Since the mid-1970s, police scanners have been the only way for civilians to access real-time updates from police departments. Scanners work by flipping through multiple open radio conversations on emergency channels, providing an overall picture of a crisis from the people on the ground reacting to it. Because they offer fast and direct first-hand accounts, scanners have been invaluable for coordinating and linking emergency response.

But yesterday, the real-time updates from Boston came mainly through Twitter. In fact, the news broke on Twitter more than 10 minutes before national media began reporting on the explosions. This photo was tweeted just four minutes after the first bomb went off:

What the fuck just happened?#bostonmarathontwitter.com/theoriginalwak…

— Tyler Wakstein (@theoriginalwak) April 15, 2013

Deadspin was first to publish a news story, 13 minutes after the attack (and the post consisted almost entirely of updates from journalists and witness on Twitter.) As more news from Boston came in, I joined at least 53,000 people in following along with the Boston, Police, and EMS emergency feed. How'd I find the feed? Twitter. Over the scanner, authorities urged listeners and Bostonians to take to social media, as phone networks were likely to be overloaded. The Cambridge Police Department Twitter account became an invaluable source of information for many as it tweeted reports of new threats and then issued all-clears when appropriate.

As with all security broadcasting, there's a potential downside-nothing filters this information away from criminal ears or eyes, and easy access to police communication poses a risk to officers who could be ambushed.

Some Twitter users have even begun transcribing mundane police scanner exchanges for a national, online audience. Mashable recently profiled Alex Thompson, the woman behind the @Venice311 Twitter account, which broadcasts scanner chatter in the Los Angeles metro area as easily-digestible written information. She was inspired to do so after witnessing a gross crime (literally, not metaphorically-someone dumped "50 gallons of raw sewage from his RV onto the street" where she lived.)

Thompson isn't alone in going directly from police scanner to Twitter. In January, students at Ohio University began tweeting scanner chatter from around Athens, Ohio, adding humor and college-specific insights.

What makes Twitter the next logical leap from the police scanner is the immediate interactivity it provides the public: Police can respond to and broadcast inquiries like a real-time FAQ. And unlike scanners, Twitter isn't regionally restricted, and it doesn't cost $100 to $500 to access.

According to a settlement that went into action yesterday (April 15), rent-to-own stores will no longer be allowed to peek at what their customers do. Previously, at least one piece of software allowed rent-to-own computer businesses to log their customers' keystrokes and GPS locations, take screenshots of the rented computers while people are using them, and snap photos of users with the computers' webcam.

The new injunction only names eight companies, but it means that the U.S. Federal Trade Commission considers these actions illegal-and that applies to any other rent-to-own businesses that use similar software, Tracy Thorleifson, a commission attorney who worked on the case, tells Popular Science. The commission is also forbidding the company that made the software from "providing others with the means to commit illegal acts," according to a commission statement.

The software under fire is called PC Rental Agent--it was designed to help computer rental businesses in situations just like this. Ars Technica has a great description of PC Rental Agent's different levels of features. Many are obviously helpful, such as the ability to clear a computer's memory before renting it out to the next customer. But the software's "Detective Mode" allowed stores to perform in-depth spying. It could also put up a fake "registration" notice on computers, enticing people to enter in their contact information.

Tim Kelly, a co-founder of DesignerWare LLC and developer of PC Rental Agent, told Ars Technica that stores were only supposed to activate the spying features as a part of their efforts to recover the computer from would-be thieves. He also said he doesn't agree with the Federal Trade Commission's ruling, although he has settled.

In a filing it made in September, the federal agency alleged that stores did not alert customers to the fact that the stores might be tracking and logging sensitive customer information such as social security numbers, banking information, and passwords. Because Detective Mode automatically snaps what it sees in computers' webcams, many stores ended up with photos of kids, undressed people and people having sex. Stores often activated Detective Mode on computers that customers were late in making payments for, but didn't intend to steal, the commission said.

With the new settlement, rent-to-own companies can't perform any spying on customers. They can't put up fake registration notices. They can only track machines' locations with customers' consent.

The settlement allows the commission to follow up on the eight named companies any time over the next 20 years, to make sure they're complying.

