Researchers found that the brain breaks experiences into the "events," or related groups that help us mentally organize the day's many situations, using subconscious mental categories it creates. These categories are based on how the brain considers people, objects and actions are related in terms of how they tend to — or tend not to — pop up near one another at specific times.
Your brain knows it's time to cook when the stove is on, and the food and pots are out. When you rush away to calm a crying child, though, cooking is over and it's time to be a parent. Your brain processes and responds to these occurrences as distinct, unrelated events.
But it remains unclear exactly how the brain breaks such experiences into "events," or the related groups that help us mentally organize the day's many situations. A dominant concept of event-perception known as prediction error says that our brain draws a line between the end of one event and the start of another when things take an unexpected turn (such as a suddenly distraught child).
April 11, 2013
Nuclear Fusion Rocket Could Reach Mars in 30 Days
Nuclear fusion, the energy source that fuels the sun and other active stars, could one day propel rockets that allow humans to go to Mars and back in 30 days, researchers say.
Fusion-powered rockets promise to solve problems of deep-space travel that have long plagued plans for manned missions to Mars — long journeys, high costs and health risks, among them. Scientists at the University of Washington and a space-propulsion company named MSNW say they are getting to closer to creating a feasible fuel for travel to other planets.
"Using existing rocket fuels, it's nearly impossible for humans to explore much beyond Earth," John Slough, a UW research associate professor of aeronautics and astronautics, said in a statement. "We are hoping to give us a much more powerful source of energy in space that could eventually lead to making interplanetary travel commonplace."
Fusion-powered rockets promise to solve problems of deep-space travel that have long plagued plans for manned missions to Mars — long journeys, high costs and health risks, among them. Scientists at the University of Washington and a space-propulsion company named MSNW say they are getting to closer to creating a feasible fuel for travel to other planets.
"Using existing rocket fuels, it's nearly impossible for humans to explore much beyond Earth," John Slough, a UW research associate professor of aeronautics and astronautics, said in a statement. "We are hoping to give us a much more powerful source of energy in space that could eventually lead to making interplanetary travel commonplace."
Innovative self-cooling, thermoelectric system consumes no electricity
Researchers at the UPNA/NUP-Public University of Navarre have produced a prototype of a self-cooling thermoelectric device that achieves "free" cooling of over 30ºC in devices that give off heat. It is a piece of equipment that acts as a traditional cooler but which consumes no electricity because it obtains the energy it needs to function from the very heat that has to be dissipated.
The researchers want to apply this system to power converters and transformers present in power stations that produce renewable electrical power employing, for example, wind, solar photovoltaic, solar thermoelectric and hydraulic energy.David Astrain-Ulibarrena, of the UPNA/NUP's Department of Engineering, Mechanics, Energy and Materials and head researcher in the project, explains what the system consists of: "When these devices are functioning, they heat up and need to be cooled down.In many cases, heat exchangers with fans are used which naturally need to be powered externally and consume a certain amount of electrical power. What we do is take advantage of the heat flow emitted by the power converter and transformer to produce the electrical power needed to make the fans work. That way we achieve the cooling of the device and control its temperature, but without any energy cost."
The researchers want to apply this system to power converters and transformers present in power stations that produce renewable electrical power employing, for example, wind, solar photovoltaic, solar thermoelectric and hydraulic energy.David Astrain-Ulibarrena, of the UPNA/NUP's Department of Engineering, Mechanics, Energy and Materials and head researcher in the project, explains what the system consists of: "When these devices are functioning, they heat up and need to be cooled down.In many cases, heat exchangers with fans are used which naturally need to be powered externally and consume a certain amount of electrical power. What we do is take advantage of the heat flow emitted by the power converter and transformer to produce the electrical power needed to make the fans work. That way we achieve the cooling of the device and control its temperature, but without any energy cost."
