December 10, 2013 1:20 pm
China’s smog problems have been all over the news, with the air pollution to blame for bringing massive cities to a snarl, forcing the shutdown of factories and transportation, and wreaking havoc on people’s health. But a new photo captured by NASA’s Terra satellite really puts China’s smog problems into perspective: the smog over Beijing is so thick that it obscures the view of the city from space.
On December 7th, says NASA’s Earth Observatory, the day this photo was captured, “ground-based sensors at U.S. embassies in Beijing and Shanghai reported PM2.5 measurements as high as 480 and 355 micrograms per cubic meter of air respectively. The World Health Organization considers PM2.5 levels to be safe when they are below 25.”
“Fine, airborne particulate matter (PM) smaller than 2.5 microns (about one thirtieth the width of a human hair) is considered dangerous because it is small enough to enter the passages of the human lungs. Most PM2.5 aerosol particles come from the burning of fossil fuels and of biomass (wood fires and agricultural burning).”
For reference, here’s what the region is supposed to look like from space, a snap captured by Terra in January of last year. Beijing is the city in the top left, nestled among the mountains. The port city in the bottom right is Tianjin.
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December 3, 2013 3:15 pm
Epigenetics has become something of a buzzword these days. Researchers have long studied how changes in an organism’s DNA sequence affect how genes behave, but epigenetics looks at how environmental factors, like diet or lifestyle, can change gene activity in a way that passes from generation to generation. There’s interest in how epigenetics might be connected to conditions ranging from cancer to kidney disease to autism. Yet scientists struggle to pin down the specifics of this phenomenon. As the New Scientist explains:
Previous studies have hinted that stressful events can affect the emotional behaviour or metabolism of future generations, possibly through chemical changes to the DNA that can turn genes off and on – a mechanism known as epigenetic inheritance.
However, although epigenetic changes have been observed, identifying which ones are relevant is a bit like searching for a needle in a haystack. That’s because many genes control behaviours or metabolic diseases like obesity.
Now, a new study published in Nature Neuroscience provides “some of the best evidence yet” that behaviors can indeed be passed from one generation to another, the New Scientist says.
In an experiment reminiscent of A Clockwork Orange, researchers trained male mice to fear a cherry blossom-like scent called acetophenone by inducing slight electric shocks every time the smell wafted into the animals’ cages. After ten days of this treatment, whenever cherry blossoms were in the air, they report, the mice trained to fear it went on edge. The researchers found that those mice developed more smell receptors associated with that particular scent, which allowed them to detect it at lower concentrations. Additionally, when researchers examined those males’ sperm they found that the gene responsible for acetophenone detection was packaged differently compared to the same gene in control mice.
After imprinting those males with a fear of acetophenone, the researchers inseminated females with the scared mice’s sperm. The baby mice never met their father, but those sired by a blossom-hating dad had more acetophenone smell receptors. Compared to pups born of other dads, most were also agitated when acetophenone filled the air. This same finding held true for those original males’ grandpups.
Information transfer from one generation to another, outside experts told the New Scientist, may play a role in human diseases such as obesity, diabetes and psychiatric disorders. But researchers are far from pinning down the mechanism by which this may be possible, how long these sensitivities may last or whether these seemingly inherited behaviors affect anything more than smell in mice.
In other words, epigenetics is a field still largely obscured by unanswered questions. As Virginia Hughes summarizes at National Geographic, about all we can know for certain is this: “Our bodies are constantly adapting to a changing world. We have many ways of helping our children make that unpredictable world slightly more predictable, and some of those ways seem to be hidden in our genome.”
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December 2, 2013 3:23 pm
Obesity is a complex problem—the result of geography, economics, culture, class, personal choice and personal genetics—and the combination of these factors has led to more than a third of American adults being considered obese. And here’s another factor in this equation: journalist Kristin Wartman writes in the New York Times that new research is showing how diets of pregnant and breast-feeding women can bias their kids towards fatty foods. When expectant or new mom’s fill their diet with junk food, she says, it can affect their baby’s brain’s chemical reward pathways and set the babies up to seek more of the same.
