Halo of Neutrinos Alters Physics of Exploding Stars

Sparse halos of neutrinos within the hearts of exploding stars exert a previously unrecognized influence on the physics of the explosion and may alter which elements can be forged by these violent events.

Full Article @ ScienceDialy

The Era of Neutrino Astronomy Has Begun

Astrophysicists using a telescope embedded in Antarctic ice have succeeded in a quest to detect and record the mysterious phenomena known as cosmic neutrinos -- nearly massless particles that stream to Earth at the speed of light from outside our solar system, striking the surface in a burst of energy that can be as powerful as a baseball pitcher's fastball. Next, they hope to build on the early success of the IceCube Neutrino Observatory to detect the source of these high-energy particles, said Physics Professor Gregory Sullivan, who led the University of Maryland's 12-person team of contributors to the IceCube Collaboration.

 Full Report @ ScienceDaily

A Digital Copy of the Universe, Encrypted

Even as he installed the landmark camera that would capture the first convincing evidence of dark energy in the 1990s, Tony Tyson, an experimental cosmologist now at the University of California, Davis, knew it could be better. The camera’s power lay in its ability to collect more data than any other. But digital image sensors and computer processors were progressing so rapidly that the amount of data they could collect and store would soon be limited only by the size of the telescopes delivering light to them, and those were growing too. Confident that engineering trends would hold, Tyson envisioned a telescope project on a truly grand scale, one that could survey hundreds of attributes of billions of cosmological objects as they changed over time.
It would record, Tyson said, “a digital, color movie of the universe.”
Tyson’s vision has come to life as the Large Synoptic Survey Telescope (LSST) project, a joint endeavor of more than 40 research institutions and national laboratories that has been ranked by the National Academy of Sciences as its top priority for the next ground-based astronomical facility. Set on a Chilean mountaintop, and slated for completion by the early 2020s, the 8.4-meter LSST will be equipped with a 3.2-billion-pixel digital camera that will scan 20 billion cosmological objects 800 times apiece over the course of a decade. That will generate well over 100 petabytes of data that anyone in the United States or Chile will be able to peruse at will. Displaying just one of the LSST’s full-sky images would require 1,500 high-definition TV screens.
The LSST epitomizes the new era of big data in physics and astronomy. Less than 20 years ago, Tyson’s cutting-edge digital camera filled 5 gigabytes of disk space per night with revelatory information about the cosmos. When the LSST begins its work, it will collect that amount every few seconds — literally more data than scientists know what to do with.
“The data volumes we [will get] out of LSST are so large that the limitation on our ability to do science isn’t the ability to collect the data, it’s the ability to understand the systematic uncertainties in the data,” said Andrew Connolly, an astronomer at the University of Washington.
Typical of today’s costly scientific endeavors, hundreds of scientists from different fields are involved in designing and developing the LSST, with Tyson as chief scientist. “It’s sort of like a federation,” said Kirk Borne, an astrophysicist and data scientist at George Mason University. The group is comprised of nearly 700 astronomers, cosmologists, physicists, engineers and data scientists.
Much of the scientists’ time and about one-half of the $1 billion cost of the project are being spent on developing software rather than hardware, reflecting the exponential growth of data since the astronomy projects of the 1990s. For the telescope to be useful, the scientists must answer a single question. As Borne put it: “How do you turn petabytes of data into scientific knowledge?”
Physics has been grappling with huge databases longer than any other field of science because of its reliance on high-energy machines and enormous telescopes to probe beyond the known laws of nature. This has given researchers a steady succession of models upon which to structure and organize each next big project, in addition to providing a starter kit of computational tools that must be modified for use with ever larger and more complex data sets.
Even backed by this tradition, the LSST tests the limits of scientists’ data-handling abilities. It will be capable of tracking the effects of dark energy, which is thought to make up a whopping 68 percent of the total contents of the universe, and mapping the distribution of dark matter, an invisible substance that accounts for an additional 27 percent. And the telescope will cast such a wide and deep net that scientists say it is bound to snag unforeseen objects and phenomena too. But many of the tools for disentangling them from the rest of the data don’t yet exist.
New Dimensions
Particle physics is the elder statesman of big data science. For decades, high-energy accelerators have been bashing particles together millions of times per second in hopes of generating exotic, never-before-seen particles. These facilities, such as the Large Hadron Collider (LHC) at CERN laboratory  in Switzerland, generate so much data that only a tiny fraction (deemed interesting by an automatic selection process) can be kept. A network of hundreds of thousands of computers spread across 36 countries called the Worldwide LHC Computing Grid stores and processes the 25 petabytes of LHC data that were archived in a year’s worth of collisions. The work of thousands of physicists went into finding the bump in that data that last summer was deemed representative of a new subatomic particle, the Higgs boson.
CERN, the organization that operates the LHC, is sharing its wisdom by working with other research organizations “so they can benefit from the knowledge and experience that has been gathered in data acquisition, processing and storage,” said Bob Jones, head of CERN openlab, which develops new IT technologies and techniques for the LHC. Scientists at the European Space Agency, the European Molecular Biology Laboratory, other physics facilities and even collaborations in the social sciences and humanities have taken cues from the LHC on data handling, Jones said.
When the LHC turns back on in 2014 or 2015 after an upgrade, higher energies will mean more interesting collisions, and the amount of data collected will grow by a significant factor. But even though the LHC will continue to possess the biggest data set in physics, its data is much simpler than those obtained from astronomical surveys such as the Sloan Digital Sky Survey and Dark Energy Survey and — to an even greater extent — those that will be obtained from future sky surveys such as the Square Kilometer Array, a radio telescope project set to begin construction in 2016, and the LSST.
“The LHC generates a lot more data right at the beginning, but they’re only looking for certain events in that data and there’s no correlation between events in that data,” said Jeff Kantor, the LSST data management project manager. “Over time, they still build up large sets, but each one can be individually analyzed.”
In combining repeat exposures of the same cosmological objects and logging hundreds rather than a handful of attributes of each one, the LSST will have a whole new set of problems to solve. “It’s the complexity of the LSST data that’s a challenge,” Tyson said. “You’re swimming around in this 500-dimensional space.”
From color to shape, roughly 500 attributes will be recorded for every one of the 20 billion objects surveyed, and each attribute is treated as a separate dimension in the database. Merely cataloguing these attributes consistently from one exposure of a patch of the sky to the next poses a huge challenge. “In one exposure, the scene might be clear enough that you could resolve two different galaxies in the same spot, but in another one, they might be blurred together,” Kantor said. “You have to figure out if it’s one galaxy or two or N.”

