The study, conducted by the University of Glasgow in collaboration with the Glasgow Centre for Population Health, compared the length of telomeres in blood samples taken from 382 Glaswegians from the most and least deprived parts of the city. Telomeres, the tails on the ends of chromosomes, shorten throughout a person’s life and can be used as a measure of the ageing process.
Over a 10-year period, telomeres shortened by 7.7% in people whose household incomes were less than £25,000, but only 0.6% in people with greater incomes. In those living in rented accommodation, telomere length was reduced by 8.7% compared to 2.2% in those who owned their homes. The telomeres of people with the poorest diets were shortened by 7.7%, compared to 1.8% in those with a better diet.
It is hoped that the findings will help to create a test which can be used for faster feedback on the effects of public health improvement measures. Currently, these effects can take decades to become apparent.
However, due to natural variation in telomere length from person to person, the test is only effective at a population level, and will not provide useful information on how long an individual can expect to live.
Dr. Paul Shiels of the University of Glasgow’s Institute of Cancer Sciences, who led this aspect of the research, said: “Glasgow’s population has one of the most extreme socioeconomic gradients in the world, which makes it an ideal place to conduct a study such as this.
“This study is a first for the city in that it provides a link between how adverse social conditions can influence the biology of ageing and hence disease. What we’ve shown is that social status and deprivation play a major part in how quickly people age and develop disease.
“Eating poorly and earning less than average is likely to increase the rate you age, and can lead to increased inflammation and risk for cardiovascular disease, which is endemic in the city.”
The results are published in the journal PLoS one by the Glasgow Centre for Public Health, a consortium of health and local authorities, the Scottish Government and the University of Glasgow.
"Brain cap" technology being developed at the University of Maryland allows users to turn their thoughts into motion. Associate Professor of Kinesiology José 'Pepe' L. Contreras-Vidal and his team have created a non-invasive, sensor-lined cap with neural interface software that soon could be used to control computers, robotic prosthetic limbs, motorized wheelchairs and even digital avatars.
"We are on track to develop, test and make available to the public- within the next few years -- a safe, reliable, noninvasive brain computer interface that can bring life-changing technology to millions of people whose ability to move has been diminished due to paralysis, stroke or other injury or illness," said Contreras-Vidal of the university's School of Public Health.
The potential and rapid progression of the UMD brain cap technology can be seen in a host of recent developments, including a just published study in the Journal of Neurophysiology, new grants from the National Science Foundation (NSF) and National Institutes of Health, and a growing list of partners that includes the University of Maryland School of Medicine, the Veterans Affairs Maryland Health Care System, the Johns Hopkins University Applied Physics Laboratory, Rice University and Walter Reed Army Medical Center's Integrated Department of Orthopaedics & Rehabilitation.
"We are doing something that few previously thought was possible," said Contreras-Vidal, who is also an affiliate professor in Maryland's Fischell Department of Bioengineering and the university's Neuroscience and Cognitive Science Program. "We use EEG [electroencephalography] to non-invasively read brain waves and translate them into movement commands for computers and other devices.
Peer Reviewed
Contreras-Vidal and his team have published three major papers on their technology over the past 18 months, the latest a just released study in the Journal of Neurophysiology in which they successfully used EEG brain signals to reconstruct the complex 3-D movements of the ankle, knee and hip joints during human treadmill walking. In two earlier studies they showed (1) similar results for 3-D hand movement and (2) that subjects wearing the brain cap could control a computer cursor with their thoughts.
Alessandro Presacco, a second-year doctoral student in Contreras-Vidal's Neural Engineering and Smart Prosthetics Lab, Contreras-Vidal and co-authors write that their Journal of Neurophysiology study indicated "that EEG signals can be used to study the cortical dynamics of walking and to develop brain-machine interfaces aimed at restoring human gait function."
There are other brain computer interface technologies under development, but Contreras-Vidal notes that these competing technologies are either very invasive, requiring electrodes to be implanted directly in the brain, or, if noninvasive, require much more training to use than does UMD's EEG-based, brain cap technology.
