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  • richardmitnick 3:16 pm on September 28, 2016 Permalink | Reply
    Tags: , , Caltech, Modular Space Telescope Could Be Assembled By Robot,   

    From Caltech: “Modular Space Telescope Could Be Assembled By Robot” 

    Caltech Logo
    Caltech

    09/28/2016
    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    Illustration shows how a robot could assemble the trusses that would support a massive telescope mirror. Credit: Sergio Pellegrino/Caltech

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    Figure shows how foldable truss modules can be combined and assembled to support stackable mirror modules, ultimately creating a single large mirror.
    Credit: Sergio Pellegrino/Caltech

    Seeing deep into space requires large telescopes. The larger the telescope, the more light it collects, and the sharper the image it provides.

    For example, NASA’s Kepler space observatory, with a mirror diameter of under one meter, is searching for exoplanets orbiting stars up to 3,000 light-years away. By contrast, the Hubble Space Telescope, with a 2.4-meter mirror, has studied stars more than 10 billion light-years away.

    Now Caltech’s Sergio Pellegrino and colleagues are proposing a space observatory that would have a primary mirror with a diameter of 100 meters—40 times larger than Hubble’s. Space telescopes, which provide some of the clearest images of the universe, are typically limited in size due to the difficulty and expense of sending large items into space. Pellegrino’s team would circumvent that issue by shipping the mirror up as separate components that would be assembled, in space, by robots.

    Their design calls for the use of more than 300 deployable truss modules that could be unfolded to form a scaffolding upon which a commensurate number of small mirror plates could be placed to create a large segmented mirror. The assembly of the scaffolding and the attachment of the many mirrors is a task well-suited to robots, Pellegrino and his colleagues say.

    In their concept, a spider-like, six-armed “hexbot” would assemble the trusswork and then crawl across the structure to build the mirror atop it. It was modeled on the JPL RoboSimian system, which in 2015 completed the DARPA Robotics Challenge, a federal competition aimed at spurring the development of robots that could perform complicated tasks that would be dangerous for humans. The hexbot would run on electrical power from the telescope’s solar grid. It would use four of its arms to walk—with one leg moving at any given time, while the three others remain securely attached to the structure. The two remaining arms would be free to assemble the trusses and mirrors.

    The team opted to pursue an ambitious 100-meter design. “We wanted to study how different kinds of architectures perform as the diameter is increased,” says Pellegrino, Joyce and Kent Kresa Professor of Aeronautics and Professor of Civil Engineering in Caltech’s Division of Engineering and Applied Science, and Jet Propulsion Laboratory Senior Research Scientist. “We found that far away from the Earth, a structurally connected telescope is much heavier than an architecture based on separate spacecraft for the primary mirror, the optics, and the instrumentation.”

    The realization of such an assembly is still decades away. However, Pellegrino and his colleagues are already working on the various technologies that will be needed to make it possible.

    The entire space observatory would be composed of the fully assembled mirror-and-truss structure and three other parts, flying in formation. An optics and instrumentation unit would be located about 400 meters from the mirror; a control unit, stationed about 400 meters beyond that, would align the system and keep it working properly; and a thin shade, roughly 20 meters in diameter, would shield the mirror from the sun to keep its temperature stable and consistent across its diameter.

    The four-part assembly would be stationed at one of the sun–earth Lagrange points—locations between the sun and the earth where the pull of gravity from two bodies locks a satellite into orbit with them, allowing it to maintain a stable position. There, the space observatory could peer deep into space without drifting out of place.

    Pellegrino collaborated with Joel Burdick, Nicolas Lee, and Kristina Hogstrom of Caltech, as well as Paul Backes, Christine Fuller, Brett Kennedy, Junggon Kim, Rudranarayan Mukherjee, Carl Seubert, and Yen-Hung Wu of JPL. A paper about the work, titled “Architecture for in-space robotic assembly of a modular space telescope,” was published by the Journal of Astronomical Telescopes, Instruments, and Systems. This research was supported by NASA and the W. M. Keck Institute for Space Studies.

    See the full article here .

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    Caltech campus
    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

     
  • richardmitnick 1:46 pm on September 7, 2016 Permalink | Reply
    Tags: , , Caltech, Milky Way simulations   

    From Caltech: “Recreating Our Galaxy in a Supercomputer” 

    Caltech Logo

    Caltech

    09/07/2016
    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Simulated view of our Milky Way galaxy, seen from a nearly face-on angle. This image was created by simulating the formation of our galaxy using a supercomputer, which, in this case, consisted of 2,000 computers linked together. Credit: Hopkins Research Group/Caltech

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    In a new simulation of the formation of our Milky Way galaxy, astronomers were able to, for the first time, correctly predict the number of dwarf galaxies observed today. Dwarf galaxies are small galaxies that swarm around the outside of the Milky Way. Prior simulations found thousands of them—far more than the 30 or so observed so far. This image from the new simulation shows our galaxy with the correct number of dwarf galaxies. The streak is a tidal tail from a torn-apart dwarf galaxy. Credit: Hopkins Research Group/Caltech

    Milky Way NASA/JPL-Caltech /ESO R. Hurt
    Milky Way NASA/JPL-Caltech /ESO R. Hurt

    Astronomers have created the most detailed computer simulation to date of our Milky Way galaxy’s formation, from its inception billions of years ago as a loose assemblage of matter to its present-day state as a massive, spiral disk of stars.

