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News Article | February 24, 2017
Site: phys.org

Since that first sighting, SN 1987A has continued to fascinate astronomers with its spectacular light show. Located in the nearby Large Magellanic Cloud, it is the nearest supernova explosion observed in hundreds of years and the best opportunity yet for astronomers to study the phases before, during, and after the death of a star. To commemorate the 30th anniversary of SN 1987A, new images, time-lapse movies, a data-based animation based on work led by Salvatore Orlando at INAF-Osservatorio Astronomico di Palermo, Italy, and a three-dimensional model are being released. By combining data from NASA's Hubble Space Telescope and Chandra X-ray Observatory, as well as the international Atacama Large Millimeter/submillimeter Array (ALMA), astronomers—and the public—can explore SN 1987A like never before. Hubble has repeatedly observed SN 1987A since 1990, accumulating hundreds of images, and Chandra began observing SN 1987A shortly after its deployment in 1999. ALMA, a powerful array of 66 antennas, has been gathering high-resolution millimeter and submillimeter data on SN 1987A since its inception. "The 30 years' worth of observations of SN 1987A are important because they provide insight into the last stages of stellar evolution," said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and the Gordon and Betty Moore Foundation in Palo Alto, California. The latest data from these powerful telescopes indicate that SN 1987A has passed an important threshold. The supernova shock wave is moving beyond the dense ring of gas produced late in the life of the pre-supernova star when a fast outflow or wind from the star collided with a slower wind generated in an earlier red giant phase of the star's evolution. What lies beyond the ring is poorly known at present, and depends on the details of the evolution of the star when it was a red giant. "The details of this transition will give astronomers a better understanding of the life of the doomed star, and how it ended," said Kari Frank of Penn State University who led the latest Chandra study of SN 1987A. Supernovas such as SN 1987A can stir up the surrounding gas and trigger the formation of new stars and planets. The gas from which these stars and planets form will be enriched with elements such as carbon, nitrogen, oxygen and iron, which are the basic components of all known life. These elements are forged inside the pre-supernova star and during the supernova explosion itself, and then dispersed into their host galaxy by expanding supernova remnants. Continued studies of SN 1987A should give unique insight into the early stages of this dispersal. Some highlights from studies involving these telescopes include: Hubble studies have revealed that the dense ring of gas around the supernova is glowing in optical light, and has a diameter of about a light-year. The ring was there at least 20,000 years before the star exploded. A flash of ultraviolet light from the explosion energized the gas in the ring, making it glow for decades. The central structure visible inside the ring in the Hubble image has now grown to roughly half a light-year across. Most noticeable are two blobs of debris in the center of the supernova remnant racing away from each other at roughly 20 million miles an hour. From 1999 until 2013, Chandra data showed an expanding ring of X-ray emission that had been steadily getting brighter. The blast wave from the original explosion has been bursting through and heating the ring of gas surrounding the supernova, producing X-ray emission. In the past few years, the ring has stopped getting brighter in X-rays. From about February 2013 until the last Chandra observation analyzed in September 2015 the total amount of low-energy X-rays has remained constant. Also, the bottom left part of the ring has started to fade. These changes provide evidence that the explosion's blast wave has moved beyond the ring into a region with less dense gas. This represents the end of an era for SN 1987A. Beginning in 2012, astronomers used ALMA to observe the glowing remains of the supernova, studying how the remnant is actually forging vast amounts of new dust from the new elements created in the progenitor star. A portion of this dust will make its way into interstellar space and may become the building blocks of future stars and planets in another system. These observations also suggest that dust in the early universe likely formed from similar supernova explosions. Astronomers also are still looking for evidence of a black hole or a neutron star left behind by the blast. They observed a flash of neutrinos from the star just as it erupted. This detection makes astronomers quite certain a compact object formed as the center of the star collapsed—either a neutron star or a black hole—but no telescope has uncovered any evidence for one yet. Astronomers combined observations from three different observatories to produce this colorful, multiwavelength image of the intricate remains of Supernova 1987A. Credit: NASA, ESA, and A. Angelich (NRAO/AUI/NSF); Hubble credit: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) Chandra credit: NASA/CXC/Penn State/K. Frank et al.; ALMA credit: ALMA (ESO/NAOJ/NRAO) and R. Indebetouw (NRAO/AUI/NSF) Explore further: Space image: New supernova remnant lights up


