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  • richardmitnick 3:24 pm on September 2, 2015 Permalink | Reply
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    From Berkeley: “CT scan of Earth links deep mantle plumes with volcanic hotspots” 

    UC Berkeley

    UC Berkeley

    September 2, 2015
    Robert Sanders

    Supercomputer simulation of plumes of hot rock rising through the mantle to the surface, where they generate volcanic eruptions that form island chains. Animation by Scott French, NERSC & Berkeley Lab; video by Roxanne Makasdjian and Stephen McNally, UC Berkeley.

    University of California, Berkeley, seismologists have produced for the first time a sharp, three-dimensional scan of Earth’s interior that conclusively connects plumes of hot rock rising through the mantle with surface hotspots that generate volcanic island chains like Hawaii, Samoa and Iceland.

    Essentially a computed tomography, or CT scan, of Earth’s interior, the picture emerged from a supercomputer simulation at the Department of Energy’s National Energy Research Scientific Computing Center (NERSC) at the Lawrence Berkeley National Laboratory.

    While medical CTs employ X-rays to probe the body, the scientists mapped mantle plumes by analyzing the paths of seismic waves bouncing around Earth’s interior after 273 strong earthquakes that shook the globe over the past 20 years.

    Previous attempts to image mantle plumes have detected pockets of hot rock rising in areas where plumes have been proposed, but it was unclear whether they were connected to volcanic hotspots at the surface or the roots of the plumes at the core mantle boundary 2,900 kilometers (1,800 miles) below the surface.

    The new, high-resolution map of the mantle — the hot rock below Earth’s crust but above the planet’s iron core — not only shows these connections for many hotspots on the planet, but reveals that below about 1,000 kilometers the plumes are between 600 and 1,000 kilometers across, up to five times wider than geophysicists thought. The plumes are likely at least 400 degrees Celsius hotter than surrounding rock.

    “No one has seen before these stark columnar objects that are contiguous all the way from the bottom of the mantle to the upper part of the mantle,” said first author Scott French, a computational scientist at NERSC who recently received his Ph.D. from UC Berkeley.

    Senior author Barbara Romanowicz, a UC Berkeley professor of earth and planetary science, noted that the connections between the lower-mantle plumes and the volcanic hotspots are not direct because the tops of the plumes spread out like the delta of a river as they merge with the less viscous upper mantle rock.

    “These columns are clearly separated in the lower mantle and they go all the way up to about 1,000 kilometers below the surface, but then they start to thin out in the upper part of the mantle, and they meander and deflect,” she said. “So while the tops of the plumes are associated with hotspot volcanoes, they are not always vertically under them.”

    Ancient anchors

    The new picture also shows that the bases of these plumes are anchored at the core-mantle boundary in two huge blobs of hot rock, each about 5,000 kilometers in diameter, that are likely denser than surrounding rock. Romanowicz estimates that those two anchors — directly opposite one another under Africa and the Pacific Ocean — have been in the same spots for 250 million years.

    The 1,800-mile thick mantle under the Pacific Ocean contains rising plumes of hot rock that fan out at the surface to stationary hotspots, where they generate island chains as Earth’s crust moves due to plate tectonics. Scott French image.

    French and Romanowicz, who also is affiliated with the Institut de Physique du Globe and the Collège de France in Paris, will publish their findings in the Sept. 3 issue of the British journal Nature.

    The Earth is layered like an onion. An exterior crust contains the oceans and continents, while under the crust lies a thick mantle of hot but solid rock 2,900 kilometers thick. Below the mantle is the outer core, composed of liquid, molten iron and nickel, which envelopes an inner core of solid iron at the center of the planet.

    Heated by the hot core, the rock in the mantle rises and falls like water gently simmering in a pan, though this convection occurs much more slowly. Seismologists proposed some 30 years ago that stationary plumes of hot rock in the mantle occasionally punched through the crust to produce volcanoes, which, as the crust moved, generated island chains such as the Galapagos, Cape Verde and Canary islands.

    The Hawaiian Islands, for example, consist of 5 million-year-old Kauai to the west but increasingly younger islands to the east, because the Pacific Plate is moving westward. The newest eruption, Loihi, is still growing underwater east of the youngest island in the chain, Hawaii.

    Until now, evidence for the plume and hotspot theory had been circumstantial, and some seismologists argued instead that hotspots are very shallow pools of hot rock feeding magma chambers under volcanoes.

    Romanowicz, who uses seismic waves to study Earth’s interior, had previously worked with French, then a graduate student, on a tomographic model of the upper 800 kilometers of the mantle, which showed periodic hot and cold regions of rock underlying hotspot volcanoes. The new study completes that picture down to the core-mantle boundary.

    Most of the known volcanic hotspots are linked to plumes of hot rock (red) rising from two spots on the boundary between the metal core and rocky mantle 1,800 miles below Earth’s surface.
    No image credit.

    She noted that if higher temperature alone were responsible for the rising plumes, they would be only 100-200 kilometers wide, ballooning out only when they approach the surface. The fact that they appear to be five times wider in the lower mantle suggests that they also differ chemically from the surrounding cooler rock.

    This supports models where the material in the plume is a mixture of normal mantle rock and primordial rock from the dense rock anchoring the plume at the core-mantle boundary. In fact, lava emerging from hotspot volcanoes is known to differ chemically and isotopically from lava from other volcanoes, such as those erupting at subduction zones where Earth’s crust dives into the upper mantle.

    The supercomputer analysis did not detect plumes under all hotspot volcanoes, such as those in Yellowstone National Park. The plumes that feed them may be too thin to be detected given the computational limits of the global modeling technique, French said.

    Millions of hours of computer time

    To create a high-resolution CT of Earth, French used very accurate numerical simulations of how seismic waves travel through the mantle, and compared their predictions to the ground motion actually measured by detectors around the globe. Earlier attempts by other researchers often approximated the physics of wave propagation and focused mainly on the arrival times of only certain types of seismic waves, such as the P (pressure) and S (shear) waves, which travel at different speeds. French used numerical simulations to compute all components of the seismic waves, such as their scattering and diffraction, and tweaked the model repeatedly to fit recorded data using a method similar to statistical regression. The final computation required 3 million CPU hours on NERSC’s supercomputers, though parallel computing shrank this to a couple of weeks.

    Romanowicz hopes eventually to obtain higher resolution supercomputer images of Earth’s interior, perhaps by zooming in on specific areas, such as that under the Pacific Ocean, or by using new data.

    “Tomography is the most powerful method to get this information, but in the future it will be combined with very sensitive gravity measurements from satellites and maybe electromagnetic sounding, where people do conductivity measurements of the interior,” she said.

