The ugly truth about summer allergies

As if a runny nose and red eyes weren’t enough to ruin your warm weather look, summer allergies can gift you with even more than you’ve bargained for this year. In fact, some unusual symptoms can leave you looking like you lost a round in a boxing ring.”Summer allergies can cause severe symptoms for some sufferers, and can be just as bad as the spring and fall seasons,” said allergist Michael Foggs, MD, president of the American College of Allergy, Asthma and Immunology (ACAAI). “Symptoms aren’t always limited to the hallmark sneezing, runny nose and watery eyes. Black eyes, lines across the nose and other cosmetic symptoms can occur.”Even if you’ve never before had allergies, they can suddenly strike at any age and time of year. You might want to consider visiting your board-certified allergist if these undesirable signs accompany your sniffle and sneeze.Allergic Shiner: Dark circles under the eyes which are due to swelling and discoloration from congestion of small blood vessels beneath the skin in the delicate eye area. Allergic (adenoidal) Face: Nasal allergies may promote swelling of the adenoids (lymph tissue that lines the back of the throat and extends behind the nose). This results in a tired and droopy appearance. Nasal Crease: This is a line which can appear across the bridge of the nose usually the result of rubbing the nose upward to relieve nasal congestion and itching. Mouth Breathing: Cases of allergic rhinitis in which severe nasal congestion occurs can result in chronic mouth breathing, associated with the development of a high, arched palate, an elevated upper lip, and an overbite. Teens with allergic rhinitis might need braces to correct dental issues. …

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Beer marinade could reduce levels of potentially harmful substances in grilled meats

The smells of summer — the sweet fragrance of newly opened flowers, the scent of freshly cut grass and the aroma of meats cooking on the backyard grill — will soon be upon us. Now, researchers are reporting that the very same beer that many people enjoy at backyard barbeques could, when used as a marinade, help reduce the formation of potentially harmful substances in grilled meats. The study appears in ACS’ Journal of Agricultural and Food Chemistry.I.M.P.L.V.O. Ferreira and colleagues explain that past studies have shown an association between consumption of grilled meats and a high incidence of colorectal cancer. Polycyclic aromatic hydrocarbons (PAHs) are substances that can form when meats are cooked at very high temperatures, like on a backyard grill. And high levels of PAHs, which are also in cigarette smoke and car exhaust, are associated with cancers in laboratory animals, although it’s uncertain if that’s true for people. Nevertheless, the European Union Commission Regulation has established the most suitable indicators for the occurrence and carcinogenic potency of PAHs in food and attributed maximum levels for these compounds in foods. Beer, wine or tea marinades can reduce the levels of some potential carcinogens in cooked meat, but little was known about how different beer marinades affect PAH levels, until now.The researchers grilled samples of pork marinated for four hours in Pilsner beer, non-alcoholic Pilsner beer or a black beer ale, to well-done on a charcoal grill. Black beer had the strongest effect, reducing the levels of eight major PAHs by more than half compared with unmarinated pork. “Thus, the intake of beer marinated meat can be a suitable mitigation strategy,” say the researchers.Story Source:The above story is based on materials provided by American Chemical Society. …

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New fast and furious black hole found

A team of Australian and American astronomers have been studying nearby galaxy M83 and have found a new superpowered small black hole, named MQ1, the first object of its kind to be studied in this much detail.Astronomers have found a few compact objects that are as powerful as MQ1, but have not been able to work out the size of the black hole contained within them until now.The team observed the MQ1 system with multiple telescopes and discovered that it is a standard-sized small black hole, rather than a slightly bigger version that was theorised to account for all its power.Curtin University senior research fellow Dr Roberto Soria, who is part of the International Centre for Radio Astronomy Research (ICRAR) and led the team investigating MQ1, said it was important to understand how stars were formed, how they evolved and how they died, within a spiral shaped galaxy like M83.”MQ1 is classed as a microquasar — a black hole surrounded by a bubble of hot gas, which is heated by two jets just outside the black hole, powerfully shooting out energy in opposite directions, acting like cosmic sandblasters pushing out on the surrounding gas,” Dr Soria said.”The significance of the huge jet power measured for MQ1 goes beyond this particular galaxy: it helps astronomers understand and quantify the strong effect that black hole jets have on the surrounding gas, which gets heated and swept away.”This must have been a significant factor in the early stages of galaxy evolution, 12 billion years ago, because we have evidence that powerful black holes like MQ1, which are rare today, were much more common at the time.””By studying microquasars such as MQ1, we get a glimpse of how the early universe evolved, how fast quasars grew and how much energy black holes provided to their environment.”As a comparison, the most powerful microquasar in our galaxy, known as SS433, is about 10 times less powerful than MQ1.Although the black hole in MQ1 is only about 100 kilometres wide, the MQ1 structure — as identified by the Hubble Space Telescope — is much bigger than our Solar System, as the jets around it extend about 20 light years from either side of the black hole.Black holes vary in size and are classed as either stellar mass (less than about 70 times the mass of our Sun) or supermassive (millions of times the mass of our Sun, like the giant black hole that is located in the middle of the Milky Way).MQ1 is a stellar mass black hole and was likely formed when a star died, collapsing to leave behind a compact mass.The discovery of MQ1 and its characteristics is just one of the results of the comprehensive study of galaxy M83, a collection of millions of stars located 15 million light years away from Earth.M83, the iconic Southern-sky galaxy, is being mapped with the Hubble Space and Magellan telescopes (detecting visible light), the Chandra X-ray Observatory (detecting light in X-ray frequencies), the Australia Telescope Compact Array and the Very Large Array (detecting radio waves).ICRAR is a joint venture between Curtin University and The University of Western Australia which receives funding from the State Government of Western Australia.