News Article | February 24, 2017
Site: www.eurekalert.org

Three decades ago, astronomers spotted one of the brightest exploding stars in more than 400 years. The titanic supernova, called Supernova 1987A (SN 1987A), blazed with the power of 100 million suns for several months following its discovery on Feb. 23, 1987. Since that first sighting, SN 1987A has continued to fascinate astronomers with its spectacular light show. Located in the nearby Large Magellanic Cloud, it is the nearest supernova explosion observed in hundreds of years and the best opportunity yet for astronomers to study the phases before, during, and after the death of a star. To commemorate the 30th anniversary of SN 1987A, new images, time-lapse movies, a data-based animation based on work led by Salvatore Orlando at INAF-Osservatorio Astronomico di Palermo, Italy, and a three-dimensional model are being released. By combining data from NASA's Hubble Space Telescope and Chandra X-ray Observatory, as well as the international Atacama Large Millimeter/submillimeter Array (ALMA), astronomers -- and the public -- can explore SN 1987A like never before. Hubble has repeatedly observed SN 1987A since 1990, accumulating hundreds of images, and Chandra began observing SN 1987A shortly after its deployment in 1999. ALMA, a powerful array of 66 antennas, has been gathering high-resolution millimeter and submillimeter data on SN 1987A since its inception. "The 30 years' worth of observations of SN 1987A are important because they provide insight into the last stages of stellar evolution," said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and the Gordon and Betty Moore Foundation in Palo Alto, California. The latest data from these powerful telescopes indicate that SN 1987A has passed an important threshold. The supernova shock wave is moving beyond the dense ring of gas produced late in the life of the pre-supernova star when a fast outflow or wind from the star collided with a slower wind generated in an earlier red giant phase of the star's evolution. What lies beyond the ring is poorly known at present, and depends on the details of the evolution of the star when it was a red giant. "The details of this transition will give astronomers a better understanding of the life of the doomed star, and how it ended," said Kari Frank of Penn State University who led the latest Chandra study of SN 1987A. Supernovas such as SN 1987A can stir up the surrounding gas and trigger the formation of new stars and planets. The gas from which these stars and planets form will be enriched with elements such as carbon, nitrogen, oxygen and iron, which are the basic components of all known life. These elements are forged inside the pre-supernova star and during the supernova explosion itself, and then dispersed into their host galaxy by expanding supernova remnants. Continued studies of SN 1987A should give unique insight into the early stages of this dispersal. Some highlights from studies involving these telescopes include: Hubble studies have revealed that the dense ring of gas around the supernova is glowing in optical light, and has a diameter of about a light-year. The ring was there at least 20,000 years before the star exploded. A flash of ultraviolet light from the explosion energized the gas in the ring, making it glow for decades. The central structure visible inside the ring in the Hubble image has now grown to roughly half a light-year across. Most noticeable are two blobs of debris in the center of the supernova remnant racing away from each other at roughly 20 million miles an hour. From 1999 until 2013, Chandra data showed an expanding ring of X-ray emission that had been steadily getting brighter. The blast wave from the original explosion has been bursting through and heating the ring of gas surrounding the supernova, producing X-ray emission. In the past few years, the ring has stopped getting brighter in X-rays. From about February 2013 until the last Chandra observation analyzed in September 2015 the total amount of low-energy X-rays has remained constant. Also, the bottom left part of the ring has started to fade. These changes provide evidence that the explosion's blast wave has moved beyond the ring into a region with less dense gas. This represents the end of an era for SN 1987A. Beginning in 2012, astronomers used ALMA to observe the glowing remains of the supernova, studying how the remnant is actually forging vast amounts of new dust from the new elements created in the progenitor star. A portion of this dust will make its way into interstellar space and may become the building blocks of future stars and planets in another system. These observations also suggest that dust in the early universe likely formed from similar supernova explosions. Astronomers also are still looking for evidence of a black hole or a neutron star left behind by the blast. They observed a flash of neutrinos from the star just as it erupted. This detection makes astronomers quite certain a compact object formed as the center of the star collapsed -- either a neutron star or a black hole -- but no telescope has uncovered any evidence for one yet. These latest visuals were made possible by combining several sources of information including simulations by Salvatore Orlando and collaborators that appear in this paper: https:/ . The Chandra study by Frank et al. can be found online at http://lanl. . Recent ALMA results on SN 87A are available at https:/ . The Chandra program is managed by NASA's Marshall Space Flight Center in Huntsville, Alabama, for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations. The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of South Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ.


News Article | February 25, 2017
Site: www.techtimes.com

Photo credit | NASA, ESA, and A. Angelich (NRAO/AUI/NSF); Hubble credit: NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation) Photo credit | NASA, ESA, and R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation), and P. Challis (Harvard-Smithsonian Center for Astrophysics) Hubble is celebrating the 30th anniversary of the discovery of Supernova 1987A, a blazing stellar explosion that provided insights into the nature of supernovas. NASA released spectacular images and time-lapse videos that display the supernova’s structure. Photo credit | NASA, ESA, R. Kirshner (Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation), and M. Mutchler and R. Avila (STScI) Thirty years have passed since NASA spotted one of the brightest supernovas in 400 years. Known as Supernova 1987A, the stellar explosion generated kaleidoscopic fireworks of color and glowed with the power of 100 million suns for several months after its first sighting on Feb. 23, 1987. The supernova continues to fascinate astronomers today with its incredible light show. To celebrate its 30th anniversary, the Hubble Space Telescope has released a set of beautiful images and new information about SN 1987A. Prior to the discovery of SN 1987A, astronomers had little knowledge about the nature of supernovas, simply because there had been no nearby events available for observation. But on that fateful night in February three decades ago, the first light from the death of a star in the Large Magellanic Cloud reached Earth. That means a new star appeared in the Southern Hemisphere and became visible to the naked eye for months before it turned faint. SN 1987A has been the brightest supernova visible from Earth since 1604. This stellar event occurred about 166,000 light-years away from Tarantula Nebula, Milky Way's satellite galaxy called, and it offered scientists an unprecedented insight into the death of massive stars. While ground-based telescopes could spot SN 1987A as a small blob in the sky, NASA's Hubble Space Telescope captured high-resolution images of the supernova in 1990. The mission revealed in detail the incredible structures that surrounded the dead star. Since then, Hubble and other telescopes such as the Atacama Large Millimeter/Submillimeter Array and the Chandra X-ray Observatory have continued to take images of the supernova. For SN 1987A's 30th birthday, the public can access time-lapse movies, images, and data-based animation on the supernova. Much of these images are based on the research of Salvatore Orlando, from Italy's INAF-Osservatorio Astronomico di Palermo. All these missions have shown a ring-like structure around the progenitor star of the supernova, which had been ejected from the star 20,000 years before its ending stages. These ring-like structures have been illuminated more than once. The first time happened through the light of the supernova explosion. The second time in 2001, when shock waves reached the distance of the rings. Now, these shock waves are moving beyond that very dense ring of gas, which was generated when the wind it produced later in life struck a slower wind produced in its earlier phase. "The details of this transition will give astronomers a better understanding of the life of the doomed star, and how it ended," said scientist Kari Frank, lead researcher in the Chandra research. However, what lies beyond this structure is still unknown and will depend on details of the star's evolution, scientists said. Full details can be viewed at NASA's website. © 2017 Tech Times, All rights reserved. Do not reproduce without permission.