    This study was supported by the National Science Foundation (EAR-1417229) and the European Research Council. NERSC is supported by the U.S. Department of Energy Office of Science (DE-AC02-05CH11231).

    See the full article here.

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  • richardmitnick 5:02 pm on August 20, 2015 Permalink | Reply
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    From Berkeley: “Experiment attempts to snare a dark energy ‘chameleon’” 

    UC Berkeley

    UC Berkeley

    August 20, 2015
    Robert Sanders

    The vacuum chamber of the atom interferometer contains a one-inch diameter aluminum sphere. If chameleons exist, cesium atoms would fall toward the sphere with a slightly greater acceleration than their gravitational attraction would predict. (Holger Muller photo)

    If dark energy is hiding in our midst in the form of hypothetical particles called “chameleons,” Holger Müller and his team at UC Berkeley plan to flush them out.

    The results of an experiment reported in this week’s issue of Science narrows the search for chameleons a thousand times compared to previous tests, and Müller, an assistant professor of physics, hopes that his next experiment will either expose chameleons or similar ultralight particles as the real dark energy, or prove they were a will-o’-the-wisp after all.

    Dark energy was first discovered in 1998 when scientists observed that the universe was expanding at an ever increasing rate, apparently pushed apart by an unseen pressure permeating all of space and making up about 68 percent of the energy in the cosmos. Several UC Berkeley scientists were members of the two teams that made that Nobel Prize-winning discovery, and physicist Saul Perlmutter shared the prize.

    Since then, theorists have proposed numerous theories to explain the still mysterious energy. It could be simply woven into the fabric of the universe, a cosmological constant [Λ] that Albert Einstein proposed in the equations of general relativity and then disavowed. Or it could be quintessence, represented by any number of hypothetical particles, including offspring of the Higgs boson.

    In 2004, theorist and co-author Justin Khoury of the University of Pennsylvania proposed one possible reason why dark energy particles haven’t been detected: they’re hiding from us.

    If chameleons exist, they would have a very small effect on the gravitational attraction between cesium atoms and an aluminum sphere.

    Specifically, Khoury proposed that dark energy particles, which he dubbed chameleons, vary in mass depending on the density of surrounding matter.

    In the emptiness of space, chameleons would have a small mass and exert force over long distances, able to push space apart. In a laboratory, however, with matter all around, they would have a large mass and extremely small reach. In physics, a low mass implies a long-range force, while a high mass implies a short-range force.

    This would be one way to explain why the energy that dominates the universe is hard to detect in a lab.

    “The chameleon field is light in empty space but as soon as it enters an object it becomes very heavy and so couples only to the outermost layer of a big object, and not to the internal parts,” said Müller, who is also a faculty scientist at Lawrence Berkeley National Laboratory. “It would pull only on the outermost nanometer.”

    Lifting the camouflage

    When UC Berkeley post-doctoral fellow Paul Hamilton read an article by theorist Clare Burrage last August outlining a way to detect such a particle, he suspected that the atom interferometer he and Müller had built at UC Berkeley would be able to detect chameleons if they existed. Müller and his team have built some of the most sensitive detectors of forces anywhere, using them to search for slight gravitational anomalies that would indicate a problem with Einstein’s General Theory of Relativity. While the most sensitive of these are physically too large to sense the short-range chameleon force, the team immediately realized that one of their less sensitive atom interferometers would be ideal.

    The dark energy group: Holger Müller, Philipp Haslinger, Justin Khoury (on computer monitor), Matt Jaffe, Paul Hamilton. (Enar de Dios Rodriguez photo)

    Burrage suggested measuring the attraction caused by the chameleon field between an atom and a larger mass, instead of the attraction between two large masses, which would suppress the chameleon field to the point of being undetectable.

    That’s what Hamilton, Müller and his team did. They dropped cesium atoms above an inch-diameter aluminum sphere and used sensitive lasers to measure the forces on the atoms as they were in free fall for about 10 to 20 milliseconds. They detected no force other than Earth’s gravity, which rules out chameleon-induced forces a million times weaker than gravity. This eliminates a large range of possible energies for the particle.

    What about symmetrons?

    Experiments at CERN in Geneva and the Fermi National Accelerator Laboratory in Illinois, as well as other tests using neutron interferometers, also are searching for evidence of chameleons, so far without luck. Müller and his team are currently improving their experiment to rule out all other possible particle energies or, in the best-case scenario, discover evidence that chameleons really do exist.

    “Holger has ruled out chameleons that interact with normal matter more strongly than gravity, but he is now pushing his experiment into areas where chameleons interact on the same scale as gravity, where they are more likely to exist,” Khoury said.

    Their experiments may also help narrow the search for other hypothetical screened dark energy fields, such as symmetrons and forms of modified gravity, such as so-called f(R) gravity.

    “In the worst case, we will learn more of what dark energy is not. Hopefully, that gives us a better idea of what it might be,” Müller said. “One day, someone will be lucky and find it.”

    The work was funded by the David and Lucile Packard Foundation, the National Science Foundation and the National Aeronautics and Space Administration. Co-authors with Müller, Hamilton and Khoury are UC Berkeley physics graduate students Matt Jaffe and Quinn Simmons and post-doctoral fellow Philipp Haslinger.


    Atom-interferometry constraints on dark energy (preprint)
    Muller’s matter wave research group

    See the full article here..

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    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

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  • richardmitnick 6:48 pm on August 4, 2015 Permalink | Reply
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    From Berkeley: “World’s quietest gas lets physicists hear faint quantum effects” 

    UC Berkeley

    UC Berkeley

    August 4, 2015
    Robert Sanders

    When the noise or entropy in a system is reduced, subtle information becomes visible, such as the faint word ‘Berkeley.’ Ryan Olf image.

    UC Berkeley physicists have cooled a gas to the quietest state ever achieved, hoping to detect faint quantum effects lost in the din of colder but noisier fluids.

    While the ultracold gas’s temperature – a billionth of a degree above absolute zero – is twice as hot as the record cold, the gas has the lowest entropy ever measured. Entropy is a measure of disorder or noise in a system; a record low temperature gas isn’t necessarily the least noisy.

    “This ‘lowest entropy’ or ‘lowest noise’ condition means that the quantum gas can be used to bring forth subtle quantum mechanical effects which are a main target for modern research on materials and on many-body physics,” said co-author Dan Stamper-Kurn, a UC Berkeley professor of physics. “When all is quiet and all is still, one might discern the subtle music of many-body quantum mechanics.”

