The US Supreme Court ruled today on the case of Maryland v. King, deciding with a 5-4 majority to uphold the Maryland state law that considers a DNA test--in this case a cheek swab--to be a legal search. That DNA will be entered into a database to be matched with existing samples.

The concept of a legal search is one of the toughest concepts in law to get your head around; it extends to much more than a search of your home or car or school locker. Your body, legally speaking, counts as your property, and you are entitled to legal protection against the violation of its bounds--which can be manifested as what we think of as privacy. That could mean what you say in the privacy of your own home, which is why wiretapping is illegal, or it could mean the right to not submit to questioning unless there is probably cause.

The case in question involved one Alonzo King, Jr., who was arrested in 2009 on an assault charge. He was fingerprinted and a DNA test was administered--but the DNA result linked him to an unsolved rape from 2003. King was sentenced to life in prison on charges from the 2003 rape, but appealed all the way to the Supreme Court on the grounds that the DNA test constituted an illegal search, violating the Fourth Amendment.

The Supreme Court decision was heated. Justice Antonin Scalia, who normally sides with the conservative bloc on the Court, instead sided with the liberal bloc, and Justice Stephen Breyer did the reverse. Scalia felt so strongly that the DNA test was an illegal search, in violation of the Fourth Amendment, that he read his dissent from the bench, something only done when the author is particularly outraged.

Justice Anthony M. Kennedy, writing for the majority, calls the DNA test "a legitimate police booking procedure." And the Court also noted that the DNA test is fairly non-invasive, that it involves no surgery. And that's true! But it's important to analyze why things like fingerprinting or photographing are police booking procedure: it's exclusively for identification. DNA tests are worthless for identification; they are only used to match one sample against another. That makes them valuable for solving older cases, but entirely unnecessary as a standard booking procedure. As a matter of protocol, DNA results are entered into a database, and automatically checked against it for matches, which is what happened in the King case.

The other issue for the future is who, exactly, can now legally be DNA-tested. The answer? Anyone who has been arrested for any reason, valid or not. A racist cop who pulls over a guy driving a car in Arizona because he looks Latino? That guy can now have his DNA taken and booked on file, even when he's released in an hour with no charges filed.

From the dissent of Justice Scalia (who, it should be noted, has been a fiercely aggressive justice on the subject of privacy as of late): "Today's judgment will, to be sure, have the beneficial effect of solving more crimes. Then again, so would the taking of DNA samples from anyone who flies on an airplane." Of course, not everyone agrees.

Read more over at MSNBC.

Design studio Dorothy (see: these awesome color wheels made from musicians and songs) have struck again with a set of "Star Charts" that map classic Hollywood films through constellations: one charts films from the Golden Age, the other charts films from the Modern Age. The individual stars represent actors and directors, and the constellations represent the movies themselves. For example: Ingrid Bergman, Humphrey Bogart and Paul Henreid make the constellation Casablanca.

In the first print, the designers at Dorothy created a print for the classics, working off what the night sky over Los Angeles looked like on October 6, 1927. That was the day The Jazz Singer, the first film with synchronized dialogue, began the slow demise of silent film and ushered in the Golden Age. Included on the print are 62 films like Gone With The Wind, The Wizard of Oz, and Casablanca.

The other print deals with modern films, modeled after the night sky over New York on June 16, 1960, when Alfred Hitchcock's Psycho premiered. There are 108 movies on that print, and they're pretty varied: Easy Rider, Pulp Fiction, and Avatar are all included.

The movies were picked by Dorothy if they were critically acclaimed or deemed to have historical relevance--if they made it to the U.S. National Film Registry, for example--or picked up a lot of Oscars on release. (A few of the designers' personal favorites are also included.) On each print, there's a key showing the actors' names, any oscar wins or nominations, and where his or her star is on the Hollywood Walk of Fame.

Both limited edition and open versions of the Golden Age and Modern Age prints are available on Dorothy's site. The limited edition colors are going for £100 (about $153) while the open editions are going for £25 (about $38).

Walk along a California beach on a warm summer day, and there are sure to be dozens of men and women, spread out on their towels, soaking in as much sun as they can. Sure enough, about six months later, in the cool months of January, February, and March, that same tan they worked so hard to obtain is... gone. What happened?

The short answer: it fell off.

The long answer? Let's start with how we tan. Put simply, a tan is a protective mechanism for the skin according to Dr. Ali Hendi, a skin cancer specialist from Georgetown University.

There are a few cells in the basal (bottom) layer of the epidermis (or outer layer of skin) called melanocytes which produce a pigment called melanin. These cells are interspersed within the skin and make up about 1 percent of the skin. Dr. Hendi compares them to octopuses with little tentacles delivering packets of melanin to surrounding skin cells. "The job of the melanin is to protect the skin, specifically the nucleus," Dr. Hendi says. "It sits right on top of the nucleus almost like a little cap." The "cap" of melanin on top of the nucleus helps protect the skin from UV radiation by absorbing some of the excess rays, which can cause mutations in skin cell DNA that can lead to skin diseases.

Melanocytes can detect Ultra Violet (UV) radiation from the sun which triggers production of the pigment. There is even some new evidence that melanocytes have eye-like abilities to help begin melanin production. Scientists at Brown University found evidence of rhodopsin in melanocytes which is a photosensitive protein found in the eye's retina used to detect light changes. Further testing led the study to conclude that these photosensitive receptors help start melanin production in the skin much faster than previously thought.