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Newly discovered marsupial the victim of fatal attraction: Due to stress hormone, males die before young are born

A QUT mammalogist has discovered a highly sexed mouse-like marsupial in Queensland’s Springbrook National Park. The Black-tailed Antechinus was found in the high-altitude regions of the World Heritage Area. It’s the third new species in the genus Antechinus Dr Andrew Baker’s research team has discovered in the past two years, all from south-east Queensland.Dr Baker said he suspected the rare, Black-tailed Antechinus was a separate species when he and his team came across it last May because it had distinctive yellow-orange markings around its eyes and on its rump, and a black tail and feet.”Comparing it to the Dusky Antechinus, which inhabits south-east Australia, we thought it was probably new,” said Dr Baker, from QUT’s Science and Engineering Faculty.”We laid about 300 traps baited with peanut butter and oats. When we caught the first black-tailed antechinus in a trap, we knew we were onto something pretty special.”Dr Baker is now applying for an endangered species listing.”Antechinus males and females are highly promiscuous; males mate for long periods of time with many females to promote their own genes,” Dr Baker said.”A single female’s brood of young will typically be sired by several fathers. But during mating, stress hormone levels rise dramatically, eventually causing the males’ bodies to shut down. The males all die before their young are born.”The results of the team’s studies have been published in the journal Zootaxa.The Black-footed Antechinus is a coup for Dr Baker and his research partners from the Queensland Museum and Queensland Parks and Wildlife Service.New mammal discoveries are rare, with only a handful typically discovered in the world each year.Dr Baker said the Black-tailed Antechinus likely won’t be the last unique creature to be unearthed in Springbrook National Park.”The Gondwanaland rainforest relic at Springbrook is special and unique,” he told the Gold Coast Bulletin. “It would not surprise me if there are other animals that are new in that area. Such things are about place not species.”Story Source:The above story is based on materials provided by Queensland University of Technology. Note: Materials may be edited for content and length.

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Fat black holes grown up in ‘cities’: Observational result using virtual observatory

Oct. 17, 2013 — Massive black holes of more than one million solar masses exist at the center of most galaxies. Some of the massive black holes are observed as active galactic nuclei (AGN) which attract surrounding gas and release huge amounts of energy.How does a massive black hole get “fat”? One possibility is that mutual interaction between galaxies leads to the growth of a black hole. If this theory is correct, there must be some relationship between properties of an supermassive black hole and environment of its host galaxy. Previous studies revealed that radio-loud AGNs are in the overcrowded region. However, it is still not clear that relation between the mass of an central black hole and the environment around an active galaxy (galaxies hosting AGNs). This is why the research team explored the distribution of galaxies surrounding active galaxies.The research team utilized the “Virtual Observatory” to examine many massive black holes and the environment of active galaxies.The Virtual Observatory is a system to make integrated use of various astronomical databases around the world via sharing over the Internet. The Astronomy Data Center of NAOJ has been developing an original portal site for the virtual observatory. To begin with this research, the team collected the data on more than 10,000 AGN whose black hole mass had been already measured by spectroscopic observation with SDSS (Note 1). …

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Antisocial texting by teens linked to bad behavior

