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  • richardmitnick 10:06 am on January 26, 2016 Permalink | Reply
    Tags: , , , Superfast 'Cannonball' Star, UC Santa Cruz   

    From UCSC via SPACE.com: “Strange Superfast ‘Cannonball’ Star Likely Blasted from Supernova” 

    UC Santa Cruz

    UC Santa Cruz

    January 25, 2016
    Sarah Lewin, Staff Writer at SPACE.com

    dwarf carbon star SDSS J1128

    A star with an unusual history is racing through the galaxy at breakneck speed — most likely blasted away by a supernova and carrying traces of the exploded star.

    The strange runaway star, which is rocketing along at more than 960,000 miles per hour (1.54 million kilometers per hour), is stained in carbon even though it’s too immature to have created the stuff itself, scientists said.

    Kathryn Plant, a senior at the University of California, Santa Cruz (UCSC), presented the new observations earlier this month at the American Astronomical Society’s 227th meeting in Kissimee, Florida. She and her co-authors said the star’s tremendous speed and its carbon signal could be linked.

    “You’re looking at this very, very, very rare star that’s moving at cannonball velocity,” study co-author Bruce Margon, an astronomer at UCSC, told Space.com. “That got us thinking — maybe there’s something about it being a dwarf carbon star that has to do with it having this crazy-high speed.”

    Their top guess is that the speedy star was in a binary system with another star that imbued it with carbon before dying in a massive supernova explosion, shooting the first star out and away. The situation may be similar for several other “cannonball” candidates the researchers have identified.

    That unusual carbon content is the key “extra clue” to the speedy stars’ origin, said Plant, the new work’s lead author.

    “For many stars, we can look at them and see how they’re moving now, but we often don’t have a lot of clues to what they might have been doing in the distant past,” she told Space.com. “Since [the star] carries this material mark, we have a clue to what it was doing in the past.”

    Perplexing stars

    The star in question, called SDSS J112801.67+004034.6 (SDSS J1128 for “short”), was originally measured through the Sloan Digital Sky Survey [SDSS] in March 2000.

    SDSS Telescope
    SDSS telescope at Apache Point, NM, USA

    Along with about 500 others found so far, it seems to fall into the strange stellar category of “dwarf carbon stars.” Different than a “white dwarf,” the super-dense remnant left at the end of a star’s life cycle, a dwarf carbon star appears to be in an early stage of evolution but contains a high level of carbon. That’s odd, because carbon is usually found shrouding red giants, which are in a much later stage.

    “The mere existence of these stars is kind of perplexing, because they are adolescent stars — they are stars at about the same evolutionary stage as our sun,” Margon said. “There shouldn’t be such a thing as a dwarf carbon star, because there’s no way for that star to have created carbon given where it is in its life cycle.”

    Instead, researchers theorize that each of these stars once orbited together with another star, a companion, which was in a later part of its life cycle and had already produced carbon. If the binary stars orbited closely enough, one star’s carbon could transfer to the other.

    The transfer of mass could happen peacefully over time — “a gentle wind puffed off for millions of years,” Margon said — but the two stars’ association might end on much more violent terms when the more mature star explodes into a supernova.

    Smoking guns

    SDSS J1128 first came to the researchers’ attention because of how quickly it was speeding away from Earth, which researchers calculated based on distortion in the wavelengths of light it put out in that first measurement. They followed up by measuring the star with Hawaii’s Keck Observatory in April 2015, and found that it was still moving away at about the same speed.

    Keck Observatory
    Keck Observatory Interior
    Keck

    But not only that: After looking at the star’s location from surveys over many years (the earliest was in 1955), the research team realized that it was visibly sweeping across the sky as well, not just fleeing from Earth. That implied that the star was dimmer and close, rather than far away and very bright.

    Researchers know stars can pick up incredible speed by whipping around the supermassive black hole in the Milky Way’s center, so this was one of the first possible explanations for this star’s great velocity. But once the collaborators calculated its approximate location — between 3,000 and 10,000 light-years away — and its speed compared with the center of the galaxy, it became clear that the star was not on that type of trajectory.

    “Even though we don’t have one exact number, we can understand what it’s most likely doing,” Plant said. “We can rule out […] certain motions that are not possible, and that lets us conclude that it’s not coming from the center of the galaxy, which is one of the main questions we wanted to answer, and also lets us conclude that it is bound to the galaxy but it’s on an extremely eccentric orbit.”

    So they turned to the supernova possibility. Other stars’ speeds have occasionally been attributed to the driving force of a supernova, the researchers said, but evidence has not been conclusive.

    “This thing has a different set of smoking guns that are pointing towards that evidence,” Margon said. “It’s the thing science fiction emerges from: You have a peaceful star minding its own business, its companion goes ‘kerblooie’ and completely demolishes itself and shoots this thing off like a cannonball,” he added. “We’re advancing this as a candidate for that [scenario].”