    The simulation solves a decades-old mystery surrounding the tiny galaxies that swarm around the outside of our much larger Milky Way. Previous simulations predicted that thousands of these satellite, or dwarf, galaxies should exist. However, only about 30 of the small galaxies have ever been observed. Astronomers have been tinkering with the simulations, trying to understand this “missing satellites” problem to no avail.

    Now, with the new simulation—which used a network of thousands of computers running in parallel for 700,000 central processing unit (CPU) hours—Caltech astronomers have created a galaxy that looks like the one we live in today, with the correct, smaller number of dwarf galaxies.

    “That was the aha moment, when I saw that the simulation can finally produce a population of dwarf galaxies like the ones we observe around the Milky Way,” says Andrew Wetzel, postdoctoral fellow at Caltech and Carnegie Observatories in Pasadena, and lead author of a paper about the new research, published August 20 in Astrophysical Journal Letters.

    One of the main updates to the new simulation relates to how supernovae, explosions of massive stars, affect their surrounding environments. In particular, the simulation incorporated detailed formulas that describe the dramatic effects that winds from these explosions can have on star-forming material and dwarf galaxies. These winds, which reach speeds up to thousands of kilometers per second, “can blow gas and stars out of a small galaxy,” says Wetzel.

    Indeed, the new simulation showed the winds can blow apart young dwarf galaxies, preventing them from reaching maturity. Previous simulations that were producing thousands of dwarf galaxies weren’t taking the full effects of supernovae into account.

    “We had thought before that perhaps our understanding of dark matter was incorrect in these simulations, but these new results show we don’t have to tinker with dark matter,” says Wetzel. “When we more precisely model supernovae, we get the right answer.”

    Astronomers simulate our galaxy to understand how the Milky Way, and our solar system within it, came to be. To do this, the researchers tell a computer what our universe was like in the early cosmos. They write complex codes for the basic laws of physics and describe the ingredients of the universe, including everyday matter like hydrogen gas as well as dark matter, which, while invisible, exerts gravitational tugs on other matter. The computers then go to work, playing out all the possible interactions between particles, gas, and stars over billions of years.

    “In a galaxy, you have 100 billion stars, all pulling on each other, not to mention other components we don’t see like dark matter,” says Caltech’s Phil Hopkins, associate professor of theoretical astrophysics and principal scientist for the new research. “To simulate this, we give a supercomputer equations describing those interactions and then let it crank through those equations repeatedly and see what comes out at the end.”

    The researchers are not done simulating our Milky Way. They plan to use even more computing time, up to 20 million CPU hours, in their next rounds. This should lead to predictions about the very faintest and smallest of dwarf galaxies yet to be discovered. Not a lot of these faint galaxies are expected to exist, but the more advanced simulations should be able to predict how many are left to find.

    The study, titled “Reconciling Dwarf Galaxies with ΛCDM Cosmology: Simulating A Realistic Population of Satellites Around a Milky Way-Mass Galaxy,” was funded by Caltech, a Sloan Research Fellowship, the National Science Foundation, NASA, an Einstein Postdoctoral Fellowship, the Space Telescope Science Institute, UC San Diego, and the Simons Foundation. Other coauthors on the study are: Ji-Hoon Kim of Stanford University, Claude-André Faucher-Giguére of Northwestern University, Dušan Kereš of UC San Diego, and Eliot Quataert of UC Berkeley.

    Carnegie Observatories Release

    See the full article here .

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 7:36 am on September 7, 2016 Permalink | Reply
    Tags: , Caltech, Optical Solitons,   

    From Caltech: “New Breed of Optical Soliton Wave Discovered” 

    Caltech Logo

    Caltech

    09/06/2016

    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    These optical microcavities are where solitons are created. The solitary waves circle around the microscopic disks at the speed of light.
    Credit: Qi-Fan Yang/Caltech

    Applied scientists led by Caltech’s Kerry Vahala have discovered a new type of optical soliton wave that travels in the wake of other soliton waves, hitching a ride on and feeding off of the energy of the other wave.

    Solitons are localized waves that act like particles: as they travel across space, they hold their shape and form rather than dispersing as other waves do. They were first discovered in 1834 when Scottish engineer John Scott Russell noted an unusual wave that formed after the sudden stop of a barge in the Union Canal that runs between Falkirk and Edinburgh. Russell tracked the resulting wave for one or two miles, and noted that it preserved its shape as it traveled, until he ultimately lost sight of it.

    He dubbed his discovery a “wave of translation.” By the end of the century, the phenomenon had been described mathematically, ultimately giving birth to the concept of the soliton wave. Under normal conditions, waves tend to dissipate as they travel through space. Toss a stone into a pond, and the ripples will slowly die down as they spread out away from the point of impact. Solitons, on the other hand, do not.

    In addition to water waves, solitons can occur as light waves. Vahala’s team studies light solitons by having them recirculate indefinitely in micrometer-scale circular circuits called optical microcavities. Solitons have applications in the creation of highly accurate optical clocks, and can be used in microwave oscillators that are used for navigation and radar systems, among other things.