Sep. 9, 2013 — For American teenagers, most text messaging is as harmless as passing notes, but University of Texas at Dallas researchers have discovered that engaging in antisocial texting can actually predict deviant behavior.In the Journal of Abnormal Child Psychology, scientists reported a correlation between the frequency with which adolescents text about antisocial behaviors and the likelihood that they will engage in them.”We were interested in how adolescents use electronic communication, particularly text messaging,” said Dr. Samuel Ehrenreich, post-doctoral researcher in the School of Behavioral and Brain Sciences at UT Dallas. “We examined how discussing antisocial behavior — substance abuse, property crimes, physical aggression, that sort of thing — how discussing that predicts actually engaging in this problem behavior. Basically, does talking about bad behavior predict bad behavior?”Although the idea of studying the texting habits of teens may not be new, looking directly at the messages they are sending is. Past studies relied on self-reported texting behaviors, which Ehrenreich said may be flawed due to teens providing inaccurate information about texts. They would not likely self-report texting about misbehavior. Teens also send an average of 60-100 texts per day, so they may simply forget about much of the texting they do. To circumvent these problems, free BlackBerry devices and service plans were given to 172 ninth-grade students with the understanding that their texts would be monitored.Texts were collected and stored offsite in a secure database. The participants were rated before and after the school year for rule breaking and aggressive behavior by parents, teachers and in self reports.Analysis of a sample of texts from two points in time revealed similarities in the types of antisocial messages between boys and girls. …

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Why are consumers more likely to participate in online gaming than gambling?

Sep. 10, 2013 — Consumers are more likely to participate in online betting if it’s called “gaming” rather than “gambling,” according to a new study in the Journal of Consumer Research.”Changing an industry label from gambling to gaming affects what consumers, especially non-users, think of betting online,” write authors Ashlee Humphreys (Kellogg School of Management, Northwestern University) and Kathryn A. LaTour (Cornell University). “A label like gaming prompts all sorts of implicit associations like entertainment and fun, while a label like gambling can prompt seedier implicit associations like crime.”These largely unconscious associations affect what people think of the industry and even their intention to participate, the authors explain. The process of changing perceptions, called framing, has an impact on whether or not people think the industry is socially acceptable. And framing can occur merely by changing a word.The authors analyzed newspapers like the New York Times and Wall Street Journal for the language used to describe online betting. They analyzed coverage of “Black Friday,” April 15, 2011, when the US government shut down the three largest online betting sites. Newspapers shifted the way they described the online activity, framing it more as a crime, which led to a shift in consumer judgments about the legitimacy of online casinos, especially among non-users.The authors conducted two experiments to explore what causes consumers to make different judgments about gambling. They found that “rags-to-riches” or “get-rich-quick” narratives prompted a set of favorable or unfavorable implicit associations among participants. In a stronger test of their hypothesis, the authors changed only one word in the narratives — gambling or gaming — and found that the “gaming” label caused non-users to judge online betting as more legitimate. …

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Powerful jets discovered blowing material out of galaxy

Sep. 5, 2013 — Astronomers using a worldwide network of radio telescopes have found strong evidence that a powerful jet of material propelled to nearly light speed by a galaxy’s central black hole is blowing massive amounts of gas out of the galaxy. This process, they said, is limiting the growth of the black hole and the rate of star formation in the galaxy, and thus is a key to understanding how galaxies develop.Astronomers have theorized that many galaxies should be more massive and have more stars than is actually the case. Scientists proposed two major mechanisms that would slow or halt the process of mass growth and star formation — violent stellar winds from bursts of star formation and pushback from the jets powered by the galaxy’s central, supermassive black hole.”With the finely-detailed images provided by an intercontinental combination of radio telescopes, we have been able to see massive clumps of cold gas being pushed away from the galaxy’s center by the black-hole-powered jets,” said Raffaella Morganti, of the Netherlands Institute for Radio Astronomy and the University of Groningen.The scientists studied a galaxy called 4C12.50, nearly 1.5 billion light-years from Earth. They chose this galaxy because it is at a stage where the black-hole “engine” that produces the jets is just turning on.As the black hole, a concentration of mass so dense that not even light can escape, pulls material toward it, the material forms a swirling disk surrounding the black hole. Processes in the disk tap the tremendous gravitational energy of the black hole to propel material outward from the poles of the disk.At the ends of both jets, the researchers found clumps of hydrogen gas moving outward from the galaxy at 1,000 kilometers per second. One of the clouds has much as 16,000 times the mass of the Sun, while the other contains 140,000 times the mass of the Sun. The larger cloud, the scientists said, is roughly 160 by 190 light-years in size.”This is the most definitive evidence yet for an interaction between the swift-moving jet of such a galaxy and a dense interstellar gas cloud,” Morganti said. “We believe we are seeing in action the process by which an active, central engine can remove gas — the raw material for star formation — from a young galaxy,” she added.The scientists also said their observations indicate that the jets from the galaxy’s core can stretch and deform clouds of interstellar gas to expand their “pushing” effect beyond the narrow width of the jets themselves. In addition, they reported that, at 4C12.50’s stage of development, the jets may turn on and off and so periodically repeat the process of removing gas from the galaxy.In July, another team of scientists, using the Atacama Large Millimeter/submillimeter Array (ALMA), announced they had found gas being blown from a more-nearby galaxy, called NGC 253, by an intense burst of star formation.”Both processes are thought to be at work, often simultaneously, in young galaxies to regulate the growth of their central black holes as well as the rate at which they can form new stars,” Morganti said.Morganti and her team used radio telescopes in Europe and the U.S., combining their signals to make one giant, intercontinental telescope.In the U.S., these included the National Science Foundation’s Very Long Baseline Array (VLBA), a continent-wide system of radio telescopes ranging from Hawaii, across the U.S. …

