The fossilized specimen, a roughly elliptical shape with multiple lobes, totaling almost seven feet in length, will be unveiled at the North-Central Section 46th Annual Meeting of the Geological Society of America, April 24, in Dayton, Ohio. Participating in the presentation will be amateur paleontologist Ron Fine of Dayton, who originally found the specimen, Carlton E. Brett and David L. Meyer of the University of Cincinnati geology department, and Benjamin Dattilo of the Indiana University Purdue University Fort Wayne geosciences faculty.

Fine is a member of the Dry Dredgers, an association of amateur paleontologists based at the University of Cincinnati. The club, celebrating its 70th anniversary this month, has a long history of collaborating with academic paleontologists.

“I knew right away that I had found an unusual fossil,” Fine said. “Imagine a saguaro cactus with flattened branches and horizontal stripes in place of the usual vertical stripes. That’s the best description I can give.”

The layer of rock in which he found the specimen near Covington, Kentucky, is known to produce a lot of nodules or concretions in a soft, clay-rich rock known as shale.

“While those nodules can take on some fascinating, sculpted forms, I could tell instantly that this was not one of them,” Fine said. “There was an ‘organic’ form to these shapes. They were streamlined.”

Fine was reminded of streamlined shapes of coral, sponges and seaweed as a result of growing in the presence of water currents.

“And then there was that surface texture,” Fine said. “Nodules do not have surface texture. They’re smooth. This fossil had an unusual texture on the entire surface.”

For more than 200 years, the rocks of the Cincinnati region have been among the most studied in all of paleontology, and the discovery of an unknown, and large, fossil has professional paleontologists scratching their heads.

“It’s definitely a new discovery,” Meyer said. “And we’re sure it’s biological. We just don’t know yet exactly what it is.”

To answer that key question, Meyer said that he, Brett, and Dattilo were working with Fine to reconstruct a timeline working backward from the fossil, through its preservation, burial, and death to its possible mode of life.

“What things had to happen in what order?” Meyer asked. “Something caused a directional pattern. How did that work? Was it there originally or is it post-mortem? What was the burial event? How did the sediment get inside? Those are the kinds of questions we have.”

It has helped, Meyer said, that Fine has painstakingly reassembled the entire fossil. This is a daunting task, since the large specimen is in hundreds of pieces.

“I’ve been fossil collecting for 39 years and never had a need to excavate. But this fossil just kept going, and going, and going,” Fine said. “I had to make 12 trips, over the course of the summer, to excavate more material before I finally found the end of it.”

Even then he still had to guess as to the full size, because it required countless hours of cleaning and reconstruction to put it all back together.

“When I finally finished it was three-and-a-half feet wide and six-and-a-half feet long,” Fine said. “In a world of thumb-sized fossils that’s gigantic!”

Meyer, co-author of A Sea without Fish: Life in the Ordovician Sea of the Cincinnati Region, agreed that it might be the largest fossil recovered from the Cincinnati area.

“My personal theory is that it stood upright, with branches reaching out in all directions similar to a shrub,” Fine said. “If I am right, then the upper-most branch would have towered nine feet high. ”

As Meyer, Brett and Dattilo assist Fine in studying the specimen, they have found a clue to its life position in another fossil. The mystery fossil has several small, segmented animals known as primaspid trilobites attached to its lower surface. These small trilobites are sometimes found on the underside of other fossilized animals, where they were probably seeking shelter.

“A better understanding of that trilobite’s behavior will likely help us better understand this new fossil,” Fine said.

Although the team has reached out to other specialists, no one has been able to find any evidence of anything similar having been found. The mystery monster seems to defy all known groups of organisms, Fine said, and descriptions, even pictures, leave people with more questions than answers.

The presentation April 24 is a “trial balloon,” Meyer said, an opportunity for the team to show a wide array of paleontologists what the specimen looks like and to collect more hypotheses to explore.

“We hope to get a lot of people stopping by to offer suggestions,” he said.

In the meantime, the team is playing around with potential names. They are leaning toward “Godzillus.”

Contact: Greg Hand
greg.hand@uc.edu
513-556-1822
University of Cincinnati

The five-ton instrument, the most advanced and sophisticated of its kind in the world, goes by the name MOSFIRE (Multi-Object Spectrometer for Infra-Red Exploration) and has been installed in the Keck I Telescope at the W.M. Keck Observatory atop Mauna Kea in Hawaii.

MOSFIRE gathers light in infrared wavelengths – invisible to the human eye – allowing it to penetrate cosmic dust and see distant objects whose light has been stretched or “redshifted” to the infrared by the expansion of the universe.

