Daylight saving impacts timing of heart attacks

Still feeling the residual effects of springing ahead for daylight saving time? The hour of sleep lost — or gained — may play a bigger, perhaps more dangerous role in our body’s natural rhythm than we think. It seems moving the clock forward or backward may alter the timing of when heart attacks occur in the week following these time changes, according to research to be presented at the American College of Cardiology’s 63rd Annual Scientific Session.Data from the largest study of its kind in the U.S. reveal a 25 percent jump in the number of heart attacks occurring the Monday after we “spring forward” compared to other Mondays during the year — a trend that remained even after accounting for seasonal variations in these events. But the study showed the opposite effect is also true. Researchers found a 21 percent drop in the number of heart attacks on the Tuesday after returning to standard time in the fall when we gain an hour back.”What’s interesting is that the total number of heart attacks didn’t change the week after daylight saving time,” said Amneet Sandhu, M.D., cardiology fellow, University of Colorado in Denver, and lead investigator of the study. “But these events were much more frequent the Monday after the spring time change and then tapered off over the other days of the week. It may mean that people who are already vulnerable to heart disease may be at greater risk right after sudden time changes.”Heart attacks historically occur most often on Monday mornings. Sandhu explains that in looking at other “normal” Mondays, there is some variation in events, but it is not significant. However, when he and his team compared admissions from a database of non-federal Michigan hospitals the Monday before the start of daylight saving time and the Monday immediately after for four consecutive years, they found a consistent 34 percent increase in heart attacks from one week to the next (93 heart attacks the Monday before compared to 125 the week after the start of daylight saving time for the duration of the study.).Although researchers cannot say what might be driving the shift in heart attack timing after the start of daylight saving time, they have a theory.”Perhaps the reason we see more heart attacks on Monday mornings is a combination of factors, including the stress of starting a new work week and inherent changes in our sleep-wake cycle,” Sandhu said. …

Read more

Hubble witnesses an asteroid mysteriously disintegrating

The NASA/ESA Hubble Space Telescope has photographed the never-before-seen break-up of an asteroid, which has fragmented into as many as ten smaller pieces. Although fragile comet nuclei have been seen to fall apart as they approach the Sun, nothing like the breakup of this asteroid, P/2013 R3, has ever been observed before in the asteroid belt.”This is a rock. Seeing it fall apart before our eyes is pretty amazing,” said David Jewitt of UCLA, USA, who led the astronomical forensics investigation.The crumbling asteroid, designated P/2013 R3, was first noticed as an unusual, fuzzy-looking object on 15 September 2013 by the Catalina and Pan-STARRS sky surveys. Follow-up observations on 1 October with the Keck Telescope on Mauna Kea, Hawaii, revealed three co-moving bodies embedded in a dusty envelope that is nearly the diameter of Earth.”Keck showed us that this thing was worth looking at with Hubble,” Jewitt said. With its superior resolution, the space-based Hubble observations soon showed that there were really ten distinct objects, each with comet-like dust tails. The four largest rocky fragments are up to 200 metres in radius, about twice the length of a football pitch.The Hubble data showed that the fragments are drifting away from each other at a leisurely 1.5 kilometres per hour — slower than the speed of a strolling human. The asteroid began coming apart early last year, but the latest images show that pieces continue to emerge.”This is a really bizarre thing to observe — we’ve never seen anything like it before,” says co-author Jessica Agarwal of the Max Planck Institute for Solar System Research, Germany. “The break-up could have many different causes, but the Hubble observations are detailed enough that we can actually pinpoint the process responsible.”The ongoing discovery of more fragments makes it unlikely that the asteroid is disintegrating due to a collision with another asteroid, which would be instantaneous and violent in comparison to what has been observed. Some of the debris from such a high-velocity smash-up would also be expected to travel much faster than has been observed.It is also unlikely that the asteroid is breaking apart due to the pressure of interior ices warming and vaporising. The object is too cold for ices to significantly sublimate, and it has presumably maintained its nearly 480-million-kilometre distance from the Sun for much of the age of the Solar System.This leaves a scenario in which the asteroid is disintegrating due to a subtle effect of sunlight that causes the rotation rate to slowly increase over time. …

