Astronomers have found a galaxy turning gas into stars with almost 100 percent efficiency, a rare phase of galaxy evolution that is the most extreme yet observed. The findings come from the IRAM Plateau de Bure interferometer in the French Alps, NASA's Wide-field Infrared Survey Explorer and NASA's Hubble Space Telescope.
"Galaxies burn gas like a car engine burns fuel. Most galaxies have fairly inefficient engines, meaning they form stars from their stellar fuel tanks far below the maximum theoretical rate," said Jim Geach of McGill University, lead author of a new study appearing in the Astrophysical Journal Letters.
"This galaxy is like a highly tuned sports car, converting gas to stars at the most efficient rate thought to be possible," he said.
The galaxy, called SDSSJ1506+54, jumped out at the researchers when they looked at it using data from WISE's all-sky infrared survey. Infrared light is pouring out of the galaxy, equivalent to more than a thousand billion times the energy of our sun.
"Because WISE scanned the entire sky, it detected rare galaxies like this one that stand out from the rest," said Ned Wright of UCLA, the WISE principal investigator.
Hubble's visible-light observations revealed that the galaxy is extremely compact, with most of its light emanating from a region just a few hundred light-years across.
"This galaxy is forming stars at a rate hundreds of times faster than our Milky Way galaxy, but the sharp vision of Hubble revealed that the majority of the galaxy's starlight is being emitted by a region just a few percent of the diameter of the Milky Way. This is star formation at its most extreme," said Geach.
The team then used the IRAM Plateau de Bure Interferometer to measure the amount of gas in the galaxy. The ground-based telescope detected millimeter-wave light coming from carbon monoxide, an indicator of the presence of hydrogen gas, which is fuel for stars. Combining the rate of star formation derived with WISE, and the gas mass measured by IRAM, the scientists get a measure of the star formation efficiency.
The results reveal that the star-forming efficiency of the galaxy is close to the theoretical maximum, called the Eddington limit. In regions of galaxies where new stars are forming, parts of gas clouds are collapsing due to gravity. When the gas is dense enough to squeeze atoms together and ignite nuclear fusion, a star is born. At the same time, winds and radiation from stars that have just formed can prevent the formation of new stars by exerting pressure on the surrounding gas, curtailing the collapse.
The Eddington limit is the point at which the force of gravity pulling gas together is balanced by the outward pressure from the stars. Above the Eddington limit, the gas clouds would be blown apart, halting star formation.
"We see some gas outflowing from this galaxy at millions of miles per hour, and this gas may have been blown away by the powerful radiation from the newly formed stars," said Ryan Hickox, an astrophysicist at Dartmouth College, Hanover, N.H., and a co-author on the study.
Why is SDSSJ1506+54 so unusual? Astronomers say they're catching the galaxy in a short-lived phase of evolution, possibly triggered by the merging of two galaxies into one. The star-formation is so ferocious that in a few tens of millions of years, the blink of an eye in a galaxy's life, the gas will be used up, and the galaxy will mature into a massive elliptical galaxy.
The scientists also used data from the Sloan Digital Sky Survey, the W.M. Keck Observatory on Mauna Kea, Hawaii and the MMT Observatory on Mount Hopkins, Arizona.
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McGill University: http://www.mcgill.ca
Thanks to McGill University for this article.
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A thousand-watt jolt of mischief, a spunky, funky, ebullient indie that packs its 81 minutes with cinematic exhilaration.
It may be a slight movie, but it has its sunny charms.
A movie about teenage taggers in the Bronx should be fast and raw, scruffy and loose, and Adam Leon's Gimme the Loot is just that.
As it lopes along, the movie offers a warm but very sharp portrait of New York's have-nots and their uneasy relationship with the haves.
"Gimme the Loot" shouldn't be as appealing and exuberant as it is, it really shouldn't.
Tashiana Washington and Ty Hickson are terrific in the main roles. So is Zo? Lescaze as Ginnie, a spoiled white kid who teaches the taggers a thing or two about drift and being dissolute.
Simultaneously real and hopeful, "Loot" has almost no plot, but when the setting is so fresh and the characters feel so raw and alive, who needs one?
