Strange! Humans Glow in Visible Light - Yahoo! News
The human body literally glows, emitting a visible light in extremely small quantities at levels that rise and fall with the day, scientists now reveal.
Past research has shown that the body emits visible light, 1,000 times less intense than the levels to which our naked eyes are sensitive. In fact, virtually all living creatures emit very weak light, which is thought to be a byproduct of biochemical reactions involving free radicals.
(This visible light differs from the infrared radiation - an invisible form of light - that comes from body heat.)
To learn more about this faint visible light, scientists in Japan employed extraordinarily sensitive cameras capable of detecting single photons. Five healthy male volunteers in their 20s were placed bare-chested in front of the cameras in complete darkness in light-tight rooms for 20 minutes every three hours from 10 a.m. to 10 p.m. for three days.
The researchers found the body glow rose and fell over the day, with its lowest point at 10 a.m. and its peak at 4 p.m., dropping gradually after that. These findings suggest there is light emission linked to our body clocks, most likely due to how our metabolic rhythms fluctuate over the course of the day.
Faces glowed more than the rest of the body. This might be because faces are more tanned than the rest of the body, since they get more exposure to sunlight - the pigment behind skin color, melanin, has fluorescent components that could enhance the body's miniscule light production.
Since this faint light is linked with the body's metabolism, this finding suggests cameras that can spot the weak emissions could help spot medical conditions, said researcher Hitoshi Okamura, a circadian biologist at Kyoto University in Japan.
"If you can see the glimmer from the body's surface, you could see the whole body condition," said researcher Masaki Kobayashi, a biomedical photonics specialist at the Tohoku Institute of Technology in Sendai, Japan.
The scientists detailed their findings online July 16 in the journal PLoS ONE.
Wednesday, July 22, 2009
Tuesday, February 24, 2009
Music-Memory Connection Found in Brain | LiveScience
Music-Memory Connection Found in Brain LiveScience
People have long known that music can trigger powerful recollections, but now a brain-scan study has revealed where this happens in our noggins.
The part of the brain known as the medial pre-frontal cortex sits just behind the forehead, acting like recent Oscar host Hugh Jackman singing and dancing down Hollywood's memory lane.
"What seems to happen is that a piece of familiar music serves as a soundtrack for a mental movie that starts playing in our head." said Petr Janata, a cognitive neuroscientist at University of California, Davis. "It calls back memories of a particular person or place, and you might all of a sudden see that person's face in your mind's eye."
Janata began suspecting the medial pre-frontal cortex as a music-processing and music-memories region when he saw that part of the brain actively tracking chord and key changes in music. He had also seen studies which showed the same region lighting up in response to self-reflection and recall of autobiographical details, and so he decided to examine the possible music-memory link by recruiting 13 UC-Davis students.
Test subjects went under an fMRI brain scanner and listened to 30 different songs randomly chosen from the Billboard "Top 100" music charts from years when the subjects would have been 8 to 18 years old. They signaled researchers when a certain 30-second music sample triggered any autobiographical memory, as opposed to just being a familiar or unfamiliar song.
"This is the first study using music to evoke autobiographical memory," Janata told LiveScience. His full study is detailed online this week in the journal Cerebral Cortex.
The students also filled out the details of their memories in a survey immediately following the MRI session, explaining the content and clarity of their recollections. Most recognized about 17 out of 30 music samples on average, with about 13 having moderate or strong links with a memory from their lives.
Janata saw that tunes linked to the strongest self-reported memories triggered the most vivid and emotion-filled responses – findings corroborated by the brain scan showing spikes in mental activity within the medial prefrontal cortex.
The brain region responded quickly to music signature and timescale, but also reacted overall when a tune was autobiographically relevant. Furthermore, music tracking activity in the brain was stronger during more powerful autobiographical memories.
This latest research could explain why even Alzheimer's patients who endure increasing memory loss can still recall songs from their distant past.
"What's striking is that the prefrontal cortex is among the last [brain regions] to atrophy," Janata noted. He pointed to behavioral observations of Alzheimer's patients singing along or brightening up when familiar songs came on.
Janata said that his research merely tried to establish a neuroscience basis for why music can tickle memory. He voiced the hope that his and other studies could encourage practices such as giving iPods to Alzheimer's patients – perhaps providing real-life testament to the power of music.
"It's not going to reverse the disease," Janata said. "But if you can make quality of life better, why not?"
People have long known that music can trigger powerful recollections, but now a brain-scan study has revealed where this happens in our noggins.
The part of the brain known as the medial pre-frontal cortex sits just behind the forehead, acting like recent Oscar host Hugh Jackman singing and dancing down Hollywood's memory lane.
"What seems to happen is that a piece of familiar music serves as a soundtrack for a mental movie that starts playing in our head." said Petr Janata, a cognitive neuroscientist at University of California, Davis. "It calls back memories of a particular person or place, and you might all of a sudden see that person's face in your mind's eye."
Janata began suspecting the medial pre-frontal cortex as a music-processing and music-memories region when he saw that part of the brain actively tracking chord and key changes in music. He had also seen studies which showed the same region lighting up in response to self-reflection and recall of autobiographical details, and so he decided to examine the possible music-memory link by recruiting 13 UC-Davis students.
Test subjects went under an fMRI brain scanner and listened to 30 different songs randomly chosen from the Billboard "Top 100" music charts from years when the subjects would have been 8 to 18 years old. They signaled researchers when a certain 30-second music sample triggered any autobiographical memory, as opposed to just being a familiar or unfamiliar song.
"This is the first study using music to evoke autobiographical memory," Janata told LiveScience. His full study is detailed online this week in the journal Cerebral Cortex.
The students also filled out the details of their memories in a survey immediately following the MRI session, explaining the content and clarity of their recollections. Most recognized about 17 out of 30 music samples on average, with about 13 having moderate or strong links with a memory from their lives.
Janata saw that tunes linked to the strongest self-reported memories triggered the most vivid and emotion-filled responses – findings corroborated by the brain scan showing spikes in mental activity within the medial prefrontal cortex.
The brain region responded quickly to music signature and timescale, but also reacted overall when a tune was autobiographically relevant. Furthermore, music tracking activity in the brain was stronger during more powerful autobiographical memories.
This latest research could explain why even Alzheimer's patients who endure increasing memory loss can still recall songs from their distant past.
"What's striking is that the prefrontal cortex is among the last [brain regions] to atrophy," Janata noted. He pointed to behavioral observations of Alzheimer's patients singing along or brightening up when familiar songs came on.
Janata said that his research merely tried to establish a neuroscience basis for why music can tickle memory. He voiced the hope that his and other studies could encourage practices such as giving iPods to Alzheimer's patients – perhaps providing real-life testament to the power of music.
"It's not going to reverse the disease," Janata said. "But if you can make quality of life better, why not?"
Wednesday, February 18, 2009
Forensic Science System Needs Overhaul | LiveScience
Forensic Science System Needs Overhaul LiveScience
On CSI, forensic science nearly always leads to a closed case. Reality is far different. And the system needs vast change, a new report claims.
With the exception of nuclear DNA analysis, says the report from the National Research Council, "no forensic method has been rigorously shown able to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source."
That means fingerprinting techniques and lie detection methods, among others, can lead to convictions of innocent people and, of course, fail to help convict bad guys. The report writers were careful not to pass judgment on any specific past cases, however. Rather, they looked at the overall state of things.
Other studies have shown the weaknesses of some common methods used in courtrooms:
In 2002, a study by the National Academy of Sciences revealed that "polygraph tests can discriminate lying from truth telling at rates well above chance, though well below perfection."
A study in 2005 found that though people often claim to recognize a suspect they had spotted from hundreds of feet away, a person with 20/20 vision can't recognize a celebrity's face at 110 feet.
A study in the Journal of Criminal Law & Criminology indicated that there are hundreds of errors made each year in fingerprint matching.
The new, congressionally mandated report "finds serious deficiencies in the nation's forensic science system and calls for major reforms and new research," according to a statement released today by the National Academy of Sciences.
Rigorous and mandatory certification programs for forensic scientists are lacking, the report says, as are strong standards and protocols for analyzing and reporting on evidence.
Non-DNA forensic disciplines have important roles, the report states, but many need substantial research to validate basic premises and techniques, assess limitations, and discern the sources and magnitude of error. "There is a dearth of peer-reviewed, published studies establishing the scientific bases and reliability of many forensic methods," the committee writes. "Moreover, many forensic science labs are underfunded, understaffed, and have no effective oversight."