According to NBC News, law enforcement is now saying that the bombs used in the attack on the Boston Marathon were constructed of pressure cookers filled with shrapnel. This is a common and low-rent bomb, typically made from a bit of TNT or other explosive in a sealed pressure cooker. They can be triggered remotely, and the pressure cooker itself turns into shrapnel. Time has a good history of the pressure cooker bomb, if you're interested.

Pressure cookers make ideal bombs; they're inexpensive and legal, they're designed to build up tremendous pressure while used legitimately, and can be outfitted with all sorts of timers and triggers, from stopwatches to garage door openers.

Pressure cooker bombs were used as recently as 2006 to kill more than 130 people in Mumbai, and were part of the attempted (and failed) attack on Times Square in 2010.

Read more at NBC.

Human eyesight is such a limiting factor in military missions that DARPA is trying to fix it. Not with lasers; those are reserved for ships, but instead with a new infrared camera using pixels only five microns wide.

Smaller pixels mean a high-resolution image can be captured in a tinier package. There are existing miniaturized infrared cameras, but their pixels are about three times the size of DARPA's latest, and their resolution is at best half as good. The new technology has made it possible for the portable camera pictured above to do the work of the sort of long-wave infrared (LWIR) camera that till now has required a truck to carry.

That tiny package should enable U.S. troops to finally master one of the great challenges of history: how to take advantage of the limits of enemy eyesight while bypassing the same limitation.

Soldiers spent centuries figuring out the best way to see enemies at night without being seen. Early methods, like carrying torches, were more dangerous for the torch-carrier than his target, as the enemy's eyes were already adjusted to the night, and the torches revealed where the advancing soldier was. In light of this, night attacks were relatively rare historical events, and daytime fighting remains the norm for regular armies.

This is frustrating for commanders looking to exploit every possible advantage to win, because night attacks have some pretty distinct advantages. A larger portion of the enemy army is usually asleep, rarity adds an element of surprise, and the darkness, undisturbed by torches, lights, or a bright moon can conceal an army.

Advancing without seeing is pretty difficult, however, which means a technological solution is the way around it. Night vision goggles, the ones with that famous green filter, amplify available light, which can turn low visibility into high visibility. The problem comes with regular light sources, which night vision also amplifies to a blinding extreme.

Infrared, instead, focuses on a different part of the visual spectrum, and so is less affected by sudden changes in visible light. Previously, however, infrared cameras this advanced have been too large for individual people to carry, and instead had to be mounted on vehicles, which are not nearly as stealthy as troops on foot. With the new camera, DARPA hopes they can outfit individuals with such cameras, making night raids or defending against night raids that much easier.

AWESOME!
Because one cell has so little DNA, scientists typically pool together millions of cells to sequence a genome. Last December, Xiaoliang Sunney Xie and colleagues at Harvard University developed a technique to carefully copy single genes and then rapidly duplicate and sequence them using existing methods. Trumping other techniques for sequencing single cells, the new method covers up to 93 percent of a cell's DNA.

NOW WHAT?
When scientists sequence together a group of cells, they can miss the mutations that make each cell unique-mutations that can also serve as important signs of disease. People may use the new technique to more quickly identify cancer cells, administer less invasive prenatal tests, perform personalized medicine, or even identify a suspect from a single cell left at a crime scene.

This article originally appeared in the May 2013 issue of Popular Science. See the rest of the magazine here.

Rebekah Rousi, a Ph.D. student in cognitive science, conducted an ethnographic study of elevator behavior in two of the tallest office buildings in Adelaide, Australia. After taking a total of 30 elevator rides in the two buildings, she discovered there was an established order to where people tended stand.

"More senior men in particular seemed to direct themselves towards the back of the elevator cabins," she writes in a blog for Ethnography Matters. "In front of them were younger men, and in front of them were women of all ages."

There was also a difference in where people directed their gaze mid-ride: "Men watched the monitors, looked in the side mirrors (in one building) to see themselves, and in the door mirrors (of the other building) to also watch others. Women would watch the monitors and avoid eye contact with other users (unless in conversation) and the mirrors."

In other words, men would check everyone else (and themselves) out during their elevator ride. Women, on the other hand, would only look in the mirrors when they were with other women.