Ghetto laughs with a sophisticated point of view.
...a magical, summery treat.
Promotes robbery and can't be serious in expecting us to care whether Malcolm and Sofia become more than friends.
The winner of the Indie Spirit 'One to Watch' award could never work again and will always have a memorable New York City film to his credit.
An impressive debut feature, Gimme the Loot is also an unusual take on characters who want to leave their stamp on "the city that never sleeps."
Much more grownup than it looks, Gimme the Loot is that rare teen-centric film whose brisk pace is unburdened by sentimentality.
Writer-director Adam Leon has crafted a classic New York story, a film imbued with the fast rhythms and muggy sensations of city life during the summer.
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JERUSALEM (AP) ? Israel's attorney general on Wednesday upheld a practice to allow security personnel to read people's email accounts when they arrive at the airport, arguing it prevents militants from entering the country.
The ruling followed an outcry last year when some people trying to enter Israel were ordered to open their emails after hours of interrogation at Israel's Ben-Gurion airport. In one instance, three Palestinian-American women were forbidden from entering after email checks were conducted.
Critics say it primarily targets Muslims and Arabs and appears to be aimed at keeping out visitors who have histories of pro-Palestinian activism, citing a history of such people being turned away from Israel's border crossings.
Security personnel may ask visitors to open their email accounts for inspection if they are perceived as being suspicious, wrote Nadim Aboud of Israel's attorney general office. In a response to the Association for Civil Rights in Israel, he said potential entrants may refuse to allow their emails to be checked, but that would be a factor in deciding whether a person would be allowed to enter the country.
Aboud said the checks were justified because there was an increasing risk of foreigners being involved in militant activity. He said security services could not properly investigate the backgrounds of some potential entrants without the additional check.
A Justice Ministry official said the search was conducted only in "extraordinary cases." He spoke anonymously in line with ministry policy.
The attorney general's office wrote the letter in response to a request for clarification by ACRI after incidents were reported last year, said attorney Lila Margalit of the organization. She said Aboud's response effectively legalized the checks, which could now be challenged only in court.
"It was a concern because of the level of invasion inherent in (checking) a personal email account," Margalit said. "It constitutes a violation of privacy."
She said inside Israel, police could search a person's computer data only with court approval, even if there was a criminal investigation underway.
Israeli officials tend to conduct exhaustive checks on foreigners entering the country, or passing through border crossings they control, if they are deemed suspicious.
It particularly affects people who hope to travel to Palestinian areas of the West Bank. The Palestinians a measure of self-government in the West Bank, a territory east of the Jewish state; but Israel controls entry into those areas.
Such visitors frequently complain that they risk not being allowed into the country if they announce they will visit areas under Palestinian Authority control; but risk being accused of lying if they omit that information to security investigators.
There are no statistics on how many people are refused entry into Israel or through border crossings that Israel controls.
One aspect of the issue is that most people entering Israel obtain visas at the airport or other border crossings. Unlike many countries, Israel does not require people to obtain visas from their embassies in advance of their trips, eliminating possible screening before visitors arrive in Israel.
In contrast, Israelis themselves are required to obtain visas far in advance before visiting many countries. Even the U.S. requires an exhaustive interview process at its embassy in Tel Aviv, and it does not grant visas to all who apply. Iranian-born Israelis, for example, are often refused visas.
The practice of email checks appears to be a step beyond what some Western countries allow, while others permit similar measures.
Germany does not allow such searches. The U.S. Department of Homeland Security has seized computers and other electronic devices from people arriving in the United States to search them.
In a narrow ruling last month, the Ninth U.S. Circuit Court of Appeals ruled that while Customs and Border Protection officers can do "a quick look" at a laptop computer or other equipment, reasonable suspicion is required for a more in-depth forensic exam of electronics. It was not immediately clear if that included email.
___
AP writers Alicia A. Caldwell in Washington and Robert Reid in Berlin contributed.
Unlike human women, female mice and some other mammals can delay the onset of their pregnancies, and researchers have now identified the molecular mechanism behind this remarkable ability.