People with darker skin have more active melanocytes that produce more melanin than those with fair skin, Hendi says. Therefore, black skin and white skin will have an almost identical number of melanocytes, but the cells in black skin produce much more melanin.

The reason you lose your tan, however, has nothing to do with melanocytes. It disappears for one simple reason: humans shed.

You lose about one million skin cells in a 24-hour period. The outside layer of human skin replaces itself every 28 to 30 days. Cells on the surface continually flake off over time; new ones grow in the bottom layers of the skin. This cell death is known as apoptosis, according to Dr. Jeffrey Banabio, a dermatologist certified by the American Academy of Dermatology. The dead cells on the surface, made of mostly fat and protein, provide the most protection against the environment and the sun. "It is a normal process that is actually optimized to protect us. It is productive to have nonliving protein and fat there rather than having living cells on the surface." The melanin in these dead cells absorbs some of the UV radiation hitting the skin.

During the winter, this cycle of regrowth and shedding continues, but the production of melanin drops off. "In the winter, the amount of UV radiation reduces significantly, so the melanocytes stop putting out so much pigment." Over the course of weeks or months, the more heavily pigmented skin cells mature and fall off. The new cells produced in the basal layer of the epidermis are exposed to less radiation in the winter and thus have less pigment making them lighter in color. This gradual change in skin cells is responsible for lighter winter skin colors.

Some scientists estimate that you lose about one million skin cells in a 24-hour period. These skin cells make up most of the dust you see on your computers, windowsills, or tables. Therefore, whenever you decide to clean your house (let's hope more often than not), you could be slowly but surely sweeping your tan right out the door.

This story was produced in partnership with Northwestern University's Medill School of Journalism. For more FYIs, go here.

This summer, billions of cicadas will rise from under the East Coast, shed their grub-like bodies, and clumsily fly to perches in trees, where they will make a terrible racket. The insects are singing to attract mates, but this year, they'll have the ear of the U.S. Navy, too. Researchers at the U.S. Naval Undersea Warfare Center are dissecting cicadas in an effort to develop a better underwater sensor. Yesterday they presented a paper on their work at the International Congress on Acoustics.

The major mystery the Navy would like to solve: How does a bug so small create a noise so loud? The answer could have major implications for compact sonar systems. Although such systems currently exist, those are based on passive sonar, which can listen to other objects underwater generating noise, so long as the noises are louder than the vessel doing the listening. A passive sonar system cannot send out sound of its own to locate other vessels.

Active sonar systems, on the other hand, emit sound and then listen for sound waves that bounce back from underwater objects. Current active sonar systems require large and complicated equipment, which means not every ship can carry them. The Navy researchers hope that by replicating cicada noisemakers, small ships like unmanned underwater vessels could begin to use active sonar. An unmanned vessel with a cicada-inspired sonar system could locate hostile forces, while also appearing to be a far bigger, more distracting threat than it really is.

To understand the cicada song, Navy researchers are using lasers to track the parts of cicadas that make sound. Cicadas' internal noisemaker consists of two parts: a pair of plates on their thorax, each of which are attached to ribs that bulge outward. Cicadas contract the plates, making the ribs click inward. A large air sac behind the ribs makes the sound reverberate in the same way that blowing air over an empty bottle creates a deeper sound. Cicadas bulge the pair of ribs over their air sac 300 to 400 times a second. Because the resultant sound waves are out of phase with each other, they somehow combine and amplify, thus creating the discordant rattle that animates the East Coast every 17 years.

Listen to Brood II cicadas below:

Researchers from Bell Labs in New Jersey have created a camera that operates without any lens, making it lighter, cheaper and immune to blurry, out-of-focus images.

The lensless camera relies on compressive sensing, a type of signal processing that uses algorithms to reconstruct images or signals based only a small sample of data. Instead of capturing a couple hundred pixels of, say, your perfectly crafted frittata, with compressive sensing, you would take a few pixels here and there and reconstruct the full image with an algorithm--kind of like turning an Impressionist painting into a photograph.

The Bell Labs camera, described in a paper here, uses only two components: an aperture array made of an LCD panel and a single sensor. By adding another sensor, it could also be used to take multiple images at the same time.

The lack of lens means the camera doesn't need to be focused, and it can be made lighter and smaller. The image resolution depends on how many elements there are in the aperture assembly.

MIT Technology Review explains:

While it uses only a fraction of the data a normal camera requires, the process takes longer to image a scene, so it's really only useful for still-lifes right now.

In addition to the visible light spectrum, the prototype, built from low cost, off-the-shelf commercial parts, can capture images in infrared and millimeter waves. The inventors suggest that it could be used in surveillance, where the multi-image function could help determine the speed of objects or compare how a scene has changed.

[MIT Technology Review via Time]

Valium, the anti-anxiety drug that was once the most popular prescription medication in America, might have a naturally occurring relative in the mammalian brain, according to a new paper in Neuron.

Stanford University researchers have discovered that a protein called diazepam binding inhibitor (DBI) can have some of the same effects as Valium.