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Milky Way gas cloud causes multiple images of distant quasar

Aug. 28, 2013 — For the first time, astronomers have seen the image of a distant quasar split into multiple images by the effects of a cloud of ionized gas in our own Milky Way Galaxy. Such events were predicted as early as 1970, but the first evidence for one now has come from the National Science Foundation’s Very Long Baseline Array (VLBA) radio telescope system.The scientists observed the quasar 2023+335, nearly 3 billion light-years from Earth, as part of a long-term study of ongoing changes in some 300 quasars. When they examined a series of images of 2023+335, they noted dramatic differences. The differences, they said, are caused by the radio waves from the quasar being bent as they pass through the Milky Way gas cloud, which moved through our line of sight to the quasar.”This event, obviously rare, gives us a new way to learn some of the properties of the turbulent gas that makes up a significant part of our Galaxy,” said Matt Lister, of Purdue University.The scientists added 2023+335 to their list of observing targets in 2008. Their targets are quasars and other galaxies with supermassive black holes at their cores. The gravitational energy of the black holes powers “jets” of material propelled to nearly the speed of light. The quasar 2023+335 initially showed a typical structure for such an object, with a bright core and a jet. In 2009, however, the object’s appearance changed significantly, showing what looked like a line of bright, new radio-emitting spots.”We’ve never seen this type of behavior before, either among the hundreds of quasars in our own observing program or among those observed in other studies,” Lister said.The multiple-imaging event came as other telescopes detected variations in the radio brightness of the quasar, caused, the astronomers said, by scattering of the waves.The scientists’ analysis indicates that the quasar’s radio waves were bent by a turbulent cloud of charged gas nearly 5,000 light-years from Earth in the direction of the constellation Cygnus. The cloud’s size is roughly comparable to the distance between the Sun and Mercury, and the cloud is moving through space at about 56 kilometers per second.Monitoring of 2023+335 over time may yield more such events, the scientists said, allowing them to learn additional details both about the process by which the waves are scattered and about the gas that does the scattering. …

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Obesity kills more Americans than previously thought: One in five Americans, Black and White, die from obesity

Aug. 15, 2013 — Obesity is a lot more deadly than previously thought. Across recent decades, obesity accounted for 18 percent of deaths among Black and White Americans between the ages of 40 and 85, according to scientists. This finding challenges the prevailing wisdom among scientists, which puts that portion at around 5%.”Obesity has dramatically worse health consequences than some recent reports have led us to believe,” says first author Ryan Masters, PhD, who conducted the research as a Robert Wood Johnson Foundation Health & Society Scholar at Columbia University’s Mailman School of Public Health. “We expect that obesity will be responsible for an increasing share of deaths in the United States and perhaps even lead to declines in U.S. life expectancy.”While there have been signs that obesity is in decline for some groups of young people, rates continue to be near historic highs. For the bulk of children and adults who are already obese, the condition will likely persist, wreaking damage over the course of their lives.In older Americans, the rising toll of obesity is already evident. Dr. Masters and his colleagues documented its increasing effect on mortality in White men who died between the ages of 65 and 70 in the years 1986 to 2006. Grade one obesity (body mass index of 30 to less than 35) accounted for about 3.5% of deaths for those born between 1915 and 1919 — a grouping known as a birth cohort. …

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A magnetar at the heart of our Milky Way