Read more

Water discovered in remnants of extrasolar rocky world orbiting white dwarf

Oct. 10, 2013 — Astrophysicists have found the first evidence of a water-rich rocky planetary body outside our solar system in its shattered remains orbiting a white dwarf.A new study by scientists at the Universities of Warwick and Cambridge published in the journal Science analysed the dust and debris surrounding the white dwarf star GD61 170 light years away.Using observations obtained with the Hubble Space Telescope and the large Keck telescope on Hawaii, they found an excess of oxygen — a chemical signature that indicates that the debris had once been part of a bigger body originally composed of 26 per cent water by mass. By contrast, only approximately 0.023 per cent of Earth’s mass is water.Evidence for water outside our solar system has previously been found in the atmosphere of gas giants, but this study marks the first time it has been pinpointed in a rocky body, making it of significant interest in our understanding of the formation and evolution of habitable planets and life.We know from our own solar system that the dwarf planet Ceres contains ice buried beneath an outer crust, and the researchers draw a parallel between the two bodies. Scientists believe that bodies like Ceres were the source of the bulk of our own water on Earth.The researchers suggest it is most likely that the water detected around the white dwarf GD 61 came from a minor planet at least 90 km in diameter but potentially much bigger, that once orbited the parent star before it became a white dwarf.Like Ceres, the water was most likely in the form of ice below the planet’s surface. From the amount of rocks and water detected in the outer envelope of the white dwarf, the researchers estimate that the disrupted planetary body had a diameter of at least 90km.However, because their observations can only detect what is being accreted in recent history, the estimate of its mass is on the conservative side.It is likely that the object was as large as Vesta, the largest minor planet in the solar system. In its former life, GD 61 was a star somewhat bigger than our Sun, and host to a planetary system.About 200 million years ago, GD 61 entered its death throes and became a white dwarf, yet, parts of its planetary system survived. The water-rich minor planet was knocked out of its regular orbit and plunged into a very close orbit, where it was shredded by the star’s gravitational force. The researchers believe that destabilising the orbit of the minor planet requires a so far unseen, much larger planet going around the white dwarf.Professor Boris Gänsicke of the Department of Physics at the University of Warwick “At this stage in its existence, all that remains of this rocky body is simply dust and debris that has been pulled into the orbit of its dying parent star.”However this planetary graveyard swirling around the embers of its parent star is a rich source of information about its former life. “In these remnants lie chemical clues which point towards a previous existence as a water-rich terrestrial body.”Those two ingredients — a rocky surface and water — are key in the hunt for habitable planets outside our solar system so it’s very exciting to find them together for the first time outside our solar system.”Lead author Jay Farihi, from Cambridge’s Institute of Astronomy, said: “The finding of water in a large asteroid means the building blocks of habitable planets existed — and maybe still exist — in the GD 61 system, and likely also around substantial number of similar parent stars.”These water-rich building blocks, and the terrestrial planets they build, may in fact be common — a system cannot create things as big as asteroids and avoid building planets, and GD 61 had the ingredients to deliver lots of water to their surfaces,” Farihi said.”Our results demonstrate that there was definitely potential for habitable planets in this exoplanetary system.”For their analysis , the researchers used ultraviolet spectroscopy data obtained with the Cosmic Origins Spectrograph on board the Hubble Space Telescope of the white dwarf GD 61. As the atmosphere of Earth blocks the ultraviolet light, such study can only be carried out from space.Additional observations were obtained with the 10m large mirror of the W.M. …

Read more

Urgent new time frame for climate change revealed by massive analysis

Oct. 9, 2013 — The seesaw variability of global temperatures often engenders debate over how seriously we should take climate change. But within 35 years, even the lowest monthly dips in temperatures will be hotter than we’ve experienced in the past 150 years, according to a new and massive analysis of all climate models. The tropics will be the first to exceed the limits of historical extremes and experience an unabated heat wave that threatens biodiversity and heavily populated countries with the fewest resources to adapt.Ecological and societal disruptions by modern climate change are critically determined by the time frame over which climates shift. Camilo Mora and colleagues in the College of Social Sciences’ Department of Geography at the University of Hawaii, Manoa have developed one such time frame. The study, entitled “The projected timing of climate departure from recent variability,” will be published in the October 10 issue of Nature and provides an index of the year when the mean climate of any given location on Earth will shift continuously outside the most extreme records experienced in the past 150 years.The new index shows a surprising result. Areas in the tropics are projected to experience unprecedented climates first — within the next decade. Under a business-as-usual scenario, the index shows the average location on Earth will experience a radically different climate by 2047. Under an alternate scenario with greenhouse gas emissions stabilization, the global mean climate departure will be 2069.”The results shocked us. Regardless of the scenario, changes will be coming soon,” said lead author Camilo Mora. …

