CLOSE
Original image
Benoit Guenard

Scientists Decode Bedbug Genome, and It Explains Why They’re So Hard to Kill

Original image
Benoit Guenard

You may remember when “Don’t let the bedbugs bite” was just a cute thing parents said to their children. These days, though, it’s a real—albeit futile—warning. After decades of near eradication, the bedbug is back, and badder than ever. Now scientists say they’ve found clues to the bug’s tenacity buried in its genome and microbiome. The scientists published their findings in the journal Nature Communications.

Bedbugs are living fossils; their outward appearance has hardly changed throughout their long lineage, noted corresponding author George Amato in a press statement. “But despite their static look, we know that they continue to evolve, mostly in ways that make it harder for humans to dissociate with them. This work gives us the genetic basis to explore the bedbug’s basic biology and its adaptation to dense human environments.” 

Trying to understand bedbugs (Cimex lectularius) is more than just an intellectual exercise. As anyone who’s ever dealt with an infestation knows, they’re not just gross—they’re persistent. Clearing a home of bedbugs can be a painfully drawn-out and expensive process, in part because the little pests have developed a resistance to common pesticides.

The roots of that resistance lie in the bedbug’s genome, project co-leader Coby Schal said in a press statement. “The genome sequence shows genes that encode enzymes and other proteins that the bedbug can use to fight insecticides, whether by degrading them or by preventing them from penetrating its body."

And that’s not all they found. In teasing out the bedbug’s genetic code, the researchers saw explanations for many of the pest’s unique traits, like sex shielding. Male bedbugs are notoriously opportunistic about sex. They’ll jab their sharp, penis-like appendages at pretty much anything, including other males. And the sex itself isn’t pretty: The male bedbug stabs the female in the abdomen, then releases his sperm freely into the wound. To ease the sting of what scientists call “traumatic insemination,” female bedbugs have developed a kind of shielded funnel on their undersides. The protein that keeps that shield strong is called resilin, and it has its own code in the bedbug’s genome.

Not all the bedbug’s genes are bedbug genes; some of them came from other organisms, including the parasitic bacterium Wolbachia. "We don't know if the bacterium is co-opting the bedbug or if the bedbug is co-opting the bacterium,” Schal said in the press statement. “Very few of these bacterial genes are functional and we don't know what proteins they are producing. But it would be fascinating if bacterial genes that are useful to the bedbug, such as those involved in B vitamin metabolism, were incorporated into the bedbug genome."

The bug's microbiome had its own insights to offer. Researchers found the genes of more than 400 species of bacteria living on and in the bugs. The scientists theorize that these microbes help keep the bedbugs alive—which means there's a chance that targeted antibiotics to knock out these bacteria could eventually help us knock out the bedbugs, too.

Another finding concerns the bedbugs' ability to take in relatively large amounts of liquid (that is, blood) without exploding. They can balloon up to 200 percent their body size while feeding through a handy diuretic system. "Bedbugs must be able to shed that water while retaining the blood's nutrients," Schal said.

And then there’s the bedbug’s bite. The scientists found proteins that act as both anesthetics and anticoagulants that keep your blood flowing while keeping you from noticing.

Blech.

Original image
iStock // Ekaterina Minaeva
arrow
technology
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
Original image
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!

Original image
iStock
arrow
technology
Why Your iPhone Doesn't Always Show You the 'Decline Call' Button
Original image
iStock

When you get an incoming call to your iPhone, the options that light up your screen aren't always the same. Sometimes you have the option to decline a call, and sometimes you only see a slider that allows you to answer, without an option to send the caller straight to voicemail. Why the difference?

A while back, Business Insider tracked down the answer to this conundrum of modern communication, and the answer turns out to be fairly simple.

If you get a call while your phone is locked, you’ll see the "slide to answer" button. In order to decline the call, you have to double-tap the power button on the top of the phone.

If your phone is unlocked, however, the screen that appears during an incoming call is different. You’ll see the two buttons, "accept" or "decline."

Either way, you get the options to set a reminder to call that person back or to immediately send them a text message. ("Dad, stop calling me at work, it’s 9 a.m.!")

[h/t Business Insider]

SECTIONS
BIG QUESTIONS
arrow
BIG QUESTIONS
WEATHER WATCH
BE THE CHANGE
JOB SