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  • richardmitnick 9:22 pm on May 22, 2015 Permalink | Reply
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    From New Scientist: “Supernova space bullets could have seeded Earth’s iron core” 

    NewScientist

    New Scientist

    20 May 2015
    Jacob Aron

    1
    Shooting stars (Image: X-ray: NASA/CXC/SAO; Infrared: NASA/JPL-Caltech; Optical: MPIA, Calar Alto, O. Krause et al)

    Supernova shoot-em-ups could be responsible for Earth’s iron core. An analysis suggests that certain stars fire off massive iron bullets when they die.

    Stars fuse the hydrogen and helium present in the early universe into heavier elements, like iron. When stars reach the end of their lives, they explode in supernovae, littering these elements throughout space where they can eventually form planets.

    A particular kind of supernova called a type Ia, the result of the explosion of a dense stellar corpse called a white dwarf star, seems to be responsible for most of the iron on Earth.

    These stars also play an important role in our understanding of distance in the universe. That’s because the white dwarfs only blow up when they reach a certain, fixed mass, so we can use the light of these explosions as a “standard candle” to tell how far away they are.

    But astronomers still haven’t figured out exactly what causes white dwarfs to hit this critical limit.

    “Most of our iron on Earth comes from supernovae of this kind,” says Noam Soker of the Technion Israel Institute of Technology in Haifa. “It is embarrassing that we still don’t know what brings these white dwarfs to explode.”

    Lumpy stars

    When a star goes supernova, it leaves behind a cloud of ejected material called a supernova remnant. This remnant should be spherical – but some have extra bumps that could offer a clue to the supernova’s origin.

    Now Soker and his colleague Danny Tsebrenko say that massive clumps of iron produced within a white dwarf in the process of going supernova could be punching through the remnant like bullets, creating these bumps. The iron bullets aren’t solid chunks of metal, but a more diffuse cloud of molecules.

    Some supernova remnants have two bumps on opposite sides, which the researchers call “ears”.

    The iron bullets form along the rotation axis of an exploding white dwarf, firing out at either end, says Soker. A white dwarf can only be spinning fast enough to allow this if it is the result of two smaller dwarfs merging, he adds.

    The bullets could also shed light on our origins. Soker and Tsebrenko estimate that these clouds of iron would be several times the mass of Jupiter. They would spread and could eventually seed dust clouds with iron that would go on to form stars and planets, providing an origin for Earth’s core, says Soker.

    Reference: arxiv.org/abs/1505.02034v1

    See the full article here.

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  • richardmitnick 9:02 pm on May 22, 2015 Permalink | Reply
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    From PPPL: “A little drop will do it: Tiny grains of lithium can dramatically improve the performance of fusion plasmas” 


    PPPL

    May 22, 2015
    Raphael Rosen

    1
    Left: DIII-D tokamak. Right: Cross-section of plasma in which lithium has turned the emitted light green. (Credits: Left, General Atomics / Right, Steve Allen, Lawrence Berkeley National Laboratory)

    Scientists from General Atomics and the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have discovered a phenomenon that helps them to improve fusion plasmas, a finding that may quicken the development of fusion energy. Together with a team of researchers from across the United States, the scientists found that when they injected tiny grains of lithium into a plasma undergoing a particular kind of turbulence then, under the right conditions, the temperature and pressure rose dramatically. High heat and pressure are crucial to fusion, a process in which atomic nuclei – or ions – smash together and release energy — making even a brief rise in pressure of great importance for the development of fusion energy.

    “These findings might be a step towards creating our ultimate goal of steady-state fusion, which would last not just for milliseconds, but indefinitely,” said Tom Osborne, a physicist at General Atomics and lead author of the paper. This work was supported by the DOE Office of Science.

    The scientists used a device developed at PPPL to inject grains of lithium measuring some 45 millionths of a meter in diameter into a plasma in the DIII-D National Fusion Facility – or tokamak – that General Atomics operates for DOE in San Diego.

    DOE DIII-D Tokamak
    DIII-D National Fusion Facility

    When the lithium was injected while the plasma was relatively calm, the plasma remained basically unaltered. Yet as reported this month in a paper in Nuclear Fusion, when the plasma was undergoing a kind of turbulence known as a “bursty chirping mode,” the injection of lithium doubled the pressure at the outer edge of the plasma. In addition, the length of time that the plasma remained at high pressure rose by more than a factor of 10.