Read more

Breaking deep-sea waves, as high as a skyscraper, reveal mechanism for global ocean mixing

Sep. 9, 2013 — Waves breaking over sandy beaches are captured in countless tourist photos. But enormous waves breaking deep in the ocean are seldom seen, although they play a crucial role in long-term climate cycles.A University of Washington study for the first time recorded such a wave breaking in a key bottleneck for circulation in the world’s largest ocean. The study was published online this month in the journal Geophysical Research Letters.The deep ocean is thought of as dark, cold and still. While this is mostly true, huge waves form between layers of water of different density. These skyscraper-tall waves transport heat, energy, carbon and nutrients around the globe. Where and how they break is important for the planet’s climate.”Climate models are really sensitive not only to how much turbulence there is in the deep ocean, but to where it is,” said lead author Matthew Alford, an oceanographer in the UW Applied Physics Laboratory. He led the expedition to the Samoan Passage, a narrow channel in the South Pacific Ocean that funnels water flowing from Antarctica.”The primary importance of understanding deep-ocean turbulence is to get the climate models right on long timescales,” Alford said.Dense water in Antarctica sinks to the deep Pacific, where it eventually surges through a 25-mile gap in the submarine landscape northeast of Samoa.”Basically the entire South Pacific flow is blocked by this huge submarine ridge,” Alford said. “The amount of water that’s trying to get northward through this gap is just tremendous — 6 million cubic meters of water per second, or about 35 Amazon Rivers.”In the 1990s a major expedition measured these currents through the Samoan Passage. The scientists inferred that a lot of mixing must also happen there, but couldn’t measure it.In the summer of 2012 the UW team embarked on a seven-week cruise to track the 800-foot-high waves that form atop the flow, 3 miles below the ocean’s surface. …

Read more

Scientists confirm existence of largest single volcano on earth

Sep. 5, 2013 — A University of Houston (UH) professor led a team of scientists to uncover the largest single volcano yet documented on Earth. Covering an area roughly equivalent to the British Isles or the state of New Mexico, this volcano, dubbed the Tamu Massif, is nearly as big as the giant volcanoes of Mars, placing it among the largest in the Solar System.William Sager, a professor in the Department of Earth and Atmospheric Sciences at UH, first began studying the volcano about 20 years ago at Texas A&M’s College of Geosciences. Sager and his team’s findings appear in the Sept. 8 issue of Nature Geoscience, the monthly multi-disciplinary journal reflecting disciplines within the geosciences.Located about 1,000 miles east of Japan, Tamu Massif is the largest feature of Shatsky Rise, an underwater mountain range formed 130 to 145 million years ago by the eruption of several underwater volcanoes. Until now, it was unclear whether Tamu Massif was a single volcano, or a composite of many eruption points. By integrating several sources of evidence, including core samples and data collected on board the JOIDES Resolution research ship, the authors have confirmed that the mass of basalt that constitutes Tamu Massif did indeed erupt from a single source near the center.”Tamu Massif is the biggest single shield volcano ever discovered on Earth,” Sager said. “There may be larger volcanoes, because there are bigger igneous features out there such as the Ontong Java Plateau, but we don’t know if these features are one volcano or complexes of volcanoes.”Tamu Massif stands out among underwater volcanoes not just for its size, but also its shape. It is low and broad, meaning that the erupted lava flows must have traveled long distances compared to most other volcanoes on Earth. The seafloor is dotted with thousands of underwater volcanoes, or seamounts, most of which are small and steep compared to the low, broad expanse of Tamu Massif.”It’s not high, but very wide, so the flank slopes are very gradual,” Sager said. …