    Not so alone

    To find out more about the high-speed star, researchers can take follow-up measurements to check for tiny variations in the speed at which it’s moving away from Earth, as well as more about its chemical composition. Ultimately, projects like Europe’s galaxy-mapping [ESA] Gaia mission could provide even more precise data about the star’s location, if it falls within the satellite’s view, the researchers said.

    ESA Gaia satellite
    ESA/Gaia

    The star is one of a few candidates the researchers found for this extreme motion — it had the fastest velocity of the bunch relative to Earth, but the others could prove even faster when measured in the context of the entire galaxy. Comparing the traits of all those “cannonball” stars could help solidify the supernova explanation or suggest another mechanism.

    “The fact that this is a super-high-velocity star isn’t going to go away,” Margon said. “The interpretation might change.”

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 8:41 pm on September 11, 2015 Permalink | Reply
    Tags: , , , UC Santa Cruz   

    From UCSC: “Study finds different ways for a black hole to swallow a star” 

    UC Santa Cruz

    UC Santa Cruz

    September 10, 2015
    Susanna Kohler (AAS) and Tim Stephens (UCSC)

    1
    In this simulated tidal disruption event, a star is pulled apart by the tidal forces of a black hole. (Image credit: NASA/S. Gezari, JHU/J. Guillochon, UCSC)

    In a tidal disruption event, an unfortunate star passes too close to a dormant supermassive black hole and gets torn apart by tidal forces, feeding the black hole for a short time. Astronomers use distinctive observational signatures to detect these events, but they are not seeing nearly as many tidal disruption events as theory says they should.

    A recent study by UC Santa Cruz researchers suggests that astronomers might be missing many of these events because of how the streams of shredded stars fall onto the black hole. James Guillochon, who earned his Ph.D. at UC Santa Cruz and is now at the Harvard-Smithsonian Center for Astrophysics, and Enrico Ramirez-Ruiz, professor and chair of astronomy and astrophysics, based their analysis on a series of computer simulations of tidal disruption events. They reported their findings in a paper published August 20 in the Astrophysical Journal.

    When a black hole tears a star apart, the star’s material is stretched out into what’s known as a tidal stream. That stream continues on a trajectory around the black hole, with roughly half the material eventually falling back on the black hole, whipping around it in a series of orbits. Where those orbits intersect each other, the material smashes together and circularizes, forming a disk that then accretes onto the black hole.

    Astronomers don’t observe anything until after the tidal streams collide and the material begins to accrete onto the black hole. At that point, they observe a sudden peak in luminosity, which then gradually decreases as the tail end of what’s left of the star accretes and the black hole’s food source eventually runs out.

    General relativity

    So why have astronomers only been observing about a tenth as many tidal disruption events (TDEs) as theory predicts they should see? By studying the structure of tidal streams in TDEs, Guillochon and Ramirez-Ruiz have found a potential reason, and the culprit is general relativity.

    “It is an effect of general relativity that is modulating the digestion process of the black hole, so the digestion rate depends strongly on the mass of the black hole,” Ramirez-Ruiz said.

    The researchers ran a series of simulations of tidal disruption events around black holes of varying masses and spins to see what form the resulting tidal streams take over time. They found that precession of the tidal stream due to the black hole’s gravitational effects changes how the stream interacts with itself, and therefore what astronomers observe. Some cases behave as expected for what’s currently considered a “typical” event, but some do not.

    For cases where the relativistic effects are small (such as black holes with masses less than a few million solar masses), the tidal stream collides with itself after only a few windings around the black hole, quickly forming a disk — but the disk forms far from the black hole, so it takes a long time to accrete. As a result, the observed flare can take 100 times longer to peak than typically expected, so these sources may not be identified as tidal disruption events.

    Furthermore, for cases where the black hole is both massive and has a spin greater than a certain value (about 20 percent of its maximum allowed spin), the tidal stream doesn’t collide with itself right away. Instead, it can take many windings around the black hole before the first intersection. In these cases, it may potentially be years after a star gets ripped apart before the material accretes and astronomers are able to observe the event.

    See the full article here .

    Please help promote STEM in your local schools.

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    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 11:34 am on September 6, 2015 Permalink | Reply
    Tags: , UC Santa Cruz   

    From UC Santa Cruz: “Tearing down the walls” 

    UC Santa Cruz

    UC Santa Cruz

    September 04, 2015
    Peggy Townsend

    1
    UC Santa Cruz pioneer faculty, 1965

    Jean Langenheim, a Harvard-trained biologist who would go on to become a renowned plant ecologist, sat around a crackling campfire with a small group of undergraduate students.

    That she was the lone female faculty member in natural sciences at the new UC Santa Cruz campus was remarkable enough. But the fact Langenheim was actually teaching a class on the ecology of redwoods, not in a classroom but beneath a starry sky and under a stand of the towering trees, was even more notable.