Meanwhile, laws governing how crime is prosecuted vary greatly by state. Recently, Washington state proposed to collect DNA samples from suspects in cases as minor as shoplifting. Yet in Los Angeles, the police department recently was found to have in cold storage nearly 7,000 untested DNA samples from sexual assault cases. Last year the department let the deadline pass for prosecuting some 200 potential sexual assault cases without ever testing DNA evidence on file that might have resulted in convictions.
"Reliable forensic evidence increases the ability of law enforcement officials to identify those who commit crimes, and it protects innocent people from being convicted of crimes they didn't commit," said committee co-chair Harry T. Edwards, senior circuit judge and chief judge emeritus of the U.S. Court of Appeals for the District of Columbia Circuit. "Because it is clear that judicial review alone will not cure the infirmities of the forensic science community, there is a tremendous need for the forensic science community to improve."
Edwards and his colleagues today urged Congress to establish a new, independent National Institute of Forensic Science to lead research efforts, set and enforce standards for forensic science professionals and laboratories, and oversee education standards.
On CSI, forensic science nearly always leads to a closed case. Reality is far different. And the system needs vast change, a new report claims.
With the exception of nuclear DNA analysis, says the report from the National Research Council, "no forensic method has been rigorously shown able to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source."
That means fingerprinting techniques and lie detection methods, among others, can lead to convictions of innocent people and, of course, fail to help convict bad guys. The report writers were careful not to pass judgment on any specific past cases, however. Rather, they looked at the overall state of things.
Other studies have shown the weaknesses of some common methods used in courtrooms:
In 2002, a study by the National Academy of Sciences revealed that "polygraph tests can discriminate lying from truth telling at rates well above chance, though well below perfection."
A study in 2005 found that though people often claim to recognize a suspect they had spotted from hundreds of feet away, a person with 20/20 vision can't recognize a celebrity's face at 110 feet.
A study in the Journal of Criminal Law & Criminology indicated that there are hundreds of errors made each year in fingerprint matching.
The new, congressionally mandated report "finds serious deficiencies in the nation's forensic science system and calls for major reforms and new research," according to a statement released today by the National Academy of Sciences.
Rigorous and mandatory certification programs for forensic scientists are lacking, the report says, as are strong standards and protocols for analyzing and reporting on evidence.
Non-DNA forensic disciplines have important roles, the report states, but many need substantial research to validate basic premises and techniques, assess limitations, and discern the sources and magnitude of error. "There is a dearth of peer-reviewed, published studies establishing the scientific bases and reliability of many forensic methods," the committee writes. "Moreover, many forensic science labs are underfunded, understaffed, and have no effective oversight."
Meanwhile, laws governing how crime is prosecuted vary greatly by state. Recently, Washington state proposed to collect DNA samples from suspects in cases as minor as shoplifting. Yet in Los Angeles, the police department recently was found to have in cold storage nearly 7,000 untested DNA samples from sexual assault cases. Last year the department let the deadline pass for prosecuting some 200 potential sexual assault cases without ever testing DNA evidence on file that might have resulted in convictions.
"Reliable forensic evidence increases the ability of law enforcement officials to identify those who commit crimes, and it protects innocent people from being convicted of crimes they didn't commit," said committee co-chair Harry T. Edwards, senior circuit judge and chief judge emeritus of the U.S. Court of Appeals for the District of Columbia Circuit. "Because it is clear that judicial review alone will not cure the infirmities of the forensic science community, there is a tremendous need for the forensic science community to improve."
Edwards and his colleagues today urged Congress to establish a new, independent National Institute of Forensic Science to lead research efforts, set and enforce standards for forensic science professionals and laboratories, and oversee education standards.
Idea of Infinity Stretched Back to Third Century B.C. | LiveScience
Idea of Infinity Stretched Back to Third Century B.C. LiveScience
CHICAGO - The first mathematical use of the concept of actual infinity has been pushed back some 2,000 years via a new analysis of a tattered page of parchment on which a medieval monk in Constantinople copied the third century B.C. work of the Greek mathematician Archimedes.
Infinity is one of the most fundamental questions in mathematics and still remains an unsolved riddle. For instance, if you add or subtract a number from infinity, the remaining value is still infinity, some Indian philosophers said. Mathematicians today refer to actual infinity as an uncountable set of numbers such as the number of points existing on a line at the same time, while a potential infinity is an endless sequence that unfolds consecutively over time.
The parchment page comes from the 348-page Archimedes Palimpsest, the oldest copy of some of the Greek genius' writings, which were hidden for centuries because a monk partly scraped them off the animal-skin parchment in the 13th century A.D. to clear the pages to print a prayer book. Also, a forger painted pictures over the prayer book hundreds of years after that.
A scholar named Johan Ludvig Heiberg in 1906 studied the written remnants behind the religious words to discover the Palimpsest, finding evidence of Archimedes' systematic use of the concept of infinity in a portion of the document called the Method of Mechanical Theorems. In the past few years, the Palimpsest was re-examined at a far higher level of detail using multispectral imaging and also a hair-thin X-ray scanning technique at Stanford University's Synchrotron Radiation Lightsource in California. The scanner can image a million pixels in less than one hour.
With one of the X-ray images, Stanford classicist Reviel Netz made out the edge of a torn page, where Heiberg had figured just one line of text was missing. The X-rays produced images of iron from the ink used on the document.
Netz examined the scan and was able to deduce the presence of previously unseen Greek letters, kappa and alpha, which were likely followed by an iota to spell the Greek word for "and." This led Netz to conclude that two lines were missing, rather than one and to arrive at a new reading of the passage, physicist Uwe Bergmann of the Synchrotron facility told a small group of reporters here Sunday at the American Association for the Advancement of Science.
"Scholars are now talking about some new words which are emerging in the reconstruction of the evidence in introduction to the Method, that Archimedes' concept of infinity was rather different from what was previously thought," Bergmann said.
In fact, the new reading reveals that Archimedes was engaged in math that made conceptual use of actual infinity, as Netz describes on the Web site ArchimedesPalimpsest.org. The calculations involved adding infinite numbers of sums, such as the number of triangles inside a prism, as well as the number of lines inside a rectangle. Archimedes tried to argue that these values are equal to each other, making a statement about actual infinity, not just potential infinity, Nets writes.
The Palimpsest resides at the Walters Museum of Art in Baltimore.
The Archimedes Palimpsest project forced researchers to come up with a new system to scan large objects, Bergmann said. A commercial-grade X-ray scanning machine might take a year to complete a scan that the Stanford Synchrotron now can complete in half a day, he said.
"It is now taking milliseconds rather than seconds to get each pixel — that has been for us the great novelty," he said.
CHICAGO - The first mathematical use of the concept of actual infinity has been pushed back some 2,000 years via a new analysis of a tattered page of parchment on which a medieval monk in Constantinople copied the third century B.C. work of the Greek mathematician Archimedes.
Infinity is one of the most fundamental questions in mathematics and still remains an unsolved riddle. For instance, if you add or subtract a number from infinity, the remaining value is still infinity, some Indian philosophers said. Mathematicians today refer to actual infinity as an uncountable set of numbers such as the number of points existing on a line at the same time, while a potential infinity is an endless sequence that unfolds consecutively over time.
The parchment page comes from the 348-page Archimedes Palimpsest, the oldest copy of some of the Greek genius' writings, which were hidden for centuries because a monk partly scraped them off the animal-skin parchment in the 13th century A.D. to clear the pages to print a prayer book. Also, a forger painted pictures over the prayer book hundreds of years after that.
A scholar named Johan Ludvig Heiberg in 1906 studied the written remnants behind the religious words to discover the Palimpsest, finding evidence of Archimedes' systematic use of the concept of infinity in a portion of the document called the Method of Mechanical Theorems. In the past few years, the Palimpsest was re-examined at a far higher level of detail using multispectral imaging and also a hair-thin X-ray scanning technique at Stanford University's Synchrotron Radiation Lightsource in California. The scanner can image a million pixels in less than one hour.
With one of the X-ray images, Stanford classicist Reviel Netz made out the edge of a torn page, where Heiberg had figured just one line of text was missing. The X-rays produced images of iron from the ink used on the document.
Netz examined the scan and was able to deduce the presence of previously unseen Greek letters, kappa and alpha, which were likely followed by an iota to spell the Greek word for "and." This led Netz to conclude that two lines were missing, rather than one and to arrive at a new reading of the passage, physicist Uwe Bergmann of the Synchrotron facility told a small group of reporters here Sunday at the American Association for the Advancement of Science.
"Scholars are now talking about some new words which are emerging in the reconstruction of the evidence in introduction to the Method, that Archimedes' concept of infinity was rather different from what was previously thought," Bergmann said.