The phenomenon, known as embryonic diapause, is a temporary state of suspended animation that occurs when environmental conditions are not favorable to the survival of the mother and the newborn. A new study, published online today (April 23) in the journal Open Biology,?reveals the genes that are responsible for pausing and resuming a pregnancy.
After an egg is fertilized, it forms a cluster of cells known as a blastocyst, which implants in the wall of the mother's uterus. But during diapause, the blastocyst is prevented from implanting and preserved in an inactive state until pregnancy resumes. Yet exactly how this process occurred was a mystery. [Gallery: Evolution's Most Extreme Mammals]
Sudhansu Dey, of Cincinnati Children's Research Foundation, and colleagues were studying the process of embryo implantation in mice when they noticed that a gene called MSX1 was very active just before implantation. They began to suspect that it might play a role in diapause, Dey told LiveScience.
To investigate further, Dey's team used hormones to induce pregnancy delays in mice, mink and Tammar wallabies. During this delayed state, the researchers measured how active the MSX1 gene and other related genes were in generating protein-making instructions. Then, they imaged tissue from the animals to see where the gene was active. Finally, they tested whether these genes were being made into proteins.
They found that the MSX genes were more active when pregnancies were delayed, and found this was true for all three animals. The genes were primarily active in epithelial cells, the type of cells that line body cavities such as the interior of the uterus, results showed. The experiments also confirmed that these genes were indeed making proteins.
Dey said the results are very exciting ? they show that MSX genes, which are part of an ancient family of genes, have been preserved over much of evolutionary time, and play an important role in delaying pregnancy under harsh conditions.
Dey wants to know whether the same genes may enable delayed pregnancies in other animals, such as the polar bear or giant panda.
Ultimately, a deeper understanding of diapause could have implications for humans, Dey said. "If we keep MSX1 maintained at higher levels in human [women], maybe we can extend the receptive phase" for fertilization, he said, though he added that such an extension may be many years away. ?
Follow Tanya Lewis on Twitter?and Google+.?Follow us @livescience, Facebook?& Google+. Original article on?LiveScience.com.
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Apr. 24, 2013 ? Prisoners who are psychopaths lack the basic neurophysiological "hardwiring" that enables them to care for others, according to a new study by neuroscientists at the University of Chicago and the University of New Mexico.
"A marked lack of empathy is a hallmark characteristic of individuals with psychopathy," said the lead author of the study, Jean Decety, the Irving B. Harris Professor in Psychology and Psychiatry at UChicago. Psychopathy affects approximately 1 percent of the United States general population and 20 percent to 30 percent of the male and female U.S. prison population. Relative to non-psychopathic criminals, psychopaths are responsible for a disproportionate amount of repetitive crime and violence in society.
"This is the first time that neural processes associated with empathic processing have been directly examined in individuals with psychopathy, especially in response to the perception of other people in pain or distress," he added.
The results of the study, which could help clinical psychologists design better treatment programs for psychopaths, are published in the article, "Brain Responses to Empathy-Eliciting Scenarios Involving Pain in Incarcerated Individuals with Psychopathy," which appears online April 24 in the journal JAMA Psychiatry.
Joining Decety in the study were Laurie Skelly, a graduate student at UChicago; and Kent Kiehl, professor of psychology at the University of New Mexico.
For the study, the research team tested 80 prisoners between ages 18 and 50 at a correctional facility. The men volunteered for the test and were tested for levels of psychopathy using standard measures.
They were then studied with functional MRI technology, to determine their responses to a series of scenarios depicting people being intentionally hurt. They were also tested on their responses to seeing short videos of facial expressions showing pain.
The participants in the high psychopathy group exhibited significantly less activation in the ventromedial prefrontal cortex, lateral orbitofrontal cortex, amygdala and periaqueductal gray parts of the brain, but more activity in the striatum and the insula when compared to control participants, the study found.
The high response in the insula in psychopaths was an unexpected finding, as this region is critically involved in emotion and somatic resonance. Conversely, the diminished response in the ventromedial prefrontal cortex and amygdala is consistent with the affective neuroscience literature on psychopathy. This latter region is important for monitoring ongoing behavior, estimating consequences and incorporating emotional learning into moral decision-making, and plays a fundamental role in empathic concern and valuing the well-being of others.