    Experiments have sustained this enhanced state for up to one-third of a second. A key scientific objective will be to extend this enhanced performance for the full duration of a plasma discharge.

    Physicists have long known that adding lithium to a fusion plasma increases its performance. The new findings surprised researchers, however, since the small amount of lithium raised the plasma’s temperature and pressure more than had been expected.

    These results “could represent the birth of a new tool for influencing or perhaps controlling tokamak edge physics,” said Dennis Mansfield, a physicist at PPPL and a coauthor of the paper who helped develop the injection device called a “lithium dropper.” Also working on the experiments were researchers from Lawrence Livermore National Laboratory, Oak Ridge National Laboratory, the University of Wisconsin-Madison and the University of California-San Diego.

    Conditions at the edge of the plasma have a profound effect on the superhot core of the plasma where fusion reactions take place. Increasing pressure at the edge region raises the pressure of the plasma as a whole. And the greater the plasma pressure, the more suitable conditions are for fusion reactions. “Making small changes at the plasma’s edge lets us increase the pressure further within the plasma,” said Rajesh Maingi, manager of edge physics and plasma-facing components at PPPL and a coauthor of the paper.

    Further experiments will test whether the lithium’s interaction with the bursty chirping modes — so-called because the turbulence occurs in pulses and involves sudden changes in pitch — caused the unexpectedly strong overall effect.

    See the full article here.

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    Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University. PPPL, on Princeton University’s Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. Results of PPPL research have ranged from a portable nuclear materials detector for anti-terrorist use to universally employed computer codes for analyzing and predicting the outcome of fusion experiments. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single supporter of basic research in the physical sciences in the United States, and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

     
  • richardmitnick 1:21 pm on May 22, 2015 Permalink | Reply
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    From Hubble: “Hubble’s Look at an Extragalactic Peculiarity” 

    NASA Hubble Telescope

    Hubble

    May 22, 2015
    Karl Hille

    1
    NASA/ESA Hubble

    This galaxy goes by the name of ESO 162-17 and is located about 40 million light-years away in the constellation of Carina. At first glance this image seems like a fairly standard picture of a galaxy with dark patches of dust and bright patches of young, blue stars. However, a closer look reveals several peculiar features.

    Firstly, ESO 162-17 is what is known as a peculiar galaxy — a galaxy that has gone through interactions with its cosmic neighbors, resulting in an unusual amount of dust and gas, an irregular shape, or a strange composition.

    Secondly, on February 23, 2010 astronomers observed the supernova known as SN 2010ae nestled within this galaxy. The supernova belongs to a recently discovered class of supernovae called Type Iax supernovae. This class of objects is related to the better known Type-Ia supernovae.

    Type Ia supernovae result when a white dwarf accumulates enough mass either from a companion or, rarely, through collision with another white dwarf, to initiate a catastrophic collapse followed by a spectacular explosion as a supernova. Type Iax supernovae also involve a white dwarf as the central star, but in this case it may survive the event. Type Iax supernovae are much fainter and rarer than Type Ia supernovae, and their exact mechanism is still a matter of open debate.

    The rather beautiful four-pointed shape of foreground stars distributed around ESO 162-17 also draws the eye. This is an optical effect introduced as the incoming light is diffracted by the four struts that support the Hubble Space Telescope’s small secondary mirror.

    See the full article here.

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 1:05 pm on May 22, 2015 Permalink | Reply
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    From Hubble: “Hubble Revisits Tangled NGC 6240″ 

    NASA Hubble Telescope

    Hubble

    May 22, 2015
    Ashley Morrow

    1
    Image credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

    Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown here in a pinky-red hue at the center of the galaxies, was only revealed in these new observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys.

    NASA Hubble WFC3
    WFC3

    NASA Hubble ACS
    ACS

    NGC 6240 lies 400 million light-years away in the constellation of Ophiuchus (The Serpent Holder). This galaxy has an elongated shape with branching wisps, loops and tails. This mess of gas, dust and stars bears more than a passing resemblance to a butterfly and a lobster.