    But despite decades of study, a soliton has never been observed behaving in a dependent—almost parasitic—manner.

    “This new soliton rides along with another soliton—essentially, in the other soliton’s wake. It also syphons energy off of the other soliton so that it is self-sustaining. It can eventually grow larger than its host,” says Vahala, Ted and Ginger Jenkins Professor of Information Science and Technology and Applied Physics and executive officer for applied physics and materials science in the Division of Engineering and Applied Science.

    Vahala likens these newly discovered solitons to pilot fish, carnivorous tropical fish that swim next to a shark so they can pick up scraps from the shark’s meals. And by swimming in the shark’s wake, the pilot fish reduce the drag of water on their own body, so they can travel with less effort.

    Vahala is the corresponding author of a paper in the journal Nature Physics announcing and describing the new type of soliton, dubbed the “Stokes soliton.” (The name “Stokes” was chosen for technical reasons having to do with how the soliton syphons energy from the host.) The new soliton was first observed by Caltech graduate students Qi-Fan Yang and Xu Yi. Because of the soliton’s ability to closely match the position and shape of the original soliton, Yang’s and Yi’s initial reaction to the wave was to suspect that laboratory instrumentation was malfunctioning.

    “We confirmed that the signal was not an artifact of the instrumentation by observing the signal on two spectrometers. We then knew it was real and had to figure out why a new soliton would spontaneously appear like this,” Yang says.

    The microcavities that Vahala and his team use include a laser input that provides the solitons with energy. This energy cannot be directly absorbed by the Stokes soliton—the “pilot fish.” Instead, the energy is consumed by the “shark” soliton. But then, Vahala and his team found, the energy is pulled away by the pilot fish soliton, which grows in size while the other soliton shrinks.

    “Once we understood the environment required to sustain the new soliton, it actually became possible to design the microcavities to guarantee their formation and even their properties like wavelength—effectively, color,” Yi says. Yi and Yang collaborated with graduate student Ki Youl Yang on the research.

    The research was funded by the Defense Advanced Research Projects Agency under the PULSE Program; NASA; the Kavli Nanoscience Institute; and the Institute for Quantum Information and Matter, a National Science Foundation Physics Frontiers Center supported by the Gordon and Betty Moore Foundation.

    See the full article here .

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    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 7:21 am on September 2, 2016 Permalink | Reply
    Tags: , Caltech, , ,   

    From Caltech: Women in STEM – “Multitasking Protein Keeps Immune System Healthy” Beth Stadtmueller 

    Caltech Logo

    Caltech

    09/01/2016
    Lori Dajose

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    Simplified diagram of pIgR binding to an antibody. A) pIgR and an antibody. B) Recognition binding. pIgR chemically recognizes an antibody. C) Conformational change. The pIgR protein opens up. D) The bound state of pIgR and an antibody. Credit: B. Stadtmueller

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    Schematic summary highlighting the differences in pIgR structure among fish, birds and humans.
    Credit: B. Stadtmueller

    The polymeric immunoglobulin receptor, or pIgR, is a multitasking protein produced in the lining of mucosal surfaces, such as the intestines. It plays a pivotal role in the body’s immune functions by sequestering bacteria and by assisting antibodies—large proteins that can identify and neutralize specific bacteria and viruses. Now, scientists at Caltech have determined the three-dimensional structure of pIgR, providing important insights into how the protein keeps the immune system running smoothly.

    Beth Stadtmueller, a postdoctoral scholar in the laboratory of Centennial Professor of Biology Pamela Björkman, is the first author on two recent papers describing the findings.

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    Beth Stadtmueller

    “Proteins such as pIgR are folded into complicated shapes,” says Stadtmueller. “Having a complete model of a protein is analogous to an architectural model of a building showing scaled dimensions of walls, the locations of windows and doors, angles of the roof, and so on. Understanding the structure of this protein provides information on how it carries out normal functions while also providing a basis to rationally engineer modified proteins with enhanced functions, which could be used as therapeutics.”

    The pIgR protein is best known for attaching to antibodies and ferrying them from the bloodstream to the interior of the intestines, where the antibodies can neutralize pathogens. In mammals such as humans, the group discovered that pIgR looks like five round beads—biologists call these regions “domains”—that are connected to form a tightly closed, triangle-shaped loop. The group also showed that upon encountering an antibody, the pIgR molecule opens up—like changing from a fist to an open hand—to enclose around the antibody and to transport it into the intestines.

    While pIgR is crucial for helping antibodies to function, the protein also has disease-fighting abilities of its own. For example, some molecules of pIgR are released into the intestines where they alone engage bacteria, such as pneumonia-causing Streptococcus pneumoniae.

    The group also studied the structures of pIgR from fish and birds, to see how the protein has changed as vertebrates evolved. In fish, pIgR has only two domains and forms a straight line. In birds, an evolutionary intermediary between fish and humans, the protein has four domains. The group was surprised to find that the shape of the bird pIgR is not fixed in a closed loop or a straight line—it can change freely between closed and open configurations, and can grasp antibodies much like the human protein.