Diazepam (Valium), belongs to a class of psychoactive drugs known as benzodiazepines, and can be used to stop epileptic seizures, especially during clusters of repeated seizures.

"Our results show for the first time that a nucleus deep in the middle of the brain generates a small protein product, or peptide, that acts just like benzodiazepines," senior author John Huguenard explained in a press statement.

DPI is also known as ACBP, and it's an intracellular transport protein that exists in every cell in the body. Researchers have found that in a certain part of the brain (the thalamic reticular nucleus), DPI becomes an anti-epileptic compound. It binds to the same nerve receptors in the brain as benzodiazepines, enhancing the inhibiting effect of a neurotransmitter called GABA.

The calming protein, which seems to only be generated in this region in the middle of the brain, could be key in developing anti-seizure treatments. The researchers suggest it could be used in anxiety and sleep disorders as well.

Every year since 2005, the University of Miami's Rosenstiel School of Marine and Atmospheric Science has judged a crop of photos for consideration in its Underwater Photography Contest. The winners and runners-up--in categories including wide-angle and portrait--are always unbelievable. We've collected our 10 favorites from the 2013 contest in the gallery here.

Hydraulic fracturing and horizontal drilling have opened up huge reservoirs of oil and gas across the U.S. The Energy Information Administration predicts that production of shale gas in particular will continue to rise steeply, increasing 44 percent between 2011 and 2040. If fossil fuels are to remain a large part of the nation's energy mix, engineers need to reduce their environmental impacts.

The Closed Cycle

Wastewater Treatment

Oil and gas companies send millions of gallons of pressurized water­-along with chemicals and sand­-down wells to fracture shale. But the liquid, called flowback, returns to the surface filled with contaminants, making it unusable for other purposes-even fracturing new wells. Water-treatment technology is still in its "45rpm phonograph" stage says David Burnett, a Texas A&M petroleum engineer who oversees pilot studies of prototype systems for the Department of Energy. Of various methods now in development, membrane-filtration technology is especially energy efficient and site adaptable: Engineers can fine-tune a series of membranes to remove different substances from water as it passes through. Such on-site systems could reduce the need for freshwater, critical in arid regions of the U.S.

The Hydrocarbon Fix

Waterless Fracking

Ideally, drillers would eliminate the use of water in hydraulic fracturing, or fracking, altogether. A Canadian well-fracturing company called GasFrac has developed a substitute: a gel made from liquefied petroleum gas (LPG) and propane. Because it's a hydrocarbon, the gel dissolves into the target oil or gas and returns to the surface with the rest of the payload. But because the gel does not dissolve salts or clay in the shale, it doesn't sweep natural contaminants back out of the well. Chevron reported that LPG used in a pilot test conducted in Colorado in 2011 significantly increased natural-gas production while minimizing water usage

The Microbial Rescue

Methane Recapture

In 2011, oil and gas operations flared or vented almost 210 billion cubic feet of natural gas that they couldn't use or store-enough to heat more than two million homes for a year. In North Dakota's Bakken shale formation, drillers flared or vented 32 percent of the gas produced during oil extraction (the national average is less than 1 percent) because they lacked sufficient pipelines and processing facilities. A consortium that includes the National Renewable Energy Laboratory launched a project in January to convert the surplus gas into diesel or jet fuel. Scientists will genetically engineer microbes that naturally feed on methane to boost the amount of lipids they produce. They will then convert those lipids into a feedstock that could be piped to a refinery or used on-site.

Consider it civilian reconnaissance. Protesters in Turkey are using Google Maps to track police movement, plot out barricades, and rally together.

Created Saturday, the map of Istanbul Police Movements centers on Taksim square, the heart of recent (and ongoing) protests against the Prime Minister Recep Tayyip Erdogan's government. It began last week with trees and a barracks. Erdogan's government plans to renovate an Ottoman barracks, a structure dating back at least a century, near the square. To get construction equipment to the barracks, officials wanted to raze trees from the nearby Gezi Park. Protesters prevented this, demonstrating in defense of the green space for over a week. Since then, protests expanded, evolving into a critique of the current ruling party.

Mapping protests and police response in real-time is a relatively new phenomena. In 2010, students protesting in London used a Google Map to track police action, documenting riot vans and helicopters moving against the protesters. But some features of the Turkish protests are straight out of Les Misérables, or indeed any number of historical protests. Barricades keep vehicles, police, and even horses away from the protesters, take time to tear down, and protect against thrown objects or gunfire, should the police response turn violent. In centuries past, governments brought in armies to quell protesters, and used cannons to knock down barricades. Paris, the site of so many protests, even underwent a major urban redesign with wider streets to make barricades more difficult.

In addition to the red triangle markers of barricades, here are some features of the map:

• A green tent to mark the heart of Taksim Square
• Road warnings in green, letting people know which one are open and which are blocked
• Pink tags for groups announcing who they are and where they are protesting
• Light blue flags for police locations and reported movements
• Warnings of police tracking servers online, confusingly under light blue as well.
• General rallying cries, slogans, and mottos from protesters are marked with house symbol

Notably absent? Sensitive information, like the location and identity of specific individuals, like volunteer doctors. In the jargon of secrecy, that's called good Operational Security. In plain talk, it's just common sense.

When Colorado and Washington state each passed ballot measures legalizing marijuana for recreational use late last year, one legal challenge was resolved, but another was just beginning Before, marijuana was simply prohibited. Now it has to be regulated. With their new legal standards for possession and use, Colorado and Washington now have to draw hard lines on a rather hazy landscape, creating legal standards not just for for taxation and licensing, but also some far more nebulous questions, like how much marijuana is reasonable for a single person to possess, and even what constitutes legal intoxication. Meanwhile, forty-eight other states are watching closely to see exactly how they do it.

For Colorado, regulation of marijuana under the new state standards (which, by the way, could still be challenged by the federal government) came to a head last month at the state house as legislators hashed out just exactly how local and state authorities will handle these questions. They also tackled the thorniest issue of all, one that has been a sticking point for previous legalization efforts and one that is eventually bound to go 'round and 'round in courtrooms: what scientifically constitutes "under the influence" of marijuana, and how can clinicians and law enforcement determine if someone -- most importantly, a driver -- is too high for the public good?

Now the state of Colorado has offered up its answer. Under House Bill 1114, the answer is five nanograms. If a blood screen detects five or more nanograms of THC (that's delta-9-tetrahydrocannabinol, the psychoactive ingredient in cannabis) per milliliter of blood in a person's bloodstream, that individual is considered legally under the influence of drugs. Washington has also set its intoxication limit at five nanograms per milliliter.

But the question is not that simple. What is marijuana impairment -- what constitutes being "too high" to drive -- and how can we scientifically evaluate it, particularly in a law enforcement context? Moreover, how can police officers test for it conclusively at the roadside, where blood tests aren't available? How lawmakers define and answer these questions will have a lot to do with marijuana policy in the U.S. going forward, and unfortunately the body of science describing marijuana's effects on the brain and body -- though vast -- isn't exactly bound by broad consensus. Five nanograms per milliliter is a place for policy to start, but it's by no means the last word determining how high is too high.

TAKING THE HIGH ROAD

"Smoking is a very efficient way to deliver drugs to the brain," says Dr. Marilyn Huestis, a senior investigator at the National Institute on Drug Abuse's Intramural Research Program, part of the National Institutes of Health. "It goes into the lungs, into the heart, and gets pumped directly to the brain."

Huestis has spent a career studying the effects of marijuana on the brain and the psychomotor capabilities of individuals, both among acute users (those that use marijuana occasionally) and chronic users who partake of marijuana daily. Unlike alcohol, which requires at least a little bit of time to work its way into the bloodstream, marijuana has shown in Huestis's own studies to manifest itself within the first minute after use. From there, one's ability to responsibly operate heavy machinery begins to come into question.

Cannabinoid receptors (known as CB₁ receptors) in the brain are found in many key regions, including the amygdala (responsible for processing memory and emotional reactions) as well as the basal ganglia and cerebellum (responsible for motor control, among other things). "We know that when people smoke marijuana the lose some of their peripheral vision," Huestis says. "We know it affects the passage of time, or the idea of how rapidly time is passing. It affects balance. And one of the most interesting areas it affects is the prefrontal cortex."

Driving is an exercise in timing, multitasking, and situational awareness -- and not one well suited for the cannabinoid-impaired. The prefrontal cortex is what separates us from other animals, Huestis says. It's home to our executive function, the place where we take in and process information and use it to make choices about various courses of action. Cannabis impacts our executive function, which can slow or alter decision-making abilities. Moreover, it makes our brains work harder, Huestis says, and not necessarily in a good way. In tests, an individual dosed with cannabis can often perform a task just as well as he or she would if sober. But brain imaging of dosed individuals shows that it requires much more brainpower to complete that task. That means that under the influence of cannabis the ability to handle multiple tasks simultaneously, or to divide attention effectively, dwindles significantly. Even more specific to driving, marijuana has been shown in various studies to affect what's known as "standard deviation of lateral pursuit," or that natural, somewhat innate ability to hold an automobile more or less right in the middle of a traffic lane.

None of this -- reduced peripheral vision, slowed decision making, inability to multitask -- enhances one's ability to drive. Humans are more prone to distraction when dosed with cannabis, and in the context of a moving vehicle a misperception of the passage of time translates to a misperception of distance as well, at least in the sense of how quickly a car traveling at a given speed will reach some distant object.

That being said, Huestis notes, individuals under the influence of cannabis -- unlike those under the influence of alcohol -- tend to be aware of their impairment. Some studies have shown that stoned drivers are more cautious behind the wheel and tend to drive more slowly. But that's not really any kind of compensation. Driving is an exercise in timing, multitasking, and situational awareness -- and not one well suited for the cannabinoid-impaired.

THE ELUSIVE MARIJUANA 'BREATHALYZER'

"The properties of marijuana are not going to liken themselves very much to a 'breathalyzer' type test," says Dr. Christina Hantsch, a toxicologist working within the Loyola University Health System. "I think it's going to have to be a different bodily fluid if you're looking for more immediate testing."

Why? For one, THC is fat-soluble, which means it can be absorbed by the body's fat cells and remain within the metabolism for extended periods of time. For heavy users, THC can remain within the body for days, making it difficult to connect the presence of THC in a person's bloodstream with that person't current state of impairment. For chronic users the picture is even murkier. Regular marijuana users who stop using cannabis can still have detectable amounts of THC in the bloodstream even 30 days after they cease using. There are even documented cases of former chronic users that haven't had a dose of cannabis in years testing positive for THC while undergoing rapid weight loss, Hantsch says. THC is really good at tucking itself away in the body's fat cells, and it can remain there for a really long time.

