar corpse lurking there — a black hole.

If that is indeed the case, then this would be the galaxy’s newest black hole — at least as far as what’s been discovered so far. A mere thousand years old, an alleged black hole at the heart of W49B would have just been born in the night sky around the same time that Vikings were first setting foot on North American shores.

Read more at Discovery News