    “I was convinced this informal atmosphere of learning in the field and the relationships students and faculty shared there often inspired life-long environmental interests,” said the now 90-year-old Langenheim.

    It was that freedom to teach in unconventional ways and engage in research among a close-knit faculty that attracted Langenheim to the Santa Cruz campus in 1966. Many of the pioneering teachers and staff who came to UC Santa Cruz between 1964 and 1967 would be drawn by the same thing.

    Born out of the vision of then-UC President Clark Kerr and Dean McHenry, a former UCLA political science professor who was named the first chancellor of the new campus, UC Santa Cruz was to be a grand experiment in education.

    It proposed knocking down the walls of a stodgy bureaucracy, encouraging innovation, and allowing students the intimacy of a small college within a large research institution.

    But it was the early staff and faculty — many of which came from places like Harvard, Yale, Stanford, and even Kings College at Cambridge University — who actually carried out the plan and, in the process, established the roots of what UC Santa Cruz is today.

    “Everybody wanted to come. It was the talk of the country,” said Todd Newberry, a Stanford-trained professor of biology who arrived at the university in 1965. “How many times in your life do you get to start a university? It was going to focus on undergrads, and that’s where my heart was.”

    The campus attracted new thinkers like a horseback-riding historian from UCLA named Page Smith, the charismatic art history professor Mary Holmes, the brilliant history professor and WWII veteran William Hitchcock, and the gangly Harvard-trained Byron Stookey Jr., who would become head of academic planning for UC Santa Cruz.

    The hires were old, young, liberal, and conservative. Some came with impressive bodies of work. Other put their academic careers in jeopardy by arriving at an institution that put an emphasis on undergraduate teaching rather than on being published. They played sports with students, ate with students, invited them into their homes.

    “Well, of course it was exceptional and we knew it and a lot of people felt it,” said UC Santa Cruz pioneer History Professor John Dizikes in his oral history. “And (Cowell College founding Provost) Page Smith propagated overwhelmingly the idea shared by most of us, to a great degree, that we were now going to help with the reform of American higher education.”

    And reform they did.

    One of the first revolutionary acts of the faculty was to toss out letter grades in favor of a pass/fail system with narrative evaluations. The move was urged by Smith, who believed letter grades created a competitive situation where some students prospered at the expense of others and had no place in learning.

    Or as the flamboyant pioneer Art History Professor Jasper Rose reportedly said, “Students are not vegetables. We don’t need to grade them.”

    Nancy Pascal, who worked in the Registrar’s Office starting in 1966, remembered the faculty writing evaluations of students on “sticky labels, and then we’d get the labels and we’d paste them onto the right student’s records. Later the college staff would have to retype them, so there was this huge effort to support the narrative evaluation for students.”

    Today, many of those who gave — and received — these narrative assessments say they were one of the best parts of UC Santa Cruz, a concrete sign that teachers were actually paying attention to students.

    Besides a lack of grades, there were other indications the early faculty and staff weren’t creating your father’s university.

    There were weekly “college nights,” where faculty, staff, and students sat down to a semi-formal dinner with stimulating guest speakers like beat poet Allen Ginsberg, writer/activist Susan Sontag, writer Anaïs Nin, and jazz musician Don Ellis.

    There were thought-provoking college courses, which pressed against the boundaries of traditional teaching. Newberry co-taught a college course on death and another on the sense of place. Courses on building a house, on dreams, and on national identity were offered.

    Harry Berger, a literature professor who came to UC Santa Cruz from Yale in 1965 and went on to become a respected literary and cultural critic, also remembered Cowell’s famous core course on world civilization. The course included seminars led, not just by humanities professors, but also, in this new world of learning, by biologists, economists, political scientists, and chemists — many who found themselves in unfamiliar territory.

    “It encouraged and supported team-teaching,” Berger said of the experience. “It made it easy for people in different fields to teach together. I team-taught courses with classicists, anthropologists, and sociologists… . For me, this meant that I was not only a teacher of undergraduates but also a student of my colleagues.”

    Many of the faculty and staff found themselves improvising, inventing, and tackling assignments they’d never imagined.

    Pioneer professor of psychology and sociology Bill Domhoff organized a two-day, all-campus “culture break” during those first years. He brought in folklorist Alan Dundes, who gave a talk on the psychology of elephant jokes, and recruited an expert who spoke on drugs and creativity. There were talks on dreams, screenings of Ingmar Bergman movies, and construction of a fake beach, complete with lifeguard, on the East Field.

    “The beauty of it turned out to be that students learned to think for themselves and to be more creative,” Domhoff said of the event he dubbed “The Fantasy Festival.”

    But the times were already changing. Student protests over the Vietnam War and Civil Rights rattled the campus, and the weight of overturning old systems began to take a toll.