    This bizarrely-shaped galaxy did not begin its life looking like this; its distorted appearance is a result of a galactic merger that occurred when two galaxies drifted too close to one another. This merger sparked bursts of new star formation and triggered many hot young stars to explode as supernovae. A new supernova, not visible in this image was discovered in this galaxy in 2013, named SN 2013dc.

    At the center of NGC 6240 an even more interesting phenomenon is taking place. When the two galaxies came together, their central black holes did so, too. There are two supermassive black holes within this jumble, spiraling closer and closer to one another. They are currently only some 3,000 light-years apart, incredibly close given that the galaxy itself spans 300,000 light-years. This proximity secures their fate as they are now too close to escape each other and will soon form a single immense black hole.

    See the full article here.

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    The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI), is a free-standing science center, located on the campus of The Johns Hopkins University and operated by the Association of Universities for Research in Astronomy (AURA) for NASA, conducts Hubble science operations.

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  • richardmitnick 12:47 pm on May 22, 2015 Permalink | Reply
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    From NASA: “Coronal Loops Over a Sunspot Group” 

    NASA

    NASA

    May 22, 2015
    Sarah Loff

    1
    Image Credit: NASA SDO

    The Atmospheric Imaging Assembly (AIA) instrument aboard NASA’s Solar Dynamics Observatory (SDO) images the solar atmosphere in multiple wavelengths to link changes in the surface to interior changes. Its data includes images of the sun in 10 wavelengths every 10 seconds. When AIA images are sharpened a bit, such as this AIA 171Å channel image, the magnetic field can be readily visualized through the bright, thin strands that are called “coronal loops”. Loops are shown here in a blended overlay with the magnetic field as measured with SDO’s Helioseismic and Magnetic Imager underneath. Blue and yellow represent the opposite polarities of the magnetic field. The combined images were taken on Oct. 24, 2014, at 23:50:37 UT.

    NASA SDO
    SDO

    See the full article here.

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    The National Aeronautics and Space Administration (NASA) is the agency of the United States government that is responsible for the nation’s civilian space program and for aeronautics and aerospace research.

    President Dwight D. Eisenhower established the National Aeronautics and Space Administration (NASA) in 1958 with a distinctly civilian (rather than military) orientation encouraging peaceful applications in space science. The National Aeronautics and Space Act was passed on July 29, 1958, disestablishing NASA’s predecessor, the National Advisory Committee for Aeronautics (NACA). The new agency became operational on October 1, 1958.

    Since that time, most U.S. space exploration efforts have been led by NASA, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle and Commercial Crew vehicles. The agency is also responsible for the Launch Services Program (LSP) which provides oversight of launch operations and countdown management for unmanned NASA launches. Most recently, NASA announced a new Space Launch System that it said would take the agency’s astronauts farther into space than ever before and lay the cornerstone for future human space exploration efforts by the U.S.

    NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics through the efforts of the Science Mission Directorate’s Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories [Hubble, Chandra, Spitzer, and associated programs. NASA shares data with various national and international organizations such as from the [JAXA]Greenhouse Gases Observing Satellite.

     
  • richardmitnick 12:26 pm on May 22, 2015 Permalink | Reply
    Tags: BNL ATF,   

    From BNL: “Brookhaven Lab’s Accelerator Test Facility Named a DOE Office of Science User Facility” Exciting News 

    Brookhaven Lab

    May 19, 2015
    Justin Eure

    New designation of Brookhaven National Laboratory’s ATF coincides with major facility upgrades and expansions to accommodate the growing demand of users from industry and academia

    1
    The Free Electron Laser at Brookhaven’s Accelerator Test Facility.

    Brookhaven National Laboratory’s Accelerator Test Facility (ATF), already one of the world’s leading facilities for advanced accelerator research and development, has been named a U.S. Department of Energy (DOE) Office of Science User Facility.

    “This designation recognizes the ATF’s past performance, current excellence, and future importance to the Office of Science and our international community of scientific users from industry, academia, and other major laboratories,” said Ilan Ben-Zvi, head of the Accelerator Research & Development Division of Brookhaven’s Collider-Accelerator Department. “We are honored and excited to continue our work at Brookhaven Lab, where accelerator science and technology has always played a key role.”