In fact, the new reading reveals that Archimedes was engaged in math that made conceptual use of actual infinity, as Netz describes on the Web site ArchimedesPalimpsest.org. The calculations involved adding infinite numbers of sums, such as the number of triangles inside a prism, as well as the number of lines inside a rectangle. Archimedes tried to argue that these values are equal to each other, making a statement about actual infinity, not just potential infinity, Nets writes.
The Palimpsest resides at the Walters Museum of Art in Baltimore.
The Archimedes Palimpsest project forced researchers to come up with a new system to scan large objects, Bergmann said. A commercial-grade X-ray scanning machine might take a year to complete a scan that the Stanford Synchrotron now can complete in half a day, he said.
"It is now taking milliseconds rather than seconds to get each pixel — that has been for us the great novelty," he said.
Monday, February 16, 2009
New Artificial DNA Points to Alien Life | LiveScience
New Artificial DNA Points to Alien Life LiveScience
CHICAGO — A strange, new genetic code a lot like that found in all terrestrial life is sitting in a beaker full of oily water in a laboratory in Florida, a scientist said today, calling it the first example of an artificial chemical system that is capable of Darwinian evolution.
The system is made of the four molecules that are the basic building blocks of our DNA along with eight synthetic modifications of them, said biochemist Steven A. Benner of the Foundation for Applied Molecular Evolution in Gainesville.
The main difference between the synthetic molecules and those that make up conventional DNA is that Benner's molecules cannot make copies of themselves, although that is just "a couple of years" away, he said.
The wild biochemistry finding, described to a small group of reporters today at the annual meeting of the American Association for the Advancement of Science, offers ideas about new types of life for scientists to look for beyond our planet, or even possibly hidden on our planet.
"Unless it happens to shoot at you with a ray gun, the life that you encounter off of Earth will not necessarily have same biochemistry as us," Benner said.
And the step from Benner's system to something that could be called artificial life is still large. "There is not enough information in them to build organisms," Benner said.
Expanded alphabet for DNA
For some 20 years, Benner's labs have been involved in trying to make artificial life or things approximating it, with similar genetic and inheritance properties to life on Earth. (Previously, Benner worked at the University of Florida.)
He and his colleagues have focused in part on expanding the DNA alphabet to develop an "Artificially Expanded Genetic Information System," which now has its own supporting molecular biology.
The building blocks of DNA are four chemicals called nucleotides that are referred to as A, C, T and G, for short. The nucleotides pair up and bond in predictable ways to form the double helix structure of DNA. Benner's new nucleotides, which he and his colleagues have named Z, P, V, J, Iso-C, Iso-G, X and K, are reshufflings of the constituents of those molecules found in our DNA.
The evolution in this system happens when the 12-letter genetic code makes copying mistakes and subsequent sequences have properties that make them more liable to get copied. Those sequences would survive in greater numbers than the original sequence.
Benner's synthetic approach was conceptualized using "ball and stick plastic model chemistry," he said, the technique used by James Watson and Francis Crick to arrive at the structure of the DNA molecule in 1953.
The human genome's DNA includes 3 billion base pairs. Some of the molecules synthesized in Benner's lab are 81 base pairs long — relatively short.
The molecules are "fed" and grow via a process called the polymerase chain reaction (PCR) that allows the molecules to make copies of themselves. Once the replication of the molecules in Benner's system is self-catalyzed, without PCR, the process is self-sustaining. Benner claims, "then it's artificial life."
Dreaming up extra-terrestrial life
The research resulted from a NASA-funded project to try to understand what life might look like beyond Earth. Such life might live in water, but it could also live in liquid nitrogen or methane (as speculated for Saturn's moon Titan) and in environments with extremely high or low acidity.
The results are published in a technical book, "Life, the Universe and the Scientific Method," of which Benner has made about 100 copies to distribute to his colleagues.
"One of the ways scientists try to understand life as a universal concept ... is you try to make life on your own in the lab," Benner said. "We try to put together chemicals that do that."
Any potential life forms made from such molecules would be "so alien in terms of their biochemistry that they will not able to eat you," Benner said.
NASA has been involved in searching for extra-terrestrial life along numerous avenues for decades, including the Viking mission to Mars in the 1970s and its recent missions to the red planet which have searched for signs of habitability there. NASA also funds an Astrobiology Institute, which partners with hundreds of researchers world-wide who study of the origins, evolution, distribution and future of life in the universe
The trick to searching for alien life is how to look for it, said Paul Davies of Arizona State University, who also spoke with reporters here today.
"All of the techniques which microbiologists use to [look for alien life] are customized to life as we know it," Davies said. "It's no surprise that microbiologists haven't come across micro-organisms that seem to have relatively different biochemistry."
In the future, more scientists could "talk with Steve Benner," Davies said, "to come up with perfectly good molecules that life could use — but doesn't."
CHICAGO — A strange, new genetic code a lot like that found in all terrestrial life is sitting in a beaker full of oily water in a laboratory in Florida, a scientist said today, calling it the first example of an artificial chemical system that is capable of Darwinian evolution.
The system is made of the four molecules that are the basic building blocks of our DNA along with eight synthetic modifications of them, said biochemist Steven A. Benner of the Foundation for Applied Molecular Evolution in Gainesville.
The main difference between the synthetic molecules and those that make up conventional DNA is that Benner's molecules cannot make copies of themselves, although that is just "a couple of years" away, he said.
The wild biochemistry finding, described to a small group of reporters today at the annual meeting of the American Association for the Advancement of Science, offers ideas about new types of life for scientists to look for beyond our planet, or even possibly hidden on our planet.
"Unless it happens to shoot at you with a ray gun, the life that you encounter off of Earth will not necessarily have same biochemistry as us," Benner said.
And the step from Benner's system to something that could be called artificial life is still large. "There is not enough information in them to build organisms," Benner said.
Expanded alphabet for DNA
For some 20 years, Benner's labs have been involved in trying to make artificial life or things approximating it, with similar genetic and inheritance properties to life on Earth. (Previously, Benner worked at the University of Florida.)
He and his colleagues have focused in part on expanding the DNA alphabet to develop an "Artificially Expanded Genetic Information System," which now has its own supporting molecular biology.
The building blocks of DNA are four chemicals called nucleotides that are referred to as A, C, T and G, for short. The nucleotides pair up and bond in predictable ways to form the double helix structure of DNA. Benner's new nucleotides, which he and his colleagues have named Z, P, V, J, Iso-C, Iso-G, X and K, are reshufflings of the constituents of those molecules found in our DNA.
The evolution in this system happens when the 12-letter genetic code makes copying mistakes and subsequent sequences have properties that make them more liable to get copied. Those sequences would survive in greater numbers than the original sequence.
Benner's synthetic approach was conceptualized using "ball and stick plastic model chemistry," he said, the technique used by James Watson and Francis Crick to arrive at the structure of the DNA molecule in 1953.
The human genome's DNA includes 3 billion base pairs. Some of the molecules synthesized in Benner's lab are 81 base pairs long — relatively short.
The molecules are "fed" and grow via a process called the polymerase chain reaction (PCR) that allows the molecules to make copies of themselves. Once the replication of the molecules in Benner's system is self-catalyzed, without PCR, the process is self-sustaining. Benner claims, "then it's artificial life."
Dreaming up extra-terrestrial life
The research resulted from a NASA-funded project to try to understand what life might look like beyond Earth. Such life might live in water, but it could also live in liquid nitrogen or methane (as speculated for Saturn's moon Titan) and in environments with extremely high or low acidity.
The results are published in a technical book, "Life, the Universe and the Scientific Method," of which Benner has made about 100 copies to distribute to his colleagues.
"One of the ways scientists try to understand life as a universal concept ... is you try to make life on your own in the lab," Benner said. "We try to put together chemicals that do that."
Any potential life forms made from such molecules would be "so alien in terms of their biochemistry that they will not able to eat you," Benner said.
NASA has been involved in searching for extra-terrestrial life along numerous avenues for decades, including the Viking mission to Mars in the 1970s and its recent missions to the red planet which have searched for signs of habitability there. NASA also funds an Astrobiology Institute, which partners with hundreds of researchers world-wide who study of the origins, evolution, distribution and future of life in the universe
The trick to searching for alien life is how to look for it, said Paul Davies of Arizona State University, who also spoke with reporters here today.
"All of the techniques which microbiologists use to [look for alien life] are customized to life as we know it," Davies said. "It's no surprise that microbiologists haven't come across micro-organisms that seem to have relatively different biochemistry."
In the future, more scientists could "talk with Steve Benner," Davies said, "to come up with perfectly good molecules that life could use — but doesn't."