Aug. 14, 2013 — Astronomers have discovered a magnetar at the centre of our Milky Way. This pulsar has an extremely strong magnetic field and enables researchers to investigate the direct vicinity of the black hole at the heart of the galaxy. An international team of scientists headed by the Max Planck Institute for Radio Astronomy in Bonn have, for the first time, measured the strength of the magnetic field around this central source and were able to show that the latter is fed by magnetic fields. These control the inflow of mass into the black hole, also explaining the x-ray emissions of this gravity trap.The discovery of a pulsar closely orbiting the candidate supermassive black hole at the centre of the Milky Way (called Sagittarius A*, or Sgr A* in short) has been one of the main aims of pulsar astronomers for the last 20 years. Pulsars, those extremely precise cosmic clocks, could be used to measure the properties of space and time around this object, and to see if Einstein’s theory of General Relativity could hold up to the strictest tests.Shortly after the announcement of a flaring X-ray source in the direction of the Galactic centre by NASA’s Swift telescope, and the subsequent discovery of pulsations with a period of 3.76 seconds by NASA’s NuSTAR telescope, a radio follow-up program was started at the Effelsberg radio observatory of the Max Planck Institute for Radio Astronomy (MPIfR).”As soon as we heard about the discovery of regular pulsations with the NuSTAR telescope we pointed the Effelsberg 100-m dish in the direction of the Galactic centre,” says Ralph Eatough from MPIfR’s Fundamental Physics Research department, the lead author of the study. “On our first attempt the pulsar was not clearly visible, but some pulsars are stubborn and require a few observations to be detected. The second time we looked, the pulsar had become very active in the radio band and was very bright. I could hardly believe that we had finally detected a pulsar in the Galactic centre!” Because this pulsar is so special, the research team spent a lot of effort to prove that it was a real object in deep space and not due to human-made radio interference created on Earth.Additional observations were performed in parallel and subsequently with other radio telescopes around the world (Jodrell Bank, Very Large Array, Nançay). “We were too excited to sleep in between observations! …

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Often misidentified, multiracial people value accurate perceptions

Aug. 4, 2013 — Multiracial people may be misidentified more often as being white than black and may value being accurately identified more so than single-race individuals, according to research presented at APA’s 121st Annual Convention.”Today, the distinctions among white, black, Latino and Asian people are becoming blurred by the increasing frequency and prominence of multiracial people,” said Jacqueline M. Chen, PhD, of the University of California, Davis. “Still, average Americans have difficulty identifying multiracial people who don’t conform to the traditional single-race categories that society has used all their lives.”Chen discussed six experiments in which participants were consistently less likely to identify people as multiracial than single-race and took longer to identify someone as multiracial compared to how easily they identified black, white and Asian people. When they made incorrect identifications, they were consistently more likely to categorize a multiracial person as white than black, the study found. Time pressure, distractions and thinking of race in either-or terms made observers significantly less likely to identify someone as multiracial. The study was conducted at the University of California, Santa Barbara and involved 435 ethnically diverse undergraduate students.Participants identified the race of black, white, Asian or multiracial individuals in photos and researchers recorded each participant’s accuracy and time to respond. Researchers used a memorization task and a time limit in two experiments to determine if either would affect a participant’s accuracy. In another experiment, participants were told the study was about reading comprehension and attention. They then read news articles about scientists claiming to find a genetic basis for race and were asked to view several photographs of faces and identify them by race.Scientists agree that the racial categories we use today are not based on biological differences but are social constructions that can change over time, Chen said, noting that until the mid-20th century, the Anglo-Saxon majority in the United States viewed Irish and Italian immigrants as different races. …

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Largest magnetic fields in the universe

July 26, 2013 — Numerical simulations by AEI scientists show for the first time the occurrence of an instability in the interior of neutron stars that can lead to gigantic magnetic fields, possibly triggering one of the most dramatic explosions observed in the Universe.An ultra-dense (“hypermassive”) neutron star is formed when two neutron stars in a binary system finally merge. Its short life ends with the catastrophic collapse to a black hole, possibly powering a short gamma-ray burst, one of the brightest explosions observed in the universe. Short gamma-ray bursts as observed with satellites like XMM Newton, Fermi or Swift release within a second the same amount of energy as our Galaxy in one year. It has been speculated for a long time that enormous magnetic field strengths, possibly higher than what has been observed in any known astrophysical system, are a key ingredient in explaining such emission. Scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) have now succeeded in simulating a mechanism which could produce such strong magnetic fields prior to the collapse to a black hole.How can such ultra-high magnetic fields — stronger than ten or hundred million billion times Earth’s magnetic field — be generated from the much lower initial neutron star magnetic fields?This could be explained by a phenomenon that can be triggered in a differentially rotating plasma in the presence of magnetic fields: neighbouring plasma layers, which rotate at different speeds, “rub against each other,” eventually setting the plasma into turbulent motion. In this process called magnetorotational instability magnetic fields can be strongly amplified. This mechanism is known to play an important role in many astrophysical systems such as accretion disks and core-collapse supernovae. It had been speculated for a long time that magnetohydrodynamic instabilities in the interior of hypermassive neutron stars could bring about the necessary magnetic field amplification. The actual demonstration that this is possible has only now been achieved with the present numerical simulations.The scientists of the Gravitational Wave Modelling Group at the AEI simulated a hypermassive neutron star with an initially ordered (“poloidal”) magnetic field, whose structure is subsequently made more complex by the star’s rotation. Since the star is dynamically unstable, it eventually collapses to a black hole surrounded by a cloud of matter, until the latter is swallowed by the black hole.These simulations have unambiguously shown the presence of an exponentially rapid amplification mechanism in the stellar interior — the magnetorotational instability. …