    The ATF joins the ranks of Brookhaven’s other major Office of Science User Facilities—the Relativistic Heavy Ion Collider, the National Synchrotron Light Source II, and the Center for Functional Nanomaterials [CFN]—all of which tailor their distinct capabilities and expertise to the needs of users. These facilities are all accessed through a peer-reviewed proposal process and are free to users conducting non-proprietary, open research.

    BNL RHIC
    RHIC

    BNL NSLS IIBNL NSLS-II Interior
    NSLS-II

    BNL Center for Functional Nanomaterials interior
    CFN

    ATF operations are funded through the Accelerator Stewardship subprogram of the DOE Office of Science’s High Energy Physics Program.

    Designing the next generation of particle accelerators

    The ATF hosts about 50 users every year, all seeking highly customizable beam lines and rapid experimental turnaround time.

    The ATF currently features the following core capabilities:

    Linear accelerator with an 80-million-electron-volt (MeV) beam of electrons
    A 2-terawatt CO2 laser synchronized for interaction with the electron beam
    A range of plasma sources, beam manipulation devices, and comprehensive diagnostics

    “We are a user-driven facility dedicated to meeting diverse and ever-changing experimental ideas,” said ATF Director Igor Pogorelsky. “Scientists come here to study and develop new principles and techniques for particle accelerators and radiation sources using a combination of high-power lasers and conventional electron accelerators. This fundamental R&D lays the foundation for the future of accelerator science, and it is always challenging and rewarding work.”

    Added Pogorelsky, “We can take an experiment from proposal to realization in the matter of a few weeks. We manipulate the beams’ parameters and introduce new scientific hardware to fit the specific needs of our users.”

    A proven track record

    The ATF has a proven track record in pioneering accelerator science for advanced concepts such as plasma and dielectric wakefield acceleration (where particles ride waves produced by electrons and laser pulses), laser accelerators, and proton and ion acceleration for cancer therapy.

    “We offer the world’s only user-accessible, high-power CO2 laser, and have blazed trails in the fields of laser acceleration, photocathode electron sources, and free electron lasers,” said ATF Operations Coordinator Mikhail Fedurin. “That work led to the development of essential technology inside facilities such as the Linac Coherent Light Source at SLAC National Accelerator Laboratory.”

    SLAC LCLS Inside
    SLAC LCLS

    Recent users and experiments include:

    NASA’s Jet Propulsion Laboratory testing the cosmic ray resilience of instrumentation for a proposed unmanned mission to Jupiter and its moon Europa
    Radiabeam Technologies producing intense space-coherent radiation for Extreme Ultraviolet Lithography metrology by colliding laser and electron beams (Inverse Compton Scattering)
    Naval Research Lab and Imperial College, London generating ions by firing a CO2 laser on a gas jet target to engineer compact and affordable machines for proton cancer therapy
    Euclid Techlab developing a terahertz radiation source by passing an electron beam through a dielectric structure
    UCLA’s Inverse Free Electron Laser experiment showing record electron acceleration in vacuum induced by a laser

    The ATF also maintains an ongoing commitment to educating and inspiring the next generation of accelerator scientists. The ATF hosts classes as part of the Center for Accelerator Science and Education (CASE) a joint venture between Stony Brook University and Brookhaven Lab. Graduate students visit ATF facilities regularly to learn the fundamentals of beam physics through actual experimental investigation. More than 37 students have completed their PhD theses based on work performed at the ATF.

    More powerful and versatile ATF

    In step with this new designation, the ATF is undergoing major upgrades to accommodate more users and a greater range of experiments. These upgrades, dubbed ATF-II, include relocating to a larger building, constructing additional experimental beam lines, and radically increasing the energy and versatility of the ATF laser and electron beams.

    2
    The highly customizable experimental hall at Brookhaven’s Accelerator Test Facility

    The ATF-II upgrade will unfold in two stages. The first phase, already underway, involves moving to a larger building on the Brookhaven campus to accommodate at least five planned beam lines.

    “Completion of stage one will open three spacious experimental halls to our users and provide a 100-MeV electron beam in femtosecond pulses,” Ben-Zvi said. “At the same time, we will also be upgrading our CO2 laser to 100 terawatts, which will be unparalleled in the world.”