Monday, February 9, 2009
Scientist Catches Criminals Online | LiveScience
Scientist Catches Criminals Online LiveScience
Editor's Note: ScienceLives is an occasional series that puts scientists under the microscope to find out what makes them tick. The series is a cooperation between the National Science Foundation and LiveScience.
Name: Roman YampolskiyAge: 29Institution: University of LouisvilleField of Study: Behavioral Biometrics (Computer Science)
Roman Yampolskiy has chosen a career path that combines two often disparate fields, human behavior and computer science, to help find ways to catch criminals by monitoring their online behavior. From poker-website phishing schemes to coordinated website attacks, Yampolskiy looks at activity patterns to deduce who might be committing crimes online. More details, including articles about his work, are available at his website:
What inspired you to choose this field of study? I was always interested in better understanding people around me; I even had a psychology concentration as an undergraduate. After enrolling in graduate school I realized that the field of behavioral biometrics (profiling people's behavior for security purposes) offers me a great chance to combine my interest in investigation of human behavior with my desire to work with cutting edge computer technologies.
What is the best piece of advice you ever received? A good friend once told me: "Don't stress about problems. In life 50 percent of problems will resolve by themselves and there is nothing you can do about the rest."
What was your first scientific experiment as a child? When I was about 3 or 4 years old and had just learned numbers, I wanted to write down ALL the numbers sequentially starting with one. After I run out of paper in my notepad I discovered the concept of infinity and terminated my experiment which really disappointed my parents who by that time have grown attached to the peace and quiet associated with my scientific experiment. Not surprisingly they have encouraged me to pursue science ever since.
What is your favorite thing about being a scientist or researcher? Being a scientist means never having to grow up and lose curiosity inherent to all children. As a scientist I can always ask "why" about anything and in some cases be the first person to truly know that the answer is not "because."
What is the most important characteristic a scientist must demonstrate in order to be an effective scientist? A scientist believes that everything which has not been proven impossible may be possible, an effective scientist knows that nothing is impossible if you pick the right set of axioms.
What are the societal benefits of your research?Today behavioral biometric systems are utilized to provide enhanced level of security at border crossing, airports, workplaces and in numerous computer networks. It is predicted that in the near future majority of authentications tasks will be performed by relying on physical or behavioral biometrics. Results of my research in particular are aimed at financial institutions and online casinos trying to secure their customers from phishing (theft of identity) attacks.
Who has had the most influence on your thinking as a researcher? I have to say the founding father of computer science, Alan Turing, is the person who influenced my thinking the most. By helping allies win WWII by decrypting Nazi communications he showed that even theoretical mathematicians armed with computers could have an immediate positive impact on the world.
What about your field or being a scientist do you think would surprise people the most?Most people know about the stereotype of an absentminded scientist incapable of taking care of his most mundane needs while being a world famous export in his field. I myself was really surprised to learn that many accomplished computer scientists lack basic computer skills such as ability to read HTML enabled emails, open compressed files or update their own webpage.
If you could only rescue one thing from your burning office or lab, what would it be? My PhD diploma, I have multiple backup copies of everything else in my office securely located in remote locations.
What music do you play most often in your lab or car?I pride myself on the diversity of my musical tastes. I have numerous compiled CDs where Beethoven, ABBA and Eminem are located on neighboring tracks.
Editor's Note: ScienceLives is an occasional series that puts scientists under the microscope to find out what makes them tick. The series is a cooperation between the National Science Foundation and LiveScience.
Name: Roman YampolskiyAge: 29Institution: University of LouisvilleField of Study: Behavioral Biometrics (Computer Science)
Roman Yampolskiy has chosen a career path that combines two often disparate fields, human behavior and computer science, to help find ways to catch criminals by monitoring their online behavior. From poker-website phishing schemes to coordinated website attacks, Yampolskiy looks at activity patterns to deduce who might be committing crimes online. More details, including articles about his work, are available at his website:
What inspired you to choose this field of study? I was always interested in better understanding people around me; I even had a psychology concentration as an undergraduate. After enrolling in graduate school I realized that the field of behavioral biometrics (profiling people's behavior for security purposes) offers me a great chance to combine my interest in investigation of human behavior with my desire to work with cutting edge computer technologies.
What is the best piece of advice you ever received? A good friend once told me: "Don't stress about problems. In life 50 percent of problems will resolve by themselves and there is nothing you can do about the rest."
What was your first scientific experiment as a child? When I was about 3 or 4 years old and had just learned numbers, I wanted to write down ALL the numbers sequentially starting with one. After I run out of paper in my notepad I discovered the concept of infinity and terminated my experiment which really disappointed my parents who by that time have grown attached to the peace and quiet associated with my scientific experiment. Not surprisingly they have encouraged me to pursue science ever since.
What is your favorite thing about being a scientist or researcher? Being a scientist means never having to grow up and lose curiosity inherent to all children. As a scientist I can always ask "why" about anything and in some cases be the first person to truly know that the answer is not "because."
What is the most important characteristic a scientist must demonstrate in order to be an effective scientist? A scientist believes that everything which has not been proven impossible may be possible, an effective scientist knows that nothing is impossible if you pick the right set of axioms.
What are the societal benefits of your research?Today behavioral biometric systems are utilized to provide enhanced level of security at border crossing, airports, workplaces and in numerous computer networks. It is predicted that in the near future majority of authentications tasks will be performed by relying on physical or behavioral biometrics. Results of my research in particular are aimed at financial institutions and online casinos trying to secure their customers from phishing (theft of identity) attacks.
Who has had the most influence on your thinking as a researcher? I have to say the founding father of computer science, Alan Turing, is the person who influenced my thinking the most. By helping allies win WWII by decrypting Nazi communications he showed that even theoretical mathematicians armed with computers could have an immediate positive impact on the world.
What about your field or being a scientist do you think would surprise people the most?Most people know about the stereotype of an absentminded scientist incapable of taking care of his most mundane needs while being a world famous export in his field. I myself was really surprised to learn that many accomplished computer scientists lack basic computer skills such as ability to read HTML enabled emails, open compressed files or update their own webpage.
If you could only rescue one thing from your burning office or lab, what would it be? My PhD diploma, I have multiple backup copies of everything else in my office securely located in remote locations.
What music do you play most often in your lab or car?I pride myself on the diversity of my musical tastes. I have numerous compiled CDs where Beethoven, ABBA and Eminem are located on neighboring tracks.
Thursday, February 5, 2009
Divorce Makes Women Look Older | LiveScience
Divorce Makes Women Look Older LiveScience
Divorce is one of several factors now found to add years to a woman's face.
Lots of things make us old. Previous research has shown smoking causes premature aging in men and women, literally etching the aging in their faces. Other research has found that poor skin tone can add a decade to a woman's perceived age.
In the new work, researchers photographed the faces of 186 pairs of identical twins, mostly women, and asked them each a series of questions about their life habits and medical backgrounds. Four other people then reviewed all the photos and guessed the ages of each person.
Women who were divorced were judged to look nearly two years older than their siblings who were married, single or widowed, according to an article at the The Los Angeles Times web site. The research was led by Bahman Guyuron, chairman of the department of plastic surgery at University Hospitals Case Medical Center, part of Case Western Reserve University. It was reported in the journal Plastic and Reconstructive Surgery.
Only the results for women were released. Other factors that made one twin look older than a sibling:
Sun exposure
Smoking and alcohol use
Antidepressant use
Antidepressants may cause facial sagging, Guyuron speculated.
Interestingly, being heavier made those under age 40 look older, but it made those over 40 look younger, Guyuron and colleagues report. Previous research has suggested that a little weight — particularly in the cheeks — looks good on people as they age. Predictably for a plastic surgeon, Guyuron said his findings support "fillers" used in plastic surgery.
For those who prefer to keep the looks they're given, perhaps some comfort can be found in the old adage "you're only as old as you feel." A study in December found that older people tend to feel about 13 years younger than their chronological age.
Divorce is one of several factors now found to add years to a woman's face.
Lots of things make us old. Previous research has shown smoking causes premature aging in men and women, literally etching the aging in their faces. Other research has found that poor skin tone can add a decade to a woman's perceived age.
In the new work, researchers photographed the faces of 186 pairs of identical twins, mostly women, and asked them each a series of questions about their life habits and medical backgrounds. Four other people then reviewed all the photos and guessed the ages of each person.
Women who were divorced were judged to look nearly two years older than their siblings who were married, single or widowed, according to an article at the The Los Angeles Times web site. The research was led by Bahman Guyuron, chairman of the department of plastic surgery at University Hospitals Case Medical Center, part of Case Western Reserve University. It was reported in the journal Plastic and Reconstructive Surgery.
Only the results for women were released. Other factors that made one twin look older than a sibling:
Sun exposure
Smoking and alcohol use
Antidepressant use
Antidepressants may cause facial sagging, Guyuron speculated.