April 8, 2013
Mind over matter? Core body temperature controlled by the brain
A team of researchers led by Associate Professor Maria Kozhevnikov from the Department of Psychology at the National University of Singapore (NUS) Faculty of Arts and Social Sciences showed, for the first time, that it is possible for core body temperature to be controlled by the brain. The scientists found that core body temperature increases can be achieved using certain meditation techniques (g-tummo) which could help in boosting immunity to fight infectious diseases or immunodeficiency.
Published in science journal PLOS ONE in March 2013, the study documented reliable core body temperature increases for the first time in Tibetan nuns practising g-tummo meditation. Previous studies on g-tummo meditators showed only increases in peripheral body temperature in the fingers and toes. The g-tummo meditative practice controls "inner energy" and is considered by Tibetan practitioners as one of the most sacred spiritual practices in the region. Monasteries maintaining g-tummo traditions are very rare and are mostly located in the remote areas of eastern Tibet.
The researchers collected data during the unique ceremony in Tibet, where nuns were able to raise their core body temperature and dry up wet sheets wrapped around their bodies in the cold Himalayan weather (-25 degree Celsius) while meditating. Using electroencephalography (EEG) recordings and temperature measures, the team observed increases in core body temperature up to 38.3 degree Celsius. A second study was conducted with Western participants who used a breathing technique of the g-tummo meditative practice and they were also able to increase their core body temperature, within limits.
Published in science journal PLOS ONE in March 2013, the study documented reliable core body temperature increases for the first time in Tibetan nuns practising g-tummo meditation. Previous studies on g-tummo meditators showed only increases in peripheral body temperature in the fingers and toes. The g-tummo meditative practice controls "inner energy" and is considered by Tibetan practitioners as one of the most sacred spiritual practices in the region. Monasteries maintaining g-tummo traditions are very rare and are mostly located in the remote areas of eastern Tibet.
The researchers collected data during the unique ceremony in Tibet, where nuns were able to raise their core body temperature and dry up wet sheets wrapped around their bodies in the cold Himalayan weather (-25 degree Celsius) while meditating. Using electroencephalography (EEG) recordings and temperature measures, the team observed increases in core body temperature up to 38.3 degree Celsius. A second study was conducted with Western participants who used a breathing technique of the g-tummo meditative practice and they were also able to increase their core body temperature, within limits.
April 5, 2013
A 'light switch' in brain illuminates neural networks: Scientists can see cells communicate by flipping a neural light switch
There are cells in your brain that recognize very specific places, and have that as one of their main jobs. These cells, called place cells, are found in an area behind your temple called the hippocampus. While these cells must be sent information from nearby cells to do their job, so far no one has been able to determine exactly what kind of nerve cells, or neurons, work with place cells to craft the code they create for each location. Neurons come in many different types with specialized functions. Some respond to edges and borders, others to specific locations, others act like a compass and react to which way you turn your head.
Now, researchers at the Kavli Institute for Systems Neuroscience at the Norwegian University of Science and Technology have combined a range of advanced techniques that enable them to identify which neurons communicate with each other at different times in the rat brain, and in doing so, create the animal's sense of location. Their findings are published in the 5 April issue of Science.
"A rat's brain is the size of a grape. Inside there are about fifty million neurons that are connected together at a staggering 450 billion places (roughly)," explains Professor Edvard Moser, director of the Kavli Institute. "Inside this grape-sized brain are areas on each side that are smaller than a grape seed, where we know that memory and the sense of location reside. This is also where we find the neurons that respond to specific places, the place cells. But from which cells do these place cells get information?"
Now, researchers at the Kavli Institute for Systems Neuroscience at the Norwegian University of Science and Technology have combined a range of advanced techniques that enable them to identify which neurons communicate with each other at different times in the rat brain, and in doing so, create the animal's sense of location. Their findings are published in the 5 April issue of Science.
"A rat's brain is the size of a grape. Inside there are about fifty million neurons that are connected together at a staggering 450 billion places (roughly)," explains Professor Edvard Moser, director of the Kavli Institute. "Inside this grape-sized brain are areas on each side that are smaller than a grape seed, where we know that memory and the sense of location reside. This is also where we find the neurons that respond to specific places, the place cells. But from which cells do these place cells get information?"