“The instrument was designed to study the most distant, faintest galaxies,” said UCLA physics and astronomy professor Ian S. McLean, project leader on MOSFIRE and director of UCLA’s Infrared Laboratory for Astrophysics. “When we look at the most distant galaxies, we see them not as they are now but as they were when the light left them that is just now arriving here. Some of the galaxies that we are studying were formed some 10 billion years ago – only a few billion years after the Big Bang. We are looking back in time to the era of the formation of some of the very first galaxies, which are small and very faint. That is an era that we need to study if we are going to understand the large-scale structure of the universe.”

With MOSFIRE, it will now become much easier to identify faint galaxies, “families of galaxies” and merging galaxies. The instrument also will enable detailed observations of planets orbiting nearby stars, star formation within our own galaxy, the distribution of dark matter in the universe and much more.

“We would like to study the environment of those early galaxies,” said McLean, who built the instrument with colleagues from UCLA, the California Institute of Technology and UC Santa Cruz, along with industrial sub-contractors. “Sometimes there are large clusters with thousands of galaxies, sometimes small clusters. Often, black holes formed in the centers of galaxies.”

Light collected by the Keck I Telescope was fed into MOSFIRE for the first time on April 4, producing an astronomical image. Astronomers are expected to start using MOSFIRE by September, following testing and evaluation in May and June.

MOSFIRE allows astronomers to take an infrared image of a field and to study 46 galaxies simultaneously, providing the infrared spectrum for each galaxy. Currently, it can take three hours or longer to obtain a good spectrum of just one galaxy, McLean noted.

McLean built the world’s first infrared camera for wide use by astronomers in 1986 and since then has built eight increasingly sophisticated infrared cameras and spectrometers – which split light into its component colors – as well as helping on a few others.

McLean and Charles Steidel, the Lee A. DuBridge Professor of Astronomy at the California Institute of Technology, led the project to build MOSFIRE from scratch over seven years. Harland Epps, a UC Santa Cruz professor of astronomy and astrophysics, designed the optics for the instrument. A team of nearly two dozen people helped, including Kristin Kulas and Gregory Mace, UCLA graduate students in physics and astronomy who work in McLean’s laboratory; Keith Matthews, an instrument designer from Caltech; and Sean Adkins, an engineer who is the instrument program manager for the Keck Observatory in Hawaii. Most of the mechanical parts for MOSFIRE were built at UCLA and Caltech. The slit unit that enables 46 objects to be isolated was manufactured in Switzerland. The computer programming was led by UCLA.

“My father, who was an engineer, called me an astronomer by inclination, a physicist by training and an engineer by default,” McLean said. “I’m an applied physicist and an astronomer.”

MOSFIRE cost $14 million and likely would have cost at least twice as much if the scientists had not built it themselves, McLean estimates.

MOSFIRE was federally funded by the National Science Foundation (through the Telescope System Instrumentation program), and by Gordon and Betty Moore. Gordon Moore is co-founder, former chairman and chief executive officer, and chairman emeritus of Intel Corp.

“He is a wonderful man with a penetrating intellect,” McLean said of Moore. “We are deeply indebted to him and hope to be able to show him MOSFIRE this summer.”

“We had an outstanding team,” he added, “with four institutions involved and many industrial partners. It was a fantastic team effort.”

In the late 1990s, McLean delivered an infrared spectrometer called NIRSPEC to the Keck Observatory in Hawaii, which housed the world’s largest optical and infrared telescope at the time and which contains what had been the most powerful infrared spectrometer in the world. NIRSPEC is still on the Keck II Telescope.

While NIRSPEC’s camera has one megapixel, MOSFIRE has four megapixels. MOSFIRE’s detectors are approximately five times more sensitive than those on NIRSPEC and about 100 times more sensitive than those from McLean’s 1986 infrared camera. In addition, the digital imaging devices available today are far superior to those of 15 years ago. The result is that MOSFIRE is much more sensitive to faint objects.

Discoveries made with NIRSPEC include the detection of water on comets, insights into the stars orbiting the enormous black hole at the center of the Milky Way galaxy, and the discovery of the chemical composition of brown dwarfs. Brown dwarfs, failed stars about the size of Jupiter but with a much larger mass, are considered the “missing link” between gas giant planets like Jupiter and small, low-mass stars.

McLean is also the principal investigator for a research imaging instrument called FLITECAM, which is scheduled to be used, starting this October, on NASA’s SOFIA (Stratospheric Observatory for Infrared Astronomy), a modified 747 SP jetliner that is the world’s largest airborne observatory. FLITECAM, which McLean and his colleagues built at UCLA, is a camera that can be converted to a spectrometer electronically, using a computer. It will be used to study planets orbiting other stars and stars eclipsed when an asteroid or comet in the outer part of the solar system passes in front of them.

McLean “was given the bug to build instruments” by his Ph.D. advisor, David Clarke, at Scotland’s University of Glasgow. McLean built an instrument in the 1970s that was able to make measurements of polarized light no one had ever made before.