Beyond N-Squared
To tease scientific discoveries out of the vast trove of data gathered by the LSST and other sky surveys, scientists will need to pinpoint unexpected relationships between attributes, which is extremely difficult in 500 dimensions. Finding correlations is easy with a two-dimensional data set: If two attributes are correlated, then there will be a one-dimensional curve connecting the data points on a two-dimensional plot of one attribute versus the other. But additional attributes plotted as extra dimensions obscure such curves. “Finding the unexpected in a higher-dimensional space is impossible using the human brain,” Tyson said. “We have to design future computers that can in some sense think for themselves.”
Algorithms exist for “reducing the dimensionality” of data, or finding surfaces on which the data points lie (like that 1-D curve in the 2-D plot), in order to find correlated dimensions and eliminate “nuisance” ones. For example, an algorithm might identify a 3-D surface of data points coursing through a database, indicating that three attributes, such as the type, size and rotation speed of galaxies, are related. But when swamped with petabytes of data, the algorithms take practically forever to run.
Identifying correlated dimensions is exponentially more difficult than looking for a needle in a haystack. “That’s a linear problem,” said Alex Szalay, a professor of astronomy and computer science at Johns Hopkins University. “You search through the haystack and whatever looks like a needle you throw in one bucket and you throw everything else away.” When you don’t know what correlations you’re looking for, however, you must compare each of the N pieces of hay with every other piece, which takes N-squared operations.
Adding to the challenge is the fact that the amount of data is doubling every year. “Imagine we are working with an algorithm that if my data doubles, I have to do four times as much computing and then the following year, I have to do 16 times as much computing,” Szalay said. “But by next year, my computers will only be twice as fast, and in two years from today, my computers will only be four times as fast, so I’m falling farther and farther behind in my ability to do this.”
A huge amount of research has gone into developing scalable algorithms, with techniques such as compressed sensing, topological analysis and the maximal information coefficient emerging as especially promising tools of big data science. But more work remains to be done before astronomers, cosmologists and physicists will be ready to fully exploit the multi-petabyte digital movie of the universe that premiers next decade. Progress is hampered by the fact that researchers in the physical sciences get scant academic credit for developing algorithms — a problem that the community widely recognizes but has yet to solve.
“It’s always been the case that the people who build the instrumentation don’t get as much credit as the people who use the instruments to do the cutting-edge science,” Connolly said. “Ten years ago, it was people who built physical instruments — the cameras that observe the sky — and today, it’s the people who build the computational instruments who don’t get enough credit. There has to be a career path for someone who wants to work on the software — because they can go get jobs at Google. So if we lose these people, it’s the science that loses.”
Coffee and Kudos
In December 2010, in an effort to encourage the development of better algorithms, an international group of astronomers issued a challenge to computer geeks everywhere: What is the best way to measure gravitational lensing, or the distorting effect that dark matter has on the light from distant galaxies? David Kirkby read about the GREAT10 (GRavitational lEnsing Accuracy Testing 2010) Challenge on Wired.com and decided to give it a go.
Kirkby, a physicist at the University of California, Irvine, and his graduate student won the contest using a modified version of a neural network algorithm that he had previously developed for the BABAR experiment, a large physics collaboration investigating the asymmetry of matter and antimatter. The victory earned Kirkby a co-author credit on the recent paper detailing the contest, easing his switch from the field of particle physics to astrophysics. Also, with the prize money, “we bought a top of the line espresso machine for the lab,” he said.
GREAT10 was one of a growing number of “data challenges” designed to find solutions to specific problems faced in creating and analyzing large physics and astronomy databases, such as the best way to reconstruct the shapes of two galaxies that are aligned relative to Earth and so appear blended together.
“One group produces a set of data — it could be blended galaxies — and then anybody can go out and try and estimate the shape of the galaxies using their best algorithm,” explained Connolly, who is involved in generating simulations of future LSST images that are used to test the performance of algorithms. “It’s quite a lot of kudos to the person who comes out on top.”
Many of the data challenges, including the GREAT series, focus on teasing out the effects of dark matter. When light from a distant galaxy travels to Earth, it is bent, or “lensed,” by the gravity of the dark matter it passes through. “It’s a bit like looking at wallpaper through a bathroom window with a rough surface,” Kirkby said. “You determine what the wallpaper would look like if you were looking at it directly, and you use that information to figure out what the shape of the glass is.”
Each new data challenge in a series includes an extra complication — additional distortions caused by atmospheric turbulence or a faulty amplifier in one of the detectors, for example — moving the goal posts of the challenge closer and closer to reality.
Data challenges are “a great way of crowd-sourcing problems in data science, but I think it would be good if software development was just recognized as part of your productivity as an academic,” Kirkby said. “At career reviews, you measure people based on their scientific contributions even though software packages could have a much broader impact.”
The culture is slowly changing, the scientists said, as the ability to analyze data becomes an ever-tightening bottleneck in research. “In the past, it was usually some post-doc or grad student poring over data who would find something interesting or something that doesn’t seem to work and stumble across some new effect,” Tyson said. “But increasingly, the amount of data is so large that you have to have machines with algorithms to do this.”
Dark Side of the Universe
Assuming that physicists can solve the computing problems they face with the LSST, the results could be transformative. There are many reasons to want a 100-petabyte digital copy of the universe. For one, it would help map the expansion of space and time caused by the still-mysterious dark energy, discovered with the help of the LSST’s predecessor, the Big Throughput Camera, which Tyson and a collaborator built in 1996.
When that camera, which could cover a patch of the sky the size of a full moon in a single exposure, was installed on the Blanco Telescope in Chile, astrophysicists immediately discovered dozens of exploding stars called Type IA supernovae strewn across the sky that revealed that most stuff in the universe is unknown. Light from nearby supernovae appeared to have stretched more than it should have during its journey through the expanding cosmos compared with light from faraway ones. This suggested that the expansion of the universe had recently sped up, driven by dark energy.
With the LSST, scientists hope to precisely track the accelerating expansion of the universe and thus to better define the nature of dark energy. They aim to do this by mapping a sort of cosmic yardstick called baryon acoustic oscillations. The yardstick was created from sound waves that rippled through the universe when it was young and hot and became imprinted in the distribution of galaxies as it cooled and expanded. The oscillations indicate the size of space at every distance away from Earth — and thus at any point back in time.
Baryon acoustic oscillations are so enormous that a truly vast astronomical survey is needed to make them a convenient measuring tool. By cataloguing billions of galaxies, the LSST promises to measure the size of these resonances more accurately than any other existing or planned astronomical survey. “The idea is that with the LSST, we will have onion shells of galaxies at different distances and we can look for this pattern and trace the size of the resonant patterns as a function of time,” Szalay said. “This will be beautiful.”
But, Szalay added, “it will be a nontrivial task to actually milk the information out of the data.”
Reprinted with permission from Quanta Magazine, an editorially independent division of SimonsFoundation.org whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences..

