University of Adelaide researchers have discovered that recent climate change is causing leaves of some Australian plants to narrow in size.
The study, which is the first of its kind in the world, highlights that plant species are already responding to changes in climate. The results are published online July 4 in the Royal Society journal Biology Letters.
Researchers analysed leaves from herbarium specimens of Narrow-leaf Hopbush (Dodonaea viscosa subsp. angustissima) dating from the 1880s to the present. The study focused on specimens from South Australia's Flinders Ranges.
The analysis revealed a 2mm decrease in leaf width (within a total range of 1-9mm) over 127 years across the region. Between 1950 and 2005, there has been a 1.2ºC increase in maximum temperatures in South Australia but little change in rainfall in the Flinders Ranges.
"Climate change is often discussed in terms of future impacts, but changes in temperature over recent decades have already been ecologically significant," says Dr Greg Guerin, a Postdoctoral Fellow with the University of Adelaide's School of Earth and Environmental Sciences and lead author of the study.
"Climate change is driving adaptive shifts within plant species and leaf shape has demonstrated adaptive significance in relation to climate.
"Our results indicate that leaf width is closely linked to maximum temperatures, and plants from warmer latitudes typically have narrower leaves.
"In the case of Narrow-leaf Hopbush, we can significantly link the changes in leaf width to changes in climate."
Dr Guerin says some Australian plant species have greater potential to respond to and cope with increasing temperatures than others. "It's important to understand how plants cope with changing climates, because species that are more adaptive to change may be good candidates for environmental restoration efforts.
Read more at Science Daily
Jul 4, 2012
Game, Set and Match to Strawberries: The Superfruit
Strawberries, the traditional summer treat associated with Wimbledon could be serving up some unexpected health benefits.
Scientists at the University of Warwick have been studying the beneficial effects of strawberries on our cardiovascular health, particularly around how they prevent the development of heart disease and diabetes.
Professor Paul Thornalley from Warwick Medical School heads the team that discovered extracts from strawberries positively activate a protein in our bodies called 'Nrf2' which is shown to increase antioxidant and other protective activities. This protein works to decrease blood lipids and cholesterol, the very things which can lead to cardiovascular problems.
Eating strawberries has previously been found to counter post-meal blood glucose and low density lipoprotein, or 'bad' cholesterol and therefore decrease risk of diabetes and heart disease, but this is the first time that strawberry extracts have been proved to actively stimulate proteins that offer us protection against disease.
Professor Thornalley explained: "We've discovered the science behind how strawberries work to increase our in-built defences to keep cells, organs and blood vessels healthy and which can reduce the risk of developing cardiovascular problems such as heart disease and diabetes.
"So don't feel guilty about serving up strawberries and cream … although I'd suggest more strawberries and less or even no cream!"
Screening and mathematical modelling techniques developed at the University of Warwick can now take this research further to help identify the best varieties of strawberries, how they are served or processed and how many strawberries should be eaten for optimum health benefit.
Read more at Science Daily
Scientists at the University of Warwick have been studying the beneficial effects of strawberries on our cardiovascular health, particularly around how they prevent the development of heart disease and diabetes.
Professor Paul Thornalley from Warwick Medical School heads the team that discovered extracts from strawberries positively activate a protein in our bodies called 'Nrf2' which is shown to increase antioxidant and other protective activities. This protein works to decrease blood lipids and cholesterol, the very things which can lead to cardiovascular problems.
Eating strawberries has previously been found to counter post-meal blood glucose and low density lipoprotein, or 'bad' cholesterol and therefore decrease risk of diabetes and heart disease, but this is the first time that strawberry extracts have been proved to actively stimulate proteins that offer us protection against disease.
Professor Thornalley explained: "We've discovered the science behind how strawberries work to increase our in-built defences to keep cells, organs and blood vessels healthy and which can reduce the risk of developing cardiovascular problems such as heart disease and diabetes.
"So don't feel guilty about serving up strawberries and cream … although I'd suggest more strawberries and less or even no cream!"
Screening and mathematical modelling techniques developed at the University of Warwick can now take this research further to help identify the best varieties of strawberries, how they are served or processed and how many strawberries should be eaten for optimum health benefit.
Read more at Science Daily
Fetal Solar System Aborted
For a long while, it looked like the young star known as TYC 8241 2652 1 was getting ready to make some planets.
The sun-like star, located about 450 light-years from Earth in the constellation Centaurus was encircled by a disk of warm, brightly glowing dust located about as far away from the star as Mercury orbits the sun.
But something strange happened between 2008, when the star was observed by a powerful ground-based infrared telescope in Chile, and 2010 when NASA's WISE infrared space telescope took a look: The dust was gone.
"We said 'Whoa, what's going on here?'" astronomer Ben Zuckerman, with the University of California Los Angeles, told Discovery News.
The discovery has scientists wondering anew about the path from dust to planet.
"It doesn't look like it is quite a monotonic progression from tiny dust grains to full-fledge rocky planets as we and others might have believed. There may be bumps and wiggles and holes along the road," Zuckerman said.
The dust that once orbited around the star likely came from two small rocky bodies that were destroyed when they smashed into each other. Astronomers have found no evidence of any planets around the star.
As far as what happened to the dust, no one knows. One theory is that friction with intervening gas caused the dust to slow and fall onto the star, lured by gravity. Another idea is that the dust grains continued crashing into each other until, too small to remain in orbit, they got blasted out of the system. But whatever happened, happened fast.
"The disappearance ... in less than two years is incredibly fast by our current understanding, and the impact of this is difficult to predict," astronomer Margaret Moerchen, with the European Southern Observatory in Chile, wrote in an analysis of the research published in Nature.
Astronomers plan to keep an eye on the star to see if another dust disk forms.
"My guess is that the star can and will make planets in the future because in order to produce so much dust a few decades ago it must have been pretty well along the way," Zuckerman said. "This was just a bit of glitch."
The star most likely has other proto-planets in orbit, similar to what produced the dust in the first place, which could be the source of a new dust disk.
Read more at Discovery News
The sun-like star, located about 450 light-years from Earth in the constellation Centaurus was encircled by a disk of warm, brightly glowing dust located about as far away from the star as Mercury orbits the sun.
But something strange happened between 2008, when the star was observed by a powerful ground-based infrared telescope in Chile, and 2010 when NASA's WISE infrared space telescope took a look: The dust was gone.
"We said 'Whoa, what's going on here?'" astronomer Ben Zuckerman, with the University of California Los Angeles, told Discovery News.
The discovery has scientists wondering anew about the path from dust to planet.
"It doesn't look like it is quite a monotonic progression from tiny dust grains to full-fledge rocky planets as we and others might have believed. There may be bumps and wiggles and holes along the road," Zuckerman said.