    Faculty discovered themselves overwhelmed by the workloads of both the colleges and what were called boards of studies. Some of the campus’s brightest teachers were denied tenure because the entrenched UC advancement system didn’t take into account the new campus’s values. Political pressures mounted. Some of the old ways crept back in.

    But one of the things that remained was UC Santa Cruz’s maverick spirit, an attitude that fostered improbable campus achievements like being the first to sequence the human genome, saving the endangered Peregrine falcon from extinction, finding new ways to peer more deeply into space, and helping to put organic food on American tables.

    “…You walk across campus now and there are all those energetic, interested young people who are finding their way in life and learning,” said Jerry Walters, a pioneering staff member whose job included the daunting task of housing 652 students after construction delays meant they had nowhere to live. “And then, there are the discoveries and other things going on (at UC Santa Cruz) that don’t just have local impact but have national and worldwide impact.”

    The man who retired as executive director of housing, dining, and childcare paused.

    “Well,” he said, “it just makes me proud.”

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 10:52 am on August 21, 2015 Permalink | Reply
    Tags: , , UC Santa Cruz   

    From UCSC: Seagate gift supports UC Santa Cruz research on genomic data storage 

    UC Santa Cruz

    UC Santa Cruz

    August 20, 2015
    Tim Stephens

    Researchers in the Baskin School of Engineering at UC Santa Cruz are working with industry partner Seagate Technologies on new ways to structure and store massive amounts of genomic data. Seagate has donated data storage devices with a total capacity of 2.5 petabytes to support this effort.

    “This gift provides the basis for a major research program on storage of genomic data,” said Andy Hospodor, executive director of the Storage Systems Research Center (SSRC) at UC Santa Cruz.

    “Seagate is pleased to be a part of this important research effort. The storage requirements for genomics are staggering and the potential for medical breakthroughs even larger,” said Mark Re, senior vice president and CTO at Seagate.

    The gift, valued at $250,000, includes 1 petabyte of Seagate’s new Kinetic disk drives for object-based storage, plus an additional 1.5 petabytes of traditional Seagate SATA disk drives for use in existing clusters within the UC Santa Cruz Genomics Institute.

    1
    Ethan Miller, professor of computer science, directs the Center for Research in Storage Systems (CRSS). (Photo by Elena Zhukova)

    Large-scale test bed

    “This gives us a large-scale test bed that we can use to explore the organization of data for large-scale disk-based storage systems. We need to develop better ways to store and organize the vast quantities of data we’re generating,” said Ethan Miller, professor of computer science and director of the Center for Research in Storage Systems (CRSS) at UCSC.

    Miller and other storage systems researchers at UC Santa Cruz work closely with industry partners such as Seagate, and several of the center’s alumni and graduate students have been working at Seagate on the company’s latest disk technology. The Seagate storage donation will support research on new ways to structure and store genomic data using object stores and newly proposed open-source standards (APIs) for genomic data that are being developed by the Global Alliance for Genomics and Health.

    “Genomic data storage is one of several areas of emerging interest where we’ll be looking at using Seagate’s new intelligent disks to build large-scale storage systems,” Miller said.

    Genomics Institute

    The donation also adds over a petabyte of storage capacity to the genomics data storage cluster maintained by the UC Santa Cruz Genomics Institute at the San Diego Supercomputing Center. For Benedict Paten, a research scientist at the Genomics Institute, it’s all about speeding up the processing of genomic data.

    “We in genomics know that we have a big data problem,” Paten said. “We need to be able to compute on much larger volumes of data than we have before. The amount of genomic data is growing exponentially, and we haven’t been keeping up.”

    Part of the solution, he said, is distributed processing of large data sets in which the processing is done where the data are stored, instead of downloading the data over a network for processing. “Now we can put a lot of disks on the compute nodes for efficient distributed computation over large amounts of data. This donation is really important for our big data genomics efforts at UC Santa Cruz,” Paten said.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 11:02 am on July 23, 2015 Permalink | Reply
    Tags: , , UC Santa Cruz   

    From UCSC: “Keck Foundation awards UC Santa Cruz $2 million for human genome variation project” 

    UC Santa Cruz

    UC Santa Cruz

    July 22, 2015
    Tim Stephens

    The UC Santa Cruz Genomics Institute has received a $2 million grant from the W. M. Keck Foundation for ongoing research to develop a comprehensive map of human genetic variation. The Human Genome Variation Map will be a valuable new resource for medical researchers, as well as for basic research on human evolution and diversity.

    2
    Human Genome Variation Map

    The Keck grant provides funding over two years for UC Santa Cruz researchers to create a full-scale map, building on the results of a one-year pilot project funded by the Simons Foundation.