Read more

Ocean fish acquire more mercury at depth

Aug. 25, 2013 — Mercury — a common industrial toxin — is carried through the atmosphere before settling on the ocean and entering the marine food web.Now, exciting new research from the University of Michigan and the University of Hawai’i at Manoa School of Ocean and Earth Science and Technology (SOEST) combines biogeochemistry and direct marine ecology observations to show how the global mercury cycle is colliding with ocean fish — and the human seafood supply — at different depths in the water.Mercury accumulation in the ocean fish we eat tends to take place at deeper depths, scientists found, in part because of photochemical reactions that break down organic mercury in well-lit surface waters. More of this accessible organic mercury is also being generated in deeper waters.”A few years ago we published work that showed that predatory fish that feed at deeper depths in the open ocean, like opah and swordfish, have higher mercury concentrations than those that feed in waters near the surface, like mahi-mahi and yellowfin tuna,” said Brian Popp, professor of geology and geophysics at UH Manoa, and a co-author of a new paper scheduled for online publication August 25 in the scientific journal Nature Geoscience. “We knew this was true, but we didn’t know why.””We knew that organic and inorganic mercury dissolved in seawater has a nutrient-like profile, with lower concentrations at the surface and higher concentrations at depth,” said Anela Choy, a PhD candidate in oceanography at UH Manoa. “We saw it in the water, and we saw it in the fish. But we couldn’t explain the gradient we saw, nor did we know exactly where and how the bioavailable organic mercury was entering the marine food web.”Bacteria in the oceans change atmospheric mercury into the organic monomethylmercury form that can accumulate in animal tissue. Large predatory fish contain high levels of methylmercury in part because they eat lots of smaller, mercury-containing fish. In 2009, researchers at UH Manoa determined that the depths at which a species feeds is nearly as important as its position in the food chain in determining how much methylmercury it contains.For the new research, the UH Manoa team worked closely with colleagues at the University of Michigan who used a highly sophisticated mass spectrometer to measure the stable isotopic compositions of mercury in nine species of marine fish that feed at different depths, including six predator fish and three prey fish.Their analysis showed that chemical reactions driven by sunlight destroy up to 80 percent of monomethylmercury in the well-lit upper depths of the central North Pacific Ocean near Hawai’i. The scientists also determined that a significant amount of monomethylmercury must be formed and enter marine food webs in oxygen-poor, deeper waters.The Michigan researchers had previously recorded mercury isotope measurements on fish in the Gulf of Mexico that suggested that up to 50 percent of monomethylmercury was destroyed by photochemical reactions before it was taken up by yellowfin and blackfin tuna living offshore.In Hawaii, the conditions were different — and better — for this type of analysis. “The crystal-clear waters surrounding Hawai’i and the unique information that we had about the depths at which our local fish feed allowed us to clearly identify both the photochemical degradation of monomethylmercury at surface levels and the microbial production of monomethylmercury from inorganic mercury in deeper waters,” Popp said.The finding that mercury is being converted to its toxic, bioavailable form at depth is important in part because scientists expect mercury levels at intermediate depths in the North Pacific to rise in coming decades.”The implication is that predictions for increased mercury in deeper water will result in higher levels in fish,” said Joel Blum of the University of Michigan, the lead author on the new paper and a professor in the department of earth and environmental sciences. …

Read more

Higher intake of fruits and vegetables may reduce the risk of bladder cancer in women

Aug. 23, 2013 — University of Hawaii Cancer Center Researcher Song-Yi Park, PhD, along with her colleagues, recently discovered that a greater consumption of fruits and vegetables may lower the risk of invasive bladder cancer in women.Share This:The investigation was conducted as part of the Multiethnic Cohort (MEC) Study, established in 1993 to assess the relationships among dietary, lifestyle, genetic factors, and cancer risk. Park and her fellow researcher’s analyzed data collected from 185,885 older adults over a period of 12.5 years, of which 581 invasive bladder cancer cases were diagnosed (152 women and 429 men).After adjusting for variables related to cancer risk (age, etc.) the researchers found that women who consumed the most fruits and vegetables had the lowest bladder cancer risk. For instance, women consuming the most yellow-orange vegetables were 52% less likely to have bladder cancer than women consuming the least yellow-orange vegetables. The data also suggested that women with the highest intake of vitamins A, C, and E had the lowest risk of bladder cancer. No associations between fruit and vegetable intake and invasive bladder cancer were found in men.”Our study supports the fruit and vegetable recommendation for cancer prevention, said Park. “However, further investigation is needed to understand and explain why the reduced cancer risk with higher consumption of fruits and vegetables was confined to only women.”Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by University of Hawaii Cancer Center, via EurekAlert!, a service of AAAS. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Journal Reference:S.-Y. …