    “The human pIgR is like a door that has to be unlocked to open, whereas the bird pIgR is constantly opening and closing like a revolving door,” Stadtmueller says. “These are very different structures, which are likely to support functions unique to each protein.”

    “The immune system has changed considerably as vertebrates have evolved,” she adds. “Studying pIgR in a spectrum of vertebrates illustrates how the protein architecture has changed to support species-specific defense systems. It helps us to understand why certain immune system functions have evolved and provides a foundation to test their contributions to specific states of health and disease.”

    The three-dimensional structure of human pIgR is described in a March 2016 paper published in the journal eLife, titled The structure and dynamics of secretory component and its interactions with polymeric immunoglobulins. A follow-up study, titled Biophysical and biochemical characterization of avian secretory component provides structural insights into the evolution of the polymeric Ig receptor, describing the structure of avian pIgR, was published in the Journal of Immunology on August 15, 2016. The work was done in collaboration with the Hubbell laboratory at UCLA and supported by grants from the National Institute of Allergy and Infectious Diseases, the Cancer Research Irving Postdoctoral Fellowship, the Jules Stein Professorship Endowment, and the National Institutes of Health.

    See the full article here .

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 4:00 pm on August 12, 2016 Permalink | Reply
    Tags: , Caltech, Mechanical chains made of soft matter that can transmit signals across long distances,   

    From Caltech: “The Utility of Instability” 

    Caltech Logo

    Caltech

    08/08/2016
    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    A 3-D–printed logic gate with bistable elements linked together by springs to transmit signals. Credit: Dennis Kochmann/Caltech

    A team of researchers from Caltech and Harvard has designed and created mechanical chains made of soft matter that can transmit signals across long distances. Because they are flexible, the circuits could be used in machines such as soft robots or lightweight aircraft constructed from pliable, nonmetallic materials.

    Unlike hard materials, which transit signals readily, soft materials tend to absorb energy as it passes through them. An analogy is hitting a firm punching bag versus a soft one: with the firm bag, the energy of your punch moves through the bag and sends it swinging, but the soft bag deforms your fist like a lump of dough and therefore will swing less.

    To overcome that response, Caltech’s Dennis Kochmann, Chiara Daraio, and their colleagues created an unstable, “nonlinear” system. Their findings have appeared in three papers published over the past few months.

    “Engineers tend to shy away from instability. Instead, we take advantage of it,” says Kochmann, assistant professor of aerospace in the Division of Engineering and Applied Sciences, and one of the lead researchers on the project.

    Stable, or “linear,” systems are attractive to engineers because they are easy to model and predict. Take, for example, a spring: If you push on a spring, it will respond by pushing back with a force that is linearly proportional to how much force you apply. The response of a nonlinear system to that same push, by comparison, is not proportional, and can include sudden changes in the direction or amplitude of the responsive force.

    The nonlinear systems that Kochmann and his colleagues designed rely on bistable elements, or elements that can be stable in two distinct states. The bistable elements that the team developed consist of arches of an elastic material, each a few millimeters in size. The elements can be in either a convex or a concave position—and are stable in either configuration. However, if you push on the element in its convex position, it responds by pushing back against the direction of force until it snaps into a concave position, accompanied by a sudden release of energy in the opposite direction.

    “It’s an elastic response, and then a snap-through,” explains Daraio, professor of aeronautics and applied physics.

    Collaborating with Katia Bertoldi, Jennifer Lewis, and Jordan Raney of Harvard University, Kochmann, Daraio, and Caltech graduate student Neel Nadkarni designed chains of the bistable elements, connected to one another by springs. When one link “pops” from the concave to the convex state, its spring tugs at the link that is next downstream in the chain, popping it to a convex position as well. The signal travels unidirectionally down the chain. The energy released by the popping balances out any energy absorbed by the soft material, allowing the process to continue down the chain across long distances and at constant speed.

    A proof-of-concept version of the design constructed from 3-D printed elements is described in a paper published August 8, 2016 in the Proceedings of the National Academy of Sciences. This paper was the third in the series of publications outlining the new concept for transmitting signals. It outlined how the design can be used to build mechanical AND and OR logic gates such as those used in computer processors. Logic gates are the building blocks of circuits, allowing signals to be processed.

    “These systems could be used as actuators to control robotic limbs, while passively performing simple logic decisions,” Daraio says. Actuators use the transfer of energy to perform mechanical work, and in this case, the transfer of energy would occur via a mechanical rather than an electrical system.

    The first paper in the series was published in March in the journal Physical Review B, and it described Kochmann’s theoretical, mathematical framework for the system. The second paper was published in Physical Review Letters in June, and it describes Daraio’s first experimental model for the system.

    While springs can be employed between the bistable elements, the team also demonstrated in the Physical Review Letters paper how magnets could be used to connect the elements—potentially allowing the chain to be reset to its original position with a reversal of polarity.

    “Though there are many applications, the fundamental principles that we explore are most exciting to me,” Kochmann says. “These nonlinear systems show very similar behavior to materials at the atomic scale but these are difficult to access experimentally or computationally. Now we have built a simple macroscale analogue that mimics how they behave.”