    The quantum gas, a so-called Bose-Einstein condensate, consisted of about a million rubidium atoms trapped by a beam of light, isolated in a vacuum and cooled to their lowest energy state. The entropy and temperature were so low that the researchers had to develop a new type of thermometer to measure them.

    While achieving extremely low temperatures may make the record books, UC Berkeley graduate student Ryan Olf said, what scientists aim for today are low-entropy states they can study to understand more interesting but difficult-to-study materials.

    In most ultracold Bose-Einstein Condensates (BEC), the quantum gas (yellow peak) is accompanied by normal gas jiggling with thermal noise (the blue hump below the peak). As the noise or entropy is decreased, however, the jiggling disappears to leave an almost pure quantum gas. Ryan Olf graphic

    The UC Berkeley team’s ability to manipulate ultracold, low-entropy gases will allow them to study these quantum systems, including quantum magnets – potentially useful in quantum computers – and high-temperature superconductors. High-temperature superconductors are experimental materials that display superconductivity – electrical flow without resistance – at relatively high temperatures compared to the 3 or 4 degrees Celsius above absolute zero typical of today’s conventional superconductors.

    “One of the holy grails of modern physics is to understand these exotic materials well enough to design one that is superconducting without requiring any cooling at all,” Olf said. “By studying the properties of low-entropy gases in various configurations, our community of researchers hope to learn what makes these fascinating materials work the way they do.”

    Olf said that the entropy per particle, rather than the temperature, is the pertinent parameter when comparing systems, and the ultracold gases that had been produced until now struggled to reach the low entropies that would be required to test models of these materials.

    “In a very real sense, this constitutes the coldest gas ever produced, at 50 times lower than the temperature at which quantum statistical effects become manifest, the Bose-Einstein condensation temperature,” he said.

    The details of the experiment were published online last month and will appear in a future print edition of the journal Nature Physics.

    Reducing the rumble

    Stamper-Kurn and his laboratory team chill gases to temperatures so low that quantum effects take over, which leads to strange “superfluid” behavior, such as frictionless flow. Superfluid helium is famous for climbing up and over the lip of a cup. Superfluid gases exhibit vortices – tiny tornadoes like those created when you stir a cup of coffee – that live forever.

    Ryan Olf dons protective glasses to adjust the lasers and vacuum chambers required to trap and cool Bose-Einstein Condensates. (Robert Sanders photo)

    At these low temperatures, Stamper-Kurn said, the low-energy excitations or jiggling of the atoms are sound waves. “Temperature generates something like a constant rumble of sound in the gas, and the entropy is like a count of how many sound-wave excitations remain. The colder a gas becomes, the less entropy it has and the quieter it is.”

    Normally, a Bose-Einstein condensate is a mixture of a quantum gas and a normal gas. Its temperature is determined by measuring the thermal properties of the normal gas. A low-entropy gas is almost all quantum gas, however, so the team had to find a different way to measure the temperature. They did so by tilting the magnetization of the atomic spins and measuring thermal properties of the tilted magnetization, essentially creating a magnon thermometer.

    The tilted spins also helped them cool the gas to its low-entropy state by enhancing the evaporative cooling that researchers have long relied on to produce ultracold gases. In addition to removing hot atoms to reduce the average temperature of the gas, they used evaporative cooling of the thermalized spins to reduce the temperature to 1 nanoKelvin (one-billionth of a degree above absolute zero), corresponding to an entropy 100 times lower than previous experiments, Olf said.

    Other co-authors are Fang Fang, G. Edward Marti and Andrew MacRae. The work is supported by the National Aeronautics and Space Administration, the U.S. Air Force Office of Scientific Research and the National Science Foundation.

    See the full article here with added references.

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  • richardmitnick 12:55 pm on June 4, 2015 Permalink | Reply
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    From UC Berkeley: “Exiled stars explode far from home” 

    UC Berkeley

    UC Berkeley

    June 4, 2015
    Robert Sanders, Media Relations

    Animated GIF contrasting the supernova as seen in 2009 by the CFHT and the sharper image obtained in 2013 by the Hubble Space Telescope. (Image by Melissa Graham, CFHT and HST)

    Sharp images obtained by the Hubble Space Telescope confirm that three supernovae discovered several years ago exploded in the dark emptiness of intergalactic space, having been flung from their home galaxies millions or billions of years earlier.

    NASA Hubble Telescope
    NASA/ESA Hubble

    Most supernovae are found inside galaxies containing hundreds of billions of stars, one of which might explode per century per galaxy.

    These lonely supernovae, however, were found between galaxies in three large clusters of several thousand galaxies each. The stars’ nearest neighbors were probably 300 light years away, nearly 100 times farther than our sun’s nearest stellar neighbor, Proxima Centauri, 4.24 light years distant.

    Such rare solitary supernovae provide an important clue to what exists in the vast empty spaces between galaxies, and can help astronomers understand how galaxy clusters formed and evolved throughout the history of the universe.

    The solitary worlds reminded study leader Melissa Graham, a University of California, Berkeley, postdoctoral fellow and avid sci-fi fan, of the fictional star Thrial, which, in the Iain Banks novel Against a Dark Background, lies a million light years from any other star. One of its inhabited planets, Golter, has a nearly starless night sky.

    Any planets around these intracluster stars – all old and compact stars that exploded in what are called Type Ia supernovae – were no doubt obliterated by the explosions, but they, like Golter, would have had a night sky depleted of bright stars, Graham said. The density of intracluster stars is about one-millionth what we see from Earth.

    “It would have been a fairly dark background indeed,” she said, “populated only by the occasional faint and fuzzy blobs of the nearest and brightest cluster galaxies.”

    Graham and her colleagues – David Sand of Texas Tech University in Lubbock, Dennis Zaritsky of the University of Arizona in Tucson and Chris Pritchet of the University of Victoria in British Columbia – will report their analysis of the three stars in a paper to be presented Friday, June 5, at a conference on supernovae at North Carolina State University in Raleigh. Their paper has also been accepted by the Astrophysical Journal.

    Clusters of thousands of galaxies

    The new study confirms the discovery between 2008 and 2010 of three apparently hostless supernovae by the Multi-Epoch Nearby Cluster Survey using the Canada-France-Hawaii Telescope [CFHT} on Mauna Kea in Hawaii.