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Behavior of turbulent flow of superfluids is opposite that of ordinary fluids

July 25, 2013 — A superfluid moves like a completely frictionless liquid, seemingly able to propel itself without any hindrance from gravity or surface tension. The physics underlying these materials — which appear to defy the conventional laws of physics — has fascinated scientists for decades.Think of the assassin T-1000 in the movie “Terminator 2: Judgment Day” — a robotic shape-shifter made of liquid metal. Or better yet, consider a real-world example: liquid helium. When cooled to extremely low temperatures, helium exhibits behavior that is otherwise impossible in ordinary fluids. For instance, the superfluid can squeeze through pores as small as a molecule, and climb up and over the walls of a glass. It can even remain in motion years after a centrifuge containing it has stopped spinning.Now physicists at MIT have come up with a method to mathematically describe the behavior of superfluids — in particular, the turbulent flows within superfluids. They publish their results this week in the journal Science.”Turbulence provides a fascinating window into the dynamics of a superfluid,” says Allan Adams, an associate professor of physics at MIT. “Imagine pouring milk into a cup of tea. As soon as the milk hits the tea, it flares out into whirls and eddies, which stretch and split into filigree. Understanding this complicated, roiling turbulent state is one of the great challenges of fluid dynamics. …

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Shedding new light on the brightest objects in the universe

July 24, 2013 — Quasars are among the brightest, oldest, most distant, and most powerful objects in the universe. Powered by massive black holes at the center of most known galaxies, quasars can emit enormous amounts of energy, up to a thousand times the total output of the hundreds of billions of stars in our entire Milky Way.Dartmouth astrophysicists Ryan Hickox and Kevin Hainline and colleagues have a paper scheduled for publication in The Astrophysical Journal, detailing discoveries based upon observations of 10 quasars. They documented the immense power of quasar radiation, which reaches out for many thousands of light years to the limits of the quasar’s galaxy.”For the first time, we are able to see the actual extent to which these quasars and their black holes can affect their galaxies, and we see that it is limited only by the amount of gas in the galaxy,” says Hainline, a Dartmouth postdoctoral research associate. “The radiation excites gas all the way to the margins of the galaxy and stops only when it runs out of gas.”The radiation released by a quasar covers the entire electromagnetic spectrum, from radio waves and microwaves at the low-frequency end through infrared, ultraviolet, and X-rays, to high-frequency gamma rays. A central black hole, also called an active galactic nucleus, may grow by swallowing material from the surrounding interstellar gas, releasing energy in the process. This leads to the creation of a quasar, emitting radiation that illuminates the gas present throughout the galaxy.”If you take this powerful, bright radiation source in the center of the galaxy and blast the gas with its radiation, it will get excited in just the same way the neon gets excited in neon lamps, producing light,” says Hickox, an assistant professor in the Department of Physics and Astronomy at Dartmouth. “The gas will produce very specific frequencies of light that only a quasar can produce. This light functioned as a tracer that we were able to use to follow the gas excited by the black hole out to large distances.”Quasars are small compared to a galaxy, like a grain of sand on a beach, but the power of their radiation can extend to the galactic boundaries and beyond.The illumination of gas can have a profound effect, since gas that is lit up and heated by the quasar is less able to collapse under its own gravity and form new stars. Thus, the tiny central black hole and its quasar can slow down star formation in the entire galaxy and influence how the galaxy grows and changes over time.”This is exciting because we know from a number of different independent arguments that these quasars have a profound effect on the galaxies in which they live,” Hickox says. “There is a lot of controversy about how they actually influence the galaxy, but now we have one aspect of the interaction that can extend on the scale of the entire galaxy. …

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Ripped apart by a black hole: Gas cloud makes closest approach to monster at center of Milky Way