Rousi wasn't sure what to make of these results. Was the back of the elevator a position of power? She told NPR's Robert Krulwich that analyzing the results as part of a power hierarchy seemed "almost too cliche." It could be that people who are more shy stand toward the front, where they can't see other passengers, whereas bolder people stand in the back, where they have a view of everyone else. Rousi says the topic begs further analysis.

While we're at it, let's get some more definitive research on why elevators are so awkward. And until proven otherwise, you can find me vying for power in the back of the elevator.

[NPR]

Behind the bars of some of the nation's finest cocktail joints, there are secrets: secret recipes, secret bottles for friends only. One of these is the Green Dragon, a liquor potently infused with marijuana.

There've been alcohol-based tinctures of cannabis before, of course -- usually seen in turbid brown jars on windowsills, But one prominent New York bartender (I'll call him Jon) has been responsible for bringing the infusion up to date with modern, artisanal cocktail culture. Jon is a serious, technologically minded craftsman of beverages; he works as a cocktail consultant, and has designed the cocktail programs of more than one Manhattan bar.

He's refined a method that's quick, gives precise, predictable results, and reportedly maximizes the delicious herbal flavor of the drug, to provide a civilized sippable for the beverage connoisseur. Jon's nitrous-powered Green Dragon "just tastes good. We've dialed the strength back substantially, not because we can't make it stronger, but just because people want to be able to drink more of it, because they like it so much."

Jon can rattle off the exact date when (friend of PopSci) Dave Arnold published on his blog the "game-changing" nitrous infusion technique, a method for rapidly forcing new flavors into liquor using gas pressure inside a whipped-cream charger. And it was not very long at all after that date when Jon first had the notion to apply the technique to cannabis.

"If you don't want to smoke, you're left with edibles, but with edibles, there's no way to dose it. Someone hands you this thing, and you're like: who made it? how was it made? You eat a half or a quarter of it, and you wait and wait, and you either feel nothing, or you're destroyed."

"We've dialed the strength back substantially, not because we can't make it stronger, but just because people want to be able to drink more of it." But alcohol absorbs through the digestive tract in a faster, much more predictable way than solid edibles--and so does whatever's dissolved in that alcohol. Hence the precision-infused Green Dragon.

The rapid infusion works--the theory goes--because high pressure forces N₂O and alcohol deep into the plant material. Then, when the gas pressure is suddenly released, it causes the nitrous oxide to come out of solution and violently bubble around the bits of plant material, agitating the mixture on a microscopic level.

Traditional infusion in alcohol takes days or weeks, and extracts a broader spectrum of compounds from the plant -- not just the more volatile molecules responsible for psychoactive effects and bright, pleasant flavors, but ones that dissolve over time and impart murky flavor and what some call a headachy effect.

"Ten years ago, I had gotten my hands on this ungodly amount of hash. We couldn't smoke it all. So we started putting it into neutral grain spirit, and it dissolved in, but the thing was, we couldn't get as high. So we gave up and forgot about it for a week, and meanwhile it sat in the car in the 120° sun for a week. The next time, we took a couple of drops and it destroyed us."

"What happened? THC [the main active ingredient in cannabis] normally has a carboxyl group that's attached to it. In order for it to fit into the lock-and-key mechanism of our bodies' cannabinoid receptors, you have to break off the carboxyl group. That takes 30 years--or heat."

The carboxyl group starts breaking off as the temperature gets higher, so Jon heats his Dragon as part of the infusing process. Toasting the cannabis before infusing can drive off some of the delicate aromatics, giving it a cooked flavor, and also runs the risk of vaporizing the THC itself. So Jon heats his only to 100°C (212°F), which gives the infusion a delicate flavor and just the strength he wants, no more.

"You can dial in the recipe to know exactly how many grams you're getting per serving."

The effect of the drug should remain steady for about four hours. One to one-and-a-half ounces is what Jon considers a single serving; six ounces is his maximum imaginable dose.