An expert on infrared detector systems, McLean is author of a 2008 book used in university courses, “Electronic Imaging in Astronomy: Detectors and Instrumentation,” which demonstrates how we can now take digital pictures across the electromagnetic spectrum, at any wavelength, from gamma rays to radio waves.

UCLA is California’s largest university, with an enrollment of nearly 38,000 undergraduate and graduate students. The UCLA College of Letters and Science and the university’s 11 professional schools feature renowned faculty and offer 337 degree programs and majors. UCLA is a national and international leader in the breadth and quality of its academic, research, health care, cultural, continuing education and athletic programs. Six alumni and five faculty have been awarded the Nobel Prize.

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Contact: Stuart Wolpert
swolpert@support.ucla.edu
310-206-0511
University of California – Los Angeles

These results may represent an important step forward in the scientific explanation of human consciousness. The study was part of the Research Programme on Neuroscience by the Academy of Finland.

“We expected to see the outer bits of brain, the cerebral cortex (often thought to be the seat of higher human consciousness), would turn back on when consciousness was restored following anesthesia. Surprisingly, that is not what the images showed us. In fact, the central core structures of the more primitive brain structures including the thalamus and parts of the limbic system appeared to become functional first, suggesting that a foundational primitive conscious state must be restored before higher order conscious activity can occur” Scheinin said.

Twenty young healthy volunteers were put under anesthesia in a brain scanner using either dexme-detomidine or propofol anesthetic drugs. The subjects were then woken up while brain activity pictures were being taken. Dexmedetomidine is used as a sedative in the intensive care unit setting and propofol is widely used for induction and maintenance of general anesthesia. Dexmedetomidineinduced unconsciousness has a close resemblance to normal physiological sleep, as it can be reversed with mild physical stimulation or loud voices without requiring any change in the dosing of the drug. This unique property was critical to the study design, as it enabled the investigators to separate the brain activity changes associated with the changing level of consciousness from the drugrelated effects on the brain. The staterelated changes in brain activity were imaged with positron emission tomography (PET).

The emergence of consciousness, as assessed with a motor response to a spoken command, was associated with the activation of a core network involving subcortical and limbic regions that became functionally coupled with parts of frontal and inferior parietal cortices upon awakening from dexme-detomidine-induced unconsciousness. This network thus enabled the subjective awareness of the external world and the capacity to behaviorally express the contents of consciousness through voluntary responses.

Interestingly, the same deep brain structures, i.e. the brain stem, thalamus, hypothalamus and the anterior cingulate cortex, were activated also upon emergence from propofol anesthesia, suggesting a common, drugindependent mechanism of arousal. For both drugs, activations seen upon regaining consciousness were thus mostly localized in deep, phylogenetically old brain structures rather than in the neocortex.

The researchers speculate that because current depth-of-anesthesia monitoring technology is based on cortical electroencephalography (EEG) measurement (i.e., measuring electrical signals on the sur-face of the scalp that arise from the brain’s cortical surface), their results help to explain why these devices fail in differentiating the conscious and unconscious states and why patient awareness during general anesthesia may not always be detected. The results presented here also add to the current understanding of anesthesia mechanisms and form the foundation for developing more reliable depth-of-anesthesia technology.

The anesthetized brain provides new views into the emergence of consciousness. Anesthetic agents are clinically useful for their remarkable property of being able to manipulate the state of consciousness. When given a sufficient dose of an anesthetic, a person will lose the precious but mysterious capacity of being aware of one’s own self and the surrounding world, and will sink into a state of oblivion. Conversely, when the dose is lightened or wears off, the brain almost magically recreates a subjective sense of being as experience and awareness returns. The ultimate nature of consciousness remains a mystery, but anesthesia offers a unique window for imaging internal brain activity when the subjective phenomenon of consciousness first vanishes and then re-emerges. This study was designed to give the clearest picture so far of the internal brain processes involved in this phenomenon.

The results may also have broader implications. The demonstration of which brain mechanisms are involved in the emergence of the conscious state is an important step forward in the scientific explanation of consciousness. Yet, much harder questions remain. How and why do these neural mechanisms create the subjective feeling of being, the awareness of self and environment the state of being conscious?

The study will be published in the 4 April 2012 issue of The Journal of Neuroscience: Jaakko W. Långsjö, Michael T. Alkire, Kimmo Kaskinoro, Hiroki Hayama, Anu Maksimow, Kaike K. Kaisti, Sargo Aalto, Riku Aantaa, Satu K. Jääskeläinen, Antti Revonsuo and Harry Scheinin. Re-turning from Oblivion: Imaging the Neural Core of Consciousness. The Journal of Neuroscience 2012;32(14):4935-4943.

The study was part of the “Neurophilosophy of Consciousness” project funded by the Academy of Finland (Research Programme on Neuroscience, project No. 8111818) trying to reveal neural correlates of consciousness by targeting different states and phenomena of consciousness. The study was also funded by Turku PET Centre and Turku University Hospital (EVO-grant No. 13323).