News Article | February 28, 2017
Site: www.eurekalert.org

By inhibiting the proteasome -- the cell's garbage disposal -- in a novel way, a new treatment causes cancer cells to fill up with 'trash' and self-destruct The genomes of cancer cells--cells that do not obey signals to stop reproducing--are riddled with genetic mutations, causing them inadvertently to make many dysfunctional proteins. Like all other cells, cancer cells need to be vigilant about cleaning themselves up in order to survive. Now, biologists in the laboratory of Ray Deshaies, Caltech professor of biology and Howard Hughes Medical Institute Investigator, have developed a new way to inhibit the cancer cell cleanup mechanism, causing the cells to fill up with defective proteins and thus self-destruct. The findings appear online in a paper in the February 27 issue of Nature Chemical Biology. The proteasome is a hollow cylindrical structure that serves as a kind of cellular garbage disposal. It lets in proteins through small openings on each end, chops them up, and spits out the remains. When a bad protein is made by a cell, the protein gets tagged with chains composed of at least four copies of a small protein called ubiquitin. The tags signal to the proteasome that the bad protein needs to be destroyed. One part of the proteasome, called Rpn11, cuts off the ubiquitin chain as the defective protein is being stuffed into the garbage disposal. This step is necessary because the ubiquitin chain is too big to fit inside the proteasome. A new compound developed by the Deshaies group, in collaboration with researchers from UC San Diego, inhibits Rpn11 activity, making it impossible for the proteasome to fully destroy bad proteins. Massive accumulation of these bad proteins causes catastrophic stress to the cell that results in cell death. While the compound affects the proteasomes in all cells, normal cells are thought to produce fewer dysfunctional proteins than cancer cells. Some types of cancer cells are therefore more sensitive than normal cells to proteasome inhibition and thus even a small dose of the drug can be fatal to them. "All current cancer drugs that target the proteasome work by inhibiting the protein-chopping enzymes on the inside of the proteasome; therefore they all have similar drawbacks and tend to lose efficacy over time," says Jing Li, a postdoctoral scholar in biology and biological engineering and first author on the paper. "Our research offers an alternative path to disabling proteasome function, including in cells that no longer respond to the existing drugs." The compound was tested in human cancer cells in the laboratory, but more work needs to be done to further improve its potency and to evaluate its potential as a therapeutic drug through testing in animals. The paper is titled "Capzimin is a potent and specific inhibitor of proteasome isopeptidase Rpn11." In addition to Li and Deshaies, other Caltech coauthors are postdoctoral fellow Tanya Yakushi and Sonja Hess, director of the Proteome Exploration Laboratory. The work was funded by grants from the Caltech Gates Grubstake Fund, Amgen, the National Institutes of Health, the Gordon and Betty Moore Foundation, the Beckman Institute, and the Howard Hughes Medical Institute.


News Article | February 2, 2016
Site: www.cemag.us

An international group of physicists led by the University of Arkansas has created an artificial material with a structure comparable to graphene. “We’ve basically created the first artificial graphene-like structure with transition metal atoms in place of carbon atoms,” says Jak Chakhalian, professor of physics and director of the Artificial Quantum Materials Laboratory. In 2014, Chakhalian was selected as a quantum materials investigator for the Gordon and Betty Moore Foundation. His selection came with a $1.8 million grant, a portion of which funded the study, Graphene, discovered in 2001, is a one-atom-thick sheet of graphite. Graphene transistors are predicted to be substantially faster and more heat tolerant than today’s silicon transistors and may result in more efficient computers and the next-generation of flexible electronics. Its discoverers were awarded the Nobel Prize in physics in 2010. The University of Arkansas -led group published its findings this week in Physical Review Letters, the journal of the American Physical Society, in a paper titled “Mott Electrons in an Artificial Graphene-like Crystal of Rare Earth Nickelate.” “This discovery gives us the ability to create graphene-like structures for many other elements,” says Srimanta Middey, a postdoctoral research associate at the University of Arkansas who led the study. The research group also included postdoctoral research associates Michael Kareev and Yanwei Cao, doctoral student Xiaoran Liu, and recent doctoral graduate Derek Meyers, now at Brookhaven National Laboratory. Additional members of the group were David Doennig of the University of Munich, Rossitza Pentcheva of the University of Duisburg-Essen in Germany, Zhenzhong Yang, Jinan Shi, and Lin Gu of the Chinese Academy of Sciences; and John W. Freeland and Phillip Ryan of the Advanced Photon Source at Argonne National Laboratory near Chicago. The research was also partially funded by the Chinese Academy of Sciences. The of their report reads: Deterministic control over the periodic geometrical arrangement of the constituent atoms is the backbone of the material properties, which, along with the interactions, define the electronic and magnetic ground state. Following this notion, a bilayer of a prototypical rare-earth nickelate, NdNiO , combined with a dielectric spacer, LaAlO , has been layered along the pseudocubic [111] direction. The resulting artificial graphenelike Mott crystal with magnetic 3D electrons has antiferromagnetic correlations. In addition, a combination of resonant X-ray linear dichroism measurements and ab initio calculations reveal the presence of an ordered orbital pattern, which is unattainable in either bulk nickelates or nickelate based heterostructures grown along the [001] direction. These findings highlight another promising venue towards designing new quantum many-body states by virtue of geometrical engineering.