Nitrous Green Dragon

Here's how Jon does it:

• a one-liter whipped-cream whipper
• two nitrous oxide chargers
• a double boiler large enough to accommodate the whipper bottle
• 750 ml mezcal at room temperature (Jon uses Vida or Sombra)
• 3.5 grams (1/8 ounce) of cannabis (Jon uses "indoor high-grade sativa")

1. Roughly break up the cannabis.
2. Put the cannabis and the mezcal in the whipper bottle.
3. Close the canister and charge it with two charges of N₂O according to the instructions.
4. Let it sit for 5 minutes.
5. Vent out the pressurized gas. NOTE: you are venting aerosolized ethanol with THC dissolved in it, as well as laughing gas. Jon says "Probably nobody would want to inhale this."
6. Stir the liquid and let it sit until the gas boils off.
7. Place the sealed canister in a double boiler and let it simmer for an hour.
8. Strain the solids out of the liquid and discard them or dry them for other uses. The liquid is nitrous green dragon.

Jon developed his recipe using mezcal, whose smokiness complements the herbal flavor of the drug. And mezcal has another advantage -- its innate low pH keeps the color of the infusion vivid green, while more alkaline liquors let it become dingier. (See photo: mezcal, gin.) But other bartenders have perfected their own preferred recipes. A New Orleans bartender uses cognac; one in Seattle makes it with gin to which he adds a little green Chartreuse, and creates a heady variation on the Last Word cocktail (equal parts gin, green Chartreuse, maraschino liqueur, and lime juice) called the Last Dragon.

"It's not on the menu. No one is selling it. You can't ask for it. But if you're a regular, an insider, your bartender just might pull out a bottle and offer you a taste."

NOTE: Neither the author nor Popular Science advocate the use of illegal intoxicants.

Temperature affects how much sperm a man makes, so there's been speculation that the freedom offered by a kilt can increase production. Turns out that that at least could be right: a new metastudy says wearing a kilt "likely produces an ideal physiological scrotal environment, which in turn helps maintain normal scrotal temperature, which is known to be beneficial for robust spermatogenesis and good sperm quality."

The study (PDF), published in the Scottish Medical Journal, reviewed the literature on the link between scrotal temperature and reproduction. We know sperm fares better in lower temperatures, and some researchers have suggested that restrictive clothing could negatively affect sperm production. Enter: the kilt, which author Erwin J.O. Kompanje describes thusly: "The Scottish kilt is a male garment that resembles (but is not!) a knee-length, pleated skirt."

The author hypothesizes that, based on past findings about temperature and sperm production, a kilt, specifically one worn in the undergarment-free "regimental" style, would be an ideal environment for sperm production. Kompanje searched through related research, focusing on statistics in Scotland and noting along the way that 70 percent of kilt-wearers choose to go regimental. Kilts (at least in Scotland or other countries where they're more commonly worn) might also be psychologically valuable, increasing feelings of masculinity when worn. Kompanje goes so far as to write that a downturn in Scottish fertility is correlated with the frequency of kilts being worn, although he admits it's still somewhat speculative until a randomized trial happens. Gentlemen, put on your kilts for science.

A newly invented "nanosponge," sheathed in armor made of red blood cells, can safely remove a wide range of toxins from the bloodstream. Scientists at the University of California-San Diego inoculated some mice with their nanosponge, and then gave the animals otherwise lethal doses of a toxin--and the mice survived.

This is especially interesting because a nanosponge can work on entire classes of toxins. Most antidotes or treatments against venom, bioweapons or bacteria are targeted to counteract a specific molecular structure, so they can't be a one-size-fits-all solution; this nanosponge can.

Scientists led by Liangfang Zhang, a nanoengineering professor at UCSD, worked with a class of proteins known as pore-forming toxins, which work just the way they sound: By ripping a hole in a cell membrane. These toxins are found in snake venom, sea anemones, and even bacteria like the dreaded drug-resistant Staph aureus. The proteins come in many different shapes and sizes, but they all work in a similar way.

They designed a nanosponge to soak up any type of pore-forming toxins. It consists of a tiny (85-nanometer) plastic ball wrapped in red blood cell membranes, which basically serve as a decoy and soak up the poison. The plastic ball holds everything together, and keeps the protein away from its real cellular targets. The entire nanosponge is 3,000 times smaller than a full red blood cell. The devices had a half-life of about 40 hours when the team tested them on lab mice, according to a release from UCSD.

They injected mice with 70 times as many toxic proteins as nanosponges, and the sponges still neutralized the poison and caused no visible damage to the animals, the team reports. Next up are clinical trials in animals, to verify that it works safely in a wide range of cases.

The paper is in this week's issue of Nature Nanotechnology.