    The PNAS paper is titled Stable propogation of mechanical signals in soft media using stored elastic energy. The authors are Nadkarni, Daraio, and Kochmann of Caltech and Jordan Raney, Jennifer Lewis, and Katia Bertoldi of Harvard University. The work was funded by the National Science Foundation.

    See the full article here .

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    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 3:54 pm on August 10, 2016 Permalink | Reply
    Tags: , , Caltech, Exploration & Collaboration,   

    From Caltech: “Exploration & Collaboration: The JPL-Caltech Connection” 

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    Caltech

    08/10/2016
    Lori Dajose

    Caltech’s partnership with NASA’s Jet Propulsion Laboratory has made possible countless discoveries about our universe—how and why black holes flare, where the water on Mars went, and how Earth’s carbon cycle works, just to name a few. Current Caltech faculty are participants on 12 missions.

    2

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 2:45 pm on August 9, 2016 Permalink | Reply
    Tags: , , Caltech, Fiona Harrison,   

    From Caltech: Women in Science – “Fiona Harrison Honored with Massey Award” 

    Caltech Logo

    Caltech

    08/09/2016
    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Fiona Harrison

    Fiona Harrison, principal investigator of NASA’s NuSTAR (Nuclear Spectroscopic Telescope Array) mission, has been selected to receive the 2016 Massey Award, given by the Committee on Space Research (COSPAR).

    NASA/NuSTAR
    NASA/NuSTAR

    Harrison is Caltech’s Benjamin M. Rosen Professor of Physics and the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy.

    The Massey Award, given in honor of the memory of Sir Harrie Massey, a mathematical physicist who served as the Physical Secretary of the Royal Society of London and a member of the COSPAR Bureau, recognizes “outstanding contributions to the development of space research in which a leadership role is of particular importance,” according to the COSPAR website.

    NuSTAR launched in June 2012, opening a new window to the universe as the first focusing telescope to operate in a high-frequency band of X-rays called hard X-rays. The observatory’s accomplishments include the creation of the first map of radioactive material in a supernova remnant; the discovery of emission from a special type of neutron star called a magnetar, which has an extremely strong magnetic field; and the detection of the brightest pulsar ever recorded.

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    This is the first map of radioactivity in a supernova remnant, the blown-out bits and pieces of a massive star that exploded. The blue color shows radioactive material mapped in high-energy X-rays using NuSTAR. Image credit: NASA/JPL-Caltech/CXC/SAO

    “These and many other discoveries make Fiona Harrison one of the most active leaders of modern high energy astrophysics,” the award citation notes.

    “It has been great to work with such a strong and talented team on NuSTAR,” says Harrison. “The whole team deserves credit in NuSTAR’s success.”

    Harrison has been the principal investigator since the mission was founded in 2005. After earning a doctoral degree in physics from UC Berkeley, she first came to Caltech in 1993 as a research fellow and began her professorial career at the Institute in 1995.

    Among other honors, Harrison received the NASA Outstanding Public Leadership medal in 2013 and the 2015 Rossi Prize for high-energy astrophysics. She was elected to the National Academy of Sciences in 2014.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 6:48 am on July 29, 2016 Permalink | Reply
    Tags: , , Caltech, , Team of Proteins Works Together to Turn on T Cells   

    From Caltech: “Team of Proteins Works Together to Turn on T Cells” 

    Caltech Logo

    Caltech

    07/15/2016
    Whitney Clavin
    (626) 395-1856
    wclavin@caltech.edu

    1
    Researchers imaged cells to identify proteins that affect the expression of a genetic switch for T cells. On the right, T cells where the switch is activated glow in yellow. On the left, the rainbow pattern, a hierarchical cluster analysis, tells researchers which genes are controlled by the switch. The horizontal stripes are the genes. If they stripes turn red going from left to right, it means they are turning on; if they turn blue, the genes are turning off. Credit: Caltech

    The fates of various cells in our bodies—whether they become skin or another type of tissue—are controlled by genetic switches. In a new study, Caltech scientists investigate the switch for T cells, which are immune cells produced in the thymus that destroy virus-infected cells and cancers. The researchers wanted to know how cells make the choice to become T cells.

    “We already know which genetic switch directs cells to commit to becoming T cells, but we wanted to figure out what enables that switch to be turned on,” says Hao Yuan Kueh, a postdoctoral scholar at Caltech and lead author of a Nature Immunology report about the work, published on July 4.

    The study found that a group of four proteins, specifically DNA-binding proteins known as transcription factors, work in a multi-tiered fashion to control the T-cell genetic switch in a series of steps. This was a surprise because transcription factors are widely assumed to work in a simultaneous, all-at-once fashion when collaborating to regulate genes.

    The results may ultimately allow doctors to boost a person’s T-cell population. This has potential applications in fighting various diseases, including AIDS, which infects mature T cells.

    “In the past, combinatorial gene regulation was thought to involve all the transcription factors being required at the same time,” says Kueh, who works in the lab of Ellen Rothenberg, Caltech’s Albert Billings Ruddock Professor of Biology. “This was particularly true in the case of the genetic switch for T-cell commitment, where it was thought that a quorum of the factors working simultaneously was needed to ensure that the gene would only be expressed in the right cell type.”