ScientificAmerican

3-D Printing: The Greener Choice

Oct. 3, 2013 — 3D printing isn't just cheaper, it's also greener, says Michigan Technological University's Joshua Pearce.

3D printing can save energy by using less raw material. These partially printed Swiss children's blocks show how a printer can partly fill the interior of an item with plastic while maintaining its strength. (Credit: Samuel Bernier photo)

Even Pearce, an aficionado of the make-it-yourself-and-save technology, was surprised at his study's results. It showed that making stuff on a 3D printer uses less energy -- and therefore releases less carbon dioxide -- than producing it en masse in a factory and shipping it to a warehouse.
Most 3D printers for home use, like the RepRap used in this study, are about the size of microwave ovens. They work by melting filament, usually plastic, and depositing it layer by layer in a specific pattern. Free designs for thousands of products are available from outlets like Thingiverse.com.
Common sense would suggest that mass-producing plastic widgets would take less energy per unit than making them one at a time on a 3D printer. Or, as Pearce says, "It's more efficient to melt things in a cauldron than in a test tube." However, his group found it's actually greener to make stuff at home.
They conducted life cycle impact analyses on three products: an orange juicer, a children's building block and a waterspout. The cradle-to-gate analysis of energy use went from raw material extraction to one of two endpoints: entry into the US for an item manufactured overseas or printing it a home on a 3D printer.
Pearce's group found that making the items on a basic 3D printer took from 41 percent to 64 percent less energy than making them in a factory and shipping them to the US.
Some of the savings come from using less raw material. "Children's blocks are normally made of solid wood or plastic," said Pearce, an associate professor of materials science and engineering/electrical and computer engineering. 3D printed blocks can be made partially or even completely hollow, requiring much less plastic.
Pearce's team ran their analysis with two common types of plastic filament used in 3D printing, including polylactic acid (PLA). PLA is made from renewable resources, such as cornstarch, making it a greener alternative to petroleum-based plastics. The team also did a separate analysis on products made using solar-powered 3D printers, which drove down the environmental impact even further.
"The bottom line is, we can get substantial reductions in energy and CO2 emissions from making things at home," Pearce said. "And the home manufacturer would be motivated to do the right thing and use less energy, because it costs so much less to make things on a 3D printer than to buy them off the shelf or on the Internet."

Source: ScienceDaily

Breakthrough in Photonics Could Allow for Faster and Faster Electronics

Oct. 1, 2013 — A pair of breakthroughs in the field of silicon photonics by researchers at the University of Colorado Boulder, the Massachusetts Institute of Technology and Micron Technology Inc. could allow for the trajectory of exponential improvement in microprocessors that began nearly half a century ago -- known as Moore's Law -- to continue well into the future, allowing for increasingly faster electronics, from supercomputers to laptops to smartphones.