Complicating things further still: an emerging body of scientific evidence suggests that this residual THC in the bloodstream of chronic users might still cause impairment. Though the effects of these trace amounts of THC in the bloodstream don't manifest themselves with nearly the intensity that a fresh blast of THC to the CB₁ receptors does, both Huestis and Hantsch note that there is research out there suggesting that just because these levels of THC are relatively low doesn't mean they aren't having some impairing effects on the psychomotor skills of both acute and chronic users for the duration that THC remains in the bloodstream.

All that is to say that detecting the presence of THC in the bloodstream doesn't necessarily correlate to impairment, and there's certainly no overwhelming body of hard science that can draw connections between a specific amount of THC in the blood (like, say, five nanograms per milliliter) and a specific degree of impairment. Things grow more dubious still at the place where government really needs certainty the most: at the roadside.

The most promising solution for the problem of roadside THC testing in recent years has been oral specimen testing (read: saliva sampling). Several academic and government labs as well as commercial companies have developed various tests claiming they can detect THC in the bloodstream via handheld devices that analyze a swab taken from inside a subject's mouth. But the results have been mixed -- mostly mixed degrees of disappointment.

"Oral fluid testing actually went into effect in Australia in 2004," Huestis says. "The reason it didn't get going in Europe or the U.S. is because the roadside devices were, frankly, terrible."

You can get really good results from THC testing via oral sample in the lab, Huestis says, but the problems with collecting and analyzing samples at the roadside became immediately apparent to early adopters of the portable oral specimen technology. First, THC is so lipophilic that it had a tendency to stick to the collection devices themselves, which dulled the sensitivity of the analysis from the point of that samples were collected. Saliva is also loaded with enzymes that break molecules down, so in the period between collecting the oral sample and getting it to a lab for analysis the samples would continue to degrade themselves, further skewing the results.

But assuming there was an oral specimen test that was effective for accurately measuring THC in the bloodstream at the roadside, there's still the problem of correlating it to impairment, which is ultimately what law enforcement officers are concerned with, especially in a context where possession and use are no longer strictly prohibited.

"There's still a lot of work to be done to really tie in all those connections, to say that if you do pick up this level of a marijuana metabolite in a oral fluid specimen there is some solid scientific evidence that also indicates some degree of impairment or effects on the behavior of the individual," says Dr. Stephen Kahn, a professor of pathology and toxicologist at Loyola University's Stritch School of Medicine. "And that's harder to do than with blood ethanol."

Nonetheless, the state of both the science and the technology is improving. The tools for oral specimen detection and analysis improve each and every year, Huestis says, and her own lab recently folded trials of a new portable oral specimen diagnostic into experiments there. Under controlled conditions in which the THC levels of dosed subjects were being tested independently in the lab this new portable device showed impressive efficacy, Huestis says, with very low incidence of false negatives or false positives.

Huestis thinks we'll see these kinds of tests used by law enforcement in the U.S. within 3-5 years. Kahn is less willing to put a firm projection on the adoption of such technologies, but he does believe that the science will eventually become good enough to gain the confidence of the courts and law enforcement.

"I think it's absolutely going to happen," Kahn says. "But I'm just not sure how long it will take."


THE FIVE-NANOGRAM RULE/>

Of course, all of this hinges on having a legal standard to measure against. Some states in the U.S. where medicinal marijuana is legal have already established zero-tolerance policies for driving under the influence of cannabis; get caught with THC in your bloodstream while driving and it's an immediate conviction regardless of how much THC that is (or whether it is the cause of your impairment). But with Washington state and Colorado opening the door to legal, recreational use of cannabis their legislatures are choosing -- like several other medicinal marijuana states -- to treat cannabis more like alcohol. That is, you can toke a responsible amount and still get behind the wheel, but should you cross a certain threshold you are in serious legal trouble.

So where does the five-nanogram-per-milliliter rule established by both Washington and Colorado come from? Not from Washington or Colorado. It's an administrative decision that might seem somewhat arbitrary, though it's no more arbitrary than decreeing that somewhere between .07 BAC and .08 BAC a person transforms from capable to dangerously drunk. The five-nanogram rule is rooted in several studies and for several scientific reasons, the first of which actually sides with the regular marijuana user. In the first studies that emerged showing that blood tests could detect residual THC in the bodies of chronic cannabis users even days after they last dosed, none of those chronic users registered higher than five nanograms per milliliter at 24 hours after their last dose, Huestis says. So the rule is in part designed to reduce the likelihood that chronic users will get slapped with D.U.I.D. convictions when in fact they haven't consumed cannabis in more than a day.

The other reason states tend to gravitate toward the five-nanogram rule is far more nebulous, but there's some scientific evidence, borne out by data, that when THC counts in the bloodstream of a driver are at five nanograms per milliliter or higher, that driver's chance of being involved in a fatal accident begin to climb steeply. One Australian study found that with any measurable THC in the bloodstream a driver is twice as likely to be involved in a fatal accident, but at five nanograms per millimeter of THC that number jumps to 6.6. times more likely, Huestis says. Five nanograms is the point where the chances of something bad happening seem to start climbing steeply.