July 17, 2013 — New observations from ESO’s Very Large Telescope show for the first time a gas cloud being ripped apart by the supermassive black hole at the centre of the galaxy. The cloud is now so stretched that its front part has passed the closest point and is travelling away from the black hole at more than 10 million km/h, whilst the tail is still falling towards it.In 2011 ESO’s Very Large Telescope (VLT) discovered a gas cloud with several times the mass of Earth accelerating towards the black hole at the centre of the Milky Way[1]. This cloud is now making its closest approach and new VLT observations show that it is being grossly stretched by the black hole’s extreme gravitational field.”The gas at the head of the cloud is now stretched over more than 160 billion kilometres around the closest point of the orbit to the black hole. And the closest approach is only a bit more than 25 billion kilometres from the black hole itself — barely escaping falling right in,” explains Stefan Gillessen (Max Planck Institute for Extraterrestrial Physics, Garching, Germany) who led the observing team [2]. “The cloud is so stretched that the close approach is not a single event but rather a process that extends over a period of at least one year.”As the gas cloud is stretched its light gets harder to see. But by staring at the region close to the black hole for more than 20 hours of total exposure time with the SINFONI instrument on the VLT — the deepest exposure of this region ever with an integral field spectrometer [3] — the team was able to measure the velocities of different parts of the cloud as it streaks past the central black hole [4].”The most exciting thing we now see in the new observations is the head of the cloud coming back towards us at more than 10 million km/h along the orbit — about 1% of the speed of light,” adds Reinhard Genzel, leader of the research group that has been studied this region for nearly twenty years. “This means that the front end of the cloud has already made its closest approach to the black hole.” The origin of the gas cloud remains mysterious, although there is no shortage of ideas [5]. The new observations narrow down the possibilities.”Like an unfortunate astronaut in a science fiction film, we see that the cloud is now being stretched so much that it resembles spaghetti. This means that it probably doesn’t have a star in it,” concludes Gillessen. “At the moment we think that the gas probably came from the stars we see orbiting the black hole.”The climax of this unique event at the centre of the galaxy is now unfolding and being closely watched by astronomers around the world. …

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Black-legged ticks linked to encephalitis in New York state

July 15, 2013 — The number of tick-borne illnesses reported to the U.S. Centers for Disease Control and Prevention is on the rise. Lyme disease leads the pack, with some 35,000 cases reported annually. In the Northeast, the black-legged ticks (Ixodes scapularis) that spread Lyme disease also infect people with other maladies, among them anaplasmosis, babesiosis, and — as a new paper in the journal Parasites and Vectors reports — Powassan encephalitis.Powassan encephalitis is caused by Powassan virus and its variant, deer tick virus. The virus is spread to people by infected ticks, and can cause central nervous system disruption, encephalitis, and meningitis. There is a 10-15% fatality rate in reported cases, with many survivors suffering long-term neurological damage.Rick Ostfeld, a disease ecologist at the Cary Institute of Ecosystem Studies and one of the paper’s authors, comments: “We’ve seen a rise in this rare but serious illness in parts of New York State that are hotspots for Lyme disease. And we suspected it was tied to an increase in black-legged ticks carrying deer tick virus, particularly on the east side of the Hudson River.”This is precisely what a 5-year assessment bore out. Researchers surveyed ticks at sites east and west of the river. Fieldwork involved collecting ticks off of small mammals and birds, as well as dragging tick cloths near animal burrows and known tick habitats. Routine surveys performed by the New York State Department of Health were also incorporated in the study.More than 13,500 ticks of seven species were assessed. …

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Mysterious radio flashes may be farewell greetings from massive stars collapsing into black holes

July 5, 2013 — Mysterious bright radio flashes that appear for only a brief moment on the sky and do not repeat could be the final farewell greetings of a massive star collapsing into a black hole, astronomers from Nijmegen and Potsdam argue.Radio telescopes have picked up some bright radio flashes that appear for only a brief moment on the sky and do not repeat. Scientists have since wondered what causes these unusual radio signals. An article in this week’s issue of Science suggests that the source of the flashes lies deep in the early cosmos, and that the short radio burst are extremely bright. However, the question of which cosmic event could produce such a bright radio emission in such a short time remained unanswered. The astrophysicists Heino Falcke from Radboud University Nijmegen and Luciano Rezzolla from the Max Planck Institute for Gravitational Physics in Potsdam provide a solution for the riddle. They propose that the radio bursts could be the final farewell greetings of a supramassive rotating neutron star collapsing into a black hole.Spinning star withstands collapseNeutron stars are the ultra-dense remains of a star that has undergone a supernova explosion. They are the size of a small city but have up to two times the mass of our Sun. However, there is an upper limit on how massive neutron stars can become. If they are formed above a critical mass of more than two solar masses, they are expected to collapse immediately into a black hole. Falcke & Rezzolla now suggest that some stars could postpone that final death through fast rotation for millions of years. …