The tastes you grew up with, the researchers say, tend to stick with you. “This early exposure leads to an imprinting-like phenomenon such that those flavors are not only preferred but they take on an emotional attachment,” says psychologist Gary Beauchamp. Pretty much everything you do affects the structure of your brain, and food is no different. If those foods you’re exposed to as a child—either in the womb or through breast milk—are energy-dense foods, like many junk foods, your brain will adapt to those foods. Wartman:
Mothers who were fed foods like Froot Loops, Cheetos and Nutella during pregnancy had offspring that showed increased expression of the gene for an opioid receptor, which resulted in a desensitization to sweet and fatty foods. “The best way to think about how having a desensitized reward pathway would affect you is to use the analogy of somebody who is addicted to drugs,” Jessica R. Gugusheff, a Ph.D. candidate at FoodPlus and the lead author of the study, wrote in an email. “When someone is addicted to drugs they become less sensitive to the effects of that drug, so they have to increase the dose to get the same high,” she wrote. “In a similar way, by having a desensitized reward pathway, offspring exposed to junk food before birth have to eat more junk food to get the same good feelings.”
So, add another layer to the complexities of obesity, and the realization that though junk foods tastes pretty good to all of us, for some it takes a little more to hit the sweet spot.
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November 29, 2013 10:49 am
Patients suffering from severe paralysis may soon enjoy a greater degree of freedom in navigating through the world. A new technology called the Tongue Drive System allows patients to control their wheelchair with the flick of their tongue. In trials, this new system has outperformed existing technologies—which rely on patients sipping and puffing air through a straw to control their wheelchairs—in speed and matched their accuracy.
In order to work the new system, patients must get a tongue piercing. That stud is magnetic and essentially acts like a joystick for controlling direction, the researchers describe. Science elaborates on how it works:
When users flick the magnetic barbell, the magnetic field around their mouth is altered. Changes in the magnetic field are picked up by four small sensors on a headset, which relays information wirelessly to an iPod carried by the user. The iPod detects the users’ tongue commands, and sends them to target devices, such as a powered wheelchair, or even a computer on which users can move a cursor simply by moving their tongue.
Clinical trials with the Tongue Drive System involved 11 paralyzed patients and 23 able-bodied volunteers. For the latter group, the researchers compared those participant’s ability to accurately navigate computer-based obstacles and activities using both the new tongue-based system and a touch screen. Comparing those two tasks allowed the researchers to determine the learning curb associated with using the tongue-based system, and they found that participants became more adept at using it as they gained practice, with improvements showing up within 30 minutes.
The paralyzed patients attempted using the tongue-based system straight away, and they soon maneuvered through obstacles three times faster on average than they did with existing technologies, despite sometimes having years of experience with those older technologies. “We saw a huge, very significant improvement in their performance from session one to session two,” the researchers said in a statement. “That’s an indicator of how quickly people learn this.”
The next step, they say, is to move the system outside of the lab and hospital and into the real-world environment for testing.
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November 29, 2013 10:03 am
Earlier this week, ten retired N.H.L. players sued the league for fraud and negligence, arguing that for years the league ignored the dangers of head injuries and failed to curb the culture of violence. The players taking action include famous players like Rick Vaive, Darren Banks and Gary Leeman, who began their careers back in the ’70s and ’80s.
In seeking unspecified compensatory and punitive damages, the players said in their complaint that the N.H.L. “knew or should have been aware” of the effects of head hits but “took no remedial action to prevent its players from unnecessary harm” until 1997, when the league created a program to research and study brain injuries. Even then, the suit said, “the N.H.L. took no action to reduce the number and severity of concussions among its players during that period and Plaintiffs relied on the N.H.L.’s silence to their detriment.”
The suit comes just a few months after the National Football League paid $765 million to former players for similar concussion related side effects. The players argue that not only did the NHL know about the risks of head injury, the league actually tried to conceal just how much it knew.
The NHL, of course, claims no wrong doing. “While the subject matter is very serious, we are completely satisfied with the responsible manner in which the league and the Players’ Assn. have managed player safety over time, including with respect to head injuries and concussions,” NHL Deputy Commissioner Bill Daly said in a statement. “We intend to defend the case vigorously and have no further comment at this time.”
Football often gets the majority of the press about head injuries, but other full contact sports like boxing and hockey are seeing players with long term side effects as well. It’s been 16 years since the NHL began studying concussions, but it wasn’t until 2011 that they issued new concussion protocols. And for players feeling the impact, that’s far too long.
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