    The authors report that a key to their finding was the ability to image live cells in real-time. They genetically engineered mouse cells so that a gene called Bcl11b—the key switch for T cells—would express a fluorescent protein in addition to its own Bcl11b protein. This caused the mouse cells to glow when the Bcl11b gene was turn on. By monitoring how different transcription factors, or proteins, affected the activation of this genetic switch in individual cells, the researchers were able to isolate the distinct roles of the proteins.

    The results showed that four proteins work together in three distinct steps to flip the switch for T cells. Kueh says to think of the process as a team of people working together to get a light turned on. He says first two proteins in the chain (TCF1 and GATA3) open a door where the main light switch is housed, while the next protein (Notch) essentially switches the light on. A fourth protein (Runx1) controls the amplitude of the signal, like sliding a light dimmer.

    “We identify the contributions of four regulators of Bcl11b, which are all needed for its activation but carry out surprisingly different functions in enabling the gene to be turned on,” says Rothenberg. “It’s interesting—the gene still needs the full quorum of transcription factors, but we now find that it also needs them to work in the right order. This makes the gene respond not only to the cell’s current state, but also to the cell’s recent developmental history.”

    Team member Kenneth Ng, a visiting student from California Polytechnic State University, says he was surprised by how much detail they could learn about gene regulation using live imaging of cells.

    “I had read about this process in textbooks, but here in this study we could pinpoint what the proteins are really doing,” he says.

    The next step in the research is to get a closer look at precisely how the T cell genetic switch itself works. Kueh says he wants to “unscrew the panels” of the switch and understand what is physically going on in the chromosomal material around the Bcl11b gene.

    The Nature Immunology paper, titled, Asynchronous combinatorial action of four regulatory factors activates Bcl11b for T cell commitment, includes seven additional Caltech coauthors: Mary Yui, Shirley Pease, Jingli Zhang, Sagar Damle, George Freedman, Sharmayne Siu, and Michael Elowitz; as well as a collaborator at the Fred Hutchinson Cancer Research Center, Irwin Bernstein. The work at Caltech was funded by a CRI/Irvington Postdoctoral Fellowship, the National Institutes of Health, the California Institute for Regenerative Medicine, the Al Sherman Foundation, and the Louis A. Garfinkle Memorial Laboratory Fund.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”
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  • richardmitnick 3:26 pm on June 30, 2016 Permalink | Reply
    Tags: , Caltech, Sensing seizmic activity   

    From Caltech: “Community Seismic Network Detected Air Pulse From Refinery Explosion” 

    Caltech Logo

    Caltech

    06/30/2016

    Robert Perkins
    (626) 395-1862
    rperkins@caltech.edu

    1
    Models of mode shapes for building motion Credit: Image courtesy of M. Kohler/Caltech

    Tight network of low-cost detectors improve resolution of seismic data gathering and could offer city inspectors crucial information on building damage after a quake.

    On February 18, 2015, an explosion rattled the ExxonMobil refinery in Torrance, causing ground shaking equivalent to that of a magnitude-2.0 earthquake and blasting out an air pressure wave similar to a sonic boom.

    Traveling at 343 meters per second—about the speed of sound—the air pressure wave reached a 52-story high-rise in downtown Los Angeles 66 seconds after the blast.

    The building’s occupants probably did not notice a thing; the building shifted at most three-hundredths of a millimeter in response. But the building’s seismometers—one is installed on every floor, as well as on the basement levels—noted and recorded the motion of each individual floor.

    Those sensors are part of the Community Seismic Network (CSN), a project launched at Caltech in 2011 to seed the Los Angeles area with relatively inexpensive seismometers aimed at providing a high level of detail of how an earthquake shakes the Southern California region, as well as how individual buildings respond. That level of detail has the potential to provide critical and immediate information about whether the building is structurally compromised in the wake of an earthquake, says Caltech’s Monica Kohler, research assistant professor in the Division of Engineering and Applied Science.

    For example, if building inspectors know that inter-story drift—the displacement of each floor relative to the floors immediately below and above it—has exceeded certain limits based on the building’s size and construction, then it is a safe bet that the building has suffered damage in a quake. Alternately, if inspectors know that a building has experienced shaking well within its tolerances, it could potentially be reoccupied sooner—helping an earthquake-struck city to more quickly get back to normal.

    “We want first responders, structural engineers, and facilities engineers to be able to make decisions based on what the data say,” says Kohler, the lead author of a paper detailing the high-rise’s response that recently appeared in the journal Earthquake Spectra.

    The keys to the CSN’s success are affordability and ease of installation of its seismic detectors. Standard, high-quality seismic detectors can cost tens of thousands of dollars and need special vaults to house and protect them that can easily double the price. By contrast, the CSN detectors use $40 accelerometers and other off-the-shelf hardware, cost roughly $300 to build, and require minimal training to install. Approximately 700 of the devices have been installed so far, mostly in Los Angeles.

    However, the CSN sensors are roughly 250 times less sensitive than their more expensive counterparts, which is why the ability to successfully detect and quantify the downtown building’s response to the ExxonMobil explosion was such an important proof-of-concept.