News Article | December 13, 2016
Site: www.eurekalert.org

Following a 'keystone dialogue' between scientists and seafood industry, 8 of world's largest seafood companies issue 10-point statement committing to action on ocean stewardship Eight of the world's largest seafood companies have issued a ten-point statement committing to action on ocean stewardship following the first "keystone dialogue" between scientists and business leaders. Through the "keystone dialogues" - a new approach to engage major international businesses in global sustainability challenges - companies have committed to improving transparency and traceability and reducing illegal, unreported and unregulated fishing in their supply chains. Antibiotic use in aquaculture, greenhouse gas emissions and plastic pollution will also now be prioritized. And the businesses commit to eliminating any products in their supply chains that may have been obtained through "modern slavery including forced, bonded and child labour". The statement says signatories "represent a global force, not only in the operation of the seafood industry, but also in contributing to a resilient planet." It was signed by the two largest companies by revenues (Maruha Nichiro Corporation and Nippon Suisan Kaisha, Ltd), two of the largest tuna companies in the world (Thai Union Group PCL and Dongwon Industries), the two largest salmon farmers (Marine Harvest ASA and Cermaq - subsidiary of Mitsubishi Corporation) and the two largest aquafeeds companies (Skretting - subsidiary of Nutreco, and Cargill Aqua Nutrition). To implement the commitments the companies plan to create a new initiative - Seafood Business for Ocean Stewardship - that will, for the first time, connect wild capture fisheries to aquaculture businesses, connect European and North American companies to Asian companies and connect the global seafood business to science. The inaugural dialogue, initiated by the Stockholm Resilience Centre, took place 11-13 November at the Soneva Fushi Resort on the Maldives under the patronage of HRH Crown Princess Victoria of Sweden - Advocate for the UN Sustainable Development Goals (SDGs). The initiative was a unique meeting between CEOs, senior leadership of major seafood companies, leading scientists from the Stockholm Resilience Centre, and advisors including The Honorable Dr Jane Lubchenco of Oregon State University and U.S. Science Envoy for the Ocean - U.S. State Department, Mr Volker Kuntzsch, CEO of Sanford Ltd., Mr Rupert Howes, CEO of Marine Stewardship Council, and Ambassador Magnus Robach, Swedish Ambassador to Japan. "We depend on a stable and resilient planet for human prosperity. However, science is already providing evidence that we have entered the Anthropocene, an epoch where humanity is now challenging the stability of Earth and its ocean," the statement goes on to say. The dialogue is the first between scientists and "keystone actors" a term coined in 2015 by Carl Folke and Henrik Österblom, science directors at the Stockholm Resilience Centre. Keystone species play a disproportionate role in ecosystems. Increasingly, large transnational corporations now play this role, for example, in the ocean and in rainforests. Österblom led research identifying the keystone actors in the world's oceans. The team identified 13 transnational corporations controlling 11-16% of wild marine catch and up to 40% of the largest and most valuable fish stocks. "We invited the leaders of these companies to a dialogue to build trust and develop a common understanding about the state of the ocean," said Österblom. "We were delighted so many companies accepted our offer. This shows they are aware of the urgency of the situation and willing to engage in these issues." According to related research published by a group of U.S. scientists in 2016, good management of global fisheries could lead to increase in annual catches of over 16 million metric tons and $53 billion in profit compared with remaining on the current trajectory. Stockholm Resilience Centre Director Johan Rockström said, "The small concentration of multinational companies means that CEOs are significant leverage points to effectively engage in transforming the entire seafood sector towards more sustainable practices". Chair of the dialogue, and founding director of Forum for the Future, Jonathon Porritt said, "It's hugely encouraging to see these leading companies in the global seafood industry making such critical commitments to help protect the world's ocean. This combination of world-class science and inspirational corporate leadership is a powerful one - and I've no doubt we'll need to see a lot more of it over the next few years." The organization was a key supporter of the dialogue. Myoung W Lee, CEO of Dongwon, one of the largest tuna companies, said, "It's remarkable that seafood companies came together to discuss the sustainability and development of the seafood industry and lay grounds for ocean stewardship. I am honored to have contributed to such a significant, historic event and will ensure that Dongwon does our part to uphold the agreement." Cermaq CEO Geir Molvik said, "Cermaq is very much engaged in Sustainable Development Goal 14 - life below water - and have encompassed the SDGs in our business strategy. Working with other keystone actors in the global seafood sector is important because it's only through partnerships we can efficiently pull in the same direction and make significant changes." President of Cargill Aqua Nutrition, a major aquafeed company, Einar Wathne said, "This initiative has a truly global perspective, from east to west. That makes me believe that we will have a powerful impact when addressing the challenges we have in our oceans and marine ecosystems, with the UN Sustainable Development Goals as our guideline." "Creating more awareness of the opportunities - and business necessities - of managing seafood sustainably should be a key priority for CEOs," added Jean-Baptiste Jouffray, PhD candidate at the Stockholm Resilience Centre and co-organiser of the event. The dialogue will now be followed up with additional meetings and dialogue between science and business. A next meeting is already scheduled for next year, where more concrete joint actions will be identified. Companies who attended and signed the statement: Maruha Nichiro Corporation Nippon Suisan Kaisha, Ltd Thai Union Group Marine Harvest ASA Dongwon Industries Nutreco (owner of Skretting) Cargill Aqua Nutrition Cermaq (subsidiary of Mitsubishi Corporation) Additional information about this initiative and the science that support it: http://www. http://www. http://www. http://www. Scientists Henrik Österblom, Deputy Science Director at Stockholm Resilience Centre: henrik.osterblom@su.se Jean-Baptiste Jouffray, PhD-student at the Stockholm Resilience Centre and the Royal Swedish Academy of Sciences: jean-baptiste.jouffray@su.se Carl Folke, Science Director at Stockholm Resilience Centre and Director, Beijer Institute of Ecological Economics at the Royal Swedish Academy of Sciences: carl.folke@beijer.kva.se Johan Rockström, Director, Stockholm Resilience Centre: johan.rockstrom@su.se The dialogue was a Stockholm Resilience Centre event supported by Forum for the Future and the Soneva Foundation. The Walton Family Foundation, the David and Lucile Packard Foundation and the Gordon and Betty Moore Foundation funded the dialogue. Photographs from the dialogue available on request. Please contact jean-baptiste.jouffray@su.se