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Dusty surprise around giant black hole

June 20, 2013 — ESO’s Very Large Telescope Interferometer has gathered the most detailed observations ever of the dust around the huge black hole at the centre of an active galaxy. Rather than finding all of the glowing dust in a doughnut-shaped torus around the black hole, as expected, the astronomers find that much of it is located above and below the torus. These observations show that dust is being pushed away from the black hole as a cool wind — a surprising finding that challenges current theories and tells us how supermassive black holes evolve and interact with their surroundings.Over the last twenty years, astronomers have found that almost all galaxies have a huge black hole at their centre. Some of these black holes are growing by drawing in matter from their surroundings, creating in the process the most energetic objects in the Universe: active galactic nuclei (AGN). The central regions of these brilliant powerhouses are ringed by doughnuts of cosmic dust [1] dragged from the surrounding space, similar to how water forms a small whirlpool around the plughole of a sink. It was thought that most of the strong infrared radiation coming from AGN originated in these doughnuts.But new observations of a nearby active galaxy called NGC 3783, harnessing the power of the Very Large Telescope Interferometer (VLTI) at ESO’s Paranal Observatory in Chile [2], have given a team of astronomers a surprise. Although the hot dust — at some 700 to 1000 degrees Celsius — is indeed in a torus as expected, they found huge amounts of cooler dust above and below this main torus [3].As Sebastian Hönig (University of California Santa Barbara, USA and Christian-Albrechts-Universität zu Kiel, Germany), lead author of the paper presenting the new results, explains, “This is the first time we’ve been able to combine detailed mid-infrared observations of the cool, room-temperature dust around an AGN with similarly detailed observations of the very hot dust. This also represents the largest set of infrared interferometry for an AGN published yet.”The newly-discovered dust forms a cool wind streaming outwards from the black hole. This wind must play an important role in the complex relationship between the black hole and its environment. The black hole feeds its insatiable appetite from the surrounding material, but the intense radiation this produces also seems to be blowing the material away. …

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Programming blood forming stem cells

June 13, 2013 — By transferring four genes into mouse fibroblast cells, researchers at the Icahn School of Medicine at Mount Sinai have produced cells that resemble hematopoietic stem cells, which produce millions of new blood cells in the human body every day. These findings provide a platform for future development of patient-specific stem/progenitor cells, and more differentiated blood products, for cell-replacement therapy.The study, titled, “Induction of a Hemogenic Program in Mouse Fibroblasts,” was published online in Cell Stem Cell on June 13. Mount Sinai researchers screened a panel of 18 genetic factors for inducing blood-forming activity and identified a combination of four transcription factors, Gata2, Gfi1b, cFos, and Etv6 as sufficient to generate blood vessel precursor cells with the subsequent appearance of hematopoietic cells. The precursor cells express a human CD34 reporter, Sca1 and Prominin1 within a global endothelial transcription program.”The cells that we grew in a petri dish are identical in gene expression to those found in the mouse embryo and could eventually generate colonies of mature blood cells,” said the first author of the study, Carlos Filipe Pereira, PhD, Postdoctoral Fellow of Developmental and Regenerative Biology at the Icahn School of Medicine.Other leaders of the research team that screened the genetic factors to find the right combination included Kateri Moore, DVM, Associate Professor of Developmental and Regenerative Biology at the Icahn School and Ihor R. Lemischka, PhD, Professor of Developmental and Regenerative Biology, Pharmacology and Systems Therapeutics and Director of The Black Family Stem Cell Institute at The Mount Sinai Medical Center.”The combination of gene factors that we used was not composed entirely of the most obvious or expected proteins,” said Dr. Lemischka. “Many investigators have been trying to grow hematopoietic stem cells from embryonic stem cells, but this process has been problematic. Instead, we used mature mouse fibroblasts, picked the right combination of proteins, and it worked.””This discovery is just the beginning of something new and exciting and can hopefully be used to identify a treatment for blood disorders,” said Dennis S. Charney, MD, Anne and Joel Ehrenkranz Dean of the Icahn School of Medicine at Mount Sinai and Executive Vice President for Academic Affairs at The Mount Sinai Medical Center.According to Dr. Pereira, there is a critical shortage of suitable donors for blood stem cell transplants. …

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