    “It’s a validation of our approach,” says CSN’s project manager, Richard Guy.

    Sonic booms have been noted by seismic networks dozens of times before, beginning in the 1980s with the first detections of seismic shaking caused by space-shuttle reentries. The sonic booms, found Hiroo Kanamori and colleagues at Caltech and the United States Geological Survey, rattled buildings that, in turn, shook the ground around them.

    “Seismologists try to understand what is happening in the earth and how that affects buildings by looking at everything we see on seismograms,” says Kanamori, Caltech’s John E. and Hazel S. Smits Professor of Geophysics, Emeritus, and coauthor of the Earthquake Spectra paper. “In most cases, signals come from the interior of the earth, but nothing prevents us from studying signals from the air. Though rare, the signals from the air provide a new dimension in the field of seismology.”

    The earlier sonic boom detections were made using single-channel devices, which typically record motion in one direction only. While this information is useful for understanding ground shaking, a three-dimensional record of the floor-by-floor motion of a building can reveal how much a building is rocking, swaying, and shifting; two or more sensors installed per floor can show the twisting of the structure.

    “The more sensors you have in a small area, the more detail you’re going to see. If there are things happening on a small scale, you’ll never see it until you have sensors deployed on that scale,” Kohler says.

    Kohler and her colleagues found that the air pressure wave from the explosion had about the same impact on the high-rise as an 8 mile-per-hour gust of wind. A pressure wave about 100 times larger would have been required to have broken windows in the building; a wave 1,000 times larger would have been necessary to cause significant damage to the building.

    The ExxonMobil blast was not the first shaking recorded by the building’s seismometers. A number of earthquakes—including a magnitude-4.2 quake on January 4, 2015, with an epicenter in Castaic Lake, about 40 miles northwest of downtown Los Angeles—also were registered by the seismic detectors on nearly every floor of the building. But the refinery explosion-induced shaking was an important test of the sensitivity of the instruments, and of the ability of researchers to separate earthquake signals from other sources of shaking.

    Other authors of the Earthquake Spectra paper, “Downtown Los Angeles 52-Story High-Rise and Free-Field Response to an Oil Refinery Explosion,” include Caltech’s Anthony Massari, Thomas Heaton, Egill Hauksson, Robert Clayton, Julian Bunn, and K. M. Chandy. Funding for the CSN came from the Gordon and Betty Moore Foundation, the Terrestrial Hazard Observation and Reporting Center at Caltech, and the Divisions of Geological and Planetary Sciences and Engineering and Applied Science at Caltech.

    See the full article here .

    You can be a part of the Quake-Cathcer Network.

    QCN bloc

    Quake-Catcher Network

    The Quake-Catcher Network is a collaborative initiative for developing the world’s largest, low-cost strong-motion seismic network by utilizing sensors in and attached to internet-connected computers. With your help, the Quake-Catcher Network can provide better understanding of earthquakes, give early warning to schools, emergency response systems, and others. The Quake-Catcher Network also provides educational software designed to help teach about earthquakes and earthquake hazards.

    After almost eight years at Stanford, and a year at CalTech, the QCN project is moving to the University of Southern California Dept. of Earth Sciences. QCN will be sponsored by the Incorporated Research Institutions for Seismology (IRIS) and the Southern California Earthquake Center (SCEC).

    The Quake-Catcher Network is a distributed computing network that links volunteer hosted computers into a real-time motion sensing network. QCN is one of many scientific computing projects that runs on the world-renowned distributed computing platform Berkeley Open Infrastructure for Network Computing (BOINC).

    BOINCLarge

    BOINC WallPaper

    The volunteer computers monitor vibrational sensors called MEMS accelerometers, and digitally transmit “triggers” to QCN’s servers whenever strong new motions are observed. QCN’s servers sift through these signals, and determine which ones represent earthquakes, and which ones represent cultural noise (like doors slamming, or trucks driving by).

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

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  • richardmitnick 12:00 pm on June 20, 2016 Permalink | Reply
    Tags: , , Caltech, New exoplanet K2-33b   

    From Caltech: “Newborn Exoplanet Discovered Around Young Star” 

    Caltech Logo

    Caltech

    06/20/2016
    Lori Dajose

    1
    K2-33b, shown in this illustration, is one of the youngest exoplanets detected to date and makes a complete orbit around its star in about five days. These two characteristics combined provide exciting new directions for planet-formation theories. K2-33b could have formed on a farther out orbit and quickly migrated inward. Alternatively, it could have formed in situ, or in place. Credit: NASA/JPL-Caltech/R. Hurt

    2
    The K2-33 system and its planet in comparison to our own solar system. The planet is on a five-day orbit, whereas Mercury orbits our Sun in 88 days. The planet is also nearly ten times closer to its star than Mercury is to the Sun. Credit: NASA/JPL-Caltech

    3
    When a planet—such as K2-33b—passes in front of its host star, it blocks some of the star’s light. Detecting this periodic dimming, called a transit, from continual monitoring of a star’s brightness allows astronomers to detect planets outside of our solar system with a high degree of certainty. This Neptune-sized planet orbits a star that is between five and 10 million years old. In addition to the planet, the star hosts a disk of planetary debris, seen as a bright ring encircling the star. Credit: NASA/JPL-Caltech/R. Hurt

    Planet transit. NASA/Ames
    Planet transit. NASA/Ames

    Planet formation is a complex and tumultuous process that remains shrouded in mystery. Astronomers have discovered more than 3,000 exoplanets—planets orbiting stars other than our Sun—however, nearly all are middle-aged, with ages of a billion years or more. For astronomers, attempting to understand the life cycles of planetary systems using existing examples is like trying to learn how people grow from babies to children to teenagers, by only studying adults. Now, a team of Caltech-led researchers have discovered the youngest fully-formed exoplanet ever detected. The planet, K2-33b, at 5 to 10 million years old, is still in its infancy.