The design firm Bjarke Ingels Group (BIG), along with a few added team members (Tess, Transsolar, Base, Transitec, and Michel Forgue) have won first place in a competition to design an experimental "urban center" in France called EuropaCity. Located in Île-de-France, the wealthiest and most populous region in France, EuropaCity is intended to be a center of culture and retail, combining all sorts of experimental sustainable technologies.

But as a design--and a pretty spectacular one at that--it's best experienced through images. Click through to the gallery to see and read more about the proposal!

Click to launch the gallery.

Yesterday, an envelope addressed to Senator Roger Wicker, Republican of Mississippi, was found to contain a white granular substance that was identified as ricin. Today, a similar letter addressed to President Obama was found. These envelopes were intercepted off-site--they never got anywhere near their targets--but as a precaution, Capitol Police have shut down mail service until they can figure out what's going on.

In the meantime, let's talk about ricin!

How poisonous is it?
Oh, man. Very. It's dangerous in just about any way it gets into your system, though ingesting (eating) it is about the least dangerous way. Injecting or inhaling requires about a thousand times less ricin to kill a human than ingesting, and that's a very small amount indeed. An average adult needs only 1.78mg of ricin injected or inhaled to die; that's about the size of a few grains of table salt--which ricin resembles visually.

How does it work?
Ricin, a toxic protein, infects cells, blocking their ability to synthesize their own protein. Without cells making protein, key functions in the body shut down; even in survivors, permanent organ damage is often the result of ricin poisoning. It's a highly unpleasant way to be poisoned: within six hours, according to the Center for Disease Control, victims who have ingested ricin will feel gastrointestinal effects like severe vomiting and diarrhea, which can lead to serious dehydration. Then the ricin infects the cells of the vital gastrointestinal organs as they pass through the body, leading to the failure of the kidneys, liver, and pancreas.

Inhalation of ricin has a different effect, since the ricin proteins aren't interacting with the same parts of the body. Instead of gastrointestinal problems, you'll develop a vicious, bloody cough, your lungs will fill with fluid, and eventually you'll lose your ability to breathe, causing death. Injection, too, is different, depending on where you've been injected, but will generally result in vomiting and flu-like symptoms, swelling around the place of injection, and eventually organ failure as your circulatory system passes the protein around the body. Death from inhalation or injection usually occurs about three to five miserable, agonizing days after contact.

Interestingly, there aren't any immediate symptoms, and indeed there can be a significant delay before symptoms show themselves, up to a day or two.

Exposure on the skin is generally not fatal, though it may cause a reaction that can range from irritation to blistering.

That sounds...horrible. Is there an antidote, at least?
Haha. No. The US and UK governments have been working on an antidote for decades--here's a nice article describing the progression of one such antidote--but there isn't one available to the public. The CDC's website states bluntly, "There is no antidote for ricin toxicity." There are some steps you can take if you get to a hospital immediately; for ingestion, a stomach pump can sometimes prevent the ricin from reaching the rest of the gastrointestinal system at its full force. But...that's about it, really.

How does it stack up against other poisons?
Well, that depends on what your aim is. Ricin is much easier to produce than other popular biological weapons like botulinum, sarin, and anthrax, but it is not as potent as any of those, which limits its effectiveness as a weapon. It also is not very long-lived; the protein can age and become inactive fairly quickly compared to, say, anthrax, which can remain dangerous for decades. There were experiments back around World War I attempting to make wide-scale ricin weapons, packaging it into bombs and coating bullets in it, but these proved not particularly effective and also violate the Hague Convention's agreements on war crimes, so the US discarded ricin.

It's much more effective, weapon-wise, as a close-contact, small-target weapon--by injecting, as with Georgi Markov, or by putting small particles into an aerosol spray and blasting a target. It's also not contagious, which limits its effectiveness as a tool of biological warfare. But it's considered highly dangerous partly because it's still outrageously toxic and partly because it takes no great skill to produce.