Partnering to Help Sufferers of Injury and Stroke
Contreras-Vidal and his team are collaborating on a rapidly growing cadre projects with researchers at other institutions to develop thought-controlled robotic prosthetics that can assist victims of injury and stroke. Their latest partnership is supported by a new $1.2 million NSF grant. Under this grant, Contreras-Vidal's Maryland team is embarking on a four-year project with researchers at Rice University, the University of Michigan and Drexel University to design a prosthetic arm that amputees can control directly with their brains, and which will allow users to feel what their robotic arm touches.
"There's nothing fictional about this," said Rice University co-principal investigator Marcia O'Malley, an associate professor of mechanical engineering. "The investigators on this grant have already demonstrated that much of this is possible. What remains is to bring all of it -- non-invasive neural decoding, direct brain control and [touch] sensory feedback -- together into one device."
In a NIH-supported project underway, Contreras-Vidal and his colleagues are pairing their brain cap's EEG-based technology with a DARPA-funded next-generation robotic arm designed by researchers at the Johns Hopkins Applied Physics Laboratory to function like a normal limb. And the UMD team is developing a new collaboration with the New Zealand's start-up Rexbionics, the developer of a powered lower-limb exoskeleton called Rex that could be used to restore gait after spinal cord injury.
Two of the earliest partnerships formed by Contreras-Vidal and his team are with the University of Maryland School of Medicine in Baltimore and the Veterans Affairs Medical Center in Baltimore. A particular focus of this research is the use of the brain cap technology to help stroke victims whose brain injuries affect their motor-sensory control. Originally funded by a seed grant from the University of Maryland, College Park and the University of Maryland, Baltimore, the work now also is supported by a VA merit grant (anklebot BMI) and an NIH grant (Stroke).
"There is a big push in brain science to understand what exercise does in terms of motor learning or motor retraining of the human brain," says Larry Forrester, an associate professor of physical therapy and rehabilitation science at the University of Maryland School of Medicine.
For the more than a year, Forrester and the UMD team have tracked the neural activity of people on a treadmill doing precise tasks like stepping over dotted lines. The researchers are matching specific brain activity recorded in real time with exact lower-limb movements.
This data could help stroke victims in several ways, Forrester says. One is a prosthetic device, called an "anklebot," or ankle robot, that stores data from a normal human gait and assists partially paralyzed people. People who are less mobile commonly suffer from other health issues such as obesity, diabetes or cardiovascular problems, Forrester says, "so we want to get [stroke survivors] up and moving by whatever means possible."
The second use of the EEG data in stroke victims is more complex, yet offers exciting possibilities. "By decoding the motion of a normal gait," Contreras-Vidal says, "we can then try and teach stroke victims to think in certain ways and match their own EEG signals with the normal signals." This could "retrain" healthy areas of the brain in what is known as neuroplasticity.
One potential method for retraining comes from one of the Maryland research team's newest members, Steve Graff, a first-year bioengineering doctoral student. He envisions a virtual reality game that matches real EEG data with on-screen characters. "It gives us a way to train someone to think the right thoughts to generate movement from digital avatars. If they can do that, then they can generate thoughts to move a device," says Graff, who brings a unique personal perspective to the work. He has congenital muscular dystrophy and uses a motorized wheelchair. The advances he's working on could allow him to use both hands -- to put on a jacket, dial his cell phone or throw a football while operating his chair with his mind.
No Surgery Required
During the past two decades a great deal of progress has been made in the study of direct brain to computer interfaces, most of it through studies using monkeys with electrodes implanted in their brains. However, for use in humans such an invasive approach poses many problems, not the least of which is that most people don't' want holes in their heads and wires attached to their brains. "EEG monitoring of the brain, which has a long, safe history for other applications, has been largely ignored by those working on brain-machine interfaces, because it was thought that the human skull blocked too much of the detailed information on brain activity needed to read thoughts about movement and turn those readings into movement commands for multi-functional high-degree of freedom prosthetics," said Contreras-Vidal. He is among the few who have used EEG, MEG or other sensing technologies to develop non-invasive neural interfaces, and the only one to have demonstrated decoding results comparable to those achieved by researchers using implanted electrodes.
A paper Contreras-Vidal and colleagues published in the Journal of Neuroscience in March 2010 showed the feasibility of Maryland's EEG-based technology to infer multidimensional natural movement from noninvasive measurements of brain activity. In their two latest studies, Contreras-Vidal and his team have further advanced the development of their EEG brain interface technology, and provided powerful new evidence that it can yield brain computer interface results as good as or better than those from invasive studies, while also requiring minimal training to use.
