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Fist Bumps Could be Good for Our Health

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It all started in the 1970s (we think), when NBA Baltimore Bullets guard Fred Carter balled up his fist and bumped it against a teammate's closed fist. Or maybe it was the Wonder Twins, who kissed fists and shouted “Wonder Twin powers, activate!” Soon, athletes and bros alike adopted the fist bump as the preferred greeting. In 2008, it received new prominence when Barack Obama and his wife fist-bumped as he accepted the Democratic presidential nomination. The Washington Post called it “the fist bump heard ’round the world.”

No matter the origin, fist bumps might actually be good for our health. A recent study finds that bumping fists rather than shaking hands in hospitals reduces the spread of bacteria.

Researchers, led by plastic surgeon Tom McClellan, asked people who had washed hands to either shake hands or bump fists. After the contact, the researchers took swabs of the subjects’ hands and cultured the samples to see how much bacteria were thriving on the hands. After 20 handshakes, people had more bacteria populating their hands than those who fist-bumped 20 times. A shake exposed three times as much skin as a bump and lasted 2.7 times longer.

“[Bumping] may lead to decreased transmission of bacteria and improved health and safety of patients and healthcare workers alike," McClellan and his colleagues wrote in their paper in the Journal of Hospital Infection.

People spread germs via handshake because they fail to clean their hands properly. According to a study in The Journal of Environmental Health, only 5 percent of people wash their hands for 15 seconds or longer. But 15 seconds is not enough—the Centers for Disease Control and Prevention recommends that people wash their hands for 20 seconds to reduce the spread of illness. This improper handwashing means that 80 percent of people carry germs on their hands. When one improperly cleaned hand grasps another in a welcoming handshake, the two swap germs that can cause everything from a cold to MRSA to pneumonia to E. coli. While McClellan’s study focused solely on bacteria, he plans on investigating how fist bumps can impact the spread of viruses.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
May 21, 2017
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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May 23, 2017
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