April 3, 2013
Feeling hungry may protect the brain against Alzheimer's disease
The feeling of hunger itself may protect against Alzheimer's disease, according to study published today in the journal PLOS ONE. Interestingly, the results of this study in mice suggest that mild hunger pangs, and related hormonal pathways, may be as important to the much-discussed value of "caloric restriction" as actually eating less.
Caloric restriction is a regimen where an individual consumes fewer calories than average, but not so few that they become malnourished. Studies in many species have suggested that it could protect against neurodegenerative disorders and extend lifespans, but the effect has not been confirmed in human randomized clinical trials.
Efforts to understand how cutting calories may protect the brain have grown increasingly important with news that American Alzheimer's deaths are increasing, and because the best available treatments only delay onset in a subset of patients.
Study authors argue that hormonal signals are the middlemen between an empty gut and the perception of hunger in the brain, and that manipulating them may effectively counter age-related cognitive decline in the same way as caloric restriction.
Caloric restriction is a regimen where an individual consumes fewer calories than average, but not so few that they become malnourished. Studies in many species have suggested that it could protect against neurodegenerative disorders and extend lifespans, but the effect has not been confirmed in human randomized clinical trials.
Efforts to understand how cutting calories may protect the brain have grown increasingly important with news that American Alzheimer's deaths are increasing, and because the best available treatments only delay onset in a subset of patients.
Study authors argue that hormonal signals are the middlemen between an empty gut and the perception of hunger in the brain, and that manipulating them may effectively counter age-related cognitive decline in the same way as caloric restriction.
Dark Matter Possibly Found by $2 Billion Space Station Experiment
A massive particle detector mounted on the International Space Station may have detected elusive dark matter at last, scientists announced today (April 3).
The detector, the Alpha Magnetic Spectrometer (AMS), measures cosmic-ray particles in space. After detecting billions of these particles over a year and a half, the experiment recorded a signal that may be the result of dark matter, the hidden substance that makes up more than 80 percent of all matter in the universe.
AMS found about 400,000 positrons, the antimatter partner particles of electrons. The energies of these positrons suggest they might have been created when particles of dark matter collided and destroyed each other.
NASA will hold a press conference detailing the AMS science results at 1:30 p.m. EDT (1830 GMT) today. You can watch the AMS science results live on SPACE.com, via NASA TV.
The detector, the Alpha Magnetic Spectrometer (AMS), measures cosmic-ray particles in space. After detecting billions of these particles over a year and a half, the experiment recorded a signal that may be the result of dark matter, the hidden substance that makes up more than 80 percent of all matter in the universe.
AMS found about 400,000 positrons, the antimatter partner particles of electrons. The energies of these positrons suggest they might have been created when particles of dark matter collided and destroyed each other.
NASA will hold a press conference detailing the AMS science results at 1:30 p.m. EDT (1830 GMT) today. You can watch the AMS science results live on SPACE.com, via NASA TV.
Laser light zaps away cocaine addiction
By stimulating one part of the brain with laser light, researchers at the National Institutes of Health (NIH) and the Ernest Gallo Clinic and Research Center at UC San Francisco (UCSF) have shown that they can wipe away addictive behavior in rats -- or conversely turn non-addicted rats into compulsive cocaine seekers.
"When we turn on a laser light in the prelimbic region of the prefrontal cortex, the compulsive cocaine seeking is gone," said Antonello Bonci, MD, scientific director of the intramural research program at the NIH's National Institute on Drug Abuse (NIDA), where the work was done. Bonci is also an adjunct professor of neurology at UCSF and an adjunct professor at Johns Hopkins University.
Described this week in the journal Nature, the new study demonstrates the central role the prefrontal cortex plays in compulsive cocaine addiction. It also suggests a new therapy that could be tested immediately in humans, said Billy Chen of NIDA, the lead author of the study.
Any new human therapy would not be based on using lasers, but would most likely rely on electromagnetic stimulation outside the scalp, in particular a technique called transcranial magnetic stimulation (TMS). Clinical trials are now being designed to test whether this approach works, Chen added.