In a paper published in April in the Journal of Neural Engineering, the Maryland team demonstrated that people wearing the EEG brain cap, could after minimal training control a computer cursor with their thoughts and achieve performance levels comparable to those by subjects using invasive implanted electrode brain computer interface systems. Contreras-Vidal and his co-authors write that this study also shows that compared to studies of other noninvasive brain control interface systems, training time with their system was substantially shorter, requiring only a single 40-minute session.
An amazing study authored by professors D. Mark Anderson (University of Montana) and Daniel Rees (University of Colorado) shows that traffic deaths have been reduced in states where medical marijuana is legalized.
The study notes that this is equal to the effect raising the drinking age to 21 had on reducing traffic fatalities.
One key factor is the reduction in alcohol consumption. The study finds that there is a direct correlation between the use of marijuana and a reduction in beer sales, especially in the younger folks aged 20-29.
A drop in beer sales supports the theory that marijuana can act as a substitute for liquor.
The study also finds that marijuana has the inverse effect that alcohol does on drivers. Drivers under the influence of alcohol tend to make rash decisions and risky moves, whereas those under the influence of marijuana tend to slow down, make safer choices, and increase following distances.
Members of a University of Arizona Eller College of Management team and a UA alumnus developed a prototype system to detect fake websites. When tested against other existing commercial systems, the team found that its system resulted in effective and more accurate detections of spoof sites – better than a human can.
The team's subsequent article, “Detecting Fake Websites: The Contribution of Statistical Learning Theory" was published last year in an issue of MIS Quarterly, or MISQ. A preeminent peer-reviewed journal in the field of management information systems, MISQ has since been named the article its top paper for 2010.
"Even to get into MISQ is very difficult, and this is probably the first technical paper to receive the Best Paper award," said Hsinchun Chen, the UA Artificial Intelligence Lab director, one of the paper's five authors.
MISQ will formally honor the researchers in Shanghai, China later this year during the International Conference on Information Systems.
"The topic of detecting fake websites and also our computational approach are both considered major contributions. This topic has great relevance to the industry, the society and the citizens in general," said Chen, also the McClelland Professor of Management Information Systems.
"This award is not something just for me, or my lab, but also for our department," he said, adding that the team's eventual goal is technology transfer.
UA alumnus Ahmed Abbasi, now a University of Virginia assistant professor of information technology, is lead author on the paper. Chen served as his dissertation adviser. Other co-authors are UA Eller College's department of management information systems faculty members Zhu Zhang and Jay F. Nunamaker Jr.; and David Zimbra, a doctoral student in the Artificial Intelligence Lab.
For the research, the team used the prototype and several other detection systems to evaluate the authenticity of 900 websites.
It is easy to pick up on a site's authenticity by checking whether the URL contains "http" when it should read "https," when it was last updated, if a security key is missing or if images appear strangely pixelated.
The team found that its system – founded on statistical learning technology, which evaluates a large accumulation of data – was more apt to detect imitation sites and those that were entirely concocted, said Abbasi, who earned his doctoral degree in management information systems from the UA in 2008.
The major difference between the authors’ prototype and the other systems? Their system relied on a tremendously rich set of fraud cues.
The team developed five categories with thousands of cues, finding that the best results were attained when utilizing thousands of highly visible and also deeply embedded cues, such as placement, URL length, the number of links, characters types on the site and how thorough the site's "frequently asked questions" section is detailed, among other features.
The project's origins were born out of the Artificial Intelligence Lab, where Abbasi developed the mathematical formula the team eventually used while working as a project lead and research associate. He continued the work after having taken a faculty position at the University of Wisconsin-Milwaukee.
"It creates a greater awareness for a problem that has been around for a while yet still remains an issue as we increasingly move to the Internet for everything – online banking, online health initiatives and medical information," Abbasi said.
Given the pervasive nature of online phishing scams, being able to readily and frequently detect a site's validity is crucial, Abbasi said, also noting research that indicates people are less than 60 percent accurate in detecting fake sites, and other security issues.
"The problem we're looking at is quite big. Fake websites constitute much of the Internet fraud's multi-billion dollar industry, and that is monetary loss…we can’t even quantify the social ramifications," Abbasi said. "That's the whole motivation. It is so profitable for fraudsters, and it is slipping through the cracks."