The dust that once orbited around the star likely came from two small rocky bodies that were destroyed when they smashed into each other. Astronomers have found no evidence of any planets around the star.
As far as what happened to the dust, no one knows. One theory is that friction with intervening gas caused the dust to slow and fall onto the star, lured by gravity. Another idea is that the dust grains continued crashing into each other until, too small to remain in orbit, they got blasted out of the system. But whatever happened, happened fast.
"The disappearance ... in less than two years is incredibly fast by our current understanding, and the impact of this is difficult to predict," astronomer Margaret Moerchen, with the European Southern Observatory in Chile, wrote in an analysis of the research published in Nature.
Astronomers plan to keep an eye on the star to see if another dust disk forms.
"My guess is that the star can and will make planets in the future because in order to produce so much dust a few decades ago it must have been pretty well along the way," Zuckerman said. "This was just a bit of glitch."
The star most likely has other proto-planets in orbit, similar to what produced the dust in the first place, which could be the source of a new dust disk.
Read more at Discovery News
Particle 'Consistent' With Higgs Boson Discovered
The discovery of a particle consistent with the Higgs boson has been announced by physicists from the Large Hadron Collider's CMS and ATLAS detectors.
The discovery was detailed at a major conference to update the world on the continuing efforts by CERN scientists to find the last remaining piece of the Standard Model that underpins the foundations of our Universe. The Higgs boson mediates the "Higgs field" that ultimately endows all matter with mass -- finding the Higgs is therefore imperative for physicists to understand what gives the Universe substance.
When reports first surfaced that Peter Higgs -- one of the six physicists who, in the 1960s, developed the theory behind Higgs boson -- had been invited to CERN for this morning's announcement, the event became hard to ignore: something historic was about to happen.
And sure enough, at 9 a.m. in Geneva, Switzerland (3 a.m. EST), the news we had all been waiting for was spelled out by Joe Incandela, lead scientist of the CMS experiment: "We have observed a new boson."
This "new boson" revealed itself in the CMS data as a "bump" at 125 GeV/c2, a value that places it at over 130 times more massive than a proton.
After combining all the results gathered over many different channels in the CMS, the level of certainty -- 4.9-sigma -- came tantalizingly close to the "Gold Standard" (5-sigma) for subatomic particle discovery. This means there is a one-in-2 million chance of the result being a random fluctuation, or noise. For all intents and purposes, this is a discovery of a particle that acts very much like a Higgs boson.
"This is very preliminary result, but it's very strong," added Incandela.
Following the CMS announcement, ATLAS' Fabiola Gianotti said: "We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV." A 5-sigma result represents a one-in-3.5 million chance of the result being noise. This is undeniable proof that a boson, with very Higgs-like qualities, has been discovered by the two detectors.
However, more work needs to be done to figure out if this is indeed a Higgs boson or some unexpected renegade particle that just acts like the Higgs (although the latter is highly unlikely). Also, if it is a Higgs boson, is it a part of a larger Higgs family of particles?
In this high-stakes game of quantum mechanics, statistics and landmark particle discoveries, it can be hard to pronounce a definitive discovery of any subatomic particle, especially if it happens to be a particle that underpins the Universe's very existence.
The ATLAS and CMS detectors are located at strategic locations around the 17-mile (27-kilometer) circumference ring of superconducting electromagnets of the LHC. Both detectors are looking for, amongst a myriad of other things, evidence for the Higgs. And both, according to this announcement, have found that evidence to a very high degree of statistical certainty.
During all the excitement of a round of LHC results announced in December 2011, physicists pointed to an "excess" of particles around the predicted energy range for one type of theoretical Higgs boson. The energy range was 115 to 130 GeV/c2 and the statistical certainty was 2.4-sigma. 2.4-sigma means that there is a 98 percent chance that the signal is real and not caused by experimental error.
Read more at Discovery News
The discovery was detailed at a major conference to update the world on the continuing efforts by CERN scientists to find the last remaining piece of the Standard Model that underpins the foundations of our Universe. The Higgs boson mediates the "Higgs field" that ultimately endows all matter with mass -- finding the Higgs is therefore imperative for physicists to understand what gives the Universe substance.
When reports first surfaced that Peter Higgs -- one of the six physicists who, in the 1960s, developed the theory behind Higgs boson -- had been invited to CERN for this morning's announcement, the event became hard to ignore: something historic was about to happen.
And sure enough, at 9 a.m. in Geneva, Switzerland (3 a.m. EST), the news we had all been waiting for was spelled out by Joe Incandela, lead scientist of the CMS experiment: "We have observed a new boson."
This "new boson" revealed itself in the CMS data as a "bump" at 125 GeV/c2, a value that places it at over 130 times more massive than a proton.
After combining all the results gathered over many different channels in the CMS, the level of certainty -- 4.9-sigma -- came tantalizingly close to the "Gold Standard" (5-sigma) for subatomic particle discovery. This means there is a one-in-2 million chance of the result being a random fluctuation, or noise. For all intents and purposes, this is a discovery of a particle that acts very much like a Higgs boson.
"This is very preliminary result, but it's very strong," added Incandela.
Following the CMS announcement, ATLAS' Fabiola Gianotti said: "We observe in our data clear signs of a new particle, at the level of five sigma, in the mass region around 126 GeV." A 5-sigma result represents a one-in-3.5 million chance of the result being noise. This is undeniable proof that a boson, with very Higgs-like qualities, has been discovered by the two detectors.
However, more work needs to be done to figure out if this is indeed a Higgs boson or some unexpected renegade particle that just acts like the Higgs (although the latter is highly unlikely). Also, if it is a Higgs boson, is it a part of a larger Higgs family of particles?
In this high-stakes game of quantum mechanics, statistics and landmark particle discoveries, it can be hard to pronounce a definitive discovery of any subatomic particle, especially if it happens to be a particle that underpins the Universe's very existence.
The ATLAS and CMS detectors are located at strategic locations around the 17-mile (27-kilometer) circumference ring of superconducting electromagnets of the LHC. Both detectors are looking for, amongst a myriad of other things, evidence for the Higgs. And both, according to this announcement, have found that evidence to a very high degree of statistical certainty.
During all the excitement of a round of LHC results announced in December 2011, physicists pointed to an "excess" of particles around the predicted energy range for one type of theoretical Higgs boson. The energy range was 115 to 130 GeV/c2 and the statistical certainty was 2.4-sigma. 2.4-sigma means that there is a 98 percent chance that the signal is real and not caused by experimental error.
Read more at Discovery News
Jul 3, 2012
First Photo of Shadow of Single Atom
In an international scientific breakthrough, a Griffith University research team has been able to photograph the shadow of a single atom for the first time.
"We have reached the extreme limit of microscopy; you can not see anything smaller than an atom using visible light," Professor Dave Kielpinski of Griffith University's Centre for Quantum Dynamics in Brisbane, Australia.