"When we turn on a laser light in the prelimbic region of the prefrontal cortex, the compulsive cocaine seeking is gone," said Antonello Bonci, MD, scientific director of the intramural research program at the NIH's National Institute on Drug Abuse (NIDA), where the work was done. Bonci is also an adjunct professor of neurology at UCSF and an adjunct professor at Johns Hopkins University.
Described this week in the journal Nature, the new study demonstrates the central role the prefrontal cortex plays in compulsive cocaine addiction. It also suggests a new therapy that could be tested immediately in humans, said Billy Chen of NIDA, the lead author of the study.
Any new human therapy would not be based on using lasers, but would most likely rely on electromagnetic stimulation outside the scalp, in particular a technique called transcranial magnetic stimulation (TMS). Clinical trials are now being designed to test whether this approach works, Chen added.
Breakthrough cancer-killing treatment has no side-effects in mice: New chemistry may cure human cancers
Cancer painfully ends more than 500,000 lives in the United States each year, according to the Centers for Disease Control and Prevention. The scientific crusade against cancer recently achieved a victory under the leadership of University of Missouri Curators' Professor M. Frederick Hawthorne. Hawthorne's team has developed a new form of radiation therapy that successfully put cancer into remission in mice. This innovative treatment produced none of the harmful side-effects of conventional chemo and radiation cancer therapies.
Clinical trials in humans could begin soon after Hawthorne secures funding.
"Since the 1930s, scientists have sought success with a cancer treatment known as boron neutron capture therapy (BNCT)," said Hawthorne, a recent winner of the National Medal of Science awarded by President Obama in the White House. "Our team at MU's International Institute of Nano and Molecular Medicine finally found the way to make BNCT work by taking advantage of a cancer cell's biology with nanochemistry."
Cancer cells grow faster than normal cells and in the process absorb more materials than normal cells. Hawthorne's team took advantage of that fact by getting cancer cells to take in and store a boron chemical designed by Hawthorne. When those boron-infused cancer cells were exposed to neutrons, a subatomic particle, the boron atom shattered and selectively tore apart the cancer cells, sparing neighboring healthy cells.
Clinical trials in humans could begin soon after Hawthorne secures funding.
"Since the 1930s, scientists have sought success with a cancer treatment known as boron neutron capture therapy (BNCT)," said Hawthorne, a recent winner of the National Medal of Science awarded by President Obama in the White House. "Our team at MU's International Institute of Nano and Molecular Medicine finally found the way to make BNCT work by taking advantage of a cancer cell's biology with nanochemistry."
Cancer cells grow faster than normal cells and in the process absorb more materials than normal cells. Hawthorne's team took advantage of that fact by getting cancer cells to take in and store a boron chemical designed by Hawthorne. When those boron-infused cancer cells were exposed to neutrons, a subatomic particle, the boron atom shattered and selectively tore apart the cancer cells, sparing neighboring healthy cells.
April 2, 2013
Monkey study reveals why middle managers suffer the most stress
A study by the universities of Manchester and Liverpool observing monkeys has found that those in the middle hierarchy suffer the most social stress. Their work suggests that the source of this stress is social conflict and may help explain studies in humans that have found that middle managers suffer the most stress at work.
Katie Edwards from Liverpool's Institute of Integrative Biology spent nearly 600 hours watching female Barbary macaques at Trentham Monkey Forest in Staffordshire. Her research involved monitoring a single female over one day, recording all incidents of social behaviour. These included agonistic behaviour like threats, chases and slaps, submissive behaviour like displacing, screaming, grimacing and hind-quarter presentation and affiliative behaviour such as teeth chatter, embracing and grooming.
The following day faecal samples from the same female were collected and analysed for levels of stress hormones at Chester Zoo's wildlife endocrinology laboratory.
Katie explains what she found: "Not unsurprisingly we recorded the highest level of stress hormones on the days following agonistic behaviour. However, we didn't find a link between lower stress hormone levels and affiliative behaviour such as grooming."