Read more

Explosion illuminates invisible galaxy in the dark ages

Aug. 6, 2013 — More than 12 billion years ago a star exploded, ripping itself apart and blasting its remains outward in twin jets at nearly the speed of light. At its death it glowed so brightly that it outshone its entire galaxy by a million times. This brilliant flash traveled across space for 12.7 billion years to a planet that hadn’t even existed at the time of the explosion — our Earth. By analyzing this light, astronomers learned about a galaxy that was otherwise too small, faint and far away for even the Hubble Space Telescope to see.”This star lived at a very interesting time, the so-called dark ages just a billion years after the Big Bang,” says lead author Ryan Chornock of the Harvard-Smithsonian Center for Astrophysics (CfA).”In a sense, we’re forensic scientists investigating the death of a star and the life of a galaxy in the earliest phases of cosmic time,” he adds.The star announced its death with a flash of gamma rays, an event known as a gamma-ray burst (GRB). GRB 130606A was classified as a long GRB since the burst lasted for more than four minutes. It was detected by NASA’s Swift spacecraft on June 6th. Chornock and his team quickly organized follow-up observations by the MMT Telescope in Arizona and the Gemini North telescope in Hawaii.”We were able to get right on target in a matter of hours,” Chornock says. “That speed was crucial in detecting and studying the afterglow.”A GRB afterglow occurs when jets from the burst slam into surrounding gas, sweeping that material up like a snowplow, heating it, and causing it to glow. As the afterglow’s light travels through the dead star’s host galaxy, it passes through clouds of interstellar gas. …

Read more

When galaxies switch off: Hubble’s COSMOS survey solves ‘quenched’ galaxy mystery

Aug. 1, 2013 — Some galaxies hit a point in their lives when their star formation is snuffed out, and they become “quenched.” Quenched galaxies in the distant past appear to be much smaller than the quenched galaxies in the Universe today. This has always puzzled astronomers — how can these galaxies grow if they are no longer forming stars? A team of astronomers has now used a huge set of Hubble observations to give a surprisingly simple answer to this long-standing cosmic riddle.Until now, these small, snuffed-out galaxies were thought to grow into the larger quenched galaxies we see nearby.As these galaxies are no longer forming new stars, they were thought to grow by colliding and merging with other smaller quenched galaxies some five to ten times less massive. However, these mergers would require many such small galaxies floating around for the quenched population to snack on — which we do not see.Until recently it had not been possible to explore a sufficient number of quenched galaxies, but now a team of astronomers has used observations from the Hubble COSMOS survey to identify and count these switched-off galaxies throughout the last eight billion years of cosmic history.”The apparent puffing up of quenched galaxies has been one of the biggest puzzles about galaxy evolution for many years,” says Marcella Carollo of ETH Zurich, Switzerland, lead author on a new paper exploring these galaxies. “No single collection of images has been large enough to enable us to study very large numbers of galaxies in exactly the same way — until Hubble’s COSMOS,” adds co-author Nick Scoville of Caltech, USA.The team used the large set of COSMOS images, alongside additional observations from the Canada-France-Hawaii Telescope and the Subaru Telescope, both in Hawaii, USA, to peer back to when the Universe was less than half its present age. These observations mapped an area in the sky almost nine times that of the full Moon.The quenched galaxies seen at these times are small and compact — and surprisingly, it seems they stay that way. Rather than puffing up and growing via mergers over time, these small galaxies mostly keep the size they had when their star formation switched off. So why do we see these galaxies apparently growing larger over time?”We found that a large number of the bigger galaxies instead switch off at later times, joining their smaller quenched siblings and giving the mistaken impression of individual galaxy growth over time,” says co-author Simon Lilly, also of ETH Zurich. “It’s like saying that the increase in the average apartment size in a city is not due to the addition of new rooms to old buildings, but rather to the construction of new, larger apartments,” adds co- author Alvio Renzini of INAF Padua Observatory, Italy.This tells us a lot about how galaxies have evolved over the last eight billion years of the Universe’s history. …