In the eyes of the law no one really cares how impaired you are, only that you are impaired.But that's not really so clear. Some German studies have shown significant impairment in subjects testing in the area between two and five nanograms per milliliter (Germany is considering adopting the five-nanogram standard as well) and in Sweden, where standards for impaired driving are among the most rigorous and enforced by stringent legal penalties (the legal BAC limit is 0.02, or a quarter that of the U.S.), one laboratory found that 90 percent of that country's cannabis impairment cases had a level of one nanogram of THC per milliliter. So where impairment is concerned there's a lot of gray area -- and a lot of scientific debate -- between zero nanograms and five nanograms per milliliter, not to mention a lot of varying opinion on what constitutes "impaired."

But ultimately the long-sought portable roadside THC test for law enforcement may be less important than many have made it out to be. After all, in the eyes of the law no one really cares how impaired you are, only that you are impaired. That's the way it works for alcohol impairment, and the way it has worked for years. Though easier to measure and evaluate at the roadside, blood alcohol concentration really has no quantifiable correlation to how impaired a person is. Alcohol affects different people in different ways, but regardless you still go to jail for driving in the U.S. with a blood alcohol concentration that tops 0.08 (celebrities and the politically well-connected notwithstanding). How capable you really are of driving is beside the point.

Like the five-nanogram standard, the 0.08 blood alcohol concentration limit was an administrative decision. And as with the 0.08 rule, governments will likely simply set THC standards wherever the existing body of science makes them feel comfortable. Creating such a threshold not only establishes a firm legal standard that can hold up in court, but it somewhat obviates the need for precision roadside testing -- a simple field sobriety test for THC impairment testing for time and depth perception, coordination, and other psychomotor abilities tied to cannabis impairment will do, and officers already have those kinds of tests in their collective toolbox.

Of course, a reliable 'breathalyzer' for marijuana -- something easily administered at the roadside that's capable of returning a number that, like blood alcohol concentration, correlates roughly to a degree of impairment -- isn't completely out of reach. If the new recreational marijuana laws in Colorado and Washington state have created something of a regulatory headache, it's a headache that recreational pot laws might also be able to cure. If necessity is the mother of invention, these new laws have certainly created a need among the legal community that is helping to focus the science and technology community on potential solutions.

"This is a hot area right now, and there really is a lot of attention being paid in my field to oral fluid testing for drugs of abuse in general," Kahn says of the potential for a portable THC testing device. "The kinds of issues we're talking about are exactly why. This is where it's headed. It may not happen in exactly the way that we think, but in one way or another I think it will happen sooner or later."

On Friday, not even two weeks after a destructive tornado ran through Moore, Oklahoma, another twister hit the city of El Reno. At last count, 18 people were confirmed dead, with six still missing, and the National Weather Service has not only categorized the storm as an EF-5--the highest on a scale of damage--but also as the widest tornado ever measured.

A mobile radar unit measured the storm at 2.6 miles across, according to the National Weather Service, making it wider than the previous record holder, a 2.5-mile twister that swept across Nebraska in 2004. That means it was considerably wider than the Moore tornado, too, which at most was two miles wide.

[NBC News]

Researchers at the University of Minnesota today revealed a drone that can be controlled merely by thought, and that's not even the coolest thing about it. Published in the Journal of Neuro Engineering, the project has implications in everything from unmanned vehicles to paraplegic mobility.

The setup here is pretty basic, futuristic though it seems. The drone is a commercially available four-blade helicopter--the Parrot AR quadrotor--which is basically a drone hobbyist's Model T. To control it, the "pilot" wears a funny hat, the sensing end of an electroencephalogram (EEG). EEGs place an array of electrodes over a person's head, in a totally non-invasive way, then pick up on electrical activity in the brain. Clusters of activity, like thinking about making a fist with a right hand, generates a spark in a specific area of the brain. That spark gets translated through a computer into a quadrotor command ("turn right"). The command is then beamed to the quadrotor via WiFi.

Ideally, it works like in the image below:

Previously, researchers showed that subjects could control a virtual helicopter with their thoughts. The latest demo--using a real, live helicopter--is just another step toward more practical applications, with the ultimate goal being to help people with disabilities and neurdegenerative dieseases regain mobility, says researcher Bin He, a professor of biomedicial engineering at the University of Michigan.

Why demonstrate the system with a drone? "It's more manageable to test in protocol than it is to do on a patient with a prosthetic arm," he says. In the published paper, the pilot is illustrated as someone in a wheelchair, sitting in front of a laptop that's streaming back everything the drone sees. A thought-controlled wheelchair would probably help that person out more, but ground-bounded wheelchairs rarely encounter something both drones and arms deal with every day: precisely navigating three dimensional space. Flying a drone through a hoop turns out to be good practice for maneuvering a hand to a mouth, say, or putting an arm through a sleeve.

The system is relatively easy to use. A series of exercises trained the five students who piloted the drone. The first is a game that looks like pong, where the subject used the EEG controls just to move a dot on a screen right or left. The second controlled up/down motions, a third combined them all in a similar, pong-like interface, and the fourth exercise before actually piloting the drone involved a flight simulation of the drone through hoops above an imaginary town.