Katie Edwards from Liverpool's Institute of Integrative Biology spent nearly 600 hours watching female Barbary macaques at Trentham Monkey Forest in Staffordshire. Her research involved monitoring a single female over one day, recording all incidents of social behaviour. These included agonistic behaviour like threats, chases and slaps, submissive behaviour like displacing, screaming, grimacing and hind-quarter presentation and affiliative behaviour such as teeth chatter, embracing and grooming.
The following day faecal samples from the same female were collected and analysed for levels of stress hormones at Chester Zoo's wildlife endocrinology laboratory.
Katie explains what she found: "Not unsurprisingly we recorded the highest level of stress hormones on the days following agonistic behaviour. However, we didn't find a link between lower stress hormone levels and affiliative behaviour such as grooming."
April 1, 2013
More Diagnoses of A.D.H.D. Causing Concern
Nearly one in five high school age boys in the United States and 11 percent of school-age children over all have received a medical diagnosis of attention deficit hyperactivity disorder, according to new data from the federal Centers for Disease Control and Prevention.
These rates reflect a marked rise over the last decade and could fuel growing concern among many doctors that the A.D.H.D. diagnosis and its medication are overused in American children.
The figures showed that an estimated 6.4 million children ages 4 through 17 had received an A.D.H.D. diagnosis at some point in their lives, a 16 percent increase since 2007 and a 53 percent rise in the past decade. About two-thirds of those with a current diagnosis receive prescriptions for stimulants like Ritalin or Adderall, which can drastically improve the lives of those with A.D.H.D. but can also lead to addiction, anxiety and occasionally psychosis.
These rates reflect a marked rise over the last decade and could fuel growing concern among many doctors that the A.D.H.D. diagnosis and its medication are overused in American children.
The figures showed that an estimated 6.4 million children ages 4 through 17 had received an A.D.H.D. diagnosis at some point in their lives, a 16 percent increase since 2007 and a 53 percent rise in the past decade. About two-thirds of those with a current diagnosis receive prescriptions for stimulants like Ritalin or Adderall, which can drastically improve the lives of those with A.D.H.D. but can also lead to addiction, anxiety and occasionally psychosis.
'OK' contact lenses: New technique shows promise in restoring near vision without glasses
By middle age, most people have age-related declines in near vision (presbyopia) requiring bifocals or reading glasses. An emerging technique called hyperopic orthokeratology (OK) may provide a new alternative for restoring near vision without the need for glasses, according to new research.
The study, "Refractive Changes from Hyperopic Orthokeratology Monovision in Presbyopes," appears in the April issue of Optometry and Vision Science, official journal of the American Academy of Optometry. The journal is published by Lippincott Williams & Wilkins , a part of Wolters Kluwer Health.
For middle-aged patients with presbyopia, wearing OK contact lenses overnight can restore up-close vision in one eye, according to the study by Paul Gifford, PhD, FAAO, and Helen A Swarbrick, PhD, FAAO, of University of New South Wales, Sydney. "The authors have shown the feasibility of correcting one eye for near vision through OK, in which overnight contact lens wear shapes the cornea of one eye to allow in-focus near vision for reading," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.
The study, "Refractive Changes from Hyperopic Orthokeratology Monovision in Presbyopes," appears in the April issue of Optometry and Vision Science, official journal of the American Academy of Optometry. The journal is published by Lippincott Williams & Wilkins , a part of Wolters Kluwer Health.
For middle-aged patients with presbyopia, wearing OK contact lenses overnight can restore up-close vision in one eye, according to the study by Paul Gifford, PhD, FAAO, and Helen A Swarbrick, PhD, FAAO, of University of New South Wales, Sydney. "The authors have shown the feasibility of correcting one eye for near vision through OK, in which overnight contact lens wear shapes the cornea of one eye to allow in-focus near vision for reading," comments Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science.