Interestingly, being heavier made those under age 40 look older, but it made those over 40 look younger, Guyuron and colleagues report. Previous research has suggested that a little weight — particularly in the cheeks — looks good on people as they age. Predictably for a plastic surgeon, Guyuron said his findings support "fillers" used in plastic surgery.
For those who prefer to keep the looks they're given, perhaps some comfort can be found in the old adage "you're only as old as you feel." A study in December found that older people tend to feel about 13 years younger than their chronological age.
Tuesday, February 3, 2009
Orphan Chimpanzees Cleverer Than Humans, Study Finds
Orphan Chimpanzees Cleverer Than Humans, Study Finds
ScienceDaily (Feb. 2, 2009) — Orphaned chimpanzee infants given special ‘mothering’ by humans are more advanced than the average child at nine months of age.
In the first study to examine the effect of different types of care for infant chimpanzees on cognition, researchers found chimpanzees who were given extra emotionally-based care were more cognitively advanced than human infants.
Humans overtake chimpanzees in development terms as they grow older but the study sends stark warnings that looking after just an infant’s physical needs is likely to result in a child who is maladjusted, unhappy and under-achieving.
The study was carried out by psychology expert Professor Kim Bard, of the Centre for the Study of Emotion at the University of Portsmouth.
She said: “The attachment system of infant chimpanzees appears surprisingly similar to that found in human infants. Early experiences, either of warm, responsive care-giving or of extreme deprivation, have a dramatic impact on emotional and cognitive outcomes in both chimpanzees and humans.
“Parental sensitivity is an important factor in human infant development, contributing to emotionally and cognitively strong children, and it would seem the same is true for great apes, as well.”
Professor Bard studied 46 chimpanzees in the Great Ape Nursery at the Yerkes National Primate Research Centre in Atlanta, America, in the 1980s and 1990s. The chimpanzees were in the nursery because their mothers’ maternal skills were so inadequate the infants were at risk of dying.
She found that chimpanzees given 20 hours a week of responsive care, which looks after the emotional and physical development, were happier, more advanced and better adjusted than chimpanzees given standard institutionalised care which meets just their physical needs.
She said: “Those given responsive care were less easily stressed, less often attached to ‘comfort blankets’, had healthier relationships with their caregivers and were less likely to develop stereotypic rocking. They were also more advanced intellectually than chimpanzees reared with standard institutionalised care.”
The responsive care was given by human caregivers who would play, groom, feed and interact with the infants. The caregivers focused on nurturing emotional and communicative well-being, similar to that found in the parenting behaviour of well adjusted mother chimpanzees. This level of care lasted through the first year of life and the chimpanzees’ development was assessed at various stages using the same tests as those used to assess development and attachment in human infants.
The chimpanzees raised with standard institutionalised care were more likely to show signs of ‘disorganised attachment’, including rocking, or clasping themselves or a blanket, instead of seeking comfort from a carer when distressed. They also showed other contradictory behaviours such as being distressed in the absence of a carer but ‘freezing’ when the main carer returned after a brief absence.
In human infants, ‘disorganised attachments’ are seen in children whose parents have unresolved losses or other trauma, and/or when the infants are abused or neglected.
Dr Bard said: “Responsive care, which meets infants’ emotional as well as physical needs, stimulates cognitive and emotional development.
“Infant chimpanzees who were given this care were more advanced and less likely to develop attachment to things like security blankets than chimpanzees whose care was only meeting their physical needs.”
It is the first study to investigate individual differences in attachment relationships in great apes and is also the first intervention study with non-human primates evaluating the effects of two types of human care, differing in quality and quantity, on infant chimpanzees’ cognitive development and attachment security.
The study was co-authored by Professor Bard and Krisztina Ivan of the University of Portsmouth’s Centre for the Study of Emotion and Professor Marinus van IJzendoorn and Dr Marian Bakermans-Kranenburg of the Centre for Child and Family Studies at Leiden University in the Netherlands. Partial funding was provided by the European Commission for the Feelix Growing project. The study is published in Developmental Psychobiology.
ScienceDaily (Feb. 2, 2009) — Orphaned chimpanzee infants given special ‘mothering’ by humans are more advanced than the average child at nine months of age.
In the first study to examine the effect of different types of care for infant chimpanzees on cognition, researchers found chimpanzees who were given extra emotionally-based care were more cognitively advanced than human infants.
Humans overtake chimpanzees in development terms as they grow older but the study sends stark warnings that looking after just an infant’s physical needs is likely to result in a child who is maladjusted, unhappy and under-achieving.
The study was carried out by psychology expert Professor Kim Bard, of the Centre for the Study of Emotion at the University of Portsmouth.
She said: “The attachment system of infant chimpanzees appears surprisingly similar to that found in human infants. Early experiences, either of warm, responsive care-giving or of extreme deprivation, have a dramatic impact on emotional and cognitive outcomes in both chimpanzees and humans.
“Parental sensitivity is an important factor in human infant development, contributing to emotionally and cognitively strong children, and it would seem the same is true for great apes, as well.”
Professor Bard studied 46 chimpanzees in the Great Ape Nursery at the Yerkes National Primate Research Centre in Atlanta, America, in the 1980s and 1990s. The chimpanzees were in the nursery because their mothers’ maternal skills were so inadequate the infants were at risk of dying.
She found that chimpanzees given 20 hours a week of responsive care, which looks after the emotional and physical development, were happier, more advanced and better adjusted than chimpanzees given standard institutionalised care which meets just their physical needs.
She said: “Those given responsive care were less easily stressed, less often attached to ‘comfort blankets’, had healthier relationships with their caregivers and were less likely to develop stereotypic rocking. They were also more advanced intellectually than chimpanzees reared with standard institutionalised care.”
The responsive care was given by human caregivers who would play, groom, feed and interact with the infants. The caregivers focused on nurturing emotional and communicative well-being, similar to that found in the parenting behaviour of well adjusted mother chimpanzees. This level of care lasted through the first year of life and the chimpanzees’ development was assessed at various stages using the same tests as those used to assess development and attachment in human infants.
The chimpanzees raised with standard institutionalised care were more likely to show signs of ‘disorganised attachment’, including rocking, or clasping themselves or a blanket, instead of seeking comfort from a carer when distressed. They also showed other contradictory behaviours such as being distressed in the absence of a carer but ‘freezing’ when the main carer returned after a brief absence.
In human infants, ‘disorganised attachments’ are seen in children whose parents have unresolved losses or other trauma, and/or when the infants are abused or neglected.
Dr Bard said: “Responsive care, which meets infants’ emotional as well as physical needs, stimulates cognitive and emotional development.
“Infant chimpanzees who were given this care were more advanced and less likely to develop attachment to things like security blankets than chimpanzees whose care was only meeting their physical needs.”
It is the first study to investigate individual differences in attachment relationships in great apes and is also the first intervention study with non-human primates evaluating the effects of two types of human care, differing in quality and quantity, on infant chimpanzees’ cognitive development and attachment security.
The study was co-authored by Professor Bard and Krisztina Ivan of the University of Portsmouth’s Centre for the Study of Emotion and Professor Marinus van IJzendoorn and Dr Marian Bakermans-Kranenburg of the Centre for Child and Family Studies at Leiden University in the Netherlands. Partial funding was provided by the European Commission for the Feelix Growing project. The study is published in Developmental Psychobiology.
Monday, January 26, 2009
Eating Less May Not Extend Human Life: Caloric Restriction May Benefit Only Obese Mice
Eating Less May Not Extend Human Life: Caloric Restriction May Benefit Only Obese Mice
ScienceDaily (Jan. 26, 2009) — If you are a mouse on the chubby side, then eating less may help you live longer.
For lean mice – and possibly for lean humans, the authors of a new study predict – the anti-aging strategy known as caloric restriction may be a pointless, frustrating and even dangerous exercise.
"Today there are a lot of very healthy people who look like skeletons because they bought into this," said Raj Sohal, professor at the University of Southern California's School of Pharmacy.
He and Michael Forster, of the University of North Texas Health Science Center, compared the life span and caloric intake of two genetically engineered strains of mice.
The "fat" strain, known as C57BL/6, roughly doubles in weight over its adult life. That strain benefited from caloric restriction, Sohal said.
The "lean" strain, DBA/2, does not become obese. Caloric restriction did not extend the life of these mice, confirming previous work by Forster and Sohal.
"Our study questions the paradigm that caloric restriction is universally beneficial," Sohal said. "Contrary to what is widely believed, caloric restriction does not extend (the) life span of all strains of mice."