Further information: Dr. Harry Scheinin, harry.scheinin(at)utu.fi, Tel. (0)400 825 599.

Photo: Returning from oblivion – Imaging the neural core of consciousness. Positron emission tomography (PET) findings showing that the emer-gence of consciousness after anesthesia is associated with activation of deep, phylogenetically old brain structures rather than the neocortex. Left: Sagittal (top) and axial (bottom) sections showing activation in the anterior cingulate cortex (i), thalamus (ii) and the brainstem (iii) locus coeruleus/parabrachial area overlaid on magnetic resonance image (MRI) slices. Right: Cortical renderings showing no evident activations.

Contact: Dr. Harry Scheinin
harry.scheinin@utu.fi
358-400-825-599
Academy of Finland

About 15,000 scientists and others are expected for the meeting of the ACS – the world’s largest scientific society. Being held this week, it includes more than 11,700 presentations on discoveries and advances in science.

Jennifer G. Blank, Ph.D., who led the research team, described experiments that recreated with powerful laboratory “guns” and computer models the conditions that existed inside comets when these celestial objects hit Earth’s atmosphere at almost 25,000 miles per hour and crashed down upon the surface. The research is part of a broader scientific effort to understand how amino acids and other ingredients for the first living things appeared on a planet that billions of years ago was barren and desolate. Amino acids make up proteins, which are the workhorses of all forms of life, ranging from microbes to people.

“Our research shows that the building blocks of life could, indeed, have remained intact despite the tremendous shock wave and other violent conditions in a comet impact,” Blank said. “Comets really would have been the ideal packages for delivering ingredients for the chemical evolution thought to have resulted in life. We like the comet delivery scenario because it includes all of the ingredients for life – amino acids, water and energy.”

Comets are chunks of frozen gases, water, ice, dust and rock that astronomers have termed “dirty snowballs.” These snowballs, however, may be 10 miles or more in diameter. Comets orbit the sun in a belt located far beyond the most distant planets in the solar system. Periodically, comets break loose and hurtle inward, where they may become visible in the sky.

Billions of years ago, however, swarms of comets and asteroids bombarded Earth with the remnants still visible as craters on the moon. Scientific evidence suggests that life on Earth began at the end of a period 3.8 billion years ago called the “late heavy bombardment” that involved both comets and asteroids. Before that, Earth was too hot for living things to survive. The earliest known fossils with evidence of life date from 3.5 billion years ago. So how could life originate so quickly when there was little evidence of water or the amino-acid building blocks for making proteins?

Blank and colleagues at the Bay Area Environmental Research Institute NASA/Ames Research Center, Moffett Field, Calif., set out to check whether amino acids could remain intact after a comet’s descent through Earth’s atmosphere. Previous analyses of comet dust samples returned to Earth by a NASA spacecraft eliminated any doubt that amino acids do occur in comets.

In one set of experiments, they used gas guns to simulate the enormous temperatures and powerful shock waves that amino acids in comets would experience on upon entering Earth’s atmosphere. The gas guns, devices that weigh thousands of pounds, hit objects with high-pressure blasts of gas moving at supersonic speeds. They shot the gas at capsules filled with amino acids, water and other materials.

The amino acids did not break down due to the heat and shock of the simulated crash. Indeed, they began forming the so-called “peptide bonds” that link amino acids together into proteins. The pressure from the impact of the crash apparently offset the intense heat and also supplied the energy needed to create the peptides, she explained. In other experiments, Blank’s team used sophisticated computer models to simulate conditions as comets collided with Earth.

Blank suggested that there may well have been multiple deliveries of seedlings of life through the years from comets, asteroids and meteorites.

The American Chemical Society is a non-profit organization chartered by the U.S. Congress. With more than 164,000 members, ACS is the world’s largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society contact newsroom@acs.org.

Abstract

Cometary impacts may have delivered the building blocks of life to Earth, though the fate of organic compounds during these impacts remains largely uncertain. Here, we will discuss modeled pressure dependence and formation rates of the dimerization rates of amino acids using ab initio electronic structure calculations, semi-empirical quantum mechanical methods, and transition state theory. We also used reactive molecular dynamics calculations to simulate the breaking and forming of chemical bonds behind a shock front. We focused on three amino acids (Gly, Pro, Lys) with very different side chain structures. Our discussion will address the role of explicit, condensed phase (H2O) molecules in defining activation volumes and transition state energies and the role of pressure in inhibiting thermal breakdown of our initial materials. Model results will be compared with data from experimental ballistic impact studies and discussed in the context of prebiotic chemical evolution.