Read more

HIV/AIDS vaccines: Defining what works

July 18, 2013 — Designing an effective HIV/AIDS vaccine is something of a paradox: a good vaccine would be safe and look enough like HIV to kick-start the immune system into neutralizing the virus — but the problem is that this is exactly what the human immune system has trouble doing even when it’s exposed to the real thing.Now a team of researchers led by scientists at The Scripps Research Institute in La Jolla, CA has developed a strategy for inducing a key part of an effective immune response to HIV. By tracing the evolution of HIV-recognizing molecules called antibodies taken from the blood of rare individuals whose immune systems are naturally able to target and neutralize the virus, they may have found a way to replicate this for everybody.At a talk next week at the American Crystallographic Association meeting in Hawaii, the team will present multiple crystal structures, which like detailed architectural blueprints show how the virus interacts with components of the immune system. Examining these structures has allowed them to reverse engineer molecules that specifically activate the precursors of effective, neutralizing antibodies against the virus — molecules that may be components of a future vaccine against HIV.”What we tried to do was to learn how those [effective] antibodies developed over the course of natural infection and attempt to guide the immune response in the direction of what we know works in certain HIV-infected individuals,” said structural biologist Jean-Philippe Julien, who is presenting the work in Hawaii.He conducted the research under the direction of Professors Ian Wilson and William Schief of The Scripps Research Institute. The work was funded by the International AIDS Vaccine Initiative Neutralizing Antibody Center, the Scripps Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery and the National Institute of Allergy and Infectious Diseases (one of the National Institutes of Health). Additional support was provided through a Canadian Institutes of Health Research fellowship.Julien cautioned that the work might not, by itself, be the final answer that shows how to make an effective HIV/AIDS vaccine — but it is a step in the right direction. Most likely, Julien said, any future HIV/AIDS vaccine would combine multiple biological components in order to give the broadest possible protection against the virus.He added that their candidate molecule was able to achieve the desired immune reactions in the test tube, and they are currently testing it in animals to see if it is able to kick start the desired immune response. If those experiments go well, he said, further studies will examine whether it can protect animals against infection, and human trials for safety and vaccine efficacy would be next — though it may be years before those results are known.While designing a vaccine against any pathogen is a long, hard process, HIV has been particularly difficult, and despite decades of efforts and hundreds of millions of dollars spent in the process, we still do not yet have an effective vaccine that can prevent infection.

Read more

Resourceful microbes reign in world’s oceans

June 24, 2013 — A research team led by Bigelow Laboratory for Ocean Sciences has discovered that marine microbes are adapted to very narrow and specialized niches in their environment. This may explain why so few of these microbes — usually less than 1% — can be grown for study in the laboratory. By utilizing new genetic tools, the researchers’ new ability to read and interpret genetic information from the remaining 99% will be pivotal in detecting and mitigating the impact of human activities in the ocean.The cutting-edge technology that proved critical to the research, and was implemented on a large scale for the first time, is called single cell genomics.”While other tools are available to analyze genes in uncultured microbes, they seldom tell us how these genes fit together and what microbes they come from,” said Ramunas Stepanauskas, the study’s senior author and director of the Bigelow Single Cell Genomics Center (SCGC). “By developing and applying high-throughput single cell genomics, we obtained the first near-complete genomic blueprints of many microbial types that dominate marine ecosystems but used to be inaccessible to scientific investigation.””We found that natural bacterioplankton are devoid of ‘genomic pork,’ such as gene duplications and noncoding nucleotides, and utilize more diverse energy sources than previously thought. This research approach opens a new chapter in the exploration of microbial life in the oceans and in other environments on our planet.””We found that genomic streamlining is the rule rather than exception among marine bacterioplankton, an important biological feature that is poorly represented in existing microbial cultures,” said Brandon Swan, lead author and postdoctoral researcher in the SCGC. “We also found that marine microbes are effectively dispersed around the globe, but they stay within their temperature ‘comfort zones.’ Bacteria that thrive in the frigid Gulf of Maine don’t show up near Hawaii. However, as long as the temperature is right, the same types are found anywhere in the world, whether on the coast of British Columbia, Northern Europe, or Tasmania.””Thanks to single cell genomics and other technological advances, we now have a much more accurate understanding of the biological diversity and processes taking place in the ocean,” said Tanja Woyke, a key co-author from the Department of Energy Joint Genome Institute. “The amount of adaptations and biochemical innovation that have accumulated in marine microorganisms over billions of years of evolution is astounding — a glass of seawater encodes more genetic information than a desktop computer can hold. This information represents a largely untapped source of novel natural products and bioenergy solutions, both essential for human well-being.”Bigelow Laboratory for Ocean Sciences is an independent, non-profit center for global ocean research, ocean science education, and technology transfer. The Laboratory conducts research ranging from microbial oceanography — examining the biology in the world’s oceans at the molecular level — to the large-scale processes that drive ocean ecosystems and global environmental conditions.Funded by the National Science Foundation, the study was published in the Proceedings of the National Academy of Sciences this week.