Today, Chen and more than one dozen of his collaborators are continuing to investigate fake sites. Meanwhile, Abbasi is undertaking an investigation of peoples' abilities to detect fake sites through a grant funded by the National Science Foundation.
Today, Chen and more than one dozen of his collaborators are continuing to investigate fake sites. Meanwhile, Abbasi is undertaking an investigation of users and peoples' abilities to detect fake sites.
Abbasi said developing better detection systems requires improved statistical learning technology that utilize larger quantities of cues. It also is important to dismiss long-held perceptions about how fake sites might and should appear.
"The idea of protecting from the front level has been around for a while," Abbasi said, adding that companies have begun to employ software that better detects fake sites. "But we are not where we need to be, and there is a lot of potential in future development."
Cannabis connoisseurs, former hippies, and college kids everywhere have long appreciated marijuana for its seemingly magical effects on mind and body. The fact that it is illegal (at least in the United States), has never stopped people from partaking in a little herbal refreshment. But it isn’t just Phish fans who have argued for the legalization of the popular recreational drug. Legalizing marijuana for medicinal purposes, specifically to alleviate the pain of those afflicted with glaucoma, is a contemporary and fairly widespread cause. But even since the 1950s, scientists have recognized, and pushed for, the antibacterial properties of Cannabis sativa.
Most recently, positive publicity for pot has emerged via a group of Italian and British researchers experimenting with tetrahydrocannabinol — the main active ingredient in marijuana. More commonly known as THC (because, let’s face it, anyone under its influence isn’t going to be able to get that octosyllabic word out of his mouth), the compound and its related compounds have proven themselves effective antibacterial agents.
A team of scientists led by Giovanni Appendino at the University of Eastern Piedmont tested the five most common cannabinoids (a group of substances that are structurally related to THC) and found each one to be effective against several common multiresistant bacterial strains. The findings were published in the Journal of Natural Products, where the team also suggested that cannabinoids without psychotropic properties may be even more useful in fighting off bacterial diseases.
Back in the fifties, scientist didn’t know much about the chemical make up of marijuana. They tested it as an agent against various infections, but their experiments never reached the practical stage. Half a century later, researchers are able to look more closely at the potential medicinal properties of the plant; however, they are still unsure of how exactly the cannabinoids work and how effective they would end up being. More research and experimentation is needed if they expect to transition it into systemic antibiotics. Still, strides are being made. Scientists say THC could be ready for use in the near(er) future as a combatant against methicillin-resistant Staphylococcus aureus (MRSA), an often fatal bacteria responsible for difficult-to-treat infections in humans, commonly found in hospitals or jails, where the residents have open wounds, invasive devices, and weakened immune systems. The compound would serve as a topical agent, preventing microbes from colonizing on the skin. Whatever name you choose to call it—pot, reefer, weed, hemp—cannabis could end up being the drug for microbial strains that no other drugs can cure. That’s one small step for medicine, one giant leap for marijuana.
Source: popsci.com - Author: Rachel Durfee - posted on 09.10.2008
We didn’t want to write about it. Seriously, we didn’t. Sure, Michael Phelps has digital technology, the 24-hour news cycle and precision blown glass to blame for his plight but we’re better than that.* But when US Swimming went and suspended Phelps for two months for, ultimately, acting his age, we felt compelled to write something. The 'Science' part of Popular Science restricts us from condemning the insanity of the punishment (note, however, they did nothing following his 2003 DUI). So below we offer an introductory, though hardly comprehensive, summary of marijuana and its (non)role as a performance-enhancing drug.
We should start by noting that US Swimming has made it quite clear that the ban of Phelps has nothing do with performance enhancement (not much to enhance) and everything to do with serving as the morality police.
“This is not a situation where any anti-doping rule was violated, but we decided to send a strong message to Michael because he disappointed so many people, particularly the hundreds of thousands of USA Swimming member kids who look up to him as a role model and a hero,” the Colorado Springs-based federation said in a statement.