    “We’ve been experimenting with pilot regions of the genome and evaluating a variety of methods. The next steps will be to take it from a prototype to a full-scale genome reference that we can release to the community,” said Benedict Paten, a research scientist at the Genomics Institute and co-principal investigator of the project.

    1
    Benedict Paten (Photo by Summer Stiegman)

    The Human Genome Variation Map is needed to overcome the limitations of using a single reference sequence for the human genome. Currently, new data from sequencing human genomes is analyzed by mapping the new sequences to one reference set of 24 human chromosomes to identify variants. But this approach leads to biases and mapping ambiguities, and some variants simply cannot be described with respect to the reference genome, according to David Haussler, distinguished professor of biomolecular engineering and scientific director of the Genomics Institute at UC Santa Cruz.

    Global Alliance

    Haussler and Paten are coordinating their work on the new map with the Global Alliance for Genomics and Health (GA4GH), which involves more than 300 collaborating institutions that have agreed to work together to enable secure sharing of genomic and clinical data. The overall vision of the global alliance includes a genomics platform based on something akin to the planned Human Genome Variation Map, along with open-source software tools to enable researchers to mine the data for new scientific and medical breakthroughs. In the long run, the map will be used to identify genomic variants encountered in precision medical care as well, Haussler said.

    The UCSC team has been collaborating with leading genomics researchers at other institutions to develop the map, which Paten began working on in 2014 as co-chair of the GA4GH Reference Variation Task Team. The new Human Genome Variation Map will replace the current assortment of isolated, incompatible databases of human genetic variation with a single, fundamental representation formalized as a very large mathematical graph. The clean mathematical formulation is a major strength of this new approach, Paten said.

    The primary reference genome is a linear sequence of DNA bases (represented by the letters A, C, T, and G). To build the Human Genome Variation Map, each new genome will be merged into the reference genome at the points where it matches the primary sequence, with variations appearing as additional alternate paths in the map.

    Mathematical structure

    This mathematical graph-based structure will augment the existing human reference genome with all common human variations, providing a means to name, identify, and analyze variations precisely and reproducibly. “The original human reference genome project gave us a detailed picture of one human genome. This map will give us a detailed picture of the world’s variety of human genomes,” Paten said.

    In the spirit of the original human genome project, the Human Genome Variation Map will be publicly and freely available to all. Haussler’s team at UC Santa Cruz made the first human genome sequence publicly available on the Internet 15 years ago. This new project has many parallels with that earlier work, in which UCSC genomics researchers assembled and posted the first human genome sequence and went on to create the widely used UCSC Genome Browser.

    “This is an infrastructure project for genomics that everyone agrees is important,” Paten said. “It is ambitious, and it requires a fundamental shift from thinking of the reference as one sequence to thinking of it as this structure that incorporates all variation. But now is the time to do it. We need to build a model that works, and make it easy enough to use to get community acceptance.”

    The UC Santa Cruz Genomics Institute is a fundraising priority of the $300-million Campaign for UC Santa Cruz.

    W. M. Keck Foundation

    Based in Los Angeles, the W. M. Keck Foundation was established in 1954 by the late W. M. Keck, founder of the Superior Oil Company. The Foundation’s grant making is focused primarily on pioneering efforts in the areas of medical, science and engineering research. The Foundation also maintains an undergraduate education program that promotes distinctive learning and research experiences for students in the sciences and in the liberal arts, and a Southern California Grant Program that provides support for the Los Angeles community, with a special emphasis on children and youth from low-income families, special needs populations and safety-net services. For more information, please visit www. wmkeck.org.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 2:55 pm on May 14, 2015 Permalink | Reply
    Tags: , , , UC Santa Cruz   

    From UCSC: “Against all odds: Astronomers baffled by discovery of rare quasar quartet” 

    UC Santa Cruz

    UC Santa Cruz

    May 14, 2015
    Tim Stephens (UCSC) & Markus Possel (MPIA)

    1
    Arrows indicated the four quasars in this image. The quasars are embedded in a giant nebula of cool dense gas, visible as a blue haze, which has an extent of one million light-years across. This false-color image is based on observations with the Keck I telescope in Hawaii. (Image Credit: Hennawi & Arrigoni-Battaia, MPIA)

    A team of astronomers including J. Xavier Prochaska, professor of astronomy and astrophysics at UC Santa Cruz, has discovered the first known quasar quartet: four quasars, each one a rare object in its own right, in close physical proximity to each other. The quartet resides in one of the most massive structures ever discovered in the distant universe (a “proto-cluster” of galaxies) and is surrounded by a giant nebula of cool dense gas.

    The findings, published May 15 in Science, are based on observations using the 10-meter Keck I Telescope at the W. M. Keck Observatory in Hawaii.

    Keck Observatory
    Keck

    Either the discovery is a one-in-ten-million coincidence, or cosmologists need to rethink their models of quasar evolution and the formation of the most massive cosmic structures, according to first author Joseph Hennawi of the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany.