Contact: Michael Bernstein
m_bernstein@acs.org
619-525-6268 (March 23-28, San Diego Press Center)
202-872-6042

Michael Woods
m_woods@acs.org
619-525-6268 (March 23-28, San Diego Press Center)
202-872-6293
American Chemical Society

“This melt-rich layer is actually quite spotty under the Pacific Ocean basin and surrounding areas, as revealed by my analysis of seismometer data,” says Dr. Nicholas Schmerr, a NASA Postdoctoral Program fellow. “Since it only exists in certain places, it can’t be the only reason why rigid crustal plates carrying the continents can slide over softer rock below.” Schmerr, who is stationed at NASA’s Goddard Space Flight Center in Greenbelt, Md., is author of a paper on this research appearing in Science on March 23.

The slow slide of Earth’s continents results from plate tectonics. Our planet is more than four billion years old, and over this time, the forces of plate tectonics have carried continents many thousands of miles, forging mountain ranges when they collided and valleys that sometimes filled with oceans when they were torn apart. This continental drift could also have changed the climate by redirecting currents in the ocean and atmosphere.

The outermost layer of Earth, the lithosphere, is broken into numerous tectonic plates. The lithosphere consists of the crust and an underlying layer of cool and rigid mantle. Beneath the oceans, the lithosphere is relatively thin (about 65 miles), though beneath continents, it can be as thick as 200 miles. Lying beneath the lithosphere is the asthenosphere, a layer of rock that is slowly deforming and gradually flowing like taffy. Heat in Earth’s core produced by the radioactive decay of elements escapes and warms mantle rocks above, making them softer and less viscous, and also causes them to convect. Like the circulating blobs in a lava lamp, rock in the mantle rises where it is warmer than its surroundings, and sinks where it’s cooler. This churn moves the continental plates above, similar to the way a raft of froth gets pushed around the surface of a simmering pot of soup.

Although the basic process that drives plate tectonics is understood, many details remain a mystery. “Something has to decouple the crustal plates from the asthenosphere so they can slide over it,” says Schmerr. “Numerous theories have been proposed, and one of those was that a melt-rich layer lubricates the boundary between the lithosphere and the asthenosphere, allowing the crustal plates to slide. However, since this layer is only present in certain regions under the Pacific plate, it can’t be the only mechanism that allows plate tectonics to happen there. Something else must be letting the plate slide in areas where the melt doesn’t exist.”

Other possible mechanisms that would make the boundary between the lithosphere and the asthenosphere flow more easily include the addition of volatile material like water to the rock and differences in composition, temperature, or the grain size of minerals in this region. However, current data lacks the resolution to distinguish among them.

Schmerr made the discovery by analyzing the arrival times of earthquake waves at seismometers around the globe. Earthquakes generate various kinds of waves; one type has a back-and-forth motion and is called a shear wave, or S-wave. S-waves traveling through the Earth will bounce or reflect off material interfaces inside the Earth, arriving at different times depending on where they interact with these interfaces.

One type of S-wave reflects from Earth’s surface halfway between an earthquake and a seismometer. An S-wave encountering a deeper melt layer at the lithosphere-asthenosphere boundary at this location will take a slightly shorter path to the seismometer and therefore arrive several tens of seconds earlier. By comparing the arrival times, heights, and shapes of the primary and the melt-layer-reflected waves at various locations, Schmerr could estimate the depth and seismic properties of melt layers under the Pacific Ocean basin.

“Most of the melt layers are where you would expect to find them, like under volcanic regions like Hawaii and various active undersea volcanoes, or around subduction zones – areas at the edge of a continental plate where the oceanic plate is sinking into the deep interior and producing melt,” said Schmerr. “However, the interesting result is that this layer does not exist everywhere, suggesting something other than melt is needed to explain the properties of the asthenosphere.”

Understanding how plate tectonics works on Earth could help us figure out how other rocky planets evolved, according to Schmerr. For example, Venus has no oceans, and no evidence of plate tectonics, either. This might be a clue that water is needed for plate tectonics to work. One theory proposes that without water, the asthenosphere of Venus will be more rigid and unable to sustain plates, suggesting internal heat is released in some other way, maybe through periodic eruptions of global volcanism.

Schmerr plans to analyze data from other seismometer networks to see if the same patchy pattern of melt layers exists under other oceans and the continents as well. The research was supported by the NASA Postdoctoral Program and the Carnegie Institution of Washington Department of Terrestrial Magnetism Postdoctoral Fellowship.

Contact: Bill Steigerwald
william.a.steigerwald@nasa.gov
301-286-5017
NASA/Goddard Space Flight Center

Neuroscience offers possibilities for cutting edge, deployable solutions for the needs of national security and defence, but are, or at least should be, tempered by questions of scientific validity, consequential ethical considerations, and concern for the relationship between science and security. This debate is explored in an essay by Jonathan D Moreno and Michael N Tennison, published March 20 in the online, open-access journal PLoS Biology.