    Stage one is scheduled for completion in 2018, but the first users will begin experiments later this year. The ATF-II upgrades, like ATF operations, are partly funded by the Office of Science’s Accelerator Stewardship program. The CO2 laser upgrade—the Brookhaven Experimental Supra-Terawatt Infrared at ATF (BESTIA)—is funded by Brookhaven’s Program Development program. The Laboratory is also making substantial upgrades to the building that will house the ATF-II. In addition, ATF-II will make extensive use of repurposed equipment from Brookhaven’s now-retired National Synchrotron Light Source and Source Development Laboratory, and the Bates Accelerator Laboratory at MIT.

    The second stage of ATF-II, not yet approved, would focus on increasing the electron beam energy to 500 MeV. This compact, powerful beam would open new experimental landscapes, including research into ultra-high-gradient structure-based accelerators, plasma-based accelerators, and beam-produced radiation such as Compton-generated gamma rays.

    “We support DOE’s mission of solving the world most challenging problems, and we offer a singular service to scientists eager to push the fundamental limits of technology,” Ben-Zvi said. “Now, as an Office of Science User Facility undergoing major upgrades, the future at ATF has never been brighter.”

    See the full article here.

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    BNL Campus

    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 9:43 am on May 22, 2015 Permalink | Reply
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    From Arizona: “New Insights Into Drivers of Earth’s Ecosystems” 

    U Arizona bloc

    University of Arizona

    May 21, 2015
    Raymond Sanchez

    1
    Seawater samples are prepared for extraction of marine viruses aboard the Tara Oceans vessel. (Photo: Anna Deniaud/Tara Oceans)

    A UA-led international team has uncovered new information about the ways marine viruses and microbes interact on a global scale.

    2
    Scientists aboard the Tara Oceans vessel prepare to lower a CTD device into the blue depths. A suite of sampling containers and instruments allows them to collect specimens and data at the same time. (Photo: Anna Deniaud/Tara Oceans)

    Hidden among Earth’s vast oceans are some of the most vital organisms to the health of delicate ecosystems. Tiny ocean microbes produce half of the oxygen we breathe, and they are important drivers in chemical reactions and energy transfers that fuel critical ecological processes.

    Much like other organisms, marine microbes are susceptible to viral infections that can alter their metabolic output, or even kill them. For example, certain ocean viruses invade algae and take control over the photosynthetic process, which replenishes the oxygen we breathe. Others simply kill off vast amounts of organisms, putting a cap on the biomass that can support food webs in the world’s oceans.

    3
    In the ship’s lab, former Sullivan lab member Melissa Duhaime filters viruses from ocean water samples. (Photo: Anna Deniaud/Tara Oceans)

    A new study from an international team led by UA scientists Matthew Sullivan, Jennifer Brum, Simon Roux and Julio Cesar Ignacio Espinoza draws on viral genome data to explain how oceanic viral communities maintain high regional diversity on par with global diversity. The findings may help researchers to predictively model the virus-microbe interactions driving Earth’s ecosystems.

    The paper is one of five landmark studies borne from the Tara Oceans Expedition featured this week in a special issue of the journal Science. Sullivan is scheduled to discuss the work this week on the National Public Radio program “Science Friday.”

    “We established a means to study viral populations within more complex communities and found that surface ocean viruses were passively transported on currents and that population abundances were structured by local environmental conditions,” said Sullivan, associate professor in the Department of Ecology and Evolutionary Biology and a member of the BIO5 Institute. The work was completed with the assistance of a Gordon and Betty Moore Foundation Investigator grant, a highly prestigious award given to researchers focused on environmental science and conservation.

    Sullivan’s work is part of the Tara Oceans Expedition, a global effort to understand complex interactions among ocean ecosystems, climate and biodiversity. For the past 10 years, the Tara Oceans research vessel has traversed more than 180,000 miles across all of the world’s oceans, collecting biological samples and information about the oceans’ physical parameters such as depth, temperature and salinity.

    “The Tara Oceans expedition provided a platform for systematically sampling ocean biota from viruses to fish larvae, and in a comprehensive environmental context,” Sullivan said. “Until now, a global picture of ocean viral community patterns and ecological drivers was something we could only dream of achieving.”