New mathematical model shows how society becomes polarized
Anyone who has spent more than a few minutes watching some of the more partisan "news" networks lurking in the bowels of cable television is aware that America has grown more polarized in recent years. What's not so certain is why. In a paper published online March 27 in the Proceedings of the National Academy of Sciences (PNAS), a team of researchers at Stanford has devised a mathematical model that helps demonstrate what's behind the growing rift.
Hint: It's you, not them.
"We believe that polarization is less a reflection on the state of our society, but instead stems from the process people go through to form opinions," said Ashish Goel, a professor in the Department of Management Science and Engineering (MS&E) and co-author of the paper.
Hint: It's you, not them.
"We believe that polarization is less a reflection on the state of our society, but instead stems from the process people go through to form opinions," said Ashish Goel, a professor in the Department of Management Science and Engineering (MS&E) and co-author of the paper.
Quantum dot commands light: A solid state ultrafast logic gate on a photon
If you could peek at the inner workings of a computer processor you would see billions of transistors switching back and forth between two states. In optical communications, information from the switches can be encoded onto light, which then travels long distances through glass fiber. Researchers at the Joint Quantum Institute and the Department of Electrical and Computer Engineering are working to harness the quantum nature of light and semiconductors to expand the capabilities of computers in remarkable ways.
All computers, even the future quantum versions, use logic operations or "gates," which are the fundamental building blocks of computational processes. JQI scientists, led by Professor Edo Waks, have performed an ultrafast logic gate on a photon, using a semiconductor quantum dot. This research is described in the March 31 Advance Online Publication of Nature Photonics.
Photons are a proven transit system for information. In quantum devices, they are the ideal information carriers that relay messages between quantum bits (qubits) such as neutral atoms, ion traps, superconducting circuits, nitrogen vacancy centers, and of course the device used here: quantum dots. A quantum dot (QD) is a semiconductor structure that acts like an atom. This means it has allowed energy levels that can be populated and even shifted around using lasers and magnetic fields. Quantum dots are an attractive platform for quantum processing because they live inside a semiconductor material, thus the technology for integration with modern electronics already exists.
All computers, even the future quantum versions, use logic operations or "gates," which are the fundamental building blocks of computational processes. JQI scientists, led by Professor Edo Waks, have performed an ultrafast logic gate on a photon, using a semiconductor quantum dot. This research is described in the March 31 Advance Online Publication of Nature Photonics.
Photons are a proven transit system for information. In quantum devices, they are the ideal information carriers that relay messages between quantum bits (qubits) such as neutral atoms, ion traps, superconducting circuits, nitrogen vacancy centers, and of course the device used here: quantum dots. A quantum dot (QD) is a semiconductor structure that acts like an atom. This means it has allowed energy levels that can be populated and even shifted around using lasers and magnetic fields. Quantum dots are an attractive platform for quantum processing because they live inside a semiconductor material, thus the technology for integration with modern electronics already exists.
March 29, 2013
Brain scans might predict future criminal behavior
A new study conducted by The Mind Research Network in Albuquerque, N.M., shows that neuroimaging data can predict the likelihood of whether a criminal will reoffend following release from prison.
The paper, which is to be published in the Proceedings of the National Academy of Sciences, studied impulsive and antisocial behavior and centered on the anterior cingulate cortex (ACC), a portion of the brain that deals with regulating behavior and impulsivity.
The study demonstrated that inmates with relatively low anterior cingulate activity were twice as likely to reoffend than inmates with high-brain activity in this region.
"These findings have incredibly significant ramifications for the future of how our society deals with criminal justice and offenders," said Dr. Kent A. Kiehl, who was senior author on the study and is director of mobile imaging at MRN and an associate professor of psychology at the University of New Mexico. "Not only does this study give us a tool to predict which criminals may reoffend and which ones will not reoffend, it also provides a path forward for steering offenders into more effective targeted therapies to reduce the risk of future criminal activity."
The paper, which is to be published in the Proceedings of the National Academy of Sciences, studied impulsive and antisocial behavior and centered on the anterior cingulate cortex (ACC), a portion of the brain that deals with regulating behavior and impulsivity.
The study demonstrated that inmates with relatively low anterior cingulate activity were twice as likely to reoffend than inmates with high-brain activity in this region.