"We wanted to investigate how few atoms are required to cast a shadow and we proved it takes just one," Professor Kielpinski said.
Published this week in Nature Communications, "Absorption imaging of a single atom "is the result of work over the last 5 years by the Kielpinski/Streed research team.
At the heart of this Griffith University achievement is a super high-resolution microscope, which makes the shadow dark enough to see.
Holding an atom still long enough to take its photo, while remarkable in itself, is not new technology; the atom is isolated within a chamber and held in free space by electrical forces.
Professor Kielpinski and his colleagues trapped single atomic ions of the element ytterbium and exposed them to a specific frequency of light. Under this light the atom's shadow was cast onto a detector, and a digital camera was then able to capture the image.
"By using the ultra hi-res microscope we were able to concentrate the image down to a smaller area than has been achieved before, creating a darker image which is easier to see," Professor Kielpinski said.
The precision involved in this process is almost beyond imagining.
"If we change the frequency of the light we shine on the atom by just one part in a billion, the image can no longer be seen," Professor Kielpinski said.
Research team member, Dr Erik Streed, said the implications of these findings are far reaching.
"Such experiments help confirm our understanding of atomic physics and may be useful for quantum computing," Dr Streed said.
There are also potential follow-on benefits for biomicroscopy.
"Because we are able to predict how dark a single atom should be, as in how much light it should absorb in forming a shadow, we can measure if the microscope is achieving the maximum contrast allowed by physics."
"This is important if you want to look at very small and fragile biological samples such as DNA strands where exposure to too much UV light or x-rays will harm the material.
"We can now predict how much light is needed to observe processes within cells,under optimum microscopy conditions, without crossing the threshold and destroying them."
Read more at Science Daily
"We have reached the extreme limit of microscopy; you can not see anything smaller than an atom using visible light," Professor Dave Kielpinski of Griffith University's Centre for Quantum Dynamics in Brisbane, Australia.
"We wanted to investigate how few atoms are required to cast a shadow and we proved it takes just one," Professor Kielpinski said.
Published this week in Nature Communications, "Absorption imaging of a single atom "is the result of work over the last 5 years by the Kielpinski/Streed research team.
At the heart of this Griffith University achievement is a super high-resolution microscope, which makes the shadow dark enough to see.
Holding an atom still long enough to take its photo, while remarkable in itself, is not new technology; the atom is isolated within a chamber and held in free space by electrical forces.
Professor Kielpinski and his colleagues trapped single atomic ions of the element ytterbium and exposed them to a specific frequency of light. Under this light the atom's shadow was cast onto a detector, and a digital camera was then able to capture the image.
"By using the ultra hi-res microscope we were able to concentrate the image down to a smaller area than has been achieved before, creating a darker image which is easier to see," Professor Kielpinski said.
The precision involved in this process is almost beyond imagining.
"If we change the frequency of the light we shine on the atom by just one part in a billion, the image can no longer be seen," Professor Kielpinski said.
Research team member, Dr Erik Streed, said the implications of these findings are far reaching.
"Such experiments help confirm our understanding of atomic physics and may be useful for quantum computing," Dr Streed said.
There are also potential follow-on benefits for biomicroscopy.
"Because we are able to predict how dark a single atom should be, as in how much light it should absorb in forming a shadow, we can measure if the microscope is achieving the maximum contrast allowed by physics."
"This is important if you want to look at very small and fragile biological samples such as DNA strands where exposure to too much UV light or x-rays will harm the material.
"We can now predict how much light is needed to observe processes within cells,under optimum microscopy conditions, without crossing the threshold and destroying them."
Read more at Science Daily
Bees Can 'Turn Back Time,' Reverse Brain Aging
Scientists at Arizona State University have discovered that older honey bees effectively reverse brain aging when they take on nest responsibilities typically handled by much younger bees. While current research on human age-related dementia focuses on potential new drug treatments, researchers say these findings suggest that social interventions may be used to slow or treat age-related dementia.
In a study published in the scientific journal Experimental Gerontology, a team of scientists from ASU and the Norwegian University of Life Sciences, led by Gro Amdam, an associate professor in ASU's School of Life Sciences, presented findings that show that tricking older, foraging bees into doing social tasks inside the nest causes changes in the molecular structure of their brains.
"We knew from previous research that when bees stay in the nest and take care of larvae -- the bee babies -- they remain mentally competent for as long as we observe them," said Amdam. "However, after a period of nursing, bees fly out gathering food and begin aging very quickly. After just two weeks, foraging bees have worn wings, hairless bodies, and more importantly, lose brain function -- basically measured as the ability to learn new things. We wanted to find out if there was plasticity in this aging pattern so we asked the question, 'What would happen if we asked the foraging bees to take care of larval babies again?"
During experiments, scientists removed all of the younger nurse bees from the nest -- leaving only the queen and babies. When the older, foraging bees returned to the nest, activity diminished for several days. Then, some of the old bees returned to searching for food, while others cared for the nest and larvae. Researchers discovered that after 10 days, about 50 percent of the older bees caring for the nest and larvae had significantly improved their ability to learn new things.
Amdam's international team not only saw a recovery in the bees' ability to learn, they discovered a change in proteins in the bees' brains. When comparing the brains of the bees that improved relative to those that did not, two proteins noticeably changed. They found Prx6, a protein also found in humans that can help protect against dementia -- including diseases such as Alzheimer's -- and they discovered a second and documented "chaperone" protein that protects other proteins from being damaged when brain or other tissues are exposed to cell-level stress.
In general, researchers are interested in creating a drug that could help people maintain brain function, yet they may be facing up to 30 years of basic research and trials.
"Maybe social interventions -- changing how you deal with your surroundings -- is something we can do today to help our brains stay younger," said Amdam. "Since the proteins being researched in people are the same proteins bees have, these proteins may be able to spontaneously respond to specific social experiences."
Read more at Science Daily
In a study published in the scientific journal Experimental Gerontology, a team of scientists from ASU and the Norwegian University of Life Sciences, led by Gro Amdam, an associate professor in ASU's School of Life Sciences, presented findings that show that tricking older, foraging bees into doing social tasks inside the nest causes changes in the molecular structure of their brains.
"We knew from previous research that when bees stay in the nest and take care of larvae -- the bee babies -- they remain mentally competent for as long as we observe them," said Amdam. "However, after a period of nursing, bees fly out gathering food and begin aging very quickly. After just two weeks, foraging bees have worn wings, hairless bodies, and more importantly, lose brain function -- basically measured as the ability to learn new things. We wanted to find out if there was plasticity in this aging pattern so we asked the question, 'What would happen if we asked the foraging bees to take care of larval babies again?"