    Exceedingly rare

    Quasars constitute a brief phase of galaxy evolution, powered by the accretion of matter onto a supermassive black hole at the center of a galaxy. During this phase, they are the most luminous objects in the universe, shining hundreds of times brighter than their host galaxies, which themselves contain hundreds of billions of stars. But these hyper-luminous episodes last only a tiny fraction of a galaxy’s lifetime. As a result, quasars are exceedingly rare and are typically separated by hundreds of millions of light years from one another. The researchers estimate that the odds of discovering a quadruple quasar by chance is one in ten million.

    How did they get so lucky? Clues come from peculiar properties of the quartet’s environment. The four quasars are surrounded by a giant nebula of cool dense hydrogen gas, which emits light because it is irradiated by the intense glare of the quasars. In addition, both the quartet and the surrounding nebula reside in an unusual region of the universe with a surprisingly large amount of matter.

    “There are several hundred times more galaxies in this region than you would expect to see at these distances,” said Prochaska, the principal investigator of the Keck observations.

    Proto-cluster

    Given the exceptionally large number of galaxies, this system resembles the massive agglomerations of galaxies known as galaxy clusters that astronomers observe in the present-day universe. But because the light from this cosmic metropolis has been travelling for 10 billion years before reaching Earth, the images show the region as it was 10 billion years ago, less than 4 billion years after the big bang. It is thus an example of a proto-cluster, the progenitor or ancestor of a present-day galaxy cluster.

    Piecing all of these anomalies together, the researchers tried to understand what appears to be their incredible stroke of luck. “If you discover something which, according to current scientific wisdom, should be extremely improbable, you can come to one of two conclusions: either you just got very lucky, or you need to modify your theory,” Hennawi said.

    The researchers speculate that some physical process might make quasar activity much more likely in certain environments. One possibility is that quasar episodes are triggered when galaxies collide or merge, because these violent interactions efficiently funnel gas onto the central black hole. Such encounters are much more likely to occur in a dense proto-cluster filled with galaxies, just as one is more likely to encounter traffic when driving through a big city.

    “The giant emission nebula is an important piece of the puzzle, since it signifies a tremendous amount of dense cool gas,” said coauthor Fabrizio Arrigoni-Battaia of MPIA. Supermassive black holes can only shine as quasars if there is gas for them to swallow, and an environment that is gas rich could provide favorable conditions for fueling quasars.

    Unexpected

    On the other hand, given the current understanding of how massive structures in the universe form, the presence of the giant nebula in the proto-cluster is totally unexpected, according to coauthor Sebastiano Cantalupo of UC Santa Cruz and ETH Zurich. “Our current models of cosmic structure formation based on supercomputer simulations predict that massive objects in the early universe should be filled with rarefied gas that is about ten million degrees, whereas this giant nebula requires gas thousands of times denser and colder,” he said.

    The discovery of the first quadruple quasar may force cosmologists to rethink their models of quasar evolution and the formation of the most massive structures in the universe.

    See the full article here.

    Please help promote STEM in your local schools.

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    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
    • kagmi 5:40 pm on May 14, 2015 Permalink | Reply

      *blink* *blink* I’m still wrapping my head around the idea of a nebula large enough to surround SEVERAL galaxies.

      Like

    • richardmitnick 6:12 pm on May 14, 2015 Permalink | Reply

      Nebulae can be beyond immense. The Carina Nebula is three light years tall. That is a lot of space. A light year is a distance of 6 trillion miles.

      Like

  • richardmitnick 9:06 am on May 7, 2015 Permalink | Reply
    Tags: , , UC Santa Cruz   

    From UCSC: “Spreading science education, one telescope at a time” This is a Great Story 

    UC Santa Cruz

    UC Santa Cruz

    May 06, 2015
    Peggy Townsend

    1
    UC Santa Cruz grad student Tuguldur Sukhbold organized a project that, last year, delivered telescopes to 7 percent of the schools in Mongolia. (Photo by Carolyn Lagattuta)

    2
    In Mongolia, horses outnumber people and science education has lagged. “Their world view is very limited,” says Tuguldur. “But with these telescopes, even if they can’t see the world, they can see the universe.”

    3
    Tuguldur and a friend purchased 44 telescopes from which kids could see craters on the moon, ice caps on Mars, the rings on Saturn, and the moons of Jupiter.

    If not for a down-on-his luck Mongolian astronomer with a penchant for drinking, 44 schools in that rugged country might not have telescopes with which to peer into the heavens.

    It was a chance encounter with that ill-fated astronomer that led UC Santa Cruz grad student Tuguldur Sukhbold from his science-poor country, where he had to build his own telescopes, to the wooded campus in Santa Cruz where he is doing advanced research in astrophysics.