    To assess geographical diversity in marine viral communities, Sullivan and his team looked at double-stranded DNA viral genomic sequence data, or viromes, and whole viral community morphological data across 43 Tara Oceans expedition samples. The samples were globally distributed throughout the surface oceans (only one deep-sea sample) and represented diverse environmental conditions.

    Specifically, Sullivan and his team were interested in the previous observation that the diversity of ocean viruses at any given site was as high as that observed globally. Such high local and low global diversity had been observed a decade ago, and scientists proposed a seed-bank hypothesis to explain it. This hypothesis suggests that high local genetic diversity can exist by drawing variation from a common and relatively limited global gene pool. Local-dominant communities consist of viruses that are influenced by environmental conditions, which affect their microbial hosts and indirectly alter the structure of the viral community. These communities serve as the low-abundance “bank” for neighboring locations, as they are passively transported by way of ocean currents.

    Since viruses lack universal genes that could be used to identify global community patterns, Sullivan had to employ different techniques to study viral communities. The first approach involved looking at viral particles themselves, and comparing morphological characteristics such as capsid size and tail length.

    “This is the low resolution way to do things — viruses that appear identical may have completely different genomes,” Sullivan explained. “The fact that all viruses don’t share a single common gene calls for some clever approaches to investigating viral diversity.”

    Next, the researchers cataloged viral populations in terms of the proteins they shared in common, in a process called protein clustering. This allowed them to establish core genes that were shared across the viral communities studied. Finally, Sullivan and his team looked at the distribution of viral populations, the majority of which had not been previously characterized, across all of the Tara Oceans sample sites.

    When they investigated the distribution patterns, they found that the directionality of viral population flow closely corresponded to that of ocean currents, affirming the seed-bank hypothesis.

    “Ocean virus-microbe interactions have a huge impact on global biogeochemistry,” Sullivan said. “As they destroy microbial cells, they change the forms of nutrients available to other, larger organisms in ocean ecosystems. This recycling of nutrients through viral lysis is an important pathway that regulates how the oceanic ecosystem functions. Viral infections simultaneously reduce the amount of nutrients and materials available to larger organisms by killing microbial cells, but also stimulate microbial activity through the release of organic matter and nutrients, which provides increased biomass available for larger organisms including fish.”

    Sullivan’s findings stem from key advances in methodology, including the ability to systematically collect biological samples on a global scale and pushing the analysis of marine viral characteristics into the realm of the quantitative.

    “Up until recently, the methods used to study virus-microbe interactions were often qualitative,” Sullivan said. “With this study, we have made great quantitative advances. The goal now is to determine how our quantitative estimates can be used to build predictive models.”

    Sullivan emphasized the uniqueness and importance of working with the Tara Oceans team.

    “This is an incredible new way of doing science,” he said. “At Tara Oceans, we are united by a common goal rather than a common funding source. These first papers show the world that we’re capable of doing science at this scale, and yet they represent just the tip of the iceberg of what is hidden in these vast data sets. We’ve got years of work ahead of us.”

    Sullivan and his lab also contributed to three other papers in the special issue. Those three papers explore the global ocean microbiome and plankton interaction networks, as well as how plankton communities change across a key ocean circulation choke point off South Africa.

    See the full article here.

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    U Arizona campus

    The University of Arizona (UA) is a place without limits-where teaching, research, service and innovation merge to improve lives in Arizona and beyond. We aren’t afraid to ask big questions, and find even better answers.

    In 1885, establishing Arizona’s first university in the middle of the Sonoran Desert was a bold move. But our founders were fearless, and we have never lost that spirit. To this day, we’re revolutionizing the fields of space sciences, optics, biosciences, medicine, arts and humanities, business, technology transfer and many others. Since it was founded, the UA has grown to cover more than 380 acres in central Tucson, a rich breeding ground for discovery.

    Where else in the world can you find an astronomical observatory mirror lab under a football stadium? An entire ecosystem under a glass dome? Visit our campus, just once, and you’ll quickly understand why the UA is a university unlike any other.