Rapid advances in basic neuroscience over the last decade facilitate many “dual use” applications; those of both military and civilian interest. Neuroscientists who receive military funding may not fully appreciate the potentially lethal implications of their work. This paper seeks to cultivate a culture of dual use awareness, in both the scientific community and the general public.

For example, brain-computer interfaces, which have already been used to make monkeys control walking robots remotely, could enable humans to operate military devices while sheltered from the reality of combat. Also, research suggests that neuromodulation technologies, such as transcranial magnetic stimulation, could be used to enhance or suppress certain neurological capacities of soldiers on the battlefield. In addition, neuroscientific deception detection, while putatively performing better than traditional ‘lie-detector’ polygraphs, raises questions of reliability and privacy.

The authors suggest that issues such as these “need to be addressed to ensure the pragmatic synthesis of ethical accountability and national security”. Just as many nuclear scientists of the time discussed the issues of using of atomic weapons, contributing to the test ban treaties of the 1960s, neuroscientists of today could engage the ethical, legal, and social implications of the militarization of their work.

Funding: The authors received no specific funding for this work.

Competing interests: The authors have declared that no competing interests exist.

Citation: Tennison MN, Moreno JD (2012) Neuroscience, Ethics, and National Security: The State of the Art. PLoS Biol 10(3): e1001289. doi:10.1371/journal.pbio.1001289

CONTACT:
Jonathan D. Moreno
Center for Bioethics, Department of History and Sociology of Science
3401 Market Street
University of Pennsylvania
Philadelphia, PA 19103
UNITED STATES
Tel: +1-215-898-7136
morenojd@mail.med.upenn.edu

Public Library of Science

The Daya Bay Reactor Neutrino Experiment, a multinational collaboration including a team from Virginia Tech, discovered a new type of neutrino oscillation in which the particles appear to vanish as they travel. The researchers found that the rate of oscillations was much larger than many scientists had expected. This surprising result could open the gateway to a new understanding of fundamental physics and may eventually solve the riddle of why the universe today is dominated by matter as opposed to antimatter.

Neutrinos can be one of three types, which physicists call flavors. Owing to their bizarre physical – quantum mechanical – nature neutrinos can mix or oscillate between flavors. The rate of oscillation is controlled by parameters known as mixing angles.

The Daya Bay researchers gathered data that allowed them to measure the mixing angle theta one-three (θ13) with unmatched precision. Theta one-three, the last of three mixing angles to be measured, controls the rate at which electron neutrinos mix.

“This is the first time that any experiment has been able to definitively say that this mixing angle, theta one-three, is not zero,” said Jonathan Link, associate professor of physics and director of Virginia Tech’s Center for Neutrino Physics, home of the university’s Daya Bay experiment team.

The Daya Bay collaboration’s first results, which measured the mixing angle as part of the expression sin2 2 θ13, and found it to be equal to 0.092 plus or minus 0.017.

Neutrinos, the wispy particles that flooded the universe in the earliest moments after the big bang, are continually produced in the cores of stars and other nuclear reactions. Untouched by electromagnetism, they respond only to weak nuclear force and even weaker gravitational force, passing mostly unhindered through everything from planets to people. The challenge of capturing these elusive particles in the act of mixing inspired the Daya Bay collaboration in the design and precise placement of its detectors.

Traveling at close to the speed of light, the three basic neutrino “flavors” – electron, muon, and tau, as well as their corresponding antineutrinos − mix together in a process scientists refer to as oscillations but this process is extremely difficult to detect.

Collecting data from Dec. 24, 2011, until Feb. 17, 2012, scientists in the Daya Bay collaboration observed tens of thousands of interactions of electron antineutrinos in six massive detectors buried in the mountains adjacent to the powerful nuclear reactors of the Daya Bay Nuclear Power Plant in south China. These reactors produce millions of quadrillions of the elusive electron antineutrinos every second.

“Although we’re still two detectors shy of the complete experimental design, we’ve had extraordinary success in determining the number of electron antineutrinos that disappear as they travel from the reactors to the detectors two kilometers away,” said Kam-Biu Luk of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California at Berkeley. Luk is co-spokesperson of the project and heads U.S. participation. “What we didn’t expect was the sizable disappearance, equal to about 6 percent. Although vanishing has been observed in other reactor experiments over large distances, this is a new kind of disappearance for the reactor electron antineutrino.”

The Daya Bay experiment counts the number of electron antineutrinos observed in detectors placed near to the reactors and calculates how many would reach the detectors placed further away if there were no oscillations. The number of antineutrinos that appear to vanish on the way due to their oscillation into other flavors determines the value of theta one-three.

“Even with only the six detectors already operating, we have more target mass than any similar experiment, plus as much or more reactor power,” said William Edwards of Berkeley Lab and UC Berkeley is the U.S. project and operations manager for the Daya Bay experiment. Since Daya Bay will continue to have an interaction rate higher than any other experiment, Edwards said, “It is the leading theta one-three experiment in the world.”