During experiments, scientists removed all of the younger nurse bees from the nest -- leaving only the queen and babies. When the older, foraging bees returned to the nest, activity diminished for several days. Then, some of the old bees returned to searching for food, while others cared for the nest and larvae. Researchers discovered that after 10 days, about 50 percent of the older bees caring for the nest and larvae had significantly improved their ability to learn new things.
Amdam's international team not only saw a recovery in the bees' ability to learn, they discovered a change in proteins in the bees' brains. When comparing the brains of the bees that improved relative to those that did not, two proteins noticeably changed. They found Prx6, a protein also found in humans that can help protect against dementia -- including diseases such as Alzheimer's -- and they discovered a second and documented "chaperone" protein that protects other proteins from being damaged when brain or other tissues are exposed to cell-level stress.
In general, researchers are interested in creating a drug that could help people maintain brain function, yet they may be facing up to 30 years of basic research and trials.
"Maybe social interventions -- changing how you deal with your surroundings -- is something we can do today to help our brains stay younger," said Amdam. "Since the proteins being researched in people are the same proteins bees have, these proteins may be able to spontaneously respond to specific social experiences."
Read more at Science Daily
Gold and DNA Could Create New Dark Matter Detector
A combined team of physicists and biologists aim to build a directional dark matter detector using strands of DNA and gold.
Dark matter is a hypothesized type of matter which accounts for much of the mass of the universe. It cannot be seen, but its existence is inferred from its gravitational influence on visible matter and the structure of the universe. Some of the most popular models of dark matter suggest that it exerts itself on galaxy clusters and surrounds the Earth like a sea as it travels around the Sun, which in turn is slowly traveling towards the constellation Cygnus as it rotates around the galactic center.
If this is the case, Earth should experience a “headwind” of dark matter in front of it (coming form the direction of Cygnus) for half of the year and a tailwind for the other half of the year, depending on where it is on its orbit around the Sun.
Many different groups are working to try and detect dark matter using expensive detectors in deep underground caverns, which protect them from radiation that could otherwise pollute the signal. They are focusing on finding the unique signature that the “sea” of dark matter supposedly produces as the Earth orbits the Sun. This should change depending on what point in the year it is and also throughout the day as the Earth rotates on its axis. A dark matter detector should be able to sense the direction change as the Earth rotates each day.
A combined team including Katherine Freese, an astrophysicist from the University of Michigan and geneticist George Church from Harvard say they can overcome challenges with detecting dark matter by using DNA to find the dark matter particles, called weakly interacting massive particles, or WIMPs.
They have created a detector using a thin gold sheet with many single strands of DNA hanging from it. The theory is that a particle of dark matter will smash into the heavy gold nucleus, pushing it out of the gold sheet and through into the DNA “forest”, knocking the strands out as it travels.
These strands fall onto a collection tray. Each of them has a unique identifier showing where they were located on the gold sheet, so researchers can reconstruct the path of the gold particle with incredible precision. The detector is made up of hundreds of thousands of these sheets placed between Mylar sheets, using around a kilogram of gold and 100g of single-strand DNA on a square-meter array.
DNA is useful in this context because its structure will separate vertically with nanometer resolution — it wills separate to the nearest nucleotide — the smallest structural units of DNA. This is many orders of magnitude better than is currently possible. Secondly, the detector can work at room temperature, rather than needing cooling. Finally, the Mylar sheets make the detector directional — each sheet should be able to absorb the gold nucleus of its energy after it has passed through the “DNA forest”. Higher energy nuclei from background radiation would pass through several of the leaves of Mylar, allowing them to be identified and excluded.
If a dark matter particle hits a gold nucleus in on direction, it will propel it into the DNA forest. If it strikes in the other direction, it will head straight into the Mylar sheet and be absorbed.
Read more at Wired Science
Dark matter is a hypothesized type of matter which accounts for much of the mass of the universe. It cannot be seen, but its existence is inferred from its gravitational influence on visible matter and the structure of the universe. Some of the most popular models of dark matter suggest that it exerts itself on galaxy clusters and surrounds the Earth like a sea as it travels around the Sun, which in turn is slowly traveling towards the constellation Cygnus as it rotates around the galactic center.
If this is the case, Earth should experience a “headwind” of dark matter in front of it (coming form the direction of Cygnus) for half of the year and a tailwind for the other half of the year, depending on where it is on its orbit around the Sun.
Many different groups are working to try and detect dark matter using expensive detectors in deep underground caverns, which protect them from radiation that could otherwise pollute the signal. They are focusing on finding the unique signature that the “sea” of dark matter supposedly produces as the Earth orbits the Sun. This should change depending on what point in the year it is and also throughout the day as the Earth rotates on its axis. A dark matter detector should be able to sense the direction change as the Earth rotates each day.
A combined team including Katherine Freese, an astrophysicist from the University of Michigan and geneticist George Church from Harvard say they can overcome challenges with detecting dark matter by using DNA to find the dark matter particles, called weakly interacting massive particles, or WIMPs.
They have created a detector using a thin gold sheet with many single strands of DNA hanging from it. The theory is that a particle of dark matter will smash into the heavy gold nucleus, pushing it out of the gold sheet and through into the DNA “forest”, knocking the strands out as it travels.
These strands fall onto a collection tray. Each of them has a unique identifier showing where they were located on the gold sheet, so researchers can reconstruct the path of the gold particle with incredible precision. The detector is made up of hundreds of thousands of these sheets placed between Mylar sheets, using around a kilogram of gold and 100g of single-strand DNA on a square-meter array.
DNA is useful in this context because its structure will separate vertically with nanometer resolution — it wills separate to the nearest nucleotide — the smallest structural units of DNA. This is many orders of magnitude better than is currently possible. Secondly, the detector can work at room temperature, rather than needing cooling. Finally, the Mylar sheets make the detector directional — each sheet should be able to absorb the gold nucleus of its energy after it has passed through the “DNA forest”. Higher energy nuclei from background radiation would pass through several of the leaves of Mylar, allowing them to be identified and excluded.
If a dark matter particle hits a gold nucleus in on direction, it will propel it into the DNA forest. If it strikes in the other direction, it will head straight into the Mylar sheet and be absorbed.
Read more at Wired Science
Spectacularly Preserved Fossil Suggests Most Dinosaurs Were Feathered
The discovery of a fantastically preserved, bushy-tailed fossil theropod has cloaked the dinosaur world in feathers.
Named Sciurumimus -- Latin for "squirrel-mimic" -- albersdoerferi, the dinosaur lived 150 million years ago in what is now Germany. When it died, it came to rest in sediments so fine-grained that they preserved an almost photographic impression of the filaments covering its body.
Other feathered theropods, the taxonomic clade including all two-legged dinosaurs and their bird descendants, have been found previously, inspiring fantastic artist renditions and speculation that plumes rather than scales were the dinosaur norm.