    Canada-France-Hawaii Telescope
    Canada France Hawaii Telescope Interior

    The CFHT was unable to rule out a faint galaxy hosting these supernovae. But the sensitivity and resolution of images from the Hubble Space Telescope’s Advanced Camera for Surveys [ACS] are 10 times better and clearly show that the supernovae exploded in empty space, far from any galaxy. They thus belong to a population of solitary stars that exist in most if not all clusters of galaxies, Graham said

    NASA Hubble ACS

    While stars and supernovae typically reside in galaxies, galaxies situated in massive clusters experience gravitational forces that wrench away about 15 percent of the stars, according to a recent survey. The clusters have so much mass, though, that the displaced stars remain gravitationally bound within the sparsely populated intracluster regions.

    One of the four supernovae (top, 2009) may be part of a dwarf galaxy or globular cluster visible on the 2013 HST image (bottom). (Image by Melissa Graham, CFHT and HST)

    Once dispersed, these lonely stars are too faint to be seen individually unless they explode as supernovae. Graham and her colleagues are searching for bright supernovae in intracluster space as tracers to determine the population of unseen stars. Such information provides clues about the formation and evolution of large scale structures in the universe.

    “We have provided the best evidence yet that intracluster stars truly do explode as Type Ia supernovae,” Graham said, “and confirmed that hostless supernovae can be used to trace the population of intracluster stars, which is important for extending this technique to more distant clusters.”

    Graham and her colleagues also found that a fourth exploding star discovered by CFHT appears to be inside a red, round region that could be a small galaxy or a globular cluster. If the supernova is in fact part of a globular cluster, it marks the first time a supernova has been confirmed to explode inside these small, dense clusters of fewer than a million stars. All four supernovae were in galaxy clusters sitting about a billion light years from Earth.

    “Since there are far fewer stars in globular clusters, only a small fraction of the supernovae are expected to occur in globular clusters,” Graham said. “This might be the first confirmed case, and may indicate that the fraction of stars that explode as supernovae is higher in either low-mass galaxies or globular clusters.”

    Graham said that most theoretical models for Type Ia supernovae involve a binary star system, so the exploding stars would have had a companion throughout their lifetimes.

    “This is no love story, though,” she added. “The companion was either a lower-mass white dwarf that eventually got too close and was tragically fragmented into a ring that was cannibalized by the primary star, or a regular star from which the primary white dwarf star stole sips of gas from its outer layers. Either way, this transfer of material caused the primary to become unstably massive and explode as a Type Ia supernova.”

    Graham’s postdoctoral fellowship is supported by gifts from Gary and Cynthia Bengier.

    See the full article here.

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  • richardmitnick 7:51 am on May 8, 2015 Permalink | Reply
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    From UC Berkeley: “UC Berkeley scientists begin monitoring tremors on San Andreas Fault” 

    UC Berkeley

    UC Berkeley

    May 7, 2015
    Robert Sanders

    San Andreas Fault Line – Fault Zone Map


    UC Berkeley seismologists were surprised last August to see a dramatic increase in faint tremors occurring under the San Andreas Fault near Parkfield, in Central California, about 10 hours after a magnitude 6.0 earthquake struck Napa. Somehow, that quake triggered tiny rumblings 250 miles away that lasted for about 100 days before dropping off.

    These same researchers have recently found two other places in California where tremors are happening below the zone where earthquakes normally occur, and have now embarked on a comprehensive search for tremors throughout the state.

    Key to discovering the connection between tremors and earthquakes is TremorScope, a set of four seismic stations to be placed about 900 feet underground near Parkfield to listen for these faint whispers. They will be added to four new surface stations already deployed as a part of the project.

    Satellite map showing potential tremorscope station locations

    “It’s a big job, but we hope to develop a near-real-time tremor monitoring capability in the TremorScope area and elsewhere,” said UC Berkeley seismologist Robert Nadeau, who will be working on the project with help from the Berkeley Institute for Data Science.

    TremorScope is funded by a $1.2 million grant from the Gordon and Betty Moore Foundation.

    “Tremors are associated with big, very slow movements on the fault, and there is speculation that they might cause big earthquakes,” said research seismologist Peggy Hellweg, UC Berkeley project lead for TremorScope and operations manager at the Berkeley Seismological Laboratory. “But we see tremor activity with earthquakes and earthquakes without tremor, so the connection is still unclear.”

    Tremors originate beneath the zone where earthquakes occur and appear to be associated with slipping rocks deep in the earth. UC Berkeley seismologists discovered tremors just south of the Parkfield area of the San Andreas Fault in 2004, and subsequent studies suggest that changes in tremor activity may precede earthquakes. Tremors also have been detected in active earthquake zones in Japan, Washington state and other subduction zones around the world.

    TremorScope is designed to measure these tremors more precisely than ever before, using geophones sensitive to high-frequency ground movement and broadband seismometers able to record low-frequency rumblings. Geophones and broadband seismometers are to be installed in four deep boreholes drilled around an area of the San Andreas Fault near Parkfield that seems to be the center of tremor activity where the northern and southern segments of the fault meet. The borehole instruments, which can detect quieter tremors because of less noise underground, complement instruments already in place at four surface stations in the area.

    A surface accelerometer was installed in January at a site on the property of Cass Vineyard and Winery, located 12 miles east of Highway 101 near Paso Robles. The borehole instruments will be installed at the winery site May 6 and 7, with installation of the three other borehole seismometers scheduled in the coming months.

    “With the four surface seismometers now installed, TremorScope is already helping us to locate tremor,” Nadeau said. “The deeper borehole seismometers will be able to give us a range of frequencies at higher resolution to figure out what is going on underground.”

    See the full article here.

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  • richardmitnick 6:13 am on March 31, 2015 Permalink | Reply
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    From UC Berkeley: “Alexei V. Filippenko, Professor of Astronomy” 

    UC Berkeley

    UC Berkeley


    Research projects:

    Alex Filippenko and his collaborators are determining the nature of the progenitor stars and the explosion mechanisms of different types of supernovae and gamma-ray bursts. He is also using supernovae as cosmological distance indicators, and was a member of both teams that discovered (in 1998) the accelerating expansion of the Universe, probably driven by “dark energy“; this discovery was honored with the 2011 Nobel Prize in Physics to the teams’ leaders. He also works on quantifying the physical properties of quasars and active galaxies, and he searches for black holes in both X-ray binary stars and nearby galactic nuclei. His group has developed the 0.76-meter Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory, which is conducting one of the world’s most successful searches for relatively nearby supernovae (see http://astro.berkeley.edu/~bait/kait.html)

    UC Berkeley KAIT telescope


    Alex Filippenko is the Richard & Rhoda Goldman Distinguished Professor in the Physical Sciences. His accomplishments, documented in about 750 research papers, have been recognized by several major prizes, and he is one of the world’s most highly cited astronomers. In 2009 he was elected to the National Academy of Sciences, and he shared part of the Gruber Cosmology Prize in 2007. He has won the top teaching awards at UC Berkeley and has been voted the “Best Professor” on campus a record 9 times. In 2006 he was selected as the Carnegie/CASE National Professor of the Year among doctoral institutions, and in 2010 he won the ASP’s Emmons Award for undergraduate teaching. He has produced five astronomy video courses with “The Great Courses,” coauthored an award-winning textbook, and appears in numerous TV documentaries including about 40 episodes of “The Universe” series. An avid tennis player, hiker, snorkeler, and skier, he enjoys world travel and is addicted to observing total solar eclipses (13 so far).