News Article | February 27, 2017
Site: news.yahoo.com

Discovered 30 years ago, Supernova 1987A is one of the brightest exploding stars of the last four centuries. To commemorate its anniversary, NASA has now released a tranche of new data about the spectacular star, including striking imagery and time-lapse video. The supernova is the closest star explosion seen in centuries, presenting an unique opportunity for astronomers to study the progress of the star’s death. The images, animations and time-lapse video have been created from data from NASA’s Hubble Space Telescope, Chandra X-ray Observatory and ALMA. All three instruments have been collecting data about the star’s explosion since it was first discovered in 1987. “The 30 years’ worth of observations of SN 1987A are important because they provide insight into the last stages of stellar evolution,” said Robert Kirshner of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, and the Gordon and Betty Moore Foundation in Palo Alto, California. NASA ESA R Kirshner Harvard-Smithsonian Center for Astrophysics and Gordon and Betty Moore Foundation and M Mutchler and R Avila STScI SN 1987A can be seen at the centre of this image, resembling a white eye with a bright white pupil. The image can be viewed in full here. The data suggests the supernova has passed a critical threshold: the shockwave is now beyond the ring of gas produced late in the life of the pre-supernova. It’s knot known what lies beyond the ring. “The details of this transition will give astronomers a better understanding of the life of the doomed star, and how it ended,” said Kari Frank of Penn State University who led the latest Chandra study of SN 1987A. Supernovas occur when a change in a star’s core causes it to explode. They are the brightest explosions in space. Edward H. White II, pilot of the Gemini 4 spacecraft, floats in the zero gravity of space with an earth limb backdrop circa November 1965. Kinescope images of astronaut Commander Neil Armstrong in the Apollo 11 space shuttle during the space mission to land on the moon for the first time in history on July 20, 1969 The ascent stage of Orion, the Apollo 16 Lunar Module, lifts of from its descent stage to rendezvous with the Apollo 16 Command and Service Module, Casper, with astronaut Thomas Mattingly aboard in lunar orbit on 23rd April 1972. Five NASA astronauts aboard the Space Shuttle Atlantis look out overhead windows on the aft flight deck toward their counterparts aboard the Mir Space Station in March of 1996. Photograph of the Milky Way Galaxy captured by NASA's Spitzer Space Telescope. Dated 2007. The exhaust plume from space shuttle Atlantis is seen through the window of a Shuttle Training Aircraft (STA) as it launches from launch pad 39A at the Kennedy Space Center July 8, 2011 in Cape Canaveral, Florida. A United Launch Alliance Delta 4 rocket carrying NASA's first Orion deep space exploration craft sits on its launch pad as it is prepared for a 7:05 AM launch on December 4, 2014 in Cape Canaveral, Florida. A military pilot sits in the cockpit of an X-15 experimental rocket aircraft, wearing an astronaut's spacesuit circa 1959. Echo 1, a spherical balloon with a metalized skin, was launched by NASA on 12th August 1960. Once in orbit the balloon was inflated until it reached its intended diameter of 30 metres and it was then used as a reflector to bounce radio signals across the oceans. Four views of Earth rising above the lunar horizon, photographed by the crew of the Apollo 10 Lunar Module, while in lunar orbit, May 1969. American geologist and Apollo 17 astronaut Harrison Hagan Schmitt stands next to the US flag on the surface of the moon, during a period of EVA (Extra-Vehicular Activity) at the Taurus-Littrow landing site, December 1972. The space shuttle 'Enterprise' (NASA Orbiter Vehicle 101) makes its way along Rideout Road (Alabama State Route 255) to the Marshall Space Flight Center near Huntsville, Alabama, 15th March 1978. A crowd of people, viewed from behind, watch the launch of the first NASA Space Shuttle mission (STS-1), with Columbia (OV-102) soaring up into the sky, leaving a trail of exhaust smoke, in the distance from the launchpad at the Kennedy Space Center, Florida, USA, 12 April 1981. Astronaut Bruce McCandless II photographed at his maximum distance (320 ft) from the Space Shuttle Challenger during the first untethered EVA, made possible by his nitrogen jet propelled backpack (Manned Manuevering Unit or MMU) in 1984. Aerial shot of the launch of Space Shuttle Discovery (STS-41-D) as it takes off, leaving a trail of exhaust smoke, from Kennedy Space Center, Florida, USA, 30 August 1984. An astronaut's bootprint leaves a mark on the lunar surface July 20, 1969 on the moon. The 30th anniversary of the Apollo 11 Moon mission is celebrated July 20, 1999. Astronaut Charles Moss Duke, Jr. leaves a photograph of his family on the surface of the moon during the Apollo 16 lunar landing mission, 23rd April 1972.