Those fossils, however, belonged to a relative latecomer group known as coelurosaurs. Whether most theropods were feathered, or just a few recent evolutionary offshoots, was an open question. The new fossil find, described July 3 in Proceedings of the National Academy of Sciences and led by paleontologist Oliver Rauhut of Germany's Ludwig Maximilian University, gives a resounding answer.
Compared to the coelurosaurs, S. albersdoerferi was "significantly more basal in the evolutionary tree of theropods," or a trunk rather than a branch, wrote Rauhut and colleagues. If it had feathers, so did the rest of the theropods.
The plumage didn't end there. Other paleontologists have found feathers in beaked, quadrupedal dinosaurs. Combine those observations with S. albersdoerferi's taxonomic significance, and "a filamentous body covering obviously represents the plesiomorphic state for dinosaurs in general," wrote Rauhut's team.
Plesiomorphic is another way of saying "ancestrally typical." In short, it was feathers all the way down.
Read more at Wired Science
Named Sciurumimus -- Latin for "squirrel-mimic" -- albersdoerferi, the dinosaur lived 150 million years ago in what is now Germany. When it died, it came to rest in sediments so fine-grained that they preserved an almost photographic impression of the filaments covering its body.
Other feathered theropods, the taxonomic clade including all two-legged dinosaurs and their bird descendants, have been found previously, inspiring fantastic artist renditions and speculation that plumes rather than scales were the dinosaur norm.
Those fossils, however, belonged to a relative latecomer group known as coelurosaurs. Whether most theropods were feathered, or just a few recent evolutionary offshoots, was an open question. The new fossil find, described July 3 in Proceedings of the National Academy of Sciences and led by paleontologist Oliver Rauhut of Germany's Ludwig Maximilian University, gives a resounding answer.
Compared to the coelurosaurs, S. albersdoerferi was "significantly more basal in the evolutionary tree of theropods," or a trunk rather than a branch, wrote Rauhut and colleagues. If it had feathers, so did the rest of the theropods.
The plumage didn't end there. Other paleontologists have found feathers in beaked, quadrupedal dinosaurs. Combine those observations with S. albersdoerferi's taxonomic significance, and "a filamentous body covering obviously represents the plesiomorphic state for dinosaurs in general," wrote Rauhut's team.
Plesiomorphic is another way of saying "ancestrally typical." In short, it was feathers all the way down.
Read more at Wired Science
Jul 2, 2012
World's Smallest Fly Decapitates Ants
A newly discovered species, Euryplatea nanaknihali, is the world's smallest fly, and has the rather unsavory habit of biting off the heads of ants, according to a paper in the latest issue of the Annals of the Entomological Society of America.
At just .4 millimeters in length, the fly is only a fraction of an inch in size. A house fly is 15 times bigger. A fruit fly is 5 times larger.
The new member to the insect record books is also the first of its genus to be discovered in Asia. Members of its fly family (Phoridae) are all believed to decapitate ants. The process isn't a simple bite and patooie either.
Members of the Phoridae family lay eggs in the bodies of ants. The resulting larvae feed in the ants' heads, eventually causing decapitation. Not easy being an ant! On the upside, from a "pest" control perspective, some of these phorid flies are being used to try to control fire ants in the southern United States.
Nature seems to have pitted the world's smallest flies against the world's smallest ants.
Author Brian Brown of the Natural History Museum of Los Angeles County explained that the newfound flies can probably decapitate ants that have heads as small as .5 millimeters. Although this is speculation at now for the new species, Brown believes it's highly likely because the fly's only known relative, Euryplatea eidmanni, is known to parasitize ants in Equatorial Guinea.
Read more at Discovery News
At just .4 millimeters in length, the fly is only a fraction of an inch in size. A house fly is 15 times bigger. A fruit fly is 5 times larger.
The new member to the insect record books is also the first of its genus to be discovered in Asia. Members of its fly family (Phoridae) are all believed to decapitate ants. The process isn't a simple bite and patooie either.
Members of the Phoridae family lay eggs in the bodies of ants. The resulting larvae feed in the ants' heads, eventually causing decapitation. Not easy being an ant! On the upside, from a "pest" control perspective, some of these phorid flies are being used to try to control fire ants in the southern United States.
Nature seems to have pitted the world's smallest flies against the world's smallest ants.
Author Brian Brown of the Natural History Museum of Los Angeles County explained that the newfound flies can probably decapitate ants that have heads as small as .5 millimeters. Although this is speculation at now for the new species, Brown believes it's highly likely because the fly's only known relative, Euryplatea eidmanni, is known to parasitize ants in Equatorial Guinea.
Read more at Discovery News
Why Do Chimps Attack?
Chimpanzees have made headlines in recent years for several unprovoked attacks against humans, the latest last week at the Jane Goodall Institute Chimpanzee Eden in South Africa. The severely injured victim, University of Texas graduate student Andrew Oberle, remains in intensive care.
Oberle was mauled by chimpanzees as he gave a lecture to about a dozen tourists. The brutal attack prompted many to wonder what, if anything, provoked the animals? Experts suggest that multiple reasons could explain the attack.
Eugene Cussons, managing director of the sanctuary and host of the Animal Planet show Escape to Chimp Eden, said Oberle received training prior to the incident, but broke the rules when he went through two fences separating the primates from humans. A male chimpanzee grabbed Oberle and pulled him under one of the fences, which was electrified.
Aside from that dangerous misstep, the fact that the attackers were male is not surprising to those who study chimpanzees. Sylvia Amsler, a lecturer in the Anthropology Program at the University of Arkansas at Little Rock, told Discovery News that male chimps in the wild commonly engage in war-like behavior to defend or acquire territory.
“Such attacks can be severe and fatal,” she said. “In the case of an adult victim, the attacking males take turns beating and jumping on the victim. Attackers use their canines to bite and tear at the victim, so that any body parts that stick out, such as testes and ears, are often ripped off during an attack.”
Jenny Short, assistant director of colony management and research services at the California National Primate Research Center, reminded that chimpanzees and other primates are not domesticated animals.
“You have to be reactive and extremely careful around them,” she told Discovery News. “We work with rhesus macaques, which are much smaller than chimpanzees, and even they require strict precautions. If you go to a zoo and look at chimps, it takes your breath away because they are so big and strong.”
Paleoanthropologist Alan Walker of Penn State University thinks that even if a human and a chimp were somehow evenly matched in size, chimpanzees wind up using all of their muscle strength, whereas humans tend to hold back.
Relative to body mass, chimpanzees have less grey matter in their spinal cords than humans have. This matter contains large numbers of nerve cells that connect to muscle fibers and regulate muscle movement.
The finely tuned motor system in humans gives us the ability to do things like make complex tools, throw accurately, and manipulate small objects. Conversely, when a chimp uses its muscles, particularly in a defense or attack mode, the action is more “all or nothing,” with each neuron triggering a higher number of muscle fibers, Walker explained.