    And, it was the opportunities he got at UC Santa Cruz, he said, that allowed him to organize a project that, last year, delivered telescopes to 7 percent of the schools in Mongolia so that science-starved kids might be exposed to the wonders of the universe.

    “A lot of these kids will probably never travel to another country, or even travel to a city,” said Tuguldur of a country where horses outnumber people and where science education has lagged in the past 20 years. “Their world view is very limited. But with these telescopes, even if they can’t see the world, they can see the universe.”

    Tuguldur, 25, who goes by one name in his country, grew up on the steppes of Mongolia, learning, like many of his compatriots, to ride a horse at the age of 3. By the time he was a teenager he’d moved to the capital city, [Ulan Bator].

    “I started looking up into the sky,” Tuguldur said. “I began to wonder what it was all about and where did I come from and why was I here. I thought I might get answers from science.”

    The difficulty was that after the collapse of the Soviet Union, which had strong influence and financial ties to the country, Mongolia’s educational system took a hit and science was one of the casualties.

    Tuguldur began building his own telescopes using instructions he found on the Internet. He formed an astronomy club, and he and his friends peered into the heavens. Still, he understood that science was a dead-end job in Mongolia and he prepared to become a lawyer.

    But that meeting with the ill-starred astronomer changed everything. The scientist had once been part of a project started by the University of Arizona that searched for asteroids from posts around the world. He’d been given a telescope but, one night, the device was struck by lightning and the project came to a halt.

    Still wearing the worn University of Arizona T-shirt he’d been given by the American scientists, the astronomer told Tuguldur that Arizona was the center of astronomical research and that he should try to go to school there.

    So, Tuguldur did.

    He got a scholarship, struggled to learn English—although he was fluent in the mathematics required for physics—and got his bachelor’s degree. He came to UC Santa Cruz for his advanced degrees because of its faculty and “because it is one of the best places for what I do.”

    Still, his homeland was always on his mind.

    Tuguldur applied for and won a $6,000 grant from the International Astronomical Union. Together with a friend, Purevdorj Davaa, who is still in Mongolia, they purchased 44 four-and-a-half-inch, F/7.9 Newtonian telescopes from which kids could see craters on the moon, ice caps on Mars, the rings of Saturn, and the moons of Jupiter.

    Some of the telescopes were delivered to city schools, but many went into the rural steppes where raising livestock—horses, camels, goats, sheep, and cattle—is still the central occupation.

    “I had this dream that it would be really great to get a lot of money and bring telescopes to Mongolia, especially to the countryside,” Tuguldur said. “I thought that would be life-changing. I wanted to share the joy.”

    Besides delivering the telescopes, Tuguldur and his partner also did several teacher trainings on Skype and wrote a manual in Mongolian that showed students how to use a telescope and gave them some basics in astronomy.

    Next year, he and his friend hope to deliver 50 more telescopes and, one day, start a nonprofit that would press for more science education in the Mongolian curriculum.

    Said Professor Greg Laughlin, chair of UC Santa Cruz’s Astronomy and Astrophysics Department, “Tuguldur has consistently shown the courage, brilliance, and creativity that we here at UC Santa Cruz Astronomy all aspire to. His efforts are pushing forward the frontiers of knowledge, and, at the same time, are uniting people with common interests from across the globe.”

    “I am, in a way, very privileged,” Tuguldur said, sitting on a couch in a quiet annex behind the Natural Sciences II building on the UC Santa Cruz campus. “When I look back in my country, I see a lot of people living just to get by, day-by-day. They don’t have the luxury of spending time and resources to wonder about science.”

    He wants to change that, one telescope at a time.

    For more information visit Tuguldur’s website or email sukhbold@ucolick.org.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 3:31 am on February 18, 2015 Permalink | Reply
    Tags: , , UC Santa Cruz   

    From UCSC: “DNA sequencer the size of a mobile phone” 

    UC Santa Cruz

    UC Santa Cruz

    February 17, 2015
    Branwyn Wagman, UC Santa Cruz Genomics Institute

    1

    Investigators at the UC Santa Cruz Genomics Institute have optimized performance of a mobile-phone-sized MinIONTM DNA sequencer, marketed by Oxford Nanopore. Their work was reported in Nature Methods on February 16, 2015.

    The MinION device reads individual DNA strands base-by-base as they pass through a nanoscale pore (nanopore) under control of an applied voltage. This process is facilitated by an enzyme bound to the DNA.

    Biomolecular engineering graduate student Miten Jain led the research with director of comparative genomics Benedict Paten and biomolecular engineering professor Mark Akeson, who along with biochemist David Deamer has helped develop the scientific foundation of the nanopore device for the past 18 years.

    To optimize the MinION’s performance, the researchers used standard reference genomes and an expectation-maximization algorithm to obtain robust maximum likelihood estimates for rates of read insertions, deletions, and substitution errors (4.9%, 7.8%, and 5.1% respectively).