     
  • richardmitnick 9:12 am on May 22, 2015 Permalink | Reply
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    From CAASTRO: “Old, gas-rich galaxies likely had early star formation boom” 

    CAASTRO bloc

    CAASTRO ARC Centre of Excellence for All Sky Astrophysics

    22 May 2015
    No Writer Credit

    The most massive stars (with masses up to a hundred times the mass of our sun) explode as supernovae at the end of their life and release huge amounts of energy and material into their neighbourhoods. These phenomena are so energetic that they can alter the rate of star formation and impact the chemical composition of galaxies since heavy elements are synthesised in the interior of stars via nuclear fusion reactions. Astronomical observations suggest that many supernova explosions adding up can halt the formation of new stars and expel enriched gas out of galaxies. Indirect observations seem also to suggest that a supermassive black hole resides at the centre of virtually all galaxies. We still do not know how these objects formed but we believe that their masses are greater than 1 million solar masses and the energy emitted by gas falling into them could produce outflows at even higher velocity than the supernova driven outflows (thousands of km/s).

    1

    In a recent University of Melbourne led paper, Dr Edoardo Tescari and colleagues present the first results of the CAASTRO supported AustraliaN GADGET-3 early Universe Simulations project, or ANGUS for short. The team ran numerical simulations of the Universe in its early stages (up to 13 billion years ago) to study formation and evolution of galaxies and how they interact with their environment. They focused in particular on the so called “feedback” effects associated with the formation of stars and supermassive black holes at the centre of galaxies.

    Including the effects of both, supernovae and supermassive black holes, their simulations tested different configurations of feedback (early/late and weak/strong). The researchers found that efficient feedback at early times is needed to reproduce new observations of the global amount of star formation in the “young” Universe. They propose the following theoretical scenario to explain their results: galaxies that formed 13 billion years ago contained a lot of gas that was quickly converted into many stars. The back-reaction of the star formation processes (i.e. feedback) has since suppressed subsequent star formation especially in low mass galaxies.

    Publication details:
    E. Tescari, A. Katsianis, S. Wyithe, K. Dolag, L. Tornatore, P. Barai, M. Viel, S. Borgani in MNRAS (2014) Simulated star formation rate functions at z ~ 4 – 7, and the role of feedback in high-z galaxies

    See the full article here.

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    Astronomy is entering a golden age, in which we seek to understand the complete evolution of the Universe and its constituents. But the key unsolved questions in astronomy demand entirely new approaches that require enormous data sets covering the entire sky.

    In the last few years, Australia has invested more than $400 million both in innovative wide-field telescopes and in the powerful computers needed to process the resulting torrents of data. Using these new tools, Australia now has the chance to establish itself at the vanguard of the upcoming information revolution centred on all-sky astrophysics.

    CAASTRO has assembled the world-class team who will now lead the flagship scientific experiments on these new wide-field facilities. We will deliver transformational new science by bringing together unique expertise in radio astronomy, optical astronomy, theoretical astrophysics and computation and by coupling all these capabilities to the powerful technology in which Australia has recently invested.

    PARTNER LINKS

    The University of Sydney
    The University of Western Australia
    The University of Melbourne
    Swinburne University of Technology
    The Australian National University
    Curtin University
    University of Queensland

     
  • richardmitnick 8:51 am on May 22, 2015 Permalink | Reply
    Tags: , , ,   

    From ANU: “Supernova ignition surprises scientists” 

    ANU Australian National University Bloc

    Australian National University

    21 May 2015
    No Writer Credit

    1
    NEWS from the Australian Gemini Office! ANU astronomer Dr Brad Tucker and his team used the Kepler Space Telescope together with the Gemini 8m telescope to catch supernovae in the act.

    Gemini South telescope
    Gemini South Interior
    Gemini

    Photo: Supernova SN2012fr, just to the left of the centre of the galaxy, outshone the rest of the galaxy for several weeks: Credit Brad Tucker and Emma Kirby

    Scientists have captured the early death throes of supernovae for the first time and found that the universe’s benchmark explosions are much more varied than expected.

    The scientists used the Kepler space telescope to photograph three type 1a supernovae in the earliest stages of ignition.

    NASA Kepler Telescope
    NASA/Kepler

    They then tracked the explosions in detail to full brightness around three weeks later, and the subsequent decline over the next few months.

    They found the initial stages of a supernova explosion did not fit with the existing theories.