Researchers have developed a new technique that allows microprocessors to use light, instead of electrical wires, to communicate with transistors on a single chip, a system that could lead to extremely energy-efficient computing and a continued skyrocketing of computing speed into the future. (Credit: Image courtesy of University of Colorado at Boulder)

The research team, led by CU-Boulder researcher Milos Popovic, an assistant professor of electrical, computer and energy engineering, developed a new technique that allows microprocessors to use light, instead of electrical wires, to communicate with transistors on a single chip, a system that could lead to extremely energy-efficient computing and a continued skyrocketing of computing speed into the future.
Popovic and his colleagues created two different optical modulators -- structures that detect electrical signals and translate them into optical waves -- that can be fabricated within the same processes already used in industry to create today's state-of-the-art electronic microprocessors. The modulators are described in a recent issue of the journal Optics Letters.
First laid out in 1965, Moore's Law predicted that the size of the transistors used in microprocessors could be shrunk by half about every two years for the same production cost, allowing twice as many transistors to be placed on the same-sized silicon chip. The net effect would be a doubling of computing speed every couple of years.
The projection has held true until relatively recently. While transistors continue to get smaller, halving their size today no longer leads to a doubling of computing speed. That's because the limiting factor in microelectronics is now the power that's needed to keep the microprocessors running. The vast amount of electricity required to flip on and off tiny, densely packed transistors causes excessive heat buildup.
"The transistors will keep shrinking and they'll be able to continue giving you more and more computing performance," Popovic said. "But in order to be able to actually take advantage of that you need to enable energy-efficient communication links."
Microelectronics also are limited by the fact that placing electrical wires that carry data too closely together can result in "cross talk" between the wires.
In the last half-dozen years, microprocessor manufacturers, such as Intel, have been able to continue increasing computing speed by packing more than one microprocessor into a single chip to create multiple "cores." But that technique is limited by the amount of communication that then becomes necessary between the microprocessors, which also requires hefty electricity consumption.
Using light waves instead of electrical wires for microprocessor communication functions could eliminate the limitations now faced by conventional microprocessors and extend Moore's Law into the future, Popovic said.
Optical communication circuits, known as photonics, have two main advantages over communication that relies on conventional wires: Using light has the potential to be brutally energy efficient, and a single fiber-optic strand can carry a thousand different wavelengths of light at the same time, allowing for multiple communications to be carried simultaneously in a small space and eliminating cross talk.
Optical communication is already the foundation of the Internet and the majority of phone lines. But to make optical communication an economically viable option for microprocessors, the photonics technology has to be fabricated in the same foundries that are being used to create the microprocessors. Photonics have to be integrated side-by-side with the electronics in order to get buy-in from the microprocessor industry, Popovic said.
"In order to convince the semiconductor industry to incorporate photonics into microelectronics you need to make it so that the billions of dollars of existing infrastructure does not need to be wiped out and redone," Popovic said.
Last year, Popovic collaborated with scientists at MIT to show, for the first time, that such integration is possible. "We are building photonics inside the exact same process that they build microelectronics in," Popovic said. "We use this fabrication process and instead of making just electrical circuits, we make photonics next to the electrical circuits so they can talk to each other."
In two papers published last month in Optics Letters with CU-Boulder postdoctoral researcher Jeffrey Shainline as lead author, the research team refined their original photonic-electronic chip further, detailing how the crucial optical modulator, which encodes data on streams of light, could be improved to become more energy efficient. That optical modulator is compatible with a manufacturing process -- known as Silicon-on-Insulator Complementary Metal-Oxide-Semiconductor, or SOI CMOS -- used to create state-of-the-art multicore microprocessors such as the IBM Power7 and Cell, which is used in the Sony PlayStation 3.
The researchers also detailed a second type of optical modulator that could be used in a different chip-manufacturing process, called bulk CMOS, which is used to make memory chips and the majority of the world's high-end microprocessors.
Vladimir Stojanovic, who leads one of the MIT teams collaborating on the project and who is the lead principal investigator for the overall research program, said the group's work on optical modulators is a significant step forward.
"On top of the energy-efficiency and bandwidth-density advantages of silicon-photonics over electrical wires, photonics integrated into CMOS processes with no process changes provides enormous cost-benefits and advantage over traditional photonic systems," Stojanovic said.

Source: ScienceDaily

Discovery of Charged Droplets Could Lead to More Efficient Power Plants

Oct. 2, 2013 — In a completely unexpected finding, MIT researchers have discovered that tiny water droplets that form on a superhydrophobic surface, and then "jump" away from that surface, carry an electric charge. The finding could lead to more efficient power plants and a new way of drawing power from the atmosphere, they say.

Images such as this, showing droplets being shed from a superhydrophobic surface (light band at center), revealed the charging of the droplets. (Credit: Nenad Miljkovic and Daniel Preston)