In the future, the initial results will be honed by collecting extensive additional data and reducing statistical and systematic errors.

“The large value of theta one-three opens up the opportunity for the scientific community to learn a great deal about the universe through neutrinos,” said Deb Mohapatra, a Virginia Tech research scientist in the Center for Neutrino Physics.

The consortium researchers will be expanding the Daya Bay facilities for further experiments aimed at learning more about how neutrinos behave.

“The Daya Bay experiment plans to stop the current data-taking this summer to install a second detector in the Ling Ao Near Hall, and a fourth detector in the Far Hall, completing the experimental design,” said Yifang Wang of China’s Institute of High Energy Physics and co-spokesperson of the Daya Bay experiment.

Refined results will open the door to further investigations and influence the design of future neutrino experiments – including how to determine which neutrino flavors are the most massive, whether there is a difference between neutrino and antineutrino oscillations, and, eventually, why there is more matter than antimatter in the universe. Matter and antimatter presumably were created in equal amounts in the big bang and should have completely annihilated one another. So, the real question is, why there is any matter in the universe at all.

“Exemplary teamwork among the partners has led to this outstanding performance,” said James Siegrist, associate director for high energy physics at the U.S. Department of Energy’s Office of Science. “These notable first results are just the beginning for the world’s foremost reactor neutrino experiment.”

Virginia Tech Center for Neutrino Physics members who participated in the Daya Bay experiment besides Link and Mohapatra, are Leo Piilonen, incoming chair of the Department of Physics and The William E. Hassinger Jr. Senior Faculty Fellow in Physics; Patrick Huber, assistant professor of physics; Joseph Hor and Yue Meng, graduate students in the Department of Physics; and Jo Ellen Morgan, a physics laboratory specialist. The center’s work was support by the U.S. Department of Energy and Virginia Tech.

The Daya Bay collaboration consists of scientists from the following countries and regions: China, the United States, Russia, the Czech Republic, Hong Kong, and Taiwan.

A copy of the paper and the participating institutions is available. Find information online, or contact Jonathan Link, Virginia Tech group leader at 540-231-5321 for further information.

The College of Science at Virginia Tech gives students a comprehensive foundation in the scientific method. Outstanding faculty members teach courses and conduct research in biological sciences, chemistry, economics, geosciences, mathematics, physics, psychology, and statistics. The college offers programs in cutting-edge areas including, among others, those in energy and the environment, developmental science across the lifespan, infectious diseases, computational science, nanoscience, and neuroscience. The College of Science is dedicated to fostering a research-intensive environment that promotes scientific inquiry and outreach.

Contact: Susan A Steeves
ssteeves@vt.edu
540-231-5224
Virginia Tech

In a paper accepted for publication in the journal Physical Review Letters – with US researchers at the Georgia Institute of Technology and the University of Nevada – UNSW’s Professor Victor Flambaum and colleague Dr Vladimir Dzuba report that their proposed single-ion clock would be accurate to 19 decimal places.

“This is nearly 100 times more accurate than the best atomic clocks we have now,” says Professor Flambaum, who is Head of Theoretical Physics in the UNSW School of Physics.

“It would allow scientists to test fundamental physical theories at unprecedented levels of precision and provide an unmatched tool for applied physics research.”

The exquisite accuracy of atomic clocks is widely used in applications ranging from GPS navigation systems and high-bandwidth data transfer to tests of fundamental physics and system synchronization in particle accelerators.

“With these clocks currently pushing up against significant accuracy limitations, a next-generation system is desired to explore the realms of extreme measurement precision and further diversified applications unreachable by atomic clocks,” says Professor Flambaum.

“Atomic clocks use the orbiting electrons of an atom as the clock pendulum. But we have shown that by using lasers to orient the electrons in a very specific way, one can use the orbiting neutron of an atomic nucleus as the clock pendulum, making a so-called nuclear clock with unparalleled accuracy.”

Because the neutron is held so tightly to the nucleus, its oscillation rate is almost completely unaffected by any external perturbations, unlike those of an atomic clock’s electrons, which are much more loosely bound.

Contact: Bob Beale
bbeale@unsw.edu.au
61-411-705-435
University of New South Wales

Neutron stars are the remnants of massive stars that exploded as supernovae. They pack more than the mass of the Sun into a sphere no larger than a medium-sized city, making them the densest objects in the Universe, except for black holes, for which the concept of density is theoretically irrelevant. Pulsars are neutron stars that emit beams of radio waves outward from the poles of their magnetic fields. When their rotation spins a beam across the Earth, radio telescopes detect that as a “pulse” of radio waves.

By precisely measuring the timing of such pulses, astronomers can use pulsars for unique “experiments” at the frontiers of modern physics. Three scientists presented the results of such work, and the promise of future discoveries, at the American Association for the Advancement of Science meeting in Vancouver, British Columbia.