"The neural response to distress of others such as pain is thought to reflect an aversive response in the observer that may act as a trigger to inhibit aggression or prompt motivation to help," the authors write in the paper.
"Hence, examining the neural response of individuals with psychopathy as they view others being harmed or expressing pain is an effective probe into the neural processes underlying affective and empathy deficits in psychopathy," the authors wrote.
The study with prisoners was supported with a $1.6 million grant from the National Institute of Mental Health.
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Journal Reference:
Jean Decety, Laurie R. Skelly, Kent A. Kiehl. Brain Response to Empathy-Eliciting Scenarios Involving Pain in Incarcerated Individuals With Psychopathy. JAMA Psychiatry, 2013 DOI: 10.1001/jamapsychiatry.2013.27
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Zalora, Rocket Internet's pan-Asian fashion retail site, has launched an iOS app, as it seeks to capture the growing base of consumers in Asia who are using smartphones as their primary, and sometimes only, way of getting online.
Pitt team finds melatonin delays ALS symptom onset and death in micePublic release date: 25-Apr-2013 [ | E-mail | Share ]
Contact: Anita Srikameswaran SrikamAV@upmc.edu 412-578-9193 University of Pittsburgh Schools of the Health Sciences
Melatonin injections delayed symptom onset and reduced mortality in a mouse model of the neurodegenerative condition amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, according to a new study by researchers at the University of Pittsburgh School of Medicine. In a report published online ahead of print in the journal Neurobiology of Disease, the team revealed that receptors for melatonin are found in the nerve cells, a finding that could launch novel therapeutic approaches.
Annually about 5,000 people are diagnosed with ALS, which is characterized by progressive muscle weakness and eventual death due to the failure of respiratory muscles, said senior investigator Robert Friedlander, M.D., UPMC Endowed Professor of neurosurgery and neurobiology and chair, Department of Neurological Surgery, Pitt School of Medicine. But the causes of the condition are not well understood, thwarting development of a cure or even effective treatments.
Melatonin is a naturally occurring hormone that is best known for its role in sleep regulation. After screening more than a thousand FDA-approved drugs several years ago, the research team determined that melatonin is a powerful antioxidant that blocks the release of enzymes that activate apoptosis, or programmed cell death.
"Our experiments show for the first time that a lack of melatonin and melatonin receptor 1, or MT1, is associated with the progression of ALS," Dr. Friedlander said. "We saw similar results in a Huntington's disease model in an earlier project, suggesting similar biochemical pathways are disrupted in these challenging neurologic diseases."
Hoping to stop neuron death in ALS just as they did in Huntington's, the research team treated mice bred to have an ALS-like disease with injections of melatonin or with a placebo. Compared to untreated animals, the melatonin group developed symptoms later, survived longer, and had less degeneration of motor neurons in the spinal cord.
"Much more work has to be done to unravel these mechanisms before human trials of melatonin or a drug akin to it can be conducted to determine its usefulness as an ALS treatment," Dr. Friedlander said. "I suspect that a combination of agents that act on these pathways will be needed to make headway with this devastating disease."
###
Co-authors of the paper include other scientists from the University of Pittsburgh School of Medicine; Harvard Medical School; Ohio State University; Weifang Medical University; Bedford VA Medical System, Boston; St. Joseph's Hospital and Medical Center, Phoenix; University of Texas Medical School at Houston; and VA Pittsburgh Health Care System.
The project was funded by grants NS051756, NS039324, and NS055072 of the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health; the U.S. Department of Defense; and the Muscular Dystrophy Association.
About the University of Pittsburgh School of Medicine
As one of the nation's leading academic centers for biomedical research, the University of Pittsburgh School of Medicine integrates advanced technology with basic science across a broad range of disciplines in a continuous quest to harness the power of new knowledge and improve the human condition. Driven mainly by the School of Medicine and its affiliates, Pitt has ranked among the top 10 recipients of funding from the National Institutes of Health since 1998. In rankings recently released by the National Science Foundation, Pitt ranked fifth among all American universities in total federal science and engineering research and development support.