“That is the reason apes seem so strong relative to humans,” he added.
Read more at Discovery News
Oberle was mauled by chimpanzees as he gave a lecture to about a dozen tourists. The brutal attack prompted many to wonder what, if anything, provoked the animals? Experts suggest that multiple reasons could explain the attack.
Eugene Cussons, managing director of the sanctuary and host of the Animal Planet show Escape to Chimp Eden, said Oberle received training prior to the incident, but broke the rules when he went through two fences separating the primates from humans. A male chimpanzee grabbed Oberle and pulled him under one of the fences, which was electrified.
Aside from that dangerous misstep, the fact that the attackers were male is not surprising to those who study chimpanzees. Sylvia Amsler, a lecturer in the Anthropology Program at the University of Arkansas at Little Rock, told Discovery News that male chimps in the wild commonly engage in war-like behavior to defend or acquire territory.
“Such attacks can be severe and fatal,” she said. “In the case of an adult victim, the attacking males take turns beating and jumping on the victim. Attackers use their canines to bite and tear at the victim, so that any body parts that stick out, such as testes and ears, are often ripped off during an attack.”
Jenny Short, assistant director of colony management and research services at the California National Primate Research Center, reminded that chimpanzees and other primates are not domesticated animals.
“You have to be reactive and extremely careful around them,” she told Discovery News. “We work with rhesus macaques, which are much smaller than chimpanzees, and even they require strict precautions. If you go to a zoo and look at chimps, it takes your breath away because they are so big and strong.”
Paleoanthropologist Alan Walker of Penn State University thinks that even if a human and a chimp were somehow evenly matched in size, chimpanzees wind up using all of their muscle strength, whereas humans tend to hold back.
Relative to body mass, chimpanzees have less grey matter in their spinal cords than humans have. This matter contains large numbers of nerve cells that connect to muscle fibers and regulate muscle movement.
The finely tuned motor system in humans gives us the ability to do things like make complex tools, throw accurately, and manipulate small objects. Conversely, when a chimp uses its muscles, particularly in a defense or attack mode, the action is more “all or nothing,” with each neuron triggering a higher number of muscle fibers, Walker explained.
“That is the reason apes seem so strong relative to humans,” he added.
Read more at Discovery News
Solar Flare Ionizes European Skies
Obviously frustrated by the headline-grabbing news of a quasi-potential Higgs boson discovery, the sun exploded with a headline-grabber of its own this morning.
At 10:52 UT, active region 1515 (AR1515) unleashed a M5.6-class solar flare bathing the Earth's atmosphere with X-ray and extreme ultraviolet radiation. At that energy, the flare wasn't that far from becoming an X-class flare -- the most powerful variety of solar eruption.
The flare's radiation isn't harmful to us on the ground, but it did have a dramatic impact on the upper atmosphere, sending waves of ionization through the ionosphere, over 60 kilometers (37 miles) above the surface. This ionization can trigger sudden ionospheric disturbances (or SIDs for short) that can severely impact global communications.
As reported by Spaceweather.com, Rob Stemmes of the Polar Light Center in Lofoten, Norway, detected a powerful SID propagate over Europe shortly after the flare erupted on the surface of the sun.
Solar flares occur in active regions above the sun's photosphere (colloquially known as the "solar surface") where intense regions of magnetic activity erupt through the sun's upper layers -- sunspots can often be observed in these regions.
Read more at Discovery News
At 10:52 UT, active region 1515 (AR1515) unleashed a M5.6-class solar flare bathing the Earth's atmosphere with X-ray and extreme ultraviolet radiation. At that energy, the flare wasn't that far from becoming an X-class flare -- the most powerful variety of solar eruption.
The flare's radiation isn't harmful to us on the ground, but it did have a dramatic impact on the upper atmosphere, sending waves of ionization through the ionosphere, over 60 kilometers (37 miles) above the surface. This ionization can trigger sudden ionospheric disturbances (or SIDs for short) that can severely impact global communications.
As reported by Spaceweather.com, Rob Stemmes of the Polar Light Center in Lofoten, Norway, detected a powerful SID propagate over Europe shortly after the flare erupted on the surface of the sun.
Solar flares occur in active regions above the sun's photosphere (colloquially known as the "solar surface") where intense regions of magnetic activity erupt through the sun's upper layers -- sunspots can often be observed in these regions.
Read more at Discovery News
Higgs Boson Hunt: 'We've Discovered Something'
After four years of high-energy particle demolition inside the detectors of the Large Hadron Collider (LHC), are physicists on the verge of announcing one of the most significant discoveries of our time? If you've seen this morning's headlines, then you'd think the answer is a huge yes. But in typical quantum physics style, we'll have to wait a little longer for definitive proof for the elusive Higgs boson.
So why all the excitement?
On Wednesday (July 4), scientists heading two major experiments at the LHC plan to announce their most recent findings at a physics conference in Australia with accompanying meetings in Geneva, Switzerland. What's more, senior scientists at European Organization for Nuclear Research (CERN) are hinting that there is strong evidence in their data that suggests the Higgs boson exists.
For the last year or so there have been "hints" of a Higgs detection, then those hints turned into "potential evidence." Now, will we finally get word of a bona fide discovery?
"I agree that any reasonable outside observer would say, 'It looks like a discovery,'" CERN physicist John Ellis told The Associated Press. "We've discovered something which is consistent with being a Higgs."
The Higgs boson is the last piece of the physics Standard Model, a collection of theories that underpin all modern physics. The Higgs particle is theorized to mediate mass -- like a photon (also a boson) mediates the electromagnetic force, i.e., light -- and creates the "Higgs field" that must pervade the entire Universe, endowing matter with mass.
If the LHC didn't detect signs of the Higgs particle, its non-discovery would turn modern physics on its head. But physicists are an inquisitive bunch, so a non-discovery would be just as exciting (if not more so) than a discovery. But for all the Higgs doubters out there, it's looking more and more likely the Higgs does exist and the Standard Model is as robust as physicists always thought.
So when the announcement comes from ATLAS and CMS physicists on Wednesday, will we get the definitive proof we've been (not-so-)patiently waiting for?
In the world of high-energy physics, it's not a question of slamming particles together and then photographing a Higgs boson screaming away from the carnage. Countless billions of collisions need to be recorded and the resulting spray of particles tracked. Like a photograph, more photons are needed to make the image appear defined and bright. If just a few photons hit the photographic paper, a very vague and fuzzy image is the result. The longer you leave the photograph under the light, more photons are collected and the better the image becomes.
This is basically what the LHC scientists are doing. They repeat the same experiment again and again and collect the huge quantities of data to gradually build an "image" of the kinds of particles produced inside the LHC as it smashes protons together at near the speed of light. Over time, statistical spikes start to appear in the data, suggesting particles of a certain energy (or mass) are being detected.