"These findings have incredibly significant ramifications for the future of how our society deals with criminal justice and offenders," said Dr. Kent A. Kiehl, who was senior author on the study and is director of mobile imaging at MRN and an associate professor of psychology at the University of New Mexico. "Not only does this study give us a tool to predict which criminals may reoffend and which ones will not reoffend, it also provides a path forward for steering offenders into more effective targeted therapies to reduce the risk of future criminal activity."
Biological transistor enables computing within living cells
When Charles Babbage prototyped the first computing machine in the 19th century, he imagined using mechanical gears and latches to control information. ENIAC, the first modern computer developed in the 1940s, used vacuum tubes and electricity. Today, computers use transistors made from highly engineered semiconducting materials to carry out their logical operations.
And now a team of Stanford University bioengineers has taken computing beyond mechanics and electronics into the living realm of biology. In a paper to be published March 28 in Science, the team details a biological transistor made from genetic material -- DNA and RNA -- in place of gears or electrons. The team calls its biological transistor the "transcriptor."
"Transcriptors are the key component behind amplifying genetic logic -- akin to the transistor and electronics," said Jerome Bonnet, PhD, a postdoctoral scholar in bioengineering and the paper's lead author.
The creation of the transcriptor allows engineers to compute inside living cells to record, for instance, when cells have been exposed to certain external stimuli or environmental factors, or even to turn on and off cell reproduction as needed.
And now a team of Stanford University bioengineers has taken computing beyond mechanics and electronics into the living realm of biology. In a paper to be published March 28 in Science, the team details a biological transistor made from genetic material -- DNA and RNA -- in place of gears or electrons. The team calls its biological transistor the "transcriptor."
"Transcriptors are the key component behind amplifying genetic logic -- akin to the transistor and electronics," said Jerome Bonnet, PhD, a postdoctoral scholar in bioengineering and the paper's lead author.
The creation of the transcriptor allows engineers to compute inside living cells to record, for instance, when cells have been exposed to certain external stimuli or environmental factors, or even to turn on and off cell reproduction as needed.
Robot ants mimic insect behaviour
Scientists in the US have built and tested robotic ants, which they say behave just like a real ant colony.
The robots do not resemble their insect counterparts; they are tiny cubes equipped with two watch motors to power the wheels that enable them to move. But their collective behaviour is remarkably ant-like.
The robots do not resemble their insect counterparts; they are tiny cubes equipped with two watch motors to power the wheels that enable them to move. But their collective behaviour is remarkably ant-like.
Sound cloaks enter the third dimension
A simple plastic shell has cloaked a three-dimensional object from sound waves for the first time. With some improvements, a similar cloak could eventually be used to reduce noise pollution and to allow ships and submarines to evade enemy detection. The experiments appear March 20 in Physical Review Letters.
“This paper implements a simplified version of invisibility using well-designed but relatively simple materials,” says Steven Cummer, an electrical engineer at Duke University, who was not involved in the study. Cummer proposed the concept of a sound cloak in 2007.
Scientists’ recent efforts to render objects invisible to the eye are based on the fact that our perception of the world depends on the scattering of waves. We can see objects because waves of light strike them and scatter. Similarly, the Navy can detect faraway submarines because they scatter sound waves (sonar) that hit them.
“This paper implements a simplified version of invisibility using well-designed but relatively simple materials,” says Steven Cummer, an electrical engineer at Duke University, who was not involved in the study. Cummer proposed the concept of a sound cloak in 2007.
Scientists’ recent efforts to render objects invisible to the eye are based on the fact that our perception of the world depends on the scattering of waves. We can see objects because waves of light strike them and scatter. Similarly, the Navy can detect faraway submarines because they scatter sound waves (sonar) that hit them.
March 28, 2013
Pesticide combination affects bees' ability to learn
Two new studies have highlighted a negative impact on bees' ability to learn following exposure to a combination of pesticides commonly used in agriculture. The researchers found that the pesticides, used in the research at levels shown to occur in the wild, could interfere with the learning circuits in the bee's brain. They also found that bees exposed to combined pesticides were slower to learn or completely forgot important associations between floral scent and food rewards.