But, that doesn’t stop us from asking why the drug is banned in sports in the first place. It’s a question English sports minister Richard Caborn , Spanish Athletics Federation President Jose Maria Odriozola and New Zealand Sports Drug Agency executive director Graeme Steel all asked several years ago. Caborn said the World Anti-Doping Agency should not be “in the business of policing society.” WADA’s science director, Dr. Olivier Rabin, added his thoughts during the discussion, “Our mandate is to fight doping in sport. We don’t go beyond that mandate and this has nothing to do with the social aspects of these drugs.”
According to WADA, prohibition of a substance is based on three questions: does it enhance performance, is it dangerous for the athlete, and is it against the ‘spirit of sport’? If the answer is yes to two of the questions, the substance is banned. Conceding that cannabinoids are dangerous to the athlete (smoke inhalation can never be good), the debate rests on performance enhancement and spirit of sport questions. Given Rabin’s comments we figured data must exist showing the power of pot in sports.
An oddity worth noting is that marijuana is only sometimes banned. During competition, athletes testing positive will suffer punishment but testing positive out of competition (during training) is okay. The rationale for this depends on whom you talk to. Some argue the ability of cannabinoids to calm nerves, thus enhancing performance, only works directly before a competition (unless you found some especially sticky stuff). Others argue it’s an example of WADA waffling on how marijuana aligns with the ‘spirit of sport’.
“In the case of marijuana, it’s a call by WADA to balance the strong views by many that it shouldn’t be on the list at all and say that their primary concern is limiting it during competition,” said Steel. “What athletes do during their own personal time is not WADA’s business. That’s my own personal opinion and not speaking officially on behalf of WADA.”
Cannabinoids are not the only substance on the ‘sometimes prohibited' list. Most stimulants with short-term effects, along with narcotics for pain relief, can be used freely outside of competition. These substances clearly can benefit performance; again, suggesting marijuana has similar capability.
So back to the core question. Can marijuana enhance performance? A cursory search of PubMed found a surprising lack of quality research on whether smoking a joint could help athletes win anything other than an eating contest. We doubt scientists would have a hard time recruiting volunteers so logic might suggest that most scientists just don’t buy for a second that inhaling Cheetos is a desirable side-effect for elite athletes. WADA provided several references for this piece that focused more generally on the pharmacology of marijuana but offered little data on actual physical performance.
Saugy, et al, published a literature review of the topic in the 2006 British Journal of Sports Medicine. Saugy first references US data suggesting that 16 percent of US adults aged 18-25 reported cannabis use in the past month (again, sample size should not be a problem for any future research). The paper refers to cannabis as an ‘ergolytic’ drug, which impairs performance, rather than a ‘ergogenic’ drug that would enhance it. A referenced study showed that 12 healthy adults cycled to exhaustion in less time after smoking 10 minutes earlier. Other studies have shown that THC (the ingredient that gets you high) increases heart rate and blood pressure while decreasing cardiac output and psychomotor activity.
A detailing of the pharmacological effects of cannabis published in the British Journal of Psychiatry by Ashton, does note that colors might seem brighter. While that might help a tennis player see the balls, these additional side effects are a little less desirable when returning a 120-mph serve.
“Spatial perception is distorted and time perception is impaired so that perceived time goes faster than clock time. Hallucinations may occur with high doses.”
Most theories on potential benefits from marijuana surround its ability to alleviate stress and relax. A study of French sport students showed that "good sleep” was one reason listed for marijuana usage and that participants in extreme sports—those where competition included elevated levels of physical dangerous—reported higher rates of usage.
A WADA spokesman added in an e-mail response that, “Research showed that cannabinoids can allow athletes to better focus and diminish stress.”
And according to Saugy, “it can have a euphoric effect, reducing anxiety and increasing the sociability of a player who may be particularly nervous before an important match.”
Steel has heard those arguments but notes that in his experience in New Zealand, it is simply not the case. More than 60 percent of the positive tests in his country are for marijuana and not once has a tribunal found that the drug was taken for performance enhancing capability.
Rabin had previously disputed that contention noting that a reduction “in the sense of fear or apprehension” can classify cannabinoids as performance enhancing in certain sports. He noted that athletes have testified to such after being caught.
But, if the issue truly was about some archer wanting to smoke a joint to help him hit the bull’s-eye, why not ban it in only that sport? WADA has precedence and existing protocol for such a move. Alcohol for examples is only banned in a handful of sports (motorcycling, powerboating, etc.). Steel doesn’t expect that change to occur.