So it's not hard to make?
Well...no. Like, not at all. It's made from the byproduct of the castor oil manufacturing process. You take the "mash" of the castor oil seeds, which contain around 5-10 percent ricin, and perform a process called chromatography. Chromatography is a blanket term for a set of techniques used to separate mixtures, usually by dissolving in liquid or gas. The US government has done its best to eradicate recipes for ricin from the internet, sort of; a patent was filed back in 1962 for ricin extraction, and the Patent Office took it off the publicly available server in 2004 for safety reasons. That said, the recipe is super easy to find; here at the PopSci offices, I'm blocked from listening to Rdio on my work computer, but I found a recipe to make an outrageously deadly poison in about a minute.

The techniques involved are undergraduate-level chemistry, creating a slurry with the castor bean mash and filtering with water and then a few easily-found substances like hydrochloric acid.

It comes from castor beans?
Ricin is a highly toxic protein that's extracted from the seed of the castor plant, often called a "castor bean" or "castor oil bean," despite not technically being a bean. The castor plant is extremely common; it's used as an ornamental plant throughout the western world, prized for its ability to grow basically anywhere as well as its pretty, spiky leaves and weird spiny fruits. It's also an important crop; the seeds are full of oil, and castor oil is used for lots of legitimate purposes. It's a common laxative, for one thing, and since it's more resistant to high temperatures than other kinds of vegetable oils, it's a nice alternative to petroleum oil in engines.

Wait, but you can eat it? So how is this a poison?
Ah, yes. Castor oil is perfectly safe, according to the FDA and your grandma, but ricin is not castor oil. Castor seeds are still poisonous; this study says that a lethal dose of castor seeds for adults is about four to eight seeds. But the oil itself does not contain ricin; the ricin protein is left behind in the "castor bean mash" after the oil is extracted from the seed. Poisoning from eating the seed itself is rare.

Have there been cases of ricin poisoning in the past?
You mean, beyond the several times it's been featured as a major plot point in Breaking Bad? Sure! The most famous is probably the assassination of Georgi Markov in 1978. Markov was a Bulgarian novelist, playwright, journalist, and dissident, and was murdered by the Bulgarian secret service, with assistance from the KGB, by ricin injection. He was crossing a bridge when he was jabbed in the leg with an umbrella, which delivered a ricin pellet into his bloodstream. He died three days later of ricin poisoning.

There are plenty of incidents of people arrested for attempting (or, more often, succeeding) to make ricin; it's a pretty easy poison to make. In fact, there was even another ricin-in-the-envelope attempt made back in 2003--a person identifying as "Fallen Angel" sent letters filled with ricin to the White House, apparently as a result of some new trucking regulations (seriously). "Fallen Angel" was never found, but the letters were intercepted and did not cause any injury.

How dangerous are these envelopes filled with ricin?
The envelope strategy has more to do with potential ease of getting the poison close to targets than its strength as a delivery system. If you're targeting the President of the United States, it's easier and more anonymous to mail a letter than to try to get close to him with an umbrella modified for ricin-stabbing. But it's not a great way to poison someone with ricin. Assuming the letter actually got into the target's hands, of the three ways ricin can get into a person's system (inhalation, injection, ingestion), only one--inhalation--is really possible, and it's not that likely.

Inhalation as a weapon is best accomplished through a mist, ideally delivered through an aerosol. But that's not possible in a letter full of powder. It's possible that small granules of ricin could be released into the air and inhaled when handling the letter, but it is not an effective way to poison someone. And whoever's sending these letters evidently doesn't know that the government set up an elaborate mail-screening system after the 2001 Anthrax scare.

Scientists at Medical University of South Carolina temporarily blunted cigarette cravings among smokers by magnetically stimulating nerve cells in their brains. The procedure, called transcranial magnetic stimulation, is already approved by the FDA to treat depression, though its efficacy is controversial (it's also been prescribed to stop people from lying and treat adult ADHD.)

In the experiment, researchers randomly assigned 16 smokers to either a 15-minute session of high-frequency transcranial magnetic stimulation (in which coils placed over the forehead send magnetic pulses into the prefrontal cortex), or 15 minutes of sham treatment. The magnetic stimulation isn't painful and doesn't require sedation or anesthesia. The scientists told the volunteers not to smoke for two hours prior to the experiment.

Before the treatment, the researchers showed the smokers both neutral images (such as mountain scenes) and images intended to provoke nicotine cravings (such as a person lightning a cigarette.) Then they asked the volunteers to rate how they felt about statements like "I would do almost anything for a cigarette now" and "I am going to smoke as soon as possible." After the magnetic stimulation, the participants saw similar images and again rated how much they craved a cigarette.