By measuring the animals' metabolic rate, Sohal and his colleagues came to a deceptively simple conclusion: Caloric restriction is only useful when, as in the case of the obese mice, an animal eats more than it can burn off.
"Your energy expenditure and your energy intake should be in balance," Sohal said. "It's as simple as that. And how do you know that? By gain or loss of weight.
"The whole thing is very commonsensical."
For humans of normal weight, Sohal strongly cautions against caloric restriction. In a 2003 study, he and Forster found that caloric restriction begun in older mice – both in DBA and leaner C57 individuals – actually shortened life span.
However, Sohal said that obese individuals are probably better off cutting calories than increasing their exercise to make up for overeating. Overly vigorous exercise can lead to injuries and long-term wear and tear.
In other words, it is better to skip the double cheeseburger than to turn up the treadmill after binging at Carl's Jr.
Sohal's study is not the first to question the allegedly universal benefits of caloric restriction. A study by Ross et al. published in Nature in 1976 ("Dietary practices and growth responses as predictors of longevity") found that caloric restriction works best in mice that gain weight rapidly in early adulthood, Sohal said.
Studies of caloric restriction in wild types of mouse strains have shown minimal life span extension, he added.
Next, the researchers want to understand why the obese mice have a lower metabolic rate that promotes weight gain.
The other members of the research team were Melissa Ferguson and Barbara Sohal of the USC School of Pharmacy.
Funding for the study came from the National Institute on Aging, part of the National Institutes of Health.
ScienceDaily (Jan. 26, 2009) — If you are a mouse on the chubby side, then eating less may help you live longer.
For lean mice – and possibly for lean humans, the authors of a new study predict – the anti-aging strategy known as caloric restriction may be a pointless, frustrating and even dangerous exercise.
"Today there are a lot of very healthy people who look like skeletons because they bought into this," said Raj Sohal, professor at the University of Southern California's School of Pharmacy.
He and Michael Forster, of the University of North Texas Health Science Center, compared the life span and caloric intake of two genetically engineered strains of mice.
The "fat" strain, known as C57BL/6, roughly doubles in weight over its adult life. That strain benefited from caloric restriction, Sohal said.
The "lean" strain, DBA/2, does not become obese. Caloric restriction did not extend the life of these mice, confirming previous work by Forster and Sohal.
"Our study questions the paradigm that caloric restriction is universally beneficial," Sohal said. "Contrary to what is widely believed, caloric restriction does not extend (the) life span of all strains of mice."
By measuring the animals' metabolic rate, Sohal and his colleagues came to a deceptively simple conclusion: Caloric restriction is only useful when, as in the case of the obese mice, an animal eats more than it can burn off.
"Your energy expenditure and your energy intake should be in balance," Sohal said. "It's as simple as that. And how do you know that? By gain or loss of weight.
"The whole thing is very commonsensical."
For humans of normal weight, Sohal strongly cautions against caloric restriction. In a 2003 study, he and Forster found that caloric restriction begun in older mice – both in DBA and leaner C57 individuals – actually shortened life span.
However, Sohal said that obese individuals are probably better off cutting calories than increasing their exercise to make up for overeating. Overly vigorous exercise can lead to injuries and long-term wear and tear.
In other words, it is better to skip the double cheeseburger than to turn up the treadmill after binging at Carl's Jr.
Sohal's study is not the first to question the allegedly universal benefits of caloric restriction. A study by Ross et al. published in Nature in 1976 ("Dietary practices and growth responses as predictors of longevity") found that caloric restriction works best in mice that gain weight rapidly in early adulthood, Sohal said.
Studies of caloric restriction in wild types of mouse strains have shown minimal life span extension, he added.
Next, the researchers want to understand why the obese mice have a lower metabolic rate that promotes weight gain.
The other members of the research team were Melissa Ferguson and Barbara Sohal of the USC School of Pharmacy.
Funding for the study came from the National Institute on Aging, part of the National Institutes of Health.
Friday, January 23, 2009
Teleportation Milestone Achieved | LiveScience
Scientists have come a bit closer to achieving the "Star Trek" feat of teleportation. No one is galaxy-hopping, or even beaming people around, but for the first time, information has been teleported between two separate atoms across a distance of a meter — about a yard.
This is a significant milestone in a field known as quantum information processing, said Christopher Monroe of the Joint Quantum Institute at the University of Maryland, who led the effort.
Teleportation is one of nature's most mysterious forms of transport: Quantum information, such as the spin of a particle or the polarization of a photon, is transferred from one place to another, without traveling through any physical medium. It has previously been achieved between photons (a unit, or quantum, of electromagnetic radiation, such as light) over very large distances, between photons and ensembles of atoms, and between two nearby atoms through the intermediary action of a third.
None of those, however, provides a feasible means of holding and managing quantum information over long distances.
Now the JQI team, along with colleagues at the University of Michigan, has succeeded in teleporting a quantum state directly from one atom to another over a meter. That capability is necessary for workable quantum information systems because they will require memory storage at both the sending and receiving ends of the transmission.
In the Jan. 23 issue of the journal Science, the scientists report that, by using their protocol, atom-to-atom teleported information can be recovered with perfect accuracy about 90 percent of the time — and that figure can be improved.
"Our system has the potential to form the basis for a large-scale 'quantum repeater' that can network quantum memories over vast distances," Monroe said. "Moreover, our methods can be used in conjunction with quantum bit operations to create a key component needed for quantum computation."
A quantum computer could perform certain tasks, such as encryption-related calculations and searches of giant databases, considerably faster than conventional machines. The effort to devise a working model is a matter of intense interest worldwide.
Teleportation and entanglement
Physicist Richard Feynman is quoted as having said that "if you think you understand quantum mechanics, you don't understand quantum mechanics." Or sometimes he is cited thusly: "I think I can safely say that nobody understand quantum mechanics."
Nonetheless, here is how the University of Maryland describes Monroe's work.
Teleportation works because of a remarkable quantum phenomenon called entanglement which only occurs on the atomic and subatomic scale. Once two objects are put in an entangled state, their properties are inextricably entwined. Although those properties are inherently unknowable until a measurement is made, measuring either one of the objects instantly determines the characteristics of the other, no matter how far apart they are.
The JQI team set out to entangle the quantum states of two individual ytterbium ions so that information embodied in the condition of one could be teleported to the other. Each ion was isolated in a separate high-vacuum trap, suspended in an invisible cage of electromagnetic fields and surrounded by metal electrodes.
The researchers identified two readily discernible ground (lowest energy) states of the ions that would serve as the alternative "bit" values of an atomic quantum bit, or qubit.Conventional electronic bits (short for binary digits), such as those in a personal computer, are always in one of two states: off or on, 0 or 1, high or low voltage, etc. Quantum bits, however, can be in some combination, called a "superposition," of both states at the same time, like a coin that is simultaneously heads and tails — until a measurement is made. It is this phenomenon that gives quantum computation its extraordinary power.
Laser pulse initiates process
At the start of the experimental process, each ion (designated A and B) is initialized in a given ground state.
Then ion A is irradiated with a specially tailored microwave burst from one of its cage electrodes, placing the ion in some desired superposition of the two qubit states — in effect "writing" into "memory" the information to be teleported.
Immediately thereafter, both ions are excited by a picosecond (one trillionth of a second) laser pulse. The pulse duration is so short that each ion emits only a single photon as it sheds the energy gained by the laser and falls back to one or the other of the two qubit ground states.
Depending on which one it falls into, the ion emits one of two kinds of photons of slightly different wavelengths (designated red and blue) that correspond to the two atomic qubit states. It is the relationship between those photons that will eventually provide the telltale signal that entanglement has occurred.
Beamsplitter encounter
Each emitted photon is captured by a lens, routed to a separate strand of fiber-optic cable, and carried to a 50-50 beamsplitter where it is equally probable for the photon to pass straight through the splitter or to be reflected. On either side of the beamsplitter are detectors that can record the arrival of a single photon.
Before it reaches the beamsplitter, each photon is in an unknowable superposition of states. After encountering the beamsplitter, however, each takes on specific characteristics.
As a result, for each pair of photons, four color combinations are possible — blue-blue, red-red, blue-red and red-blue — as well as one of two polarizations: horizontal or vertical. In nearly all of those variations, the photons either cancel each other out or both end up in the same detector. But there is one — and only one — combination in which both detectors will record a photon at exactly the same time.
In that case, however, it is physically impossible to tell which ion produced which photon because it cannot be known whether the photon arriving at a detector passed through the beamsplitter or was reflected by it.