    Specialty areas:
    Supernovae, active galaxies, black holes, gamma-ray bursts, and the expansion of the Universe

    See the full article here.

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  • richardmitnick 5:48 am on February 10, 2015 Permalink | Reply
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    From UC Berkeley: “Google gives Lick Observatory $1 million” 

    UC Berkeley

    UC Berkeley

    Google Inc. has given $1 million to the University of California’s Lick Observatory in what astronomers hope is the first of many private gifts to support an invaluable teaching and research resource for the state.

    Telescope using laser guide star adaptive optics at UC’s Lick Observatory. (Laurie Hatch photo)

    The unrestricted funds, spread over two years, will go toward general expenses, augmenting the $1.5 million the UC Office of the President gives annually to operate the mountaintop observatory for the 10-campus UC system.

    “Lick Observatory has been making important discoveries while training generations of scientists for more than 100 years,” said Chris DiBona, director of open source for Google. “Google is proud to support their efforts in 2015 to bring hands-on astronomical experiences to students and the public.”

    “This is very exciting,” said UC Berkeley astronomy professor Alex Filippenko, who has been beating the bushes for funds to operate the observatory after UC support dropped as a result of the recent recession.

    “Astronomy is the ‘gateway science’ – kids are enthralled by cosmic discoveries, spectacular images, and far-out concepts, which can inspire them to pursue technical fields such as applied physics, engineering and computer science,” Filippenko said. “So there’s a real opportunity to make a difference, through the research, education and public outreach we do at Lick Observatory.”

    “I am delighted that Google is supporting the Lick effort and thus helping provide UC students with unique hands-on experiences in valuable astronomy research,” said UC Berkeley Vice Chancellor for Research Graham Fleming.

    “We at UC highly value Lick Observatory’s unique capabilities,” said Claire Max, interim director of the University of California Observatories (UCO), which operates Lick, and which manages UC’s share of the twin 10-meter W. M. Keck Telescopes in Hawaii and the planned Thirty Meter Telescope that broke ground last year close to Keck on Mauna Kea. “For example, Lick’s telescopes enable science projects that need lots of repeated observations during the course of a year or more; these can be done much more successfully at Lick than at the 8−10-meter telescopes, where observing time is extremely tight. Google’s very generous gift will make it possible for Lick to provide these opportunities and to continue to develop forefront tools such as adaptive optics, which removes image blurring caused by turbulence in Earth’s atmosphere.”

    “For 127 years, Lick Observatory has been vital in fundamental astronomical research, the development of new observational techniques, training students and connecting the general public to the heavens.”
    – U.S. Rep. Mike Honda

    Lick Observatory, located atop Mt. Hamilton east of San Jose, was established in 1888 and currently houses seven telescopes, including the Katzman Automatic Imaging Telescope run by Filippenko that scans the sky each night in search of exploding stars (supernovae), which help astronomers understand the accelerating expansion of the universe and dark energy.

    UCO LICK Kait

    Another robotic telescope, the Automated Planet Finder, closely examines many stars each night to find planets that may be orbiting them.

    UCO Lick Automated Planet Finder Telescope
    APF telescope

    Faculty, researchers, postdoctoral scholars and students throughout the UC system can observe remotely on the main general-use telescopes, the three-meter Shane telescope and the one-meter Nickel telescope. “These telescopes provide undergraduates with a unique opportunity to participate in substantial astronomical research,” Filippenko said. “I have about a dozen undergraduate students doing Lick research now, many more than ever before.”

    Defining the cutting edge

    Before the recession, Lick’s budget was about $2.5 million annually to support astronomers and students from eight of the 10 UC campuses as well as the UC-managed Department of Energy labs. Most of the first 100 planets orbiting other stars were discovered at Lick using a forefront instrument that was the best of its kind at the time. Lick observations also helped reveal the presence of giant black holes in the centers of galaxies. In part thanks to large numbers of relatively nearby supernovae found or studied at Lick, astronomers discovered and verified the accelerating expansion of the universe, a feat recognized with the 2011 Nobel Prize in Physics to the leaders of two competing teams and the 2015 Breakthrough Prize in Fundamental Physics to all team members.

    The telescopes are used not only for original observing in the optical and infrared, but also to design and test new instruments destined for larger telescopes, such as the 10-meter Keck telescopes. For example, laser guide star adaptive optics, which allows the world’s largest telescopes to stabilize their images to improve sharpness and achieve results in some ways superior to those of the Hubble Space Telescope, was pioneered at Lick.

    “At this time, UC is providing basic support at $1.5 million per year, but we really need at least $2.5 million per year to improve the observatory, moving forward vigorously at the cutting edge of research and education. To maintain and expand Lick in the long run, we seek an endowment of about $50 million,” Filippenko said. The interest on that endowment would be used to provide annual operating funds. “This major award from Google should go far, giving us time to raise additional funds.”

    “I was delighted to learn of this wonderful gift from Google,” said Aimée Dorr, UC provost and executive vice president for academic affairs. “It will do great things for the astronomical research and education that can be carried out at Lick Observatory. Congratulations to Professor Filippenko, who knows firsthand how valuable Lick is and has dedicated his considerable energy and expertise to ensuring it is available far into the future.”

    Alex Filippenko with his Katzman Automated integrating Telescope at Lick Observatory

    “I’m pleased that this generous award will help Lick Observatory keep its doors open to the public, to future astronomers and to the scientific community in a capacity that is simply unavailable anywhere else,” said U.S. Rep. Zoe Lofgren, who previously spearheaded two letters of congressional support for Lick to the UC Office of the President. “Lick is an historic Santa Clara County landmark, and the facility has proven invaluable for students, researchers and the Bay Area community. I hope this is the beginning of many gifts recognizing Lick Observatory’s important role in inspiring future scientists and adding to our understanding of what lies beyond our solar system.”