“Yes, it would be an option, but there are some strong entrenched views that it has no place in and around sports so that view is unlikely to prevail,” said Steel. “Some strong lobbying groups think it shouldn’t be there whether it effects performance or not.”
Apparently suggestions otherwise would just be blowing the proverbial smoke.
*Though we can't help but note how potent is the irony of a man with scientifically-inexplicably large lungs inhaling smoke from an oversized bong.
Source: popsci.com - Author: Brett Zarda (article from 02.09.2009)
Stanford materials science professor Yi Cui, who led the work, says a tremendous amount of research goes into making batteries store more energy for longer, but little attention has been paid to making them "more beautiful, and fancier."
Researchers have previously made transparent variations on other major classes of electronics, including transistors and the components used to control displays, but not yet batteries. "And if you can't make the battery transparent, you can't make the gadget transparent," says Cui.
Some battery components are easier to make using transparent materials than others. The electrodes are the tricky part, says Cui. One way to make a transparent electrode is to make it very thin, on the order of about 100 nanometers thick. But a thin electrode typically can't store enough energy to be useful.
Another approach is to make the electrode in the form of a pattern that has features smaller than the naked eye can see. As long as there is enough total electrode material in the battery, this type of electrode can still store a significant amount of energy. Cui designed a mesh electrode where all the lines of the mesh are on the order of 50 micrometers, effectively invisible, and the squares inside the mesh contain no battery materials.
Fabrication is also tricky, since the usual methods for making components at this resolution require harsh chemical processes that damage battery materials. The Stanford group instead used a relatively simple method to make the transparent mesh electrodes, which are held together inside a clear, squishy polymer called PDMS.
They start by using lithography to make a mold on a silicon wafer. Then they pour liquid PDMS over the mold, cure the polymer to solidify it, and peel it off the mold. The PDMS sheet is then engraved with a grid of narrow channels. Next they drip a solution of electrode materials onto the surface of the PDMS. Capillary action pulls the materials in until they have filled all the channels to create the mesh. The researchers used standard lithium-ion battery materials to make their electrodes.
To make the complete battery, they sandwich a clear gel electrolyte between the two electrodes, and put it all inside a protective plastic wrapping. The Stanford researchers created prototypes, and used them to power an LED whose light can be seen through the battery itself.
Cui says these batteries should, in theory, be able to store about half as much energy as an equivalent-sized opaque battery, because there is a trade-off between energy density and transparency. They can lay down a thicker mesh of electrode materials to store more energy, but that means less light will get through.
So far, his lab's prototypes can store 20 watt-hours per liter, about as much energy as a nickel-cadmium battery, but Cui expects to improve this by an order of magnitude, in part by reducing the thickness of the polymer substrate, and also making the trenches that hold the electrode materials deeper.
Another way to store more energy without sacrificing transparency would be to stack multiple cells on top of one another in such a way that the grid of the electrodes lined up, allowing light to pass through. So far, the group has made electrodes that are about an inch across, but Cui says they could be made much larger, and the material could simply be cut to the desired size.
As the government runs out of fiat currency, it grows more fearful of the people. Freedomain Radio is the largest and most popular philosophy show on the web - http://www.freedomainradio.com
Molyneux speaking at Drexel University
Barack Obama has abandoned a commitment to veto a new security law that allows the military to indefinitely detain without trial American terrorism suspects arrested on US soil who could then be shipped to Guantánamo Bay.
These particles, called antineutrinos, suggest that about half of Earth's heat comes from the radioactive decay of uranium and thorium – and give clues to the location of geological stashes of these elements.
Heat is needed to drive the convection currents in Earth's outer core that create its magnetic field. But exactly how much of this heat comes from radioactive decay wasn't known until now.
In 2005, researchers from the international KamLAND collaboration used a detector buried in Japan to measure antineutrinos that are produced when elements decay, allowing a rough estimate.
Chemical window
Now they have enough data – 111 geological antineutrinos to be precise – to refine their measurement, suggesting that about 20 terawatts of heat come from radioactive decay. Earth's total heat production is about 40 terawatts.
The researchers also had enough neutrinos to confirm that some must be coming from places other than the crust, something that wasn't possible before. "The uncertainty is small enough that some contribution must be from the mantle," says Giorgio Gratta, a physicist at Stanford University in California who is part of the KamLAND collaboration.