    “The stars all blow up uniquely. It doesn’t make sense,” said Dr Brad Tucker, from the Research School of Astronomy and Astrophysics.

    “It’s particularly weird for these supernovae because even though their initial shockwaves are very different, they end up doing the same thing.”

    Before this study, the earliest type 1a supernovae had been glimpsed was more than 2.5 hours after ignition, after which the explosions all followed an identical pattern.

    This led astronomers to theorise that supernovae, the brilliant explosions of dying stars, all occurred through an identical process.

    Astronomers had thought supernovae all happened when a dense star steadily sucked in material from a large nearby neighbour until it became so dense that carbon in the star’s core ignited.

    “Somewhat to our surprise the results suggest an alternative hypothesis, that a violent collision between two smallish white dwarf stars sets off the explosion,” said lead researcher Dr Robert Olling, from the University of Maryland in the United States.

    At the peak of their brightness, supernovae are brighter than the billions of stars in their galaxy. Because of their brightness, astronomers have been able to use them to calculate distances to distant galaxies.

    Measurements of distant supernovae led to the discovery that some unknown force, now called dark energy, is causing the accelerated expansion of the universe. Brian Schmidt from the ANU, Saul Perlmutter (Berkeley) and Adam Reiss (Johns Hopkins) were awarded the Nobel prize in 2011 for this discovery.

    Dr Tucker said the new results did not undermine the discovery of dark energy.

    “The accelerating universe will not now go away – they will not have to give back their Nobel prizes,” he said.

    “The new results will actually help us to better understand the physics of supernovae, and figure out what is this dark energy that is dominating the universe.”

    The findings are published in Nature.

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    ANU Campus

    ANU is a world-leading university in Australia’s capital city, Canberra. Our location points to our unique history, ties to the Australian Government and special standing as a resource for the Australian people.

    Our focus on research as an asset, and an approach to education, ensures our graduates are in demand the world-over for their abilities to understand, and apply vision and creativity to addressing complex contemporary challenges.

     
  • richardmitnick 8:28 am on May 22, 2015 Permalink | Reply
    Tags: , , , , ,   

    From CERN: “First images of collisions at 13 TeV” 

    CERN New Masthead

    21 May 2015
    Cian O’Luanaigh

    1
    Test collisions continue today at 13 TeV in the Large Hadron Collider (LHC) to prepare the detectors ALICE, ATLAS, CMS, LHCb, LHCf, MOEDAL and TOTEM for data-taking, planned for early June (Image: LHC page 1)

    Last night, protons collided in the Large Hadron Collider (LHC) at the record-breaking energy of 13 TeV for the first time. These test collisions were to set up systems that protect the machine and detectors from particles that stray from the edges of the beam.

    A key part of the process was the set-up of the collimators. These devices which absorb stray particles were adjusted in colliding-beam conditions. This set-up will give the accelerator team the data they need to ensure that the LHC magnets and detectors are fully protected.

    Today the tests continue. Colliding beams will stay in the LHC for several hours. The LHC Operations team will continue to monitor beam quality and optimisation of the set-up.

    This is an important part of the process that will allow the experimental teams running the detectors ALICE, ATLAS, CMS, LHCb, LHCf, MOEDAL and TOTEM to switch on their experiments fully. Data taking and the start of the LHC’s second run is planned for early June.

    2
    Protons collide at 13 TeV sending showers of particles through the ALICE detector (Image: ALICE)

    3
    Protons collide at 13 TeV sending showers of particles through the CMS detector (Image: CMS)

    4
    Protons collide at 13 TeV sending showers of particles through the ATLAS detector (Image: ATLAS)

    5
    Protons collide at 13 TeV sending showers of particles through the LHCb detector (Image: LHCb)

    6
    Protons collide at 13 TeV sending showers of particles through the TOTEM detector (Image: TOTEM)

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    Meet CERN in a variety of places:

    Cern Courier

    THE FOUR MAJOR PROJECT COLLABORATIONS

    ATLAS
    CERN ATLAS New
    ALICE
    CERN ALICE New

    CMS
    CERN CMS New

    LHCb
    CERN LHCb New

    LHC

    CERN LHC New
    CERN LHC Grand Tunnel

    LHC particles

    Quantum Diaries

     
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