    U.S. Rep. Mike Honda, a longtime supporter and advocate for the observatory, added, “I am delighted that Google has decided to give $1 million to Lick Observatory. For 127 years, Lick Observatory has been vital in fundamental astronomical research, the development of new observational techniques, training students and connecting the general public to the heavens. I am pleased to see private companies step up and invest in America’s scientific leadership. I look forward to others joining Google to ensure that Lick Observatory will continue to explore the universe for years to come.”

    “Lick Observatory has provided critical data for University of California researchers, and Google’s major support will ensure that the observatory will continue to serve as the foundation for countless scientific discoveries to come,” said state Assemblymember Mark Stone.

    One of the first uses for the money, which comes through the UC Berkeley Foundation, will be to hire another telescope operator for the Shane three-meter telescope to eliminate periodic closures caused by the current shortage of staff, Filippenko said.

    UCO Lick Shane Telescope
    UCO Lick Shane Telescope interior

    Interim UCO director Max said that another probable use of the funds will be to continue the development of laser guide star adaptive optics, which is breaking new ground at Lick Observatory.

    Lick also recently received $350,000 in combined grants from the Heising-Simons Foundation and donors Bill and Marina Kast to enable an upgrade of the Kast spectrograph on the three-meter telescope, used to analyze faint celestial objects – including supernovae – at distances ranging from our own solar system to the far reaches of the universe.

    “Graduate students and postdoctoral scholars can be leaders of research done at Lick,” Filippenko said. ”They conceive, propose, execute and complete their own projects, thereby adding immensely to their development as strong, skilled, independent research scientists. We have to keep this unique research and educational institution, a Bay Area treasure and California landmark, thriving.”

    See the full article here.

    Please help promote STEM in your local schools.

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    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

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  • richardmitnick 5:46 pm on January 28, 2015 Permalink | Reply
    Tags: , , , UC Berkeley, Isotropy   

    From UC Berkeley: “Quantum computer as detector shows space is not squeezed” 

    UC Berkeley

    UC Berkeley

    January 28, 2015
    Robert Sanders

    As the Earth rotates every 24 hours, the orientation of the ions in the quantum computer/detector changes with respect to the Sun’s rest frame. If space were squeezed in one direction and not another, the energies of the electrons in the ions would have shifted with a 12-hour period. Hartmut Haeffner image.

    A new experiment by University of California, Berkeley, physicists used partially entangled atoms – identical to the qubits in a quantum computer – to demonstrate more precisely than ever before that this is true, to one part in a billion billion.

    The classic experiment that inspired Albert Einstein was performed in Cleveland by Albert Michelson and Edward Morley in 1887 and disproved the existence of an “ether” permeating space through which light was thought to move like a wave through water. What it also proved, said Hartmut Häffner, a UC Berkeley assistant professor of physics, is that space is isotropic and that light travels at the same speed up, down and sideways.

    “Michelson and Morley proved that space is not squeezed,” Häffner said. “This isotropy is fundamental to all physics, including the Standard Model of physics. If you take away isotropy, the whole Standard Model will collapse. That is why people are interested in testing this.”

    The Standard Model of elementary particles, with the three generations of matter, gauge bosons in the fourth column, and the Higgs boson in the fifth.

    The Standard Model of particle physics describes how all fundamental particles interact, and requires that all particles and fields be invariant under Lorentz transformations, and in particular that they behave the same no matter what direction they move.

    Häffner and his team conducted an experiment analogous to the Michelson-Morley experiment, but with electrons instead of photons of light. In a vacuum chamber he and his colleagues isolated two calcium ions, partially entangled them as in a quantum computer, and then monitored the electron energies in the ions as Earth rotated over 24 hours.

    If space were squeezed in one or more directions, the energy of the electrons would change with a 12-hour period. It didn’t, showing that space is in fact isotropic to one part in a billion billion (10^18), 100 times better than previous experiments involving electrons, and five times better than experiments like Michelson and Morley’s that used light.

    The results disprove at least one theory that extends the Standard Model by assuming some anisotropy of space, he said.

    Häffner and his colleagues, including former graduate student Thaned Pruttivarasin, now at the Quantum Metrology Laboratory in Saitama, Japan, will report their findings in the Jan. 29 issue of the journal Nature.

    Entangled qubits

    Häffner came up with the idea of using entangled ions to test the isotropy of space while building quantum computers, which involve using ionized atoms as quantum bits, or qubits, entangling their electron wave functions, and forcing them to evolve to do calculations not possible with today’s digital computers. It occurred to him that two entangled qubits could serve as sensitive detectors of slight disturbances in space.

    “I wanted to do the experiment because I thought it was elegant and that it would be a cool thing to apply our quantum computers to a completely different field of physics,” he said. “But I didn’t think we would be competitive with experiments being performed by people working in this field. That was completely out of the blue.”

    He hopes to make more sensitive quantum computer detectors using other ions, such as ytterbium, to gain another 10,000-fold increase in the precision measurement of Lorentz symmetry. He is also exploring with colleagues future experiments to detect the spatial distortions caused by the effects of dark matter particles, which are a complete mystery despite comprising 27 percent of the mass of the universe.

    “For the first time we have used tools from quantum information to perform a test of fundamental symmetries, that is, we engineered a quantum state which is immune to the prevalent noise but sensitive to the Lorentz-violating effects,” Häffner said. “We were surprised the experiment just worked, and now we have a fantastic new method at hand which can be used to make very precise measurements of perturbations of space.”

    Other co-authors are UC Berkeley graduate student Michael Ramm, former UC Berkeley postdoc Michael Hohensee of Lawrence Livermore National Laboratory, and colleagues from the University of Delaware and University of Maryland and institutions in Russia. The work was supported by the National Science Foundation.

    See the full article here.

    Please help promote STEM in your local schools.

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    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

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  • richardmitnick 8:18 pm on December 8, 2014 Permalink | Reply
    Tags: , , UC Berkeley   

    From UC Berkeley: “New therapy holds promise for restoring vision” 

    UC Berkeley

    UC Berkeley

    December 8, 2014
    Robert Sanders

    A new genetic therapy not only helped blind mice regain enough light sensitivity to distinguish flashing from non-flashing lights, but also restored light response to the retinas of dogs, setting the stage for future clinical trials of the therapy in humans.

    In normal mice with working photoreceptors (PR driven), stimulating the retina produces a variety of responses in retinal ganglion cells, the output of the eye. This can be seen in the colorful lower square, where measurements of the activity of different retinal ganglion cells are shown in response to the same stimulation. Photoswitches inserted into retinal ganglion cells (RGC) of blind mice produce much less variety of response (all evenly red means the cells fire at the same time), while blind mice with photoswitches inserted into bipolar cells (ON-BC driven) exhibit much more variety in their retinal response to light, closer to that of normal mice.