Thanks to the peculiar laws of quantum mechanics, that inherent uncertainty projects the ions into an entangled state. That is, each ion is in a superposition of the two possible qubit states. The simultaneous detection of photons at the detectors does not occur often, so the laser stimulus and photon emission process has to be repeated many thousands of times per second. But when a photon appears in each detector, it is an unambiguous signature of entanglement between the ions.
When an entangled condition is identified, the scientists immediately take a measurement of ion A. The act of measurement forces it out of superposition and into a definite condition: one of the two qubit states.
But because ion A's state is irreversibly tied to ion B's, the measurement also forces B into the complementary state. Depending on which state ion A is found in, the researchers now know precisely what kind of microwave pulse to apply to ion B in order to recover the exact information that had been written to ion A by the original microwave burst. Doing so results in the accurate teleportation of the information.
Teleportation vs. other communications
What distinguishes this outcome as teleportation, rather than any other form of communication, is that no information pertaining to the original memory actually passes between ion A and ion B. Instead, the information disappears when ion A is measured and reappears when the microwave pulse is applied to ion B.
"One particularly attractive aspect of our method is that it combines the unique advantages of both photons and atoms," says Monroe. "Photons are ideal for transferring information fast over long distances, whereas atoms offer a valuable medium for long-lived quantum memory ... Also, the teleportation of quantum information in this way could form the basis of a new type of quantum internet that could outperform any conventional type of classical network for certain tasks."
The work was supported by the Intelligence Advanced Research Project Activity program under U.S. Army Research Office contract, the National Science Foundation (NSF) Physics at the Information Frontier Program, and the NSF Physics Frontier Center at the Joint Quantum Institute.
This is a significant milestone in a field known as quantum information processing, said Christopher Monroe of the Joint Quantum Institute at the University of Maryland, who led the effort.
Teleportation is one of nature's most mysterious forms of transport: Quantum information, such as the spin of a particle or the polarization of a photon, is transferred from one place to another, without traveling through any physical medium. It has previously been achieved between photons (a unit, or quantum, of electromagnetic radiation, such as light) over very large distances, between photons and ensembles of atoms, and between two nearby atoms through the intermediary action of a third.
None of those, however, provides a feasible means of holding and managing quantum information over long distances.
Now the JQI team, along with colleagues at the University of Michigan, has succeeded in teleporting a quantum state directly from one atom to another over a meter. That capability is necessary for workable quantum information systems because they will require memory storage at both the sending and receiving ends of the transmission.
In the Jan. 23 issue of the journal Science, the scientists report that, by using their protocol, atom-to-atom teleported information can be recovered with perfect accuracy about 90 percent of the time — and that figure can be improved.
"Our system has the potential to form the basis for a large-scale 'quantum repeater' that can network quantum memories over vast distances," Monroe said. "Moreover, our methods can be used in conjunction with quantum bit operations to create a key component needed for quantum computation."
A quantum computer could perform certain tasks, such as encryption-related calculations and searches of giant databases, considerably faster than conventional machines. The effort to devise a working model is a matter of intense interest worldwide.
Teleportation and entanglement
Physicist Richard Feynman is quoted as having said that "if you think you understand quantum mechanics, you don't understand quantum mechanics." Or sometimes he is cited thusly: "I think I can safely say that nobody understand quantum mechanics."
Nonetheless, here is how the University of Maryland describes Monroe's work.
Teleportation works because of a remarkable quantum phenomenon called entanglement which only occurs on the atomic and subatomic scale. Once two objects are put in an entangled state, their properties are inextricably entwined. Although those properties are inherently unknowable until a measurement is made, measuring either one of the objects instantly determines the characteristics of the other, no matter how far apart they are.
The JQI team set out to entangle the quantum states of two individual ytterbium ions so that information embodied in the condition of one could be teleported to the other. Each ion was isolated in a separate high-vacuum trap, suspended in an invisible cage of electromagnetic fields and surrounded by metal electrodes.
The researchers identified two readily discernible ground (lowest energy) states of the ions that would serve as the alternative "bit" values of an atomic quantum bit, or qubit.Conventional electronic bits (short for binary digits), such as those in a personal computer, are always in one of two states: off or on, 0 or 1, high or low voltage, etc. Quantum bits, however, can be in some combination, called a "superposition," of both states at the same time, like a coin that is simultaneously heads and tails — until a measurement is made. It is this phenomenon that gives quantum computation its extraordinary power.
Laser pulse initiates process
At the start of the experimental process, each ion (designated A and B) is initialized in a given ground state.
Then ion A is irradiated with a specially tailored microwave burst from one of its cage electrodes, placing the ion in some desired superposition of the two qubit states — in effect "writing" into "memory" the information to be teleported.
Immediately thereafter, both ions are excited by a picosecond (one trillionth of a second) laser pulse. The pulse duration is so short that each ion emits only a single photon as it sheds the energy gained by the laser and falls back to one or the other of the two qubit ground states.
Depending on which one it falls into, the ion emits one of two kinds of photons of slightly different wavelengths (designated red and blue) that correspond to the two atomic qubit states. It is the relationship between those photons that will eventually provide the telltale signal that entanglement has occurred.
Beamsplitter encounter
Each emitted photon is captured by a lens, routed to a separate strand of fiber-optic cable, and carried to a 50-50 beamsplitter where it is equally probable for the photon to pass straight through the splitter or to be reflected. On either side of the beamsplitter are detectors that can record the arrival of a single photon.
Before it reaches the beamsplitter, each photon is in an unknowable superposition of states. After encountering the beamsplitter, however, each takes on specific characteristics.
As a result, for each pair of photons, four color combinations are possible — blue-blue, red-red, blue-red and red-blue — as well as one of two polarizations: horizontal or vertical. In nearly all of those variations, the photons either cancel each other out or both end up in the same detector. But there is one — and only one — combination in which both detectors will record a photon at exactly the same time.
In that case, however, it is physically impossible to tell which ion produced which photon because it cannot be known whether the photon arriving at a detector passed through the beamsplitter or was reflected by it.
Thanks to the peculiar laws of quantum mechanics, that inherent uncertainty projects the ions into an entangled state. That is, each ion is in a superposition of the two possible qubit states. The simultaneous detection of photons at the detectors does not occur often, so the laser stimulus and photon emission process has to be repeated many thousands of times per second. But when a photon appears in each detector, it is an unambiguous signature of entanglement between the ions.
When an entangled condition is identified, the scientists immediately take a measurement of ion A. The act of measurement forces it out of superposition and into a definite condition: one of the two qubit states.
But because ion A's state is irreversibly tied to ion B's, the measurement also forces B into the complementary state. Depending on which state ion A is found in, the researchers now know precisely what kind of microwave pulse to apply to ion B in order to recover the exact information that had been written to ion A by the original microwave burst. Doing so results in the accurate teleportation of the information.
Teleportation vs. other communications
What distinguishes this outcome as teleportation, rather than any other form of communication, is that no information pertaining to the original memory actually passes between ion A and ion B. Instead, the information disappears when ion A is measured and reappears when the microwave pulse is applied to ion B.
"One particularly attractive aspect of our method is that it combines the unique advantages of both photons and atoms," says Monroe. "Photons are ideal for transferring information fast over long distances, whereas atoms offer a valuable medium for long-lived quantum memory ... Also, the teleportation of quantum information in this way could form the basis of a new type of quantum internet that could outperform any conventional type of classical network for certain tasks."
The work was supported by the Intelligence Advanced Research Project Activity program under U.S. Army Research Office contract, the National Science Foundation (NSF) Physics at the Information Frontier Program, and the NSF Physics Frontier Center at the Joint Quantum Institute.
Sunday, January 11, 2009
14 Percent of U.S. Adults Can't Read | LiveScience
14 Percent of U.S. Adults Can't Read LiveScience
About 14 percent of U.S. adults won't be reading this article. Well, okay, most people won't read it, given all the words that are published these days to help us understand and navigate the increasingly complex world.
But about 1 in 7 can't read it. They're illiterate.
Statistics released by the U.S. Education Department this week show that some 32 million U.S. adults lack basic prose literacy skill. That means they can't read a newspaper or the instruction on a bottle of pills.
The figures are for 2003, the latest year available. State and county results are available here.
"The crisis of adult literacy is getting worse, and investment in education and support programs is critical," said David C. Harvey, president and CEO of ProLiteracy, in response to the finding.
This is about jobs and the economy, Harvey said.
"More than 1 million people lost their jobs in 2008 and the new unemployment figures are the highest in 16 years," Harvey said. "A large number of the unemployed are low-skilled individuals who struggle with everyday reading, writing and math tasks. The administration wants to create new jobs with the stimulus packages, but to take advantage of those new positions, these adults need basic literacy skills."
A separate study released last month named Minneapolis and Seattle as the most literate cities.