WASHINGON, D.C. -- The American Association for the Advancement of Science (AAAS) will release a new report Connecting Scientists to Policy Around the World: Landscape Analysis of Mechanisms Around the World Engaging Scientists and Engineers in Policy, that documents best practices for immersive science-policy connection mechanisms. A session on the report will be held at the AAAS Annual Meeting in Boston, MA, from 10:30 a.m. to noon on Thursday, February 16, at the Sheraton Boston Hotel, in Constitution Ballroom B (see program and list of speakers at end of this release). AAAS conducted the landscape analysis in response to growing interest in establishing programs modeled on its successful Science & Technology Policy Fellowships. Sponsored by the Gordon and Betty Moore Foundation, the project affirmed global demand to strengthen connections between science and policy, highlighted factors for productive engagement of scientists in the policy sphere, identified more than 150 science-policy linkage mechanisms, and clarified criteria to support their success. The need to engage and nurture a new generation of scientists globally to meet current and future demand at the science-policy interface emerged as a primary focal point. The report recommends critical actions to cultivate and network boundary-spanning STEM (science, technology, engineering, mathematics) leaders and support them to engage successfully at the intersection of science and policy around the world, including: "Successful boundary spanning is all about cultivating relationships, establishing connections, and developing collaborations to address complex problems," says Cynthia Robinson, senior policy advisor at AAAS, and former director of the Science & Technology Policy Fellowships. "Finding solutions to tough challenges won't happen by simply ensuring scientific information is available. It requires scientists actually engaging in problem-solving policy processes, and participating to implement solutions." Since 1973, the AAAS S&T Policy Fellowships program has trained more than 3,000 scientists and engineers to successfully support evidence-based policymaking at the federal level through its model of embedding participants in government offices and the policymaking processes. The majority of STPF alumni continue in careers that build bridges between science and policy. Ten programs have been launched modeled on STPF, operating in the U.S. at the national and state levels, internationally in the ASEAN region, and in Canada, Israel, and Switzerland. New programs are planned for Argentina and Spain. "We are now seeing a new generation of young scientists around the world eager to contribute their science to policy and diplomacy," notes Marga Gual Soler, project director in the AAAS Center for Science Diplomacy. "This report will serve as a guide for the scientific and policy communities to establish new science policy immersion programs and strengthen existing linkages between scientists and policymakers at all levels." International collaboration to build science policy capacity is an emerging dimension of science diplomacy. The landscape analysis identified programs operating at binational and regional levels that present effective approaches for establishing relationships between countries as well as connecting the scientific and policy communities. This is especially important for addressing challenges that are transboundary in nature. "This report captures what currently exists. The next step is to build on what we know and have learned from existing programs to develop new mechanisms that address the specific unmet needs of individual countries or regions," says Tom Wang, chief international officer of AAAS, and director of the Center for Science Diplomacy. The report concludes with recommendations to foster a global network of boundary-spanning scientists empowered to share knowledge, collaborate, and expand their impact to address global challenges that no nation can solve alone. Following is the program for the report release event. 10:30am Opening remarks Cynthia R. Robinson, Senior Policy Advisor, Center of Science, Policy and Society Programs; Principal Investigator, Science & Technology Policy Fellowships, AAAS Tom C. Wang, Chief International Officer; Director, Center for Science Diplomacy, AAAS 10:40am Presentation of the "Connecting Scientists to Policy Around the World" report Marga Gual Soler, Project Director, Center for Science Diplomacy, AAAS 11:00am Panel: Experiences and examples of mechanisms for science policy engagement Frances Colón, Member of the External Advisory Committee, Immediate Past Deputy Science and Technology Adviser to the U.S. Secretary of State Rachael Maxwell, Lead, Canadian Science Policy Fellowship Atsushi Sunami, Member of the External Advisory Committee, Vice- President and Professor, National Graduate Institute for Policy Studies (GRIPS), Japan Agustin Campero, Secretary for Scientific and Technological Articulation, Ministry of Science, Technology and Productive Innovation, Argentina 11:50 Closing remarks: Importance of international cooperation in building science policy capacity H.R.H. Princess Sumaya Bint El Hassan, President, Royal Scientific Society of Jordan To download a copy of the full report and the executive summary please visit http://www. . For more information email: globalsciencepolicy@aaas.org.