    The first signals of the planet’s existence were measured by NASA’s Kepler space telescope during its K2 mission. The telescope detected a periodic dimming in the light emitted by the planet’s host star—called K2-33—that hinted at the existence of an orbiting planet. Observations from the W.M. Keck Observatory in Hawaii validated that the dimming was indeed caused by a planet, later named K2-33b. A paper detailing the finding appears in the June 20 advance online issue of the journal Nature.

    “At 4.5 billion years old, the Earth is a middle-aged planet—about 45 in human-years,” says Trevor David, the first author on the paper and a graduate student working with professor of astronomy Lynne Hillenbrand. “By comparison, the planet K2-33b would be an infant of only a few weeks old.”

    “This discovery is a remarkable milestone in exoplanet science,” says Erik Petigura, a postdoctoral scholar in planetary science and a coauthor on the paper. “The newborn planet K2-33b will help us understand how planets form, which is important for understanding the processes that led to the formation of the earth and eventually the origin of life.”

    When stars form, they are encircled by dense regions of gas and dust, called protoplanetary disks, from which planets form. By the time a young star is a few million years old, this disk has largely dissipated and planet formation is mostly complete.

    The star orbited by K2-33b has a small amount of disk material left, indicated by observations from NASA’s Spitzer space telescope, demonstrating that it is in the final stages of dissipating. K2-33b was previously identified as a planet candidate in a survey of stars done with the K2 mission, the extended mission phase of the Kepler Space Telescope.

    “Astronomers know that star formation has just completed in this region, called Upper Scorpius, and roughly a quarter of the stars still have bright protoplanetary disks,” David says. “The remainder of stars in the region do not have such disks, so we reasoned that planet formation must be nearly complete for these stars, and that there would be a good chance of finding young exoplanets around them.”

    K2-33b, like many other exoplanets, was detected due to the periodic dimming in the central star’s light as the planet passes in front of it. By studying the frequency of dips in the star’s light and measuring by how much the light dimmed, the team was able to determine the size and orbital period of the planet. K2-33b is “a remarkable world,” according to Petigura. The exoplanet, which is about six times the size of Earth, or about 50 percent larger than Neptune, makes a complete orbit around its host star in about five days. This implies that it is 20 times closer to its star than Earth is to the Sun.

    K2-33b is a large planet like the gas giants in our solar system. In our solar system these giant planets are all far from the Sun. As it turns out, the proximity of the giant planet K2-33b to its star is not too out of the ordinary for planets in our galaxy—many have been discovered “close in,” often completing an orbit around their parent star in weeks or even days. The explanation for this is that large planets can be formed far from their star and migrate inward over time. The position of K2-33b so close to its parent star at such an early age implies that if migration occurred, it must have occurred quickly. Alternatively, the planet could be evidence against the migration theory, suggesting that giant planets can in fact form close in to their stars.

    “Discovering and studying K2-33b required using several of the most powerful astronomical instruments available, both in space and on Earth,” says Sasha Hinkley, now a senior lecturer at Exeter University and co-author on the study. As a NASA Sagan Postdoctoral Fellow at Caltech, Hinkley acquired data from the Keck telescope which was later used to help confirm the existence of the planet.

    K2-33b is fully formed, but it may still evolve over time. The next step is to measure the planet’s mass and determine its density. These measurements will offer insights into the planet’s fate later in life—whether it will stay roughly the same size or if it will cool and contract.

    “In the last 20 years, we have learned that nature can produce a staggering diversity of planets—from planets that orbit two stars to planets that complete a full orbit every few hours,” Petigura says. “We have much to learn, and K2-33b is giving us new clues.”

    The findings are detailed in a paper titled, A Neptune-sized transiting planet closely orbiting a 5–10 million-year-old star.” The work was supported by a National Science Foundation Graduate Research Fellowship and included data funded by NASA. Professor Lynne Hillenbrand, staff scientist David Ciardi, and senior faculty associate in astronomy Charles Beichman were additional Caltech coauthors on this paper.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    Caltech campus
    The California Institute of Technology (commonly referred to as Caltech) is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering. Its 124-acre (50 ha) primary campus is located approximately 11 mi (18 km) northeast of downtown Los Angeles. “The mission of the California Institute of Technology is to expand human knowledge and benefit society through research integrated with education. We investigate the most challenging, fundamental problems in science and technology in a singularly collegial, interdisciplinary atmosphere, while educating outstanding students to become creative members of society.”

     
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