The researchers found that the participants who got the real magnet treatment expressed significantly less desire to smoke at the end of the experiment compared with those who got the fake treatment. In fact, the craving reduction was positively correlated with how nicotine-dependent the volunteer was, meaning that those who smoked the most saw the greatest decrease in cigarette craving after the magnetic stimulation.

The authors of the study note that people trying to quit smoking would need several sessions of transcranial magnetic stimulation per day in order to see longer-lasting reductions in cravings. The paper appears in Biological Psychiatry.

At the GPU Technology Conference 2013 show in San Jose, Audi announced some of its plans for its Cars of the Future, The Register reports. One of the coolest ideas: cars that can predict where traffic will be, so drivers can avoid it.

The amply named Predictive Traffic function would mine traffic records and current reports, including social media, as well as scheduled events like sports games that could bring cars to a standstill. The system, under Audi's plan, could also predict a driver's most likely destination based on their traffic history.

Pretty neat! Along with that, Audi announced a concept for a reworked directions system that would operate in a "human-like" way, giving directions based on landmarks instead of streets. A Smart Parking feature would work similarly to the traffic-predicting system, but do it for parking spots: mapping out available spots and prices for those spots, rather than making you drive around in circles hunting one down.

We don't have too many details yet on exactly how these systems would work, but since Audi did make a self-driving car, hopefully we'll see these projects come to life soon, too.

[The Register]

While cats may feel effects from marijuana-no word on whether Sir Harry Paus actually likes the experience-"kitty pot" does not have a reciprocal effect on humans.

In the late 1960s, some researchers reported catnip gave people a marijuana-like high, but it turned out they had simply mixed up the two plants. As veterinarian Arnold Plotnick of Manhattan Cat Specialists in New York wrote to me in an email, "Think about it… catnip is cheap and legal. If it had a significant effect on people, everyone would be smoking it."

Meanwhile, cats do feel effects from marijuana, but it may be scary for them. "Animals can't understand they're being intoxicated, therefore it can cause considerable anxiety," says Bruce Kornreich, associate director of the Cornell Feline Health Center in upstate New York.

It's not clear why the active chemical in catnip, nepetalactone, doesn't affect humans, Kornreich says. Pot affects cats because like many mammals, including humans and dogs, cats have receptors in their brains for pot's active chemicals, cannabinoids. Cannabinoid receptors make pets susceptible to feeling symptoms when they inhale secondhand smoke or, more commonly, accidentally eat their owners' stashes. (It's actually a bigger problem with dogs, he says, because dogs eat everything.)

Kornreich has seen pets come into veterinary emergency rooms after marijuana exposure. "The pets are presented for anxiety, active heart rate, acting a little unusual," he says. "They may react differently to sound and to being touched" perhaps because, like humans, drugs alter their perception.

Kornreich urges pet owners to take their pets to a vet if this happens, adding that vets are not required by law to report marijuana they run into during their practice. Most veterinarians care more about making pets better, he says. "It's more just focused on the well-being of the patient."

He also strongly discourages purposefully exposing a pet to marijuana. Fido and Kitty can't consent to getting high. "I don't think it's right or fair to make that decision for an animal," he says.

If pot affects cats because they have cannabinoid receptors, does that mean people aren't affected by catnip because they don't have nepetalactone receptors? Scientists aren't sure. "While it seems that this is a reasonable hypothesis to explain why humans don't respond to catnip like cats do, I cannot find any studies that rigorously test it," Kornreich says. While many brain receptors are common across different animals, many receptors also differ, so it wouldn't be unprecedented for humans to lack a receptor present in cat brains.

In cats, inhaled nepetalactone stimulates the olfactory bulb, the part of the brain that processes odors. The olfactory bulb then interacts with the amygdala, the brain region associated with emotion and decision-making, and hypothalamus, which controls a variety of bodily functions. From the hypothalamus, nepetalactone stimulates a sexual response in cats that are genetically predisposed to sensitivity to catnip. (About 20 to 30 percent of cats don't seem to react to the plant.)