Read more

Three planets in habitable zone of nearby star — Gliese 667c

June 25, 2013 — A team of astronomers has combined new observations of Gliese 667C with existing data from HARPS at ESO’s 3.6-metre telescope in Chile, to reveal a system with at least six planets. A record-breaking three of these planets are super-Earths lying in the zone around the star where liquid water could exist, making them possible candidates for the presence of life. This is the first system found with a fully packed habitable zone.Gliese 667C is a very well-studied star. Just over one third of the mass of the Sun, it is part of a triple star system known as Gliese 667 (also referred to as GJ 667), 22 light-years away in the constellation of Scorpius (The Scorpion). This is quite close to us — within the Sun’s neighbourhood — and much closer than the star systems investigated using telescopes such as the planet-hunting Kepler space telescope.Previous studies of Gliese 667C had found that the star hosts three planets with one of them in the habitable zone. Now, a team of astronomers led by Guillem Anglada-Escudé of the University of Göttingen, Germany and Mikko Tuomi of the University of Hertfordshire, UK, has reexamined the system. They have added new HARPS observations, along with data from ESO’s Very Large Telescope, the W.M. Keck Observatory and the Magellan Telescopes, to the already existing picture [1]. The team has found evidence for up to seven planets around the star [2].These planets orbit the third fainter star of a triple star system. Viewed from one of these newly found planets the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon. …

Read more

Unusual supernova is doubly unusual for being perfectly normal

June 19, 2013 — August, 2011, saw the dazzling appearance of the closest and brightest Type Ia supernova since Type Ia’s were established as “standard candles” for measuring the expansion of the universe. The brilliant visitor, labeled SN 2011fe, was caught by the Palomar Transient Factory less than 12 hours after it exploded in the Pinwheel Galaxy in the Big Dipper.Easy to see through binoculars, 2011fe was soon dubbed the Backyard Supernova. Major astronomical studies from the ground and from space followed close on its heels, recording its luminosity and colors as it rapidly brightened and then slowly faded away.The international Nearby Supernova Factory (SNfactory), led by Greg Aldering of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), has now released a unique dataset based on 32 nights of repeated observations of 2011fe with the SuperNova Integral Field Spectrograph (SNIFS), built by the SNfactory’s partners in Lyon and Paris, France, and mounted on the University of Hawaii’s 2.2-meter telescope on Mauna Kea. The observations began two weeks before the supernova reached its peak brightness and continued for over three months after maximum light had passed.”We’d never before seen a Type Ia supernova this early,” says Aldering, a cosmologist in Berkeley Lab’s Physics Division. “Our measurements showed how remarkably normal 2011fe is.”SNfactory member Rui Pereira of the Institut de Physique Nucléaire de Lyon says that the collected data “will be the benchmark atlas for all future studies of Type Ia’s.” Pereira is the lead author of the article presenting the observations in the journal Astronomy & Astrophysics.Why a perfectly normal supernova is so oddType Ia supernovae aren’t so much standard candles as “standardizable” ones. Graphs of how their brightness and spectral features change over time — their light curves — vary, but because timing and brightness are related, the light curves can be stretched (or squeezed) to match the standard. SN 2011fe’s light curve falls right in the peak of the distribution — as astrophysicists say, it has “stretch 1.”Rollin Thomas, of Berkeley Lab’s Computational Research Division, was deeply involved in the 2011fe analysis. As new data arrived from the telescope each night he recalls thinking “please don’t be peculiar, please don’t be peculiar,” and was pleased to find that the supernova was so normal.2011fe not only looks like a textbook case, it passes important tests. Its brightness at different times (epochs) could be accurately recorded because the distance to its home galaxy had been measured independently, and there was little or no dust in the line of sight to affect color or brightness.Normal as it is, however, 2011fe’s light curve doesn’t match the leading computational models, none of which fit the SNfactory data. …

Read more

Utilizzando il sito, accetti l'utilizzo dei cookie da parte nostra. maggiori informazioni

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.

Close