There's a funny story about the sixth test pilot. The researchers were asked to put together a video of how the drone worked, and on short notice they couldn't find one of the original test pilots. Instead, graduate student Brad Edelman had passed the first couple of tests, and he happened to be in the lab at the time, so they sat him down to try out the full thing. As you can see below, he flew it perfectly, suggesting that the technology is intuitive enough for some people to just pick up and use it.

Click to launch the gallery.

Imagine you are walking through a park and suddenly thousands of Volkswagen Beetles start falling from the sky. They are falling at a speed that is five times as fast as you can run, so dodging them is not an option. Game over for you, right? Not if you're a mosquito. Sure, a raindrop is to the pesky insect what a Volkswagen would be to us, but mosquitoes have some natural advantages in this scenario that humans don't.

The secret to a mosquito's survival during a rainstorm isn't due to any fancy maneuvers or midair acrobatics. It is a combination of their low mass, hydrophobic wings, and go-with-the-flow mentality, according to David Hu, assistant professor of mechanical engineering at the Georgia Institute of Technology. Hu has researched mosquitoes' flight behavior in rainy conditions to better understand the limits of micro-airborne vehicles (MAVs). These tiny robot airplanes can be as small as an insect, so understanding how mosquitoes survive collisions with raindrops can help scientist develop more reliable MAVs.

Understanding how mosquitoes survive collisions with raindrops can help scientist develop more reliable MAVs."There is still a question of how to build these things and once you build them what their limits are," Hu says. A mosquito can provide some solutions to these limits-providing ideas for how MAVs can be better adapted to in-air collisions.

A raindrop falls from the sky at about 10 miles per hour. When it hits a solid surface at this speed, it rapidly decelerates by 100 percent and generates a force that is about 10,000 times the weight of a mosquito-enough to kill it, Hu says.

But a mosquito is very lightweight, so a raindrop only decelerates by 2 to 20 percent when it collides with the insect in midair, creating a force of about 50 to 300 mosquito weights-still a significant force, but because of the mosquito's extremely strong exoskeleton, not enough to kill on impact, Hu says. "It is like you take a down feather out of your jacket and put it right on top of the mosquito," Hu says.

It's easy to imagine that a swipe of a feather won't harm a mosquito, but how does a mosquito handle the force of a raindrop? One of two things happens: If the raindrop hits the mosquito's legs or wings, the mosquito gets knocked off balance and spins in the air as the raindrop slips off of its water resistant extremities. The mosquito recalibrates and is back on track in about one-hundredth of a second.

The mosquito is back on track in about one-hundredth of a second. If a raindrop directly hits a mosquito's body, the impact is much greater. Instead of spinning in midair, the raindrop grabs hold of the mosquito, rapidly accelerating it downward. It's like walking down the street, then a bus going 10,000 miles per hour hits you and carries you along with it.

The mosquito hitches a ride on the raindrop at super speed for about 5 to 10 centimeters and then it does something unexpected-it peels away from the raindrop and continues on its flight path.

This process would be like if that unfortunate guy who got hit by the bus happened to be covered in newspapers, Hu says. As he and the bus collide, his newspaper limbs begin to flap in the wind. Because the mosquito's long legs and wings extend past the perimeter of the drop, they generate wind and torques that free the mosquito, Hu says.

Mosquitoes are the ultimate tai chi masters: they don't resist the force. Throughout all this turmoil, you'd think the mosquitoes would alter their behavior to avoid raindrops. Yeah, they can survive the impact forces, but it can't be comfortable to hurtle toward the earth on the back of speeding raindrops. You'd be wrong.

"I call the mosquitoes the ultimate tai chi masters because they don't resist the force at all," Hu says. Instead, the mosquito just goes along for the ride despite the jet-speed acceleration.

But this carefree attitude may work against the mosquitoes when they are flying too close to the ground. If the mosquito is 10 centimeters or fewer from the ground and gets a direct body hit from a raindrop, it doesn't have enough time to peel off. Instead, it gets smashed into the ground. Game over for the tai chi master.

This story was produced in partnership with Northwestern University's Medill School of Journalism. For more FYIs, go here.

While it seems like the more barriers between you and a ginormous wall of water, the better, new research shows the same islands that can insulate a beach against your average wind-driven wave can make the devastating effects of a tsunami way worse, according to a paper submitted to arXiv on May 31.

In the aftermath of the 1992 tsunami that hit Flores, Indonesia, Costas Synolakis, one of the paper's authors and the director of USC's Tsunami Research Center, observed that some of the worst damage on the small island of Babi hit where you'd least expect it--on the lee side of the island, closest to the shore. Instead of creating a shadow zone sheltered from the destruction, as classic wave theory would suggest, the island seemed to amplify the intensity of the wave.

To study how common this phenomenon is, Synolakis worked with Ph.D. candidate Themistoklis Stefanakis, mathematical sciences professor Frédéric Dias and their colleagues at France's ENS Cachan to create a computer simulation to study the effect of a conical island a few hundred kilometers away from a straight stretch of beach.