Likewise, the School of Medicine is equally committed to advancing the quality and strength of its medical and graduate education programs, for which it is recognized as an innovative leader, and to training highly skilled, compassionate clinicians and creative scientists well-equipped to engage in world-class research. The School of Medicine is the academic partner of UPMC, which has collaborated with the University to raise the standard of medical excellence in Pittsburgh and to position health care as a driving force behind the region's economy. For more information about the School of Medicine, see http://www.medschool.pitt.edu.
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Pitt team finds melatonin delays ALS symptom onset and death in micePublic release date: 25-Apr-2013 [ | E-mail | Share ]
Contact: Anita Srikameswaran SrikamAV@upmc.edu 412-578-9193 University of Pittsburgh Schools of the Health Sciences
Melatonin injections delayed symptom onset and reduced mortality in a mouse model of the neurodegenerative condition amyotrophic lateral sclerosis (ALS), or Lou Gehrig's disease, according to a new study by researchers at the University of Pittsburgh School of Medicine. In a report published online ahead of print in the journal Neurobiology of Disease, the team revealed that receptors for melatonin are found in the nerve cells, a finding that could launch novel therapeutic approaches.
Annually about 5,000 people are diagnosed with ALS, which is characterized by progressive muscle weakness and eventual death due to the failure of respiratory muscles, said senior investigator Robert Friedlander, M.D., UPMC Endowed Professor of neurosurgery and neurobiology and chair, Department of Neurological Surgery, Pitt School of Medicine. But the causes of the condition are not well understood, thwarting development of a cure or even effective treatments.
Melatonin is a naturally occurring hormone that is best known for its role in sleep regulation. After screening more than a thousand FDA-approved drugs several years ago, the research team determined that melatonin is a powerful antioxidant that blocks the release of enzymes that activate apoptosis, or programmed cell death.
"Our experiments show for the first time that a lack of melatonin and melatonin receptor 1, or MT1, is associated with the progression of ALS," Dr. Friedlander said. "We saw similar results in a Huntington's disease model in an earlier project, suggesting similar biochemical pathways are disrupted in these challenging neurologic diseases."
Hoping to stop neuron death in ALS just as they did in Huntington's, the research team treated mice bred to have an ALS-like disease with injections of melatonin or with a placebo. Compared to untreated animals, the melatonin group developed symptoms later, survived longer, and had less degeneration of motor neurons in the spinal cord.
"Much more work has to be done to unravel these mechanisms before human trials of melatonin or a drug akin to it can be conducted to determine its usefulness as an ALS treatment," Dr. Friedlander said. "I suspect that a combination of agents that act on these pathways will be needed to make headway with this devastating disease."
###
Co-authors of the paper include other scientists from the University of Pittsburgh School of Medicine; Harvard Medical School; Ohio State University; Weifang Medical University; Bedford VA Medical System, Boston; St. Joseph's Hospital and Medical Center, Phoenix; University of Texas Medical School at Houston; and VA Pittsburgh Health Care System.
The project was funded by grants NS051756, NS039324, and NS055072 of the National Institute of Neurological Disorders and Stroke, part of the National Institutes of Health; the U.S. Department of Defense; and the Muscular Dystrophy Association.
About the University of Pittsburgh School of Medicine
As one of the nation's leading academic centers for biomedical research, the University of Pittsburgh School of Medicine integrates advanced technology with basic science across a broad range of disciplines in a continuous quest to harness the power of new knowledge and improve the human condition. Driven mainly by the School of Medicine and its affiliates, Pitt has ranked among the top 10 recipients of funding from the National Institutes of Health since 1998. In rankings recently released by the National Science Foundation, Pitt ranked fifth among all American universities in total federal science and engineering research and development support.
Likewise, the School of Medicine is equally committed to advancing the quality and strength of its medical and graduate education programs, for which it is recognized as an innovative leader, and to training highly skilled, compassionate clinicians and creative scientists well-equipped to engage in world-class research. The School of Medicine is the academic partner of UPMC, which has collaborated with the University to raise the standard of medical excellence in Pittsburgh and to position health care as a driving force behind the region's economy. For more information about the School of Medicine, see http://www.medschool.pitt.edu.
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Public release date: 25-Apr-2013
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