The finding is reported in a paper in the journal Nature Communications written by MIT postdoc Nenad Miljkovic, mechanical engineering professor Evelyn Wang, and two others.
Miljkovic says this was an extension of previous work by the MIT team. That work showed that under certain conditions, rather than simply sliding down and separating from a surface due to gravity, droplets can actually leap away from it. This occurs when droplets of water condense onto a metal surface with a specific kind of superhydrophobic coating and at least two of the droplets coalesce: They can then spontaneously jump from the surface, as a result of a release of excess surface energy.
In the new work, "We found that when these droplets jump, through analysis of high-speed video, we saw that they repel one another midflight," Miljkovic says. "Previous studies have shown no such effect. When we first saw that, we were intrigued."
In order to understand the reason for the repulsion between jumping droplets after they leave the surface, the researchers performed a series of experiments using a charged electrode. Sure enough, when the electrode had a positive charge, droplets were repelled by it as well as by each other; when it had a negative charge, the droplets were drawn toward it. This established that the effect was caused by a net positive electrical charge forming on the droplets as they jumped away from the surface.
The charging process takes place because as droplets form on a surface, Miljkovic says, they naturally form an electric double layer -- a layer of paired positive and negative charges -- on their surfaces. When neighboring drops coalesce, which leads to their jumping from the surface, that process happens "so fast that the charge separates," he says. "It leaves a bit of charge on the droplet, and the rest on the surface."
The initial finding that droplets could jump from a condenser surface -- a component at the heart of most of the world's electricity-generating power plants -- provided a mechanism for enhancing the efficiency of heat transfer on those condensers, and thus improving power plants' overall efficiency. The new finding now provides a way of enhancing that efficiency even more: By applying the appropriate charge to a nearby metal plate, jumping droplets can be pulled away from the surface, reducing the likelihood of their being pushed back onto the condenser either by gravity or by the drag created by the flow of the surrounding vapor toward the surface, Miljkovic says.
"Now we can use an external electric field to mitigate" any tendency of the droplets to return to the condenser, "and enhance the heat transfer," he says.
But the finding also suggests another possible new application, Miljkovic says: By placing two parallel metal plates out in the open, with "one surface that has droplets jumping, and another that collects them … you could generate some power" just from condensation from the ambient air. All that would be needed is a way of keeping the condenser surface cool, such as water from a nearby lake or river. "You just need a cold surface in a moist environment," he says. "We're working on demonstrating this concept."
The research team also included graduate student Daniel Preston and Ryan Enright, who was a postdoc at MIT and the University of Limerick and is now at Bell Labs Ireland, part of Alcatel-Lucent. The work received funding from the U.S. Department of Energy through the MIT Solid-State Solar-Thermal Energy Conversion Center, the Office of Naval Research and the National Science Foundation.

Source: ScienceDaily

Tears for Fears: Juvenile Mice Secrete a Protective Pheromone in Their Tears, Blocking Adult Mating

Oct. 2, 2013 — Nocturnal animals need their noses to stay alive. Mice, among others, depend on their impressive olfactory powers to sniff out food or avoid danger in the dark.

Young mice produce a pheromone in their tears that protects them from mating activity by adult male mice. (Credit: © Michey Kirilloff / Fotolia)

Hard-wired to flee a predator or fight a mating rival in response to a whiff of urine, mice use a streamlined system that sends the sensory cue to neural centers in the brain that need only a few synapses to rapidly initiate the instinctive behavior. By comparison, the visual system on which humans rely to sense a threat must process many more variables, detecting the edges and colors and contrast of that looming tiger they see, rather than sniffing the aroma of a cat -- pungent only to animals -- before scuttling away.
In mice, social behaviors are also driven by these chemical signals, called pheromones. Scientists have observed differences in how mice interact with adult, juvenile or newborn mice, but they have not known which sensory cues allow mice to discriminate by age.
While looking for novel pheromones that can control different instinctive mouse behaviors, researchers, led by Stephen Liberles, HMS associate professor of cell biology, have discovered a pheromone found only in the tears of young mice. Their experiments showed that this molecule, an exocrine-gland peptide named ESP22, protects prepubescent mice from mating activity by adult male mice. The research, reported October 2 in Nature, provides the first step toward a detailed understanding of how a sensory system can regulate social behavior.
"By identifying specific pheromones and the receptors they activate, you have a handle on the neural circuits that control these instinctive behaviors," Liberles said. "The idea is to generate a toolbox of different pheromones that control different behaviors. Then you can dissect how the olfactory system selectively channels these inputs to enact appropriate behavioral responses."
The researchers examined the genomes of mice to identify genes that encode pheromones. They studied whether pheromone genes were turned on in male and female mice of different ages and physiological states. In adult mice, sex pheromones made by males influence sexual behavior in adult females and aggression in males, but less is known about pheromones in younger mice.
The gene expression screen found Esp22 not in newborn mice but in the tears of juvenile mice. Juvenile pheromones had not been reported before, and much less attention has been focused on tears compared to urine, which is much easier to collect.
"This framed how we thought about what ESP22 might be doing," Liberles said.
To better understand the response pathway this molecule activated, the scientists traced it to sensory neurons in the vomeronasal organ (VNO), an olfactory structure that humans lack. Adult mice that have signaling deficits in this organ displayed increased sexual behavior toward the juvenile mice, the scientists observed.
The scientists also saw adult mice exhibit the same behavior toward two strains of juvenile mice that don't produce ESP22. But when ESP22 was painted onto these juvenile mice, there was a substantial reduction in sexual behavior by the adult males, suggesting that ESP22 is a protective pheromone.
Further tracking showed that ESP22 activates neurons in the limbic system, an area in the brain controlling instinctive drives: sexual behavior, aggression and self-defense. Much more remains in the dark, Liberles said.
"We'd love to know what those neurons are, how they compare to other neurons in the limbic system, and how they might mediate responses to other types of pheromones and predator odors," he said. "We would also like to find the receptor that detects this cue."
Mice are important models for understanding human behavior -- the ultimate goal of this research program -- but there are important differences. Humans don't have a juvenile pheromone like ESP22. They don't have an organ like the VNO. They also don't recognize predator odors the way a mouse would. But humans do exhibit fear, aggression and sexual behavior.
"Many of the behaviors are similar," Liberles said. "We use the mouse as a model for understanding human behavior. This work provides a way to study mechanisms underlying behavior."
Lisa Stowers, an associate professor of molecular and cellular neuroscience at the Scripps Research Institute in San Diego, called the study "convincing and complete." While she leads a lab that investigates similar questions in the field, she was not involved in the research.
"This is a very important molecule to study brain circuitry," she said. "We don't have the special olfactory system that mice have and we don't have the odors that trigger behavior, but they trigger the same place in the brain, across evolution."
Stowers was cautious in drawing conclusions about mice in the wild versus mice in laboratory cages, much less leaping across species. What does a male mouse do when it is attracted to a female and smells a cat at the same time, for example?
"By having thesecues we can begin to find the neurons they activate and ask what happens in this balancing act between mating and fear," she said. "We can ask how these behaviors are modulated and, in dysfunction, how they are not modulated."
ESP22 and other molecules Liberles has found provide powerful tools to understand how innate behaviors are produced in the brain, she said.
"Thirty percent of humans take drugs to modulate stress and anxiety and aggression," Stowers said. Despite how important these behaviors are, "we have no idea how they are produced in the brain by any animal -- not worms, not flies, not mice and not humans. This is a first step, opening up whole new ways to study them."

Source: ScienceDaily 

Human Robot Getting Closer: iCub Robot Must Learn from Its Experiences

Sep. 27, 2013 — A robot that feels, sees and, in particular, thinks and learns like us. It still seems like science fiction, but if it's up to University of Twente (UT) researcher Frank van der Velde, it won't be. In his work he wants to implement the cognitive process of the human brain in robots. The research should lead to the arrival of the latest version of the iCub robot in Twente. This human robot (humanoid) blurs the boundaries between robot and human.

A robot that feels, sees and, in particular, thinks and learns like us. It still seems like science fiction, but if it's up to UT researcher Frank van der Velde, it won't be. In his work he wants to implement the cognitive process of the human brain in robots. The research should lead to the arrival of the latest version of the iCub robot in Twente. This human robot (humanoid) blurs the boundaries between robot and human. (Credit: Image courtesy of University of Twente)

Decades of scientific research into cognitive psychology and the brain have given us knowledge about language, memory, motor skills and perception. We can now use that knowledge in robots, but Frank van der Velde's research goes even further. "The application of cognition in technical systems should also mean that the robot learns from its experiences and the actions it performs. A simple example: a robot that spills too much when pouring a cup of coffee can then learn how it should be done."
Possible first iCub in the Netherlands
The arrival of the iCub robot at the University of Twente should signify the next step in this research. Van der Velde submitted an application together with other UT researchers Stefano Stramigioli, Vanessa Evers, Dirk Heylen and Richard van Wezel, all active in the robotics and cognitive research. At the moment, twenty European laboratories have an iCub, which was developed in Italy (thanks to a European FP7 grant for the IIT). The Netherlands is still missing from the list. Moreover, a newer version is currently being developed, with for example haptic sensors. In February it will be announced whether the robotics club will actually bring the latest iCub to the UT. The robot costs a quarter of a million Euros and NWO (Netherlands Organisation for Scientific Research) will reimburse 75% of the costs. Then the TNO (Netherlands Organisation for Applied Scientific Research) and the universities of Groningen, Nijmegen, Delft and Eindhoven can also make use of it. Within the UT, the iCub can be deployed in different laboratories thanks to a special transport system.
Robot guide dog
The possibilities are endless, according to Van der Velde. "The new iCub has a skin and fingers that have a much better sense of touch and can feel strength. That makes interaction with humans much more natural. We want to ensure that this robot continues to learn and understands how people function. This research ensures, for example, that robots actually gather knowledge by focusing on certain objects or persons. In areas of application like healthcare and nursing, such robots can play an important role. A good example would be that in ten years' time you see a blind person walking with a robot guide dog."
Nano-neural circuits
A recent line of research that is in line with this profile is the development of electronic circuits that resemble a web of neurons in the human brain. Contacts have already been made to start this research in Twente. In the iCub robot, this can for example be used for the robot's visual perception. This requires a lot of relatively simple operations that must all be performed in parallel. This takes a lot of time and energy in the current systems. With electronic circuits in the form of a web of nerve cells this is much easier.
"These connections are only possible at the nanoscale, that is to say the scale at which the material is only a few atoms thick. In combination with the iCub robot, it can be investigated how the experiences of the robot are recorded in such materials and how the robot is controlled by nano-neural circuitry. The bottleneck of the existing technical systems is often the energy consumption and the size. The limits of Moore's Law, the proposition that the number of transistors in a circuit doubles every two years through technological advances, are reached. In this area we are therefore also on the verge of many new applications."
Video: http://www.youtube.com/watch?v=ZcTwO2dpX8A

Sorce: ScienceDaily

First Cloud Map of a Planet Beyond Our Solar System

Sep. 30, 2013 — Astronomers using data from NASA's Kepler and Spitzer space telescopes have created the first cloud map of a planet beyond our solar system, a sizzling, Jupiter-like world known as Kepler-7b.

Kepler-7b (left), which is 1.5 times the radius of Jupiter (right), is the first exoplanet to have its clouds mapped. The cloud map was produced using data from NASA's Kepler and Spitzer space telescopes. (Credit: NASA/JPL-Caltech/MIT)