"After running 200 simulations, we have found that in none of the situations considered [did the island] offer protection to the coastal area behind it," they write. Rather, small islands actually made the wave's impact on the nearby beach worse, increasing the tsunami's run-up, or rise in sea level. The islands amplified the severity of the wave by as much as 70 percent.

Tsunamis are much longer than normal ocean waves, and don't behave in quite the same way, acting more like a rising tide than a breaking wave. Because of their length, as tsunamis wrap around an island, they split off into two separate wave fronts that then collide as they reach the lee side of the island, and continue onto shore with even greater energy. If the island is far enough away from the mainland, the two fronts have time to join again and continue as one tsunami, but for a short time, it has a double the destructive power. "If the distance to the mainland is just right, the two fronts superpose and focus right at the section of the coastline right behind the island," Synolakis explained in an email.

"Our results help explain a vexing mystery, which we had earlier thought of as fluke," he writes.

Since coastal communities near islands have an increased risk of damage from tsunamis, they could benefit even more from early warning systems, as well as tsunami education and preparation programs.

[MIT Technology Review]

A long time ago, Doors lead singer Jim Morrison sang/said I am the Lizard King, I can do anything (because he was reaaaaally high). Now scientists have named an ancient, extinct species of gigantic lizard after Morrison, just as he intended.

The lizard, which lived between 36 and 40 million years ago, was first discovered in Myanmar in the 1970s, but was described (and named) this week by researchers writing in the journal Proceedings of the Royal Society B. The lizard, Barbaturex morrisoni, really was a king, too: at about 6 feet long and 60 pounds, it's one of the biggest lizards ever.

Most huge lizards, like the Komodo dragon, exist in isolated environments where natural predators won't stifle their development into behemoths. But morrisoni lived in an ecosystem with both herbivores and carnivores. One theory suggests that temperatures affect the size lizards grow to. Morrisoni lived during a particular warm four-million-year stretch, lending credence to that theory, the researchers say.

So in addition to being on the ever-growing list of species named after famous people, morrisoni has potential to teach researchers more about evolutionary processes. Even if the family resemblance is a bit of a stretch.

[University of Nebraska-Lincoln]

A tiny, beady-eyed, long-tailed primate with hand-like feet is now the world's oldest known fossil primate skeleton. In a study to be released in the journal Nature this week, an international team of researchers describe their discovery of the Archicebus achilles and how it's adding to what we understand about our own evolution.

The Archicebus achilles--named for its long tail and strange feet--was found in an ancient lakebed in China. The lack of oxygen at the bottom of the lake means that this specimen is remarkably complete and well-preserved. Recovered from sedimentary rock strata deposited in an ancient lake roughly 55 million years ago, this fossil is the oldest primate fossil, beating the previous record-holders--including Darwinius from Messel in Germany and Notharctus from the Bridger Basin in Wyoming --by 7 million years.

"It's not just that it's the oldest primate, but it turns out that this fossil tells us that primates had already been evolving for quite some time. This primate was already fairly advanced in terms of the evolutionary tree," says Christopher Beard, a coauthor of the study and paleontologist from the Carnegie Museum of Natural History.

The Archicebus sits at a branch of the evolutionary tree, which goes in two directions: one toward living tarsiers-large-eyed night-dwelling small primates-and anthropoids, the monkeys, apes and humans, which have smaller eyes and are most active during the day.

This is the first time that we have had such a complete picture of the divergence between these two branches.

"Any time you find a specimen like this, it's a bit special. It's adding a lot of depth of history," says John Flynn, another coauthor and curator for the American Museum of Natural History.

Given Archicebus's size-weighing about an ounce and measuring 7 to 9 inches long including the tail-and its basal evolutionary position, this discover supports the idea that the common ancestor of both tarsiers and anthropoids were quite small. These two branches, anthropoids and tarsiers, have been thought to be evolutionarily linked for some time, and now scientists are starting to understand the age of that split.

Beyond its addition to our understanding of evolution, the ancient primate is also unique in its physique. One of the most curious characteristics of the Archicebus is its feet. Tarsiers tend to have elongated heel bones, which help give them leverage for their giant leaps. Anthropoids have feet specially designed for grasping-though humans are a bit of a special case, given our unique disposition of walking bipedally.

"I was convinced pretty early on by the foot of this creature, which looked like nothing else but a little marmoset, which is a type of monkey from South America. I was convinced this thing was going to be a very primitive anthropoid," Beard says. "Here's an animal that combines features that we've just never seen before in one fossil primate."

But after the exhaustive analysis, it became clear that Archicebus was also closely linked to tarsiers.

To fully analyze the fragile fossil, researchers collaborated with the European Synchrotron Radiation Facility in Grenoble, France. Using a high-intensity X-ray beam, the Synchrotron scanned the fossil, producing high-resolution data. This data was then rendered into 3-D versions to be analyzed and compared with other primates, both living and fossilized.

The analysis and data-gathering was one of the longest and most extensive phases of the study. Researchers created a matrix that included data from more than 150 species and more than 2,000 different characteristics. All told, the process took 10 years and required collaboration from many institutions internationally. But the patience and practice is now finally paying off.

"[The Archicebus is like] what we find so often in paleontology, but we can never predict it, and that's an animal that's unlike everything else we've ever seen," Beard says. "It's a kind of hybrid or mosaic of different features that are found in different animals today, but never together in one. It's truly a unique creature."