News Article | September 26, 2016
Site: www.cemag.us

Researchers have created an exotic 3D racetrack for electrons in ultrathin slices of a nanomaterial they fabricated at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). The international team of scientists from Berkeley Lab, UC Berkeley, and Germany observed, for the first time, a unique behavior in which electrons rotate around one surface, then through the bulk of the material to its opposite surface and back. The possibility of developing so-called “topological matter” that can carry electrical current on its surface without loss at room temperature has attracted significant interest in the research community. The ultimate goal is to approach the lossless conduction of another class of materials, known as superconductors, but without the need for the extreme, freezing temperatures that superconductors require. “Microchips lose so much energy through heat dissipation that it’s a limiting factor,” said James Analytis, a staff scientist at Berkeley Lab and assistant professor of physics at UC Berkeley who led the study, published in Nature. “The smaller they become, the more they heat up.” The studied material, an inorganic semimetal called cadmium arsenide (Cd3As2), exhibits quantum properties—which are not explained by the classical laws of physics—that offer a new approach to reducing waste energy in microchips. In 2014, scientists discovered that cadmium arsenide shares some electronic properties with graphene, a single-atom-thick material also eyed for next-generation computer components, but in a 3-D form. “What’s exciting about these phenomena is that, in theory, they are not affected by temperature, and the fact they exist in three dimensions possibly makes fabrication of new devices easier,” Analytis said. The cadmium arsenide samples displayed a quantum property known as “chirality” that couples an electron’s fundamental property of spin to its momentum, essentially giving it left- or right-handed traits. The experiment provided a first step toward the goal of using chirality for transporting charge and energy through a material without loss. In the experiment, researchers manufactured and studied how electric current travels in slices of a cadmium arsenic crystal just 150 nanometers thick, or about 600 times smaller than the width of a human hair, when subjected to a high magnetic field. The crystal samples were crafted at Berkeley Lab’s Molecular Foundry, which has a focus in building and studying nanoscale materials, and their 3-D structure was detailed using X-rays at Berkeley Lab’s Advanced Light Source. Many mysteries remain about the exotic properties of the studied material, and as a next step researchers are seeking other fabrication techniques to build a similar material with built-in magnetic properties, so no external magnetic field is required. “This isn’t the right material for an application, but it tells us we’re on the right track,” Analytis said. If researchers are successful in their modifications, such a material could conceivably be used for constructing interconnects between multiple computer chips, for example, for next-generation computers that rely on an electron’s spin to process data (known as “spintronics”), and for building thermoelectric devices that convert waste heat to electric current. It wasn’t clear at first whether the research team would even be able to manufacture a pure enough sample at the tiny scale required to carry out the experiment, Analytis said. “We wanted to measure the surface states of electrons in the material. But this 3-D material also conducts electricity in the bulk—it’s central region—as well as at the surface,” he said. As a result, when you measure the electric current, the signal is swamped by what is going on in the bulk so you never see the surface contribution.” So they shrunk the sample from millionths of a meter to the nanoscale to give them more surface area and ensure that the surface signal would be the dominant one in an experiment. “We decided to do this by shaping samples into smaller structures using a focused beam of charged particles,” he said. “But this ion beam is known to be a rough way to treat the material—it is typically intrinsically damaging to surfaces, and we thought it was never going to work.” But Philip J.W. Moll, now at the Max Planck Institute for Chemical Physics of Solids in Germany, found a way to minimize this damage and provide finely polished surfaces in the tiny slices using tools at the Molecular Foundry. “Cutting something and at the same time not damaging it are natural opposites. Our team had to push the ion beam fabrication to its limits of low energy and tight beam focus to make this possible.” When researchers applied an electric current to the samples, they found that electrons race around in circles similar to how they orbit around an atom’s nucleus, but their path passes through both the surface and the bulk of the material. The applied magnetic field pushes the electrons around the surface. When they reach the same energy and momentum of the bulk electrons, they get pulled by the chirality of the bulk and pushed through to the other surface, repeating this oddly twisting path until they are scattered by material defects. The experiment represents a successful marriage of theoretical approaches with the right materials and techniques, Analytis said. “This had been theorized by Andrew Potter on our team and his co-workers, and our experiment marks the first time it was observed,” Analytis said. “It is very unusual—there is no analogous phenomena in any other system. The two surfaces of the material ‘talk’ to each other over large distances due to their chiral nature.” “We had predicted this behavior as a way to measure the unusual properties expected in these materials, and it was very exciting to see these ideas come to life in real experimental systems,” said Potter, an assistant physics professor at the University of Texas at Austin. “Philip and collaborators made some great innovations to produce extremely thin and high-quality samples, which really made these observations possible for the first time.” Researchers also learned that disorder in the patterning of the material’s crystal surface doesn’t seem to affect the behavior of electrons there, though disorder in the central material does have an impact on whether the electrons move across the material from one surface to the other. The motion of the electrons exhibits a dual handedness, with some electrons traveling around the material in one direction and others looping around in an opposite direction. Researchers are now building on this work in designing new materials for ongoing studies, Analytis said. “We are using techniques normally restricted to the semiconductor industry to make prototype devices from quantum materials.” Berkeley Lab’s Molecular Foundry and Advanced Light Source are both DOE Office of Science User Facilities. This work was supported by the Department of Energy’s Office of Science, the Gordon and Betty Moore Foundation, and the Swiss Federal Institute of Technology in Zurich (ETH Zurich).