The planet is marked by high clouds in the west and clear skies in the east. Previous studies from Spitzer have resulted in temperature maps of planets orbiting other stars, but this is the first look at cloud structures on a distant world.
"By observing this planet with Spitzer and Kepler for more than three years, we were able to produce a very low-resolution 'map' of this giant, gaseous planet," said Brice-Olivier Demory of Massachusetts Institute of Technology in Cambridge. Demory is lead author of a paper accepted for publication in the Astrophysical Journal Letters. "We wouldn't expect to see oceans or continents on this type of world, but we detected a clear, reflective signature that we interpreted as clouds."
Kepler has discovered more than 150 exoplanets, which are planets outside our solar system, and Kepler-7b was one of the first. The telescope's problematic reaction wheels prevent it from hunting planets any more, but astronomers continue to pore over almost four years' worth of collected data.
Kepler's visible-light observations of Kepler-7b's moon-like phases led to a rough map of the planet that showed a bright spot on its western hemisphere. But these data were not enough on their own to decipher whether the bright spot was coming from clouds or heat. The Spitzer Space Telescope played a crucial role in answering this question.
Like Kepler, Spitzer can fix its gaze at a star system as a planet orbits around the star, gathering clues about the planet's atmosphere. Spitzer's ability to detect infrared light means it was able to measure Kepler-7b's temperature, estimating it to be between 1,500 and 1,800 degrees Fahrenheit (1,100 and 1,300 Kelvin). This is relatively cool for a planet that orbits so close to its star -- within 0.06 astronomical units (one astronomical unit is the distance from Earth and the sun) -- and, according to astronomers, too cool to be the source of light Kepler observed. Instead, they determined, light from the planet's star is bouncing off cloud tops located on the west side of the planet.
"Kepler-7b reflects much more light than most giant planets we've found, which we attribute to clouds in the upper atmosphere," said Thomas Barclay, Kepler scientist at NASA's Ames Research Center in Moffett Field, Calif. "Unlike those on Earth, the cloud patterns on this planet do not seem to change much over time -- it has a remarkably stable climate."
The findings are an early step toward using similar techniques to study the atmospheres of planets more like Earth in composition and size.
"With Spitzer and Kepler together, we have a multi-wavelength tool for getting a good look at planets that are trillions of miles away," said Paul Hertz, director of NASA's Astrophysics Division in Washington. "We're at a point now in exoplanet science where we are moving beyond just detecting exoplanets, and into the exciting science of understanding them."
Kepler identified planets by watching for dips in starlight that occur as the planets transit, or pass in front of their stars, blocking the light. This technique and other observations of Kepler-7b previously revealed that it is one of the puffiest planets known: if it could somehow be placed in a tub of water, it would float. The planet was also found to whip around its star in just less than five days.
Explore all 900-plus exoplanet discoveries with NASA's "Eyes on Exoplanets," a fully rendered 3D visualization tool, available for download at http://eyes.nasa.gov/exoplanets. The program is updated daily with the latest findings from NASA's Kepler mission and ground-based observatories around the world as they search for planets like our own.
Other authors include: Julien de Wit, Nikole Lewis, Andras Zsom and Sara Seager of Massachusetts Institute of Technology; Jonathan Fortney of the University of California, Santa Cruz; Heather Knutson and Jean-Michel Desert of the California Institute of Technology, Pasadena; Kevin Heng of the University of Bern, Switzerland; Nikku Madhusudhan of Yale University, New Haven, Conn.; Michael Gillon of the University of Liège, Belgium; Vivien Parmentier of the French National Center for Scientific Research, France; and Nicolas Cowan of Northwestern University, Evanston, Ill. Lewis is also a NASA Sagan Fellow.
The technical paper is online at http://www.mit.edu/~demory/preprints/kepler-7b_clouds.pdf .
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA. Science operations are conducted at the Spitzer Science Center at Caltech. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit: http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .
Ames is responsible for Kepler's ground system development, mission operations and science data analysis. JPL managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery Mission and was funded by the agency's Science Mission Directorate. For more information about the Kepler mission, visit: http://www.nasa.gov/kepler and http://www.kepler.nasa.gov .

Source: ScienceDaily

Grand Theft Auto Franchise Playfully Flicks Mud at Its Birthplace: Scotland

Grand Theft Auto V. Far from the predatory turf its avatars inhabit, the game franchise was first conceived in Dundee, Scotland.

Since its introduction 16 years ago, the wildly popular video game franchise Grand Theft Auto has been set in some of the most recognizable cities in the United States. There were New York, Miami and San Francisco, and in the fifth installment, released to great fanfare this month, Los Angeles. 

Yet the roots of the game can be traced directly back to Dundee, a former shipbuilding city in Scotland, better known as the humble home of jam and jute, a vegetable fiber used to make rope and burlap. It is a city that has, instead of the raw urbanity celebrated in the video game, a quaint coastline, as well as a population that prizes irreverence and wit.

“There’s a cultural aspect in the U.K. of not taking other people too seriously,” said Brian Baglow, a writer for the series’ first installment and the head of the Scottish Games Network. “That’s a very large part of why G.T.A. works the way it does.”

He added: “Basically, we’re all just sarcastic. There’s a strong tradition of satire here, which is centuries old. I think that in an American studio, you would run the risk of being entirely serious and straight-faced, whereas there is subversion in G.T.A. all the way through. It’s black humor.”

Grand Theft Auto was created in 1995 by four friends — David Jones, Russell Kay, Steve Hammond and Mike Dailly — in a two-room office above a small shop in Dundee that sold baby clothes.

Mr. Dailly, a programmer, had been toying with the idea of creating a “virtual 3-D city” that would allow players to roam freely and choose their actions. The team initially intended the protagonist to be a police officer, but it quickly scrapped the idea in favor of inhabiting a criminal.

“You just can’t go around running over people if you’re a cop — nobody liked playing the cop,” said Mr. Baglow, an early member of the team.

Fascinated by American gangster films like “Goodfellas” and “Scarface,” the four, who ran a company called DMA Design, based the narratives on their vision of the United States. (At the time, none of them had been there.)