One statistical spike, at around the energy of one predicted variety of Higgs boson, has been growing stronger and more defined over the months, but at what point does that "spike" become a discovery and not just background noise? As this is a lesson in statistics of huge numbers, physicists have a way of categorizing how strong the signal is.
So far, the strength of this particular Higgs signal hasn't exceeded 4.3-sigma -- which relates to a 99.996 percent chance of the signal being real (and a 0.0004 percent chance that it's just noise). A 5-sigma signal, on the other hand, is regarded as the "Gold Standard" in particle physics, relating to a 99.99994 percent chance that the signal is real (and only a 0.00006 percent chance of it being noise). Only when the signal hits that magical 5-sigma standard can a discovery be announced.
This is why Ellis says that to any "reasonable outside observer" Wednesday's announcement will appear to confirm a Higgs boson discovery, but to particle physicists, the signal may be just shy of the 5-sigma mark.
There is another possibility. By combining the results of both the CMS and ATLAS detectors, CERN can check the results of one against the other. In the pursuit of the Higgs, they also combine the data from both (which is how the previous 4.3-sigma signal was derived). On Wednesday, however, we're not going to see a combined signal from both detectors.
"Combining the data from two experiments is a complex task, which is why it takes time, and why no combination will be presented on Wednesday," said CERN spokesman James Gillies.
Read more at Discovery News
So why all the excitement?
On Wednesday (July 4), scientists heading two major experiments at the LHC plan to announce their most recent findings at a physics conference in Australia with accompanying meetings in Geneva, Switzerland. What's more, senior scientists at European Organization for Nuclear Research (CERN) are hinting that there is strong evidence in their data that suggests the Higgs boson exists.
For the last year or so there have been "hints" of a Higgs detection, then those hints turned into "potential evidence." Now, will we finally get word of a bona fide discovery?
"I agree that any reasonable outside observer would say, 'It looks like a discovery,'" CERN physicist John Ellis told The Associated Press. "We've discovered something which is consistent with being a Higgs."
The Higgs boson is the last piece of the physics Standard Model, a collection of theories that underpin all modern physics. The Higgs particle is theorized to mediate mass -- like a photon (also a boson) mediates the electromagnetic force, i.e., light -- and creates the "Higgs field" that must pervade the entire Universe, endowing matter with mass.
If the LHC didn't detect signs of the Higgs particle, its non-discovery would turn modern physics on its head. But physicists are an inquisitive bunch, so a non-discovery would be just as exciting (if not more so) than a discovery. But for all the Higgs doubters out there, it's looking more and more likely the Higgs does exist and the Standard Model is as robust as physicists always thought.
So when the announcement comes from ATLAS and CMS physicists on Wednesday, will we get the definitive proof we've been (not-so-)patiently waiting for?
In the world of high-energy physics, it's not a question of slamming particles together and then photographing a Higgs boson screaming away from the carnage. Countless billions of collisions need to be recorded and the resulting spray of particles tracked. Like a photograph, more photons are needed to make the image appear defined and bright. If just a few photons hit the photographic paper, a very vague and fuzzy image is the result. The longer you leave the photograph under the light, more photons are collected and the better the image becomes.
This is basically what the LHC scientists are doing. They repeat the same experiment again and again and collect the huge quantities of data to gradually build an "image" of the kinds of particles produced inside the LHC as it smashes protons together at near the speed of light. Over time, statistical spikes start to appear in the data, suggesting particles of a certain energy (or mass) are being detected.
One statistical spike, at around the energy of one predicted variety of Higgs boson, has been growing stronger and more defined over the months, but at what point does that "spike" become a discovery and not just background noise? As this is a lesson in statistics of huge numbers, physicists have a way of categorizing how strong the signal is.
So far, the strength of this particular Higgs signal hasn't exceeded 4.3-sigma -- which relates to a 99.996 percent chance of the signal being real (and a 0.0004 percent chance that it's just noise). A 5-sigma signal, on the other hand, is regarded as the "Gold Standard" in particle physics, relating to a 99.99994 percent chance that the signal is real (and only a 0.00006 percent chance of it being noise). Only when the signal hits that magical 5-sigma standard can a discovery be announced.
This is why Ellis says that to any "reasonable outside observer" Wednesday's announcement will appear to confirm a Higgs boson discovery, but to particle physicists, the signal may be just shy of the 5-sigma mark.
There is another possibility. By combining the results of both the CMS and ATLAS detectors, CERN can check the results of one against the other. In the pursuit of the Higgs, they also combine the data from both (which is how the previous 4.3-sigma signal was derived). On Wednesday, however, we're not going to see a combined signal from both detectors.
"Combining the data from two experiments is a complex task, which is why it takes time, and why no combination will be presented on Wednesday," said CERN spokesman James Gillies.
Read more at Discovery News
Jul 1, 2012
Falling Lizards Use Tail for Mid-Air Twist, Inspiring Lizard-Like 'RightingBot'
Lizards, just like cats, have a knack for turning right side up and landing on their feet when they fall. But how do they do it? Unlike cats, which twist and bend their torsos to turn upright, lizards swing their large tails one way to rotate their body the other, according to a recent study that will be presented at the Society for Experimental Biology meeting on 29th June in Salzburg, Austria. A lizard-inspired robot, called 'RightingBot', replicates the feat.
This work, carried out by Ardian Jusufi, Robert Full and colleagues at the University of California, Berkeley, explains how large-tailed animals can turn themselves right side up while falling through the air. It could also help engineers to design air- or land-based robots with better stability.
"It is not immediately obvious which mechanism an animal will use to accomplish aerial righting and recover from falling in an upside-down posture. Depending on body size, morphology and mass distribution there are multiple strategies for animals to execute this behavior," said Ardian Jusufi, lead author of the study.
Lizards in their natural environment encounter various situations where they could fall. For instance, they could fall while fighting over territory, seeking food, or even mating. To avoid injuries, they must have a way to turn themselves during a fall to land safely on their feet.
For over a century, people have been studying if and how cats and other mammals right themselves when they fall. Other animals like lizards, which have different body plans and probably use different strategies, have been largely unexplored.
The researchers used high-speed videography to dissect the motion of two common lizards -- the flat-tailed house gecko and green anole -- as they fall, starting upside down. Watching as the lizards righted themselves in mid-air before alighting on extended legs, the researchers discovered that both lizards swing their tails in one direction, causing their bodies to turn in the other.
The team also compared the righting movement of the two lizards, which have similar body sizes but different tail lengths and inertial properties. The gecko, with its shorter tail, has to swing its tail further to the side to right itself, making a larger angle relative to its body. By contrast, relatively smaller movements of the anole tail, which is twice as long, are enough to reorient its body.