News Article | December 19, 2016
Site: news.mit.edu

Around the world, wide swaths of open ocean are nearly depleted of oxygen. Not quite dead zones, they are “oxygen minimum zones,” where a confluence of natural processes has led to extremely low concentrations of oxygen. Only the hardiest of organisms can survive in such severe conditions, and now MIT oceanographers have found that these tough little life-forms — mostly bacteria — have a surprisingly low limit to the amount of oxygen they need to breathe. In a paper published by the journal Limnology and Oceanography, the team reports that ocean bacteria can survive on oxygen concentrations as low as approximately 1 nanomolar per liter. To put this in perspective, that’s about 1/10,000th the minimum amount of oxygen that most small fish can tolerate and about 1/1,000th the level that scientists previously suspected for marine bacteria. The researchers have found that below this critical limit, microbes either die off or switch to less common, anaerobic forms of respiration, taking up nitrogen instead of oxygen to breathe. With climate change, the oceans are projected to undergo a widespread loss of oxygen, potentially increasing the spread of oxygen minimum zones around the world. The MIT team says that knowing the minimum oxygen requirements for ocean bacteria can help scientists better predict how future deoxygenation will change the ocean’s balance of nutrients and the marine ecosystems that depend on them. “There’s a question, as circulation and oxygen change in the ocean: Are these oxygen minimum zones going to shoal and become more shallow, and decrease the habitat for those fish near the surface?” says Emily Zakem, the paper’s lead author and a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS). “Knowing this biological control on the process is really necessary to making those sorts of predictions.” How low does oxygen go? Oxygen minimum zones, sometimes referred to as “shadow zones,” are typically found at depths of 200 to 1,000 meters. Interestingly, these oxygen-depleted regions are often located just below a layer of high oxygen fluxes and primary productivity, where fish swimming near the surface are in contact with the oxygen-rich atmosphere. Such areas generate a huge amount of organic matter that sinks to deeper layers of the ocean, where bacteria use oxygen — far less abundant than at the surface — to consume the detritus. Without a source to replenish the oxygen supply at such depths, these zones quickly become depleted. Other groups have recently measured oxygen concentrations in depleted zones using a highly sensitive instrument and observed, to their surprise, levels as low as a few nanomolar per liter — about 1/1,000th of what many others had previously measured — across hundreds of meters of deep ocean. Zakem and Follows sought to identify an explanation for such low oxygen concentrations, and looked to bacteria for the answer. “We’re trying to understand what controls big fluxes in the Earth system, like concentrations of carbon dioxide and oxygen, which set the parameters of life,” Zakem says. “Bacteria are among the organisms on Earth that are integral to setting large-scale nutrient distributions. So we came into this wanting to develop how we think of bacteria at the climate scale.” The researchers developed a simple model to simulate how a bacterial cell grows. They focused on particularly resourceful strains that can switch between aerobic, oxygen-breathing respiration, and anaerobic, nonoxygen-based respiration. Zakem and Follows assumed that when oxygen is present, such microbes should use oxygen to breathe, as they would expend less energy to do so. When oxygen concentrations dip below a certain level, bacteria should switch over to other forms of respiration, such as using nitrogen instead of oxygen to fuel their metabolic processes. The team used the model to identify the critical limit at which this switch occurs. If that critical oxygen concentration is the same as the lowest concentrations recently observed in the ocean, it would suggest that bacteria regulate the ocean’s lowest oxygen zones. To identify bacteria’s critical oxygen limit, the team included in its model several key parameters that regulate a bacterial population: the size of an individual bacterial cell; the temperature of the surrounding environment; and the turnover rate of the population, or the rate at which cells grow and die. They modeled a single bacterial cell’s oxygen intake with changing parameter values and found that, regardless of the varying conditions, bacteria’s critical limit for oxygen intake centered around vanishingly small values. “What’s interesting is, we found that across all this parameter space, the critical limit was always centered at about 1 to 10 nanomolar per liter,” Zakem says. “This is the minimum concentration for most of the realistic space you would see in the ocean. This is useful because we now think we have a good handle on how low oxygen gets in the ocean, and [we propose] that bacteria control that process.” Looking forward, Zakem says the team’s simple bacterial model can be folded into global models of atmospheric and ocean circulation. This added nuance, she says, can help scientists better predict how changes to the world’s climate, such as widespread warming and ocean deoxygenation, may affect bacteria. While they are the smallest organisms, bacteria can potentially have global effects, Zakem says. For instance, as more bacteria switch over to anaerobic forms of respiration in deoxygenated zones, they may consume more nitrogen and give off as a byproduct nitrogen dioxide, which can be released back into the atmosphere as a potent greenhouse gas. “We can think of this switch in bacteria as setting the ocean’s fertility,” Zakem says. “When nitrogen is lost from the ocean, you’re losing accessible nutrients back into the atmosphere. To know how much denitrification and nitrogen dioxide flux will change in the future, we absolutely need to know what controls that switch from using oxygen to using nitrogen. In that regard, this work is very fundamental.” This research was supported, in part, by the Gordon and Betty Moore Foundation, the Simons Foundation, NASA, and the National Science Foundation.

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