Pulsars are at the forefront of research on gravity. Albert Einstein published his theory of General Relativity in 1916, and his description of the nature of gravity has, so far, withstood numerous experimental tests. However, there are competing theories.

“Many of these alternate theories do just as good a job as General Relativity of predicting behavior within our Solar System. One area where they differ, though, is in the extremely dense environment of a neutron star,” said Ingrid Stairs, of the University of British Columbia.

In some of the alternate theories, gravity’s behavior should vary based on the internal structure of the neutron star.

“By carefully timing pulsar pulses, we can precisely measure the properties of the neutron stars. Several sets of observations have shown that pulsars’ motions are not dependent on their structure, so General Relativity is safe so far,” Stairs explained.

Recent research on pulsars in binary-star systems with other neutron stars, and, in one case, with another pulsar, offer the best tests yet of General Relativity in very strong gravity. The precision of such measurements is expected to get even better in the future, Stairs said.

Another prediction of General Relativity is that motions of masses in the Universe should cause disturbances of space-time in the form of gravitational waves. Such waves have yet to be directly detected, but study of pulsars in binary-star systems have given indirect evidence for their existence. That work won a Nobel Prize in 1993.

Now, astronomers are using pulsars throughout our Milky Way Galaxy as a giant scientific instrument to directly detect gravitational waves.

“Pulsars are such extremely precise timepieces that we can use them to detect gravitational waves in a frequency range to which no other experiment will be sensitive,” said Benjamin Stappers, of the University of Manchester in the UK.

By carefully timing the pulses from pulsars widely scattered within our Galaxy, the astronomers hope to measure slight variations caused by the passage of the gravitational waves. The scientists hope such Pulsar Timing Arrays can detect gravitational waves caused by the motions of supermassive pairs of black holes in the early Universe, cosmic strings, and possibly from other exotic events in the first few seconds after the Big Bang.

“At the moment, we can only place limits on the existence of the very low-frequency waves we’re seeking, but planned expansion and new telescopes will, we hope, result in a direct detection within the next decade,” Stappers said.

With densities as much as several times greater than that in atomic nuclei, pulsars are unique laboratories for nuclear physics. Details of the physics of such dense objects are unknown.

“By measuring the masses of neutron stars, we can put constraints on their internal physics,” said Scott Ransom of the National Radio Astronomy Observatory. “Just in the past three to four years, we’ve found several massive neutron stars that, because of their large masses, rule out some exotic proposals for what’s going on at the centers of neutron stars,” Ransom said.

The work is ongoing, and more measurements are needed. “Theorists are clever, so when we provide new data, they tweak their exotic models to fit what we’ve found,” Ransom said.

Pulsars were discovered in 1967 and that discovery earned the Nobel Prize in 1974.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Contact: Dave Finley
dfinley@nrao.edu
575-835-7302
National Radio Astronomy Observatory

IQ tests are based on two types of problems: progressive matrices, which test the ability to see patterns in pictures, and number sequences, which test the ability to see patterns in numbers. The most common math computer programmes score below 100 on IQ tests with number sequences. For Claes Strannegård, researcher at the Department of Philosophy, Linguistics and Theory of Science, this was a reason to try to design ‘smarter’ computer programmes.

‘We’re trying to make programmes that can discover the same types of patterns that humans can see,’ he says.

The research group, which consists of Claes Strannegård, Fredrik Engström, Rahim Nizamani and three students working on their degree projects, believes that number sequence problems are only partly a matter of mathematics – psychology is important too. Strannegård demonstrates this point:

’1, 2, …, what comes next? Most people would say 3, but it could also be a repeating sequence like 1, 2, 1 or a doubling sequence like 1, 2, 4. Neither of these alternatives is more mathematically correct than the others. What it comes down to is that most people have learned the 1-2-3 pattern.’

The group is therefore using a psychological model of human patterns in their computer programmes. They have integrated a mathematical model that models human-like problem solving. The programme that solves progressive matrices scores IQ 100 and has the unique ability of being able to solve the problems without having access to any response alternatives. The group has improved the programme that specialises in number sequences to the point where it is now able to ace the tests, implying an IQ of at least 150.

‘Our programmes are beating the conventional math programmes because we are combining mathematics and psychology. Our method can potentially be used to identify patterns in any data with a psychological component, such as financial data. But it is not as good at finding patterns in more science-type data, such as weather data, since then the human psyche is not involved,’ says Strannegård.

The research group has recently started collaborating with the Department of Psychology at Stockholm University, with a goal to develop new IQ tests with different levels of difficulty.

‘We have developed a pretty good understanding of how the tests work. Now we want to divide them into different levels of difficulty and design new types of tests, which we can then use to design computer programmes for people who want to practice their problem solving ability,’ says Strannegård.

Contact: Claes Strannegard
claes.strannegard@ituniv.se
46-031-772-6036
University of Gothenburg