The ability to determine the location of the radioactive elements could permit better models of the Earth's interior, says Gratta. Seismic waves tell us about elasticity of the crust and mantle: now we have a small window into their chemistry, which should allow their behaviour to be better modelled. The presence of radioactive elements in the mantle, for example, could affect its flow.
There's still some uncertainly in the new measurement, because detections of antineutrinos are so infrequent. Larger detectors would help improve the measurements and might even be used to monitor undeclared nuclear facilities from afar, says Gratta.
Craig Gundersen, a professor of agricultural and consumer economics at Illinois, says food and exercise alone are not to blame for the extent of obesity among children in the United States. Psychosocial factors, such as stressors brought about by uncertainty about the economy, income inequality, and a fraying social safety net also must be considered, he says.
"Energy-in, energy-out is important, but energy imbalance isn't the only thing leading to overweight status among children," said Gundersen, the executive director of the National Soybean Research Laboratory at Illinois. "We also know that people have very different ways of responding to the same amount of food intake and exercise, and one of the factors that may influence how people react to eating and exercise is through the amount of stress they're under."
Gundersen says stressors are particularly prevalent for low-income children, a demographic group that has high rates of obesity in the U.S. and other developed countries.
"As a society, we're always looking for different ways we can address public health issues, whether it's reducing food insecurity or reducing obesity," he said. "Although there have been many different ways to reduce obesity, what we've found is that stress is a leading cause of obesity among children. So if there's any way we can reduce stressors from a policy standpoint, that will also have the effect of reducing obesity."
The calls for trimming the social safety net that are currently in vogue in Washington, D.C., as part of a larger program of government austerity would likely lead to more obesity over time because it places more stress on low-income families, Gundersen says. "If we cut back on benefits for the Supplemental Nutrition Assistance Program, or otherwise reduce its availability to people, that would increase the amount of stress that low-income families would face, which would then subsequently lead to increases in obesity," he said.
According to Gundersen, programs such as SNAP play a vital role in the social safety net as well as in efforts to end obesity.
"I really cannot stress how great of a program SNAP is," he said. "It's a fantastic program, and I think it can do a lot to help in our fight against obesity as it's currently constructed."
But there have been calls to restrict what SNAP recipients can purchase. For example, New York City recently proposed prohibiting children from purchasing sports drinks with their SNAP benefits. Gundersen views this development as setting a "dangerous precedent."
"Ultimately, placing restrictions on what people can buy only discourage them from participating in the program because it stigmatizes the benefits," he said. "The best way to reduce obesity isn't to introduce more restrictions, but to expand SNAP as it's currently structured."
Since SNAP allows families to purchase more healthy foods that they would otherwise be able to, any further restrictions or cutbacks to the program would have a two-fold effect, Gundersen says.
"Reducing access to SNAP would increase stress, which leads to increases in obesity, but it also means that families wouldn't be able to afford healthy foods and would subsequently have to purchase less healthy foods," he said. "When thinking about these sort of policy considerations, we have to think about who bears the brunt of these cutbacks, because not only could they lead to more obesity, but also to more inequality."
Gundersen says that while many families who are facing tough times may not be eligible for SNAP, which is only available to those below 130 percent of the poverty line, private food assistance networks can also play a key role in helping reduce food-scarcity stress.
"People know that if they're short on funds at the end of the month, they can go to their local food pantry and get some food," he said. "So a lot of people may be ineligible for SNAP but are still facing a very a stressful financial situation. Food banks really help those people, which in turn lowers stress and, by extension, obesity."
As many families face financial hardship as a result of the sluggish economy, Gundersen says that public policymakers need to be aware of the relationship between stressors and childhood obesity, which has only become more pronounced as income-inequality has grown over the last three decades.
"If present trends of income inequality are maintained, and if people are stressed by this – and there is some evidence to suggest that they are, to the extent that it's your position versus others in society, and not your absolute level of income – that, too, could lead to more obesity," Gundersen said.
More information: The study, published in the journal Obesity Reviews, was co-written by Duhita Mahatmya, Steven Garasky and Brenda J. Lohman, all of Iowa State University. The paper, "Linking Psychosocial Stressors and Childhood Obesity," is available online.
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