    The therapy employs a virus to insert a gene for a common ion channel into normally blind cells of the retina that survive after the light-responsive rod and cone photoreceptor cells die as a result of diseases such as retinitis pigmentosa. Photoswitches – chemicals that change shape when hit with light – are then attached to the ion channels to make them open in response to light, activating the retinal cells and restoring light sensitivity.

    Afflicting people of all ages, retinitis pigmentosa causes a gradual loss of vision, akin to losing pixels in a digital camera. Sight is lost from the periphery to the center, usually leaving people with the inability to navigate their surroundings. Some 100,000 Americans suffer from this group of inherited retinal diseases.

    In a paper appearing online this week in the early edition of the journal Proceedings of the National Academy of Sciences, University of California, Berkeley, scientists who invented the photoswitch therapy and vision researchers at the School of Veterinary Medicine of the University of Pennsylvania (PennVet) report that blind mice regained the ability to navigate a water maze as well as normal mice.

    The treatment worked equally well to restore light responses to the degenerated retinas of mice and dogs, indicating that it may be feasible to restore some light sensitivity in blind humans.

    “The dog has a retina very similar to ours, much more so than mice, so when you want to bring a visual therapy to the clinic, you want to first show that it works in a large animal model of the disease,” said lead researcher Ehud Isacoff, professor of molecular and cell biology at UC Berkeley. “We’ve now showed that we can deliver the photoswitch and restore light response to the blind retina in the dog as well as in the mouse, and that the treatment has the same sensitivity and speed of response. We can reanimate the dog retina.”

    Advantages over other gene therapies

    The therapy has several advantages over other sight restoration therapies now under investigation, says vision scientist John Flannery, UC Berkeley professor of vision science and of molecular and cell biology. It uses a virus already approved by the Food and Drug Administration for other genetic therapies in the eye; it delivers an ion channel gene similar to one normally found in humans, unlike others that employ genes from other species; and it can easily be reversed or adjusted by supplying new chemical photoswitches. Dogs with the retinal degeneration provide a key test of the new therapy.

    “Our ability to test vision is very, very limited in mice because, even in the healthy state, they are not very visual animals, their behaviors are largely driven by their other senses,” he says. “Dogs have a very sophisticated visual system, and are being used already for testing ophthalmic gene therapy.”

    Benjamin Gaub and John Flannery observing a mouse in a water maze, in which the mouse swims to a platform designated by bright flashing lights. Mervi Kuronen image.

    The dogs were chosen because they have inherited a genetic disease caused by the same gene defect as some people with retinitis pigmentosa. Several of them at PennVet were treated and are currently undergoing tests to determine what degree of light sensitivity they now have.

    “Seeing that some of the UC Berkeley results with this pharmaco-optogenetic strategy that worked so nicely in mice could be reproduced by our group at PennVet in dogs with late-stage retinal degeneration was really exciting,” said William Beltran, an associate professor of ophthalmology at the UPenn School of Veterinary Medicine. “Use of such a clinically relevant large animal model allows us to begin tackling the next challenges on the road to translating this novel therapeutic strategy to human patients.”

    Hybrid chemical-genetic therapy

    Genetic diseases like retinitis pigmentosa destroy the photosensitive cells of the eye, the photoreceptors, but often leave intact the other cells in the retina: the bipolar cells that the photoreceptors normally talk to, and the ganglion cells that are the retina’s output to the brain. Isacoff, Flannery and UC Berkeley colleagues have developed several optogenetic techniques for restoring light-sensitivity to surviving retinal cells other than the photoreceptors. These involve using the adeno-associated virus – a common and harmless vector or carrier for gene therapy – to successfully carry a modified gene into these cells. The virus inserts the therapeutic gene into the cell’s DNA and uses its instructions to produce a receptor protein – a modified version of a common glutamate receptor ion channel – that they display on their surface.

    The researchers then inject a chemical photoswitch into the eye, “basically, a glutamate dangling on a light-sensitive string,” said Isacoff, “which anchors to the modified receptor and stuffs the glutamate into its docking site on the receptor when activated by light.” The newest version of the photoswitch is fast enough to turn the activity of retinal neurons on and off at a rate that approaches video rate of 30 frames per second.

    In mice, they can successfully insert the gene into almost every one of the million or so retinal ganglion cells. This, the researchers say, should restore useful vision.

    “So we have reasonable speed and a lot of pixels, now the question is: What can the treated animals see? So far we can say that the treated mice can distinguish between steady light and flashing light. Our next step is to figure out how good they are at telling images apart,” said Isacoff, who holds the Class of 1933 chair.

    Which cells get gift of sight?

    One key question the researchers wanted to answer is whether it is best to insert photoswitches into ganglion cells or bipolar cells. Viruses can be made to target one or the other. Because activity flowing from upstream bipolar cells to the retina’s output ganglion cells undergoes a lot of processing in the retinal circuit, the researchers were hoping that this same processing would occur when bipolar cells were given a new function they never had before, light-sensitivity.


    NIH funding keeps giving
    The work was funded in part by a nine-year NIH grant for the Nanomedicine Development Center for the Optical Control of Biological Function.
    “The NIH funding got us all the way from designing the chemical photoswitch to an experimental therapy in the dog,” Flannery said, noting the essential role played by a UC Berkeley interdisciplinary team of chemists, molecular biologists and vision scientists.
    “And along the way, we developed tools that could be applied to the basic science of how synapses work and how neural circuits work,” Isacoff added. “These are spinoffs that themselves could have implications for the clinic.”
    These tools are now the basis of new UC Berkeley projects recently funded by NIH and NSF through President Obama’s BRAIN Initiative.


    “When we put the photoswitched channels into bipolar cells and record the output of the ganglion cells, we see complicated patterns that look a lot like the activity you get in a normal retina, compared to the on-off activity you get when you put the same photoswitch into a ganglion cell,” Isacoff said.

    “The dogs’ behavior should show us if there is a functional difference between driving the system from the bipolar cells versus the ganglion cells,” Flannery said.

    He notes that the therapy works only for about a week after a single “charging” with the photoswitch, because the protein and attached chemical get recycled by the cell. While the modified receptors are replaced continually, since the new gene remains forever in the DNA, the chemical photoswitch – maleimide-azobenzene-glutamate, or MAG – must be resupplied by injection into the eyeball. Right now this means injection every week or so, with the future development of a slow release formulation less often.

    “This is not necessarily a disadvantage,” Isacoff said, “because the therapy can be stopped, and new photo-sensitive chemicals can be tried as they are improved.”