In the study published today (27 March 2013) in Nature Communications, the University of Dundee's Dr Christopher Connolly and his team investigated the impact on bees' brains of two common pesticides: pesticides used on crops called neonicotinoid pesticides, and another type of pesticide, coumaphos, that is used in honeybee hives to kill the Varroa mite, a parasitic mite that attacks the honey bee.
The intact bees' brains were exposed to pesticides in the lab at levels predicted to occur following exposure in the wild and brain activity was recorded. They found that both types of pesticide target the same area of the bee brain involved in learning, causing a loss of function. If both pesticides were used in combination, the effect was greater.
The study is the first to show that these pesticides have a direct impact on pollinator brain physiology. It was prompted by the work of collaborators Dr Geraldine Wright and Dr Sally Williamson at Newcastle University who found that combinations of these same pesticides affected learning and memory in bees. Their studies established that when bees had been exposed to combinations of these pesticides for 4 days, as many as 30% of honeybees failed to learn or performed poorly in memory tests. Again, the experiments mimicked levels that could be seen in the wild, this time by feeding a sugar solution mixed with appropriate levels of pesticides.
In the study published today (27 March 2013) in Nature Communications, the University of Dundee's Dr Christopher Connolly and his team investigated the impact on bees' brains of two common pesticides: pesticides used on crops called neonicotinoid pesticides, and another type of pesticide, coumaphos, that is used in honeybee hives to kill the Varroa mite, a parasitic mite that attacks the honey bee.
The intact bees' brains were exposed to pesticides in the lab at levels predicted to occur following exposure in the wild and brain activity was recorded. They found that both types of pesticide target the same area of the bee brain involved in learning, causing a loss of function. If both pesticides were used in combination, the effect was greater.
The study is the first to show that these pesticides have a direct impact on pollinator brain physiology. It was prompted by the work of collaborators Dr Geraldine Wright and Dr Sally Williamson at Newcastle University who found that combinations of these same pesticides affected learning and memory in bees. Their studies established that when bees had been exposed to combinations of these pesticides for 4 days, as many as 30% of honeybees failed to learn or performed poorly in memory tests. Again, the experiments mimicked levels that could be seen in the wild, this time by feeding a sugar solution mixed with appropriate levels of pesticides.
New way to lose weight? Changing microbes in guts of mice resulted in rapid weight loss
New research, conducted in collaboration with researchers at Massachusetts General Hospital, has found that the gut microbes of mice undergo drastic changes following gastric bypass surgery. Transfer of these microbes into sterile mice resulted in rapid weight loss. The study is described in a March 27 paper in Science Translational Medicine.
"Simply by colonizing mice with the altered microbial community, the mice were able to maintain a lower body fat, and lose weight -- about 20% as much as they would if they underwent surgery," said Peter Turnbaugh, a Bauer Fellow at Harvard's Faculty of Arts and Sciences (FAS) Center for Systems Biology, and one of two senior authors of the paper.
But as striking as those results were, they weren't as dramatic as they might have been.
"In some ways we were biasing the results against weight loss," Turnbaugh said, explaining that the mice used in the study hadn't been given a high-fat, high-sugar diet to increase their weight beforehand. "The question is whether we might have seen a stronger effect if they were on a different diet."
"Simply by colonizing mice with the altered microbial community, the mice were able to maintain a lower body fat, and lose weight -- about 20% as much as they would if they underwent surgery," said Peter Turnbaugh, a Bauer Fellow at Harvard's Faculty of Arts and Sciences (FAS) Center for Systems Biology, and one of two senior authors of the paper.
But as striking as those results were, they weren't as dramatic as they might have been.
"In some ways we were biasing the results against weight loss," Turnbaugh said, explaining that the mice used in the study hadn't been given a high-fat, high-sugar diet to increase their weight beforehand. "The question is whether we might have seen a stronger effect if they were on a different diet."
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