“In the 1980s, Dundee was a shadow of its former self — it wasn’t the nicest of places,” said Mr. Kay, who rewrote the game for consoles. “We didn’t think it would be exciting if the games were set in Dundee.”

Creating the game was a form of escapism, he said: “We made a lot of inside jokes.”

And while the game — which has sold more than 125 million units worldwide since its debut in 1997 — satirizes much of American culture, it is also peppered with Scottish references. San Fierro, a fictional city, features a wealthy district called Calton Heights, after the dilapidated Calton area of Glasgow. San Fierro is also home to the Hippy Shopper chain, a twist on Happy Shopper, a grocery chain with stores in Scotland and Britain. In another city, a Saltire, the blue-and-white national flag, flies over a building. And a racehorse named Scotland Nil alludes to the long, humiliating history of goal-less matches by Scotland’s national soccer team.

DMA Design was eventually sold, through a series of complicated takeovers, to Rockstar Games, a label of the American game publisher Take-Two Interactive Software, and the Dundee connection was broken. Rockstar Games has eight studios, including Rockstar North, based in Edinburgh, which is responsible for the creative content of Grand Theft Auto. Rockstar North is one of the biggest game developers in Britain, employing 300 people.

Scotland is now the biggest hub for game developers in Britain and among the biggest in Europe, with around 80 developers huddled around Dundee.

While some consider the game Scotland’s greatest cultural export since “Auld Lang Syne,” the game’s louche tone does not resonate with everyone. David Paterson, a councilor for the Scottish town of Hawick, said recently that he was “absolutely disgusted” at the use of the town’s name for a “druggie hipster” district in its latest installment.

“It is going to destroy the good reputation of this town,” he said.

Still, for those who were there at the game’s beginnings, its sly references to their home bring smiles to their faces.

“These little inside jokes are very clever,” said Mr. Baglow, who is Scottish. “It makes me very happy.” 

Source: Technology News @ NY Times

Black Holes Lead Galaxy Growth

Gas in Distant Galaxy. VLA image (right) of gas in young galaxy seen as it was when the Universe was only 870 million years old. (Credit: NRAO/AUI/NSF, SDSS)

Jan. 7, 2009 — Astronomers may have solved a cosmic chicken-and-egg problem -- the question of which formed first in the early Universe -- galaxies or the supermassive black holes seen at their cores.

 Full Story @ ScienceDaily

Our Universe at Home Within a Larger Universe? So Suggests Physicist's Wormhole Research

Einstein-Rosen bridges like the one visualized above have never been observed in nature, but they provide theoretical physicists and cosmologists with solutions in general relativity by combining models of black holes and white holes. (Credit: Image courtesy of Indiana University)

 

Apr. 7, 2010 ---- SCIENCE DAILY — Could our universe be located within the interior of a wormhole which itself is part of a black hole that lies within a much larger universe?

 

Full Story @ ScienceDaily

Do Black Holes Have 'Hair'? New Hypothesis Challenges 'Clean' Model

Artist's illustration of a black hole. (Credit: iStockphoto)

Sep. 30, 2013 — A black hole. A simple and clear concept, at least according to the hypothesis by Roy Kerr, who in 1963 proposed a "clean" black hole model, which is the current theoretical paradigm. From theory to reality things may be quite different. According to a new research carried out by a group of scientists that includes Thomas Sotiriou, a physicist of the International School for Advanced Studies (SISSA) of Trieste, black holes may be much "dirtier" than what Kerr believed.

Full story @ ScienceDaily

Edward Lear's Nonsense Botany

A selection of Edward Lear’s drawings from the Houghton Library’s collections

Anna Lena Phillips

In a January–February Science Observer, we considered the resurgence of interest in Edward Lear’s scientific illustration—and the possibility that his nonsense drawings and verse might have practical use as well. Lear (1812–1888) made his name with a monograph on parrots, published in 1832. As he labored over his exacting illustrations, he also made whimsical poetry and drawings for children. Concerned that the latter would cause people to take his scientific work less seriously, he published them pseudonymously at first. Later he became well known for these limericks, nonsense alphabets and other poems.

Full Article @ AmericanScientist

Accelerator On a Chip: Technology Could Spawn New Generations of Smaller, Less Expensive Devices for Science, Medicine

Sep. 27, 2013 — In an advance that could dramatically shrink particle accelerators for science and medicine, researchers used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice.

Full Story @ ScienceDaily

Despite Early Criticism, Apple’s iOS 7 Quickly Gains Traction

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Samsung Unveils Galaxy Gear Smartwatch

BERLIN — Samsung Electronics unveiled on Wednesday its highly anticipated digital wristwatch that can snap photos, track workouts and use an array of apps — gadgetry that the company hopes will catapult it into a market of smart portable devices that leave cellphones in users’ pockets.

Full Story @ NY Times

Digital Forensics

Modern crime often leaves an electronic trail. Finding and preserving that evidence requires careful methods as well as technical skill

Law enforcement can rarely get through a case these days without having to examine some kind of technology. Computers may not be used to commit a particular crime, but they might contain evidence. Similarly, cell phones and other data devices need to be examined regularly. This has led to the development of the field of digital forensics, which examines how equipment has to be handled to ensure that it hasn’t been altered once it has been taken for evidence, how to copy material reliably, and how to maintain equipment that can sometimes erase itself if left unpowered. 

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NASA's Deep Space Comet Hunter Mission Comes to an End

Sep. 20, 2013 — After almost 9 years in space that included an unprecedented July 4th impact and subsequent flyby of a comet, an additional comet flyby, and the return of approximately 500,000 images of celestial objects, NASA's Deep Impact mission has ended.

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