    The researchers continue to study the effects of treatment in both mice and dogs, improve the photoswitch, and develop ways of attaching the photoswitch to other receptors, including some that could amplify the signal and allow perception of fainter light, as occurs normally in rods and cones.

    The experiments, analysis and much of the design of the study were performed by first co-authors Benjamin Gaub, a graduate student, and Michael Berry, a technician, along with postdoctoral fellows Michael Keinzler and Andreas Reiner and technician Amy Holt, all from UC Berkeley, and Natalia Dolgova and Sergei Nikonov in the labs of Gustavo Aguirre and William Beltran of UPenn.

    The work was funded by a nine-year grant from the National Institutes of Health for the Nanomedicine Development Center for the Optical Control of Biological Function and by a grant from the Foundation Fighting Blindness, USA.

    See the full article here.

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    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

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  • richardmitnick 8:38 am on October 17, 2014 Permalink | Reply
    Tags: , , , , UC Berkeley   

    From UC Berkeley: “New front in war on Alzheimer’s, other protein-folding diseases” 

    UC Berkeley

    UC Berkeley

    October 16, 2014
    Robert Sanders

    A surprise discovery that overturns decades of thinking about how the body fixes proteins that come unraveled greatly expands opportunities for therapies to prevent diseases such as Alzheimer’s and Parkinson’s, which have been linked to the accumulation of improperly folded proteins in the brain.

    “This finding provides a whole other outlook on protein-folding diseases; a new way to go after them,” said Andrew Dillin, the Thomas and Stacey Siebel Distinguished Chair of Stem Cell Research in the Department of Molecular and Cell Biology and Howard Hughes Medical Institute investigator at the University of California, Berkeley.

    A cell suffering heat shock is like a country besieged, where attackers first sever lines of communications. The pat-10 gene helps repair communication to allow chaperones to treat misfolded proteins. (Andrew Dillin graphic)

    Dillin, UC Berkeley postdoctoral fellows Nathan A. Baird and Peter M. Douglas and their colleagues at the University of Michigan, The Scripps Research Institute and Genentech Inc., will publish their results in the Oct. 17 issue of the journal Science.

    Cells put a lot of effort into preventing proteins – which are like a string of beads arranged in a precise three-dimensional shape – from unraveling, since a protein’s activity as an enzyme or structural component depends on being properly shaped and folded. There are at least 350 separate molecular chaperones constantly patrolling the cell to refold misfolded proteins. Heat is one of the major threats to proteins, as can be demonstrated when frying an egg – the clear white albumen turns opaque as the proteins unfold and then tangle like spaghetti.

    Heat shock

    For 35 years, researchers have worked under the assumption that when cells undergo heat shock, as with a fever, they produce a protein that triggers a cascade of events that field even more chaperones to refold unraveling proteins that could kill the cell. The protein, HSF-1 (heat shock factor-1), does this by binding to promoters upstream of the 350-plus chaperone genes, upping the genes’ activity and launching the army of chaperones, which originally were called “heat shock proteins.”

    Injecting animals with HSF-1 has been shown not only to increase their tolerance of heat stress, but to increase lifespan.

    Because an accumulation of misfolded proteins has been implicated in aging and in neurodegenerative diseases such as Alzheimer’s, Parkinson’s and Huntington’s diseases, scientists have sought ways to artificially boost HSF-1 in order to reduce the protein plaques and tangles that eventually kill brain cells. To date, such boosters have extended lifespan in lab animals, including mice, but greatly increased the incidence of cancer.

    Dillin’s team found in experiments on the nematode worm C. elegans that HSF-1 does a whole lot more than trigger release of chaperones. An equal if not more important function is to stabilize the cell’s cytoskeleton, which is the highway that transports essential supplies – healing chaperones included – around the cell.

    “We are suggesting that, rather than making more of HSF-1 to prevent diseases like Huntington’s, we should be looking for ways to make the actin cytoskeleton better,” Dillin said. Such tactics might avoid the carcinogenic side effects of upping HSF-1.

    Dillin is codirector of the Paul F. Glenn Center for Aging Research, a new collaboration between UC Berkeley and UC San Francisco supported by the Glenn Foundation for Medical Research. Center investigators will study the many ways that proteins malfunction within cells, ideally paving the way for novel treatments for neurodegenerative diseases.

    A cell at war

    Dillin compares a cell experiencing heat shock to a country under attack. In a war, an aggressor first cuts off all communications, such as roads, train and bridges, which prevents the doctors from treating the wounded. Similarly, heat shock disrupts the cytoskeletal highway, preventing the chaperone “doctors” from reaching the patients, the misfolded proteins.

    Chaperones help newborn proteins (polypeptides) fold properly, but also fix misfolded proteins.

    “We think HSF-1 not only makes more chaperones, more doctors, but also insures that the roadways stay intact to keep everything functional and make sure the chaperones can get to the sick and wounded warriors,” he said.

    The researchers found specifically that HSF-1 up-regulates another gene, pat-10, that produces a protein that stabilizes actin, the building blocks of the cytoskeleton.

    By boosting pat-10 activity, they were able to cure worms that had been altered to express the Huntington’s disease gene, and also extend the lifespan of normal worms.

    Dillin suspects that HSF-1’s main function is, in fact, to protect the actin cytoskeleton. He and his team mutated HSF-1 so that it no longer boosted chaperones, demonstrating, he said, that “you can survive heat shock with the normal level of heat shock proteins, as long as you make your cytoskeleton work better.”

    He noted that the team’s results – that boosting chaperones is not essential to surviving heat stress – were so contradictory to current thinking that “I made my post-docs’ lives hell for three years” insisting on more experiments to rule out errors. Yet, when Dillin presented the results recently to members of the protein-folding community, he said the first reaction of many was, “That makes perfect sense.”

    Dillin’s colleagues include Milos S. Simic and Suzanne C. Wolff of UC Berkeley, Ana R. Grant of the University of Michigan in Ann Arbor, James J. Moresco and John R. Yates III of Scripps in La Jolla, Calif., and Gerard Manning of Genentech, South San Francisco, Calif. The work is funded by the Howard Hughes Medical Institute as well as by the National Institute of General Medical Sciences (8 P41 GM103533-17) and National Institute on Aging (R01AG027463-04) of the National Institutes of Health.

    See the full article here.

    Founded in the wake of the gold rush by leaders of the newly established 31st state, the University of California’s flagship campus at Berkeley has become one of the preeminent universities in the world. Its early guiding lights, charged with providing education (both “practical” and “classical”) for the state’s people, gradually established a distinguished faculty (with 22 Nobel laureates to date), a stellar research library, and more than 350 academic programs.

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