Some insects seem to react to nepetalactone, too. Strangely enough, chemical companies are studying nepetalactone because it seems to repel mosquitoes, ticks and mites, like a kind of natural DEET. For the insects to change their behavior around nepetalactone, even if negatively, suggests that they have nepetalactone receptors.

As for smoking catnip: not only does it fail to get people high, it can make them feel pretty awful. Too much catnip, whether smoked or drunk as a tea, could cause headaches and vomiting.

Have a burning science question you'd like to see answered in our FYI section? Email it to fyi@popsci.com.

Like the best of statesmen, bone is both strong and a little bit flexible. That's because it combines a soft, gel-like substance (collagen) with a stiff, strong one (mineral hydroxyapatite). Now, one team of engineers say they've figured out that balancing act in detail, elucidating how the molecular structure of bone fibers help them take advantage of the best of both worlds.

Fibers of collagen, strengthened with hydroxyapatite crystals, are the basic building blocks of bone. They're found in many different animal species, and they show up in skeleton bone, teeth and antlers.

Using a supercomputer, engineers from MIT calculated what those fibers look like at a nearly atomic level. They compared their fibers with data from previous studies of real bone, to check their computer-generated model was accurate. Then they carried out tests on their virtual fibers with different levels of collagen versus mineral, to see how they respond to stress and strain.

Among the discoveries they made was that the hydroxyapatite in bone fibers likely forms tiny platelets just a few nanometers thick. Large pieces of hydroxyapatite are brittle, like chalk, but at such small sizes, the mineral is actually ductile. The researchers also found that under stress tests, the mineral parts of the fibers took on four times as much stress as the collagen portions, whereas bending happened almost exclusively in the collagen.

Such computer-based experiments would have been impossible even just a few years ago, the MIT group's lead scientist, Mark Buehler, told MIT News. Modeling the molecular structure of bone fibers would have taken years on a supercomputer. For this study, the calculations took a few months.

Buehler now hopes to replicate bone fibers in lab, for different engineering projects, he said. He and his team published their supercomputer work yesterday, in the journal Nature Communications.

You know you share genes with your biological parents and kids, but what about microbes? A new study finds that families share skin, tongue and gut microbes with each other... and their dogs.

The study shows how the people and pets you live with affect the microscopic bacteria, fungi and other creatures living all over your body.

Researchers from universities across the U.S. studied 17 families with heterosexual parents and children ranging from infants to 18-year-olds; 17 families with one or more dogs, but no children; 18 families with kids and dogs; and 18 couples with no children or dogs. Volunteers sent in Q-tip-like swabs that they had rubbed on their foreheads, the palms of their hands, the tops of their tongues and a smudge of their feces (really). Study volunteers also sent in swabs of their dogs' paws, fur and tongues.

The researchers ran genetic analyses on the samples, looking for the genetic material of microbes. They found that family members had more similar microbes on all parts of their bodies than people from different families. Family members' skin microbes were the most alike, demonstrating that people share microbes on the surfaces they touch, and from touching each other. The adults in the family shared the most microbes.

Parents also shared many microbes with their children, but only if the kids were older than three. Younger kids may have vastly different microbes than their older family members because they're still developing, the researchers wrote in a paper they published April 16 in the journal eLIFE.

As for Rover, he seems to have a some interesting effects on his humans' microbes. As with other family members, adults share more microbes with their own dogs than they do with other people's dogs.

But the researchers also found that simply owning a dog seems to have an effect on overall microbe-sharing. Cohabiting couples shared more microbes with one another if they had a dog, compared with couples that didn't have dogs. Dog owners also had more species in common with other dog owners than they did with puppy-less people.

Want to know about the little critters that live on Fido? Dogs have more diverse microbes living on their bodies than humans do, including groups of microbes normally associated with humans, plus microbes that live in soil and water. One of the major groups of bacteria that dog owners and their pets share is Betaproteobacteria, which appear on human skin and on dog tongues.

When China completes its newest telescope project in 2016, the Five-hundred-meter Aperture Spherical radio Telescope (FAST), it will have a dish nearly half the size of a country (OK, only the world's smallest country, Vatican City, but still). With FAST, scientists will be better equipped to study the universe and its mysteries, but other telescopes help research study the cosmos too, regardless of their size. Bigger isn't always better-here are six other telescopes making astronomy better in ingenious ways.

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