ProLiteracy, which promotes reading programs for the disadvantaged and encourages more government funding, estimates that illiteracy costs American businesses more than $60 billion each year in lost productivity and health and safety issues. Lack of funding at the federal, state and local levels prevents about 90 percent of the illiterate from getting help, the organization claims.
ProLiteracy also estimates:
63 percent of prison inmates can't read
774 million people worldwide are illiterate
Two-thirds of the world's illiterate are women
If parents can't read, there's a good chance children will be poor readers, the organization notes.
About 14 percent of U.S. adults won't be reading this article. Well, okay, most people won't read it, given all the words that are published these days to help us understand and navigate the increasingly complex world.
But about 1 in 7 can't read it. They're illiterate.
Statistics released by the U.S. Education Department this week show that some 32 million U.S. adults lack basic prose literacy skill. That means they can't read a newspaper or the instruction on a bottle of pills.
The figures are for 2003, the latest year available. State and county results are available here.
"The crisis of adult literacy is getting worse, and investment in education and support programs is critical," said David C. Harvey, president and CEO of ProLiteracy, in response to the finding.
This is about jobs and the economy, Harvey said.
"More than 1 million people lost their jobs in 2008 and the new unemployment figures are the highest in 16 years," Harvey said. "A large number of the unemployed are low-skilled individuals who struggle with everyday reading, writing and math tasks. The administration wants to create new jobs with the stimulus packages, but to take advantage of those new positions, these adults need basic literacy skills."
A separate study released last month named Minneapolis and Seattle as the most literate cities.
ProLiteracy, which promotes reading programs for the disadvantaged and encourages more government funding, estimates that illiteracy costs American businesses more than $60 billion each year in lost productivity and health and safety issues. Lack of funding at the federal, state and local levels prevents about 90 percent of the illiterate from getting help, the organization claims.
ProLiteracy also estimates:
63 percent of prison inmates can't read
774 million people worldwide are illiterate
Two-thirds of the world's illiterate are women
If parents can't read, there's a good chance children will be poor readers, the organization notes.
Life As We Know It Nearly Created in Lab | LiveScience
Life As We Know It Nearly Created in Lab LiveScience
One of life's greatest mysteries is how it began. Scientists have pinned it down to roughly this:
Some chemical reactions occurred about 4 billion years ago — perhaps in a primordial tidal soup or maybe with help of volcanoes or possibly at the bottom of the sea or between the mica sheets — to create biology.
Now scientists have created something in the lab that is tantalizingly close to what might have happened. It's not life, they stress, but it certainly gives the science community a whole new data set to chew on.
The researchers, at the Scripps Research Institute, created molecules that self-replicate and even evolve and compete to win or lose. If that sounds exactly like life, read on to learn the controversial and thin distinction.
Know your RNA
To understand the remarkable breakthrough, detailed Jan. 8 in the early online edition of the journal Science, you have to know a little about molecules called RNA and DNA.
DNA is the software of life, the molecules that pack all the genetic information of a cell. DNA and the genes within it are where mutations occur, enabling changes that create new species.
RNA is the close cousin to DNA. More accurately, RNA is thought to be a primitive ancestor of DNA. RNA can't run a life form on its own, but 4 billion years ago it might have been on the verge of creating life, just needing some chemical fix to make the leap. In today's world, RNA is dependent on DNA for performing its roles, which include coding for proteins.
If RNA is in fact the ancestor to DNA, then scientists have figured they could get RNA to replicate itself in a lab without the help of any proteins or other cellular machinery. Easy to say, hard to do.
But that's exactly what the Scripps researchers did. Then things went surprisingly further.
'Immortalized'
Specifically, the researchers synthesized RNA enzymes that can replicate themselves without the help of any proteins or other cellular components, and the process proceeds indefinitely. "Immortalized" RNA, they call it, at least within the limited conditions of a laboratory.
More significantly, the scientists then mixed different RNA enzymes that had replicated, along with some of the raw material they were working with, and let them compete in what's sure to be the next big hit: "Survivor: Test Tube."
Remarkably, they bred.
And now and then, one of these survivors would screw up, binding with some other bit of raw material it hadn't been using. Hmm. That's exactly what life forms do ...
When these mutations occurred, "the resulting recombinant enzymes also were capable of sustained replication, with the most fit replicators growing in number to dominate the mixture," the scientists report.
The "creatures" — wait, we can't call them that! — evolved, with some "species" winning out.
"It kind of blew me away," said team member Tracey Lincoln of the Scripps Research Institute, who is working on her Ph.D. "What we have is non-living, but we've been able to show that it has some life-like properties, and that was extremely interesting."
Indeed.
Knocking on life's door
Lincoln's advisor, professor Gerald Joyce, reiterated that while the self-replicating RNA enzyme systems share certain characteristics of life, they are not life as we know it.
"What we've found could be relevant to how life begins, at that key moment when Darwinian evolution starts," Joyce said in a statement.
Joyce's restraint, clear also on an NPR report of the finding, has to be appreciated. He allows that some scientists familiar with the work have argued that this is life. Another scientist said that what the researchers did is equivalent to recreating a scenario that might have led to the origin of life.
Joyce insists he and Lincoln have not created life: "We're knocking on that door," he says, "but of course we haven't achieved that."
Only when a system is developed in the lab that has the capability of evolving novel functions on its own can it be properly called life, Joyce said. In short, the molecules in Joyce's lab can't evolve any totally new tricks, he said.
One of life's greatest mysteries is how it began. Scientists have pinned it down to roughly this:
Some chemical reactions occurred about 4 billion years ago — perhaps in a primordial tidal soup or maybe with help of volcanoes or possibly at the bottom of the sea or between the mica sheets — to create biology.
Now scientists have created something in the lab that is tantalizingly close to what might have happened. It's not life, they stress, but it certainly gives the science community a whole new data set to chew on.
The researchers, at the Scripps Research Institute, created molecules that self-replicate and even evolve and compete to win or lose. If that sounds exactly like life, read on to learn the controversial and thin distinction.
Know your RNA
To understand the remarkable breakthrough, detailed Jan. 8 in the early online edition of the journal Science, you have to know a little about molecules called RNA and DNA.
DNA is the software of life, the molecules that pack all the genetic information of a cell. DNA and the genes within it are where mutations occur, enabling changes that create new species.
RNA is the close cousin to DNA. More accurately, RNA is thought to be a primitive ancestor of DNA. RNA can't run a life form on its own, but 4 billion years ago it might have been on the verge of creating life, just needing some chemical fix to make the leap. In today's world, RNA is dependent on DNA for performing its roles, which include coding for proteins.
If RNA is in fact the ancestor to DNA, then scientists have figured they could get RNA to replicate itself in a lab without the help of any proteins or other cellular machinery. Easy to say, hard to do.
But that's exactly what the Scripps researchers did. Then things went surprisingly further.
'Immortalized'
Specifically, the researchers synthesized RNA enzymes that can replicate themselves without the help of any proteins or other cellular components, and the process proceeds indefinitely. "Immortalized" RNA, they call it, at least within the limited conditions of a laboratory.
More significantly, the scientists then mixed different RNA enzymes that had replicated, along with some of the raw material they were working with, and let them compete in what's sure to be the next big hit: "Survivor: Test Tube."
Remarkably, they bred.
And now and then, one of these survivors would screw up, binding with some other bit of raw material it hadn't been using. Hmm. That's exactly what life forms do ...
When these mutations occurred, "the resulting recombinant enzymes also were capable of sustained replication, with the most fit replicators growing in number to dominate the mixture," the scientists report.
The "creatures" — wait, we can't call them that! — evolved, with some "species" winning out.
"It kind of blew me away," said team member Tracey Lincoln of the Scripps Research Institute, who is working on her Ph.D. "What we have is non-living, but we've been able to show that it has some life-like properties, and that was extremely interesting."
Indeed.
Knocking on life's door
Lincoln's advisor, professor Gerald Joyce, reiterated that while the self-replicating RNA enzyme systems share certain characteristics of life, they are not life as we know it.
"What we've found could be relevant to how life begins, at that key moment when Darwinian evolution starts," Joyce said in a statement.
Joyce's restraint, clear also on an NPR report of the finding, has to be appreciated. He allows that some scientists familiar with the work have argued that this is life. Another scientist said that what the researchers did is equivalent to recreating a scenario that might have led to the origin of life.
Joyce insists he and Lincoln have not created life: "We're knocking on that door," he says, "but of course we haven't achieved that."
Only when a system is developed in the lab that has the capability of evolving novel functions on its own can it be properly called life, Joyce said. In short, the molecules in Joyce's lab can't evolve any totally new tricks, he said.
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