"A comparative approach provides useful insights in the study of aerial righting responses and could be beneficial to the design of robots that navigate complex environments," said Ardian Jusufi.
For the study, Jusufi and his colleagues developed a three-dimensional mathematical model to test their understanding of the lizards' righting movement.
Read more at Science Daily
This work, carried out by Ardian Jusufi, Robert Full and colleagues at the University of California, Berkeley, explains how large-tailed animals can turn themselves right side up while falling through the air. It could also help engineers to design air- or land-based robots with better stability.
"It is not immediately obvious which mechanism an animal will use to accomplish aerial righting and recover from falling in an upside-down posture. Depending on body size, morphology and mass distribution there are multiple strategies for animals to execute this behavior," said Ardian Jusufi, lead author of the study.
Lizards in their natural environment encounter various situations where they could fall. For instance, they could fall while fighting over territory, seeking food, or even mating. To avoid injuries, they must have a way to turn themselves during a fall to land safely on their feet.
For over a century, people have been studying if and how cats and other mammals right themselves when they fall. Other animals like lizards, which have different body plans and probably use different strategies, have been largely unexplored.
The researchers used high-speed videography to dissect the motion of two common lizards -- the flat-tailed house gecko and green anole -- as they fall, starting upside down. Watching as the lizards righted themselves in mid-air before alighting on extended legs, the researchers discovered that both lizards swing their tails in one direction, causing their bodies to turn in the other.
The team also compared the righting movement of the two lizards, which have similar body sizes but different tail lengths and inertial properties. The gecko, with its shorter tail, has to swing its tail further to the side to right itself, making a larger angle relative to its body. By contrast, relatively smaller movements of the anole tail, which is twice as long, are enough to reorient its body.
"A comparative approach provides useful insights in the study of aerial righting responses and could be beneficial to the design of robots that navigate complex environments," said Ardian Jusufi.
For the study, Jusufi and his colleagues developed a three-dimensional mathematical model to test their understanding of the lizards' righting movement.
Read more at Science Daily
Beyond Base-Pairs: Mapping the Functional Genome
Popularly dubbed "the book of life," the human genome is extraordinarily difficult to read. But without full knowledge of its grammar and syntax, the genome's 2.9 billion base-pairs of adenine and thymine, cytosine and guanine provide limited insights into humanity's underlying genetics.
In a paper published in the July 1, 2012 issue of the journal Nature, researchers at the Ludwig Institute for Cancer Research and the University of California, San Diego School of Medicine open the book further, mapping for the first time a significant portion of the functional sequences of the mouse genome, the most widely used mammalian model organism in biomedical research.
"We've known the precise alphabet of the human genome for more than a decade, but not necessarily how those letters make meaningful words, paragraphs or life," said Bing Ren, PhD, head of the Laboratory of Gene Regulation at the Ludwig Institute for Cancer Research at UC San Diego. "We know, for example, that only one to two percent of the functional genome codes for proteins, but that there are highly conserved regions in the genome outside of protein-coding that affect genes and disease development. It's clear these regions do something or they would have changed or disappeared."
Chief among those regions are cis-regulatory elements, key stretches of DNA that appear to regulate the transcription of genes. Misregulation of genes can result in diseases like cancer. Using high-throughput sequencing technologies, Ren and colleagues mapped nearly 300,000 mouse cis-regulatory elements in 19 different types of tissue and cell. The unprecedented work provided a functional annotation of nearly 11 percent of the mouse genome, and more than 70 percent of the conserved, non-coding sequences shared with other mammalian species, including humans.
As expected, the researchers identified different sequences that promote or start gene activity, enhance its activity and define where it occurs in the body during development. More surprising, said Ren, was that the structural organization of the cis-regulatory elements are grouped into discrete clusters corresponding to spatial domains. "It's a case of form following function," he said. "It makes sense."
While the research is fundamentally revealing, Ren noted it is also just a beginning, a partial picture of the functional genome. Additional studies will be needed in other types of cells and at different stages of development.
"We've mapped and understand 11 percent of the genome," said Ren. "There's still a long way to march."
Co-authors are Yin Shen, Feng Yue, David F. McCleary, Zhen Ye, Lee Edsall, Samantha Kuan, Ulrich Wagner and Leonard Lee, all at the Ludwig Institute for Cancer Research; Jesse Dixon, Ludwig Institute for Cancer Research, Medical Scientist Training Program and Biomedical Sciences Graduate Program, UC San Diego; and Victor Lobanenkov, National Institute of Allergy and Infectious Diseases.
Read more at Science Daily
In a paper published in the July 1, 2012 issue of the journal Nature, researchers at the Ludwig Institute for Cancer Research and the University of California, San Diego School of Medicine open the book further, mapping for the first time a significant portion of the functional sequences of the mouse genome, the most widely used mammalian model organism in biomedical research.
"We've known the precise alphabet of the human genome for more than a decade, but not necessarily how those letters make meaningful words, paragraphs or life," said Bing Ren, PhD, head of the Laboratory of Gene Regulation at the Ludwig Institute for Cancer Research at UC San Diego. "We know, for example, that only one to two percent of the functional genome codes for proteins, but that there are highly conserved regions in the genome outside of protein-coding that affect genes and disease development. It's clear these regions do something or they would have changed or disappeared."
Chief among those regions are cis-regulatory elements, key stretches of DNA that appear to regulate the transcription of genes. Misregulation of genes can result in diseases like cancer. Using high-throughput sequencing technologies, Ren and colleagues mapped nearly 300,000 mouse cis-regulatory elements in 19 different types of tissue and cell. The unprecedented work provided a functional annotation of nearly 11 percent of the mouse genome, and more than 70 percent of the conserved, non-coding sequences shared with other mammalian species, including humans.
As expected, the researchers identified different sequences that promote or start gene activity, enhance its activity and define where it occurs in the body during development. More surprising, said Ren, was that the structural organization of the cis-regulatory elements are grouped into discrete clusters corresponding to spatial domains. "It's a case of form following function," he said. "It makes sense."
While the research is fundamentally revealing, Ren noted it is also just a beginning, a partial picture of the functional genome. Additional studies will be needed in other types of cells and at different stages of development.
"We've mapped and understand 11 percent of the genome," said Ren. "There's still a long way to march."
Co-authors are Yin Shen, Feng Yue, David F. McCleary, Zhen Ye, Lee Edsall, Samantha Kuan, Ulrich Wagner and Leonard Lee, all at the Ludwig Institute for Cancer Research; Jesse Dixon, Ludwig Institute for Cancer Research, Medical Scientist Training Program and Biomedical Sciences Graduate Program, UC San Diego; and Victor Lobanenkov, National Institute of Allergy and Infectious Diseases.
Read more at Science Daily
Subscribe to:
Posts (Atom)