    The MinION technology is constantly evolving, resulting in multiple updates to the platform in the past six months, Akeson explained. “Each of these updates has resulted in improved read quality,” he said.

    “In this study we saw performance significantly better than what has been seen with this device before,” Akeson said. “Over 99% of high-quality, two-dimensional MinION reads mapped to the reference genome at a mean identity of 85%.”

    The UC Santa Cruz investigators also presented a tool that can be used to detect single nucleotide variants from MinION data. It employs maximum-likelihood parameter estimates and marginalization over many possible read alignments.

    “In this study, we were able to detect single-nucleotide variations with precision and recall of up to 99%,” said Paten.

    By pairing a high-confidence alignment strategy with long MinION reads, the group resolved the copy number for a cancer/testis gene family (CT47) within an unresolved region of human chromosome Xq24, a feat possible only with long-read sequencing such as the MinION makes possible.

    “The MinION nanopore sequencer is changing how we think about DNA sequencing,” Jain said. He explained that while DNA base read lengths of 8-10 kilobases are now considered normal, the MinION device has achieved reads exceeding 48 kilobases.

    “With the combination of long-reads and portability, the MinION is primed to disrupt the way we do genomics,” Jain said.

    The paper’s co-authors also included biomolecular engineering graduate student Ian Fiddes, postdoctoral scholar Karen Miga, and staff scientist Hugh Olsen. All are from the UC Santa Cruz Genomics Institute.

    The study was supported by National Human Genome Research Institute (NHGRI) grant HG006321.

    Read the report in Nature Methods.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
  • richardmitnick 6:39 am on January 20, 2015 Permalink | Reply
    Tags: , Hunger, , UC Santa Cruz   

    From UCSC: “Researchers find a novel signaling pathway involved in appetite control” 

    UC Santa Cruz

    UC Santa Cruz

    January 19, 2015
    Tim Stephens

    1
    Agouti-related protein regulates feeding behavior, illustrated here in the Eastern chipmunk. (Photo by Ed Reschke)

    A new study has revealed important details of a molecular signaling system in the brain that is involved in the control of body weight and metabolism. The study, published January 19 in Nature, provides a new understanding of the melanocortin pathway and could lead to new treatments for obesity.

    Coauthor Glenn Millhauser, a distinguished professor of chemistry and biochemistry at UC Santa Cruz, said the findings are very exciting and have broad biomedical implications. “We are getting to the real molecular features of what’s controlling this important signaling system in the brain,” Millhauser said.

    The study, led by researchers at Vanderbilt University, focused on a receptor embedded in the membranes of nerve cells called the melanocortin-4 receptor, or MC4R. It belongs to a class of receptors known as G-protein coupled receptors (GPCRs), which typically act like on-off switches, signaling over short time frames, according to Roger Cone, who led the study at Vanderbilt.

    “This finding identifies a molecular mechanism for converting an on-off switch into a rheostat,” Cone said. “This could help explain slow, sustained biological processes that also are mediated by GPCRs, such as tanning or weight regain after dieting.”

    Millhauser’s lab has done extensive research on proteins that bind to the MC4R receptor, such as agouti-related protein (AgRP). AgRP is a potent appetite stimulant. Its role in regulating energy balance is to suppress metabolism and increase feeding when the body needs to put on weight and store energy, Millhauser said. His lab has developed modified versions of the AgRP protein that alter its activity. In the new study, the modified proteins from Millhauser’s lab helped researchers identify a previously unsuspected effect of AgRP.

    Millhauser’s previous studies have shown that a single dose of AgRP given to laboratory animals can stimulate daily food intake for up to 10 days. This observation didn’t fit with the traditional “on-off” signaling model for the receptor it binds to, MC4R. G-protein coupled receptors can only take so much stimulation before they shut down, and this phenomenon, called desensitization, often happens rapidly.

    Cone’s lab discovered a companion protein–a potassium channel in the membrane called Kir7.1–that couples to the MC4R receptor and acts independently from G-protein signaling. The researchers found that AgRP induces MC4R to open the potassium channel, which “hyperpolarizes” and inhibits neurons that are involved in blocking appetite.

    “Moreover, with modifications to AgRP discovered previously by our lab, we can increase or decrease this coupling of the receptor to the potassium channel,” Millhauser said. “These concepts could ultimately lead to new generations of therapeutics for treating metabolic disorders, including obesity, anorexia, and cachexia, the wasting condition that often occurs in cancer treatment.”

    Coauthor Rafael Palomino, a graduate student and NIH Fellow in Millhauser’s lab, did the protein synthesis and purification work for the study. The first author is Masoud Ghamari-Langroudi at Vanderbilt. Other contributors include Jerod Denton and Robert Matthews at Vanderbilt and Helen Cox at King’s College, London. This research was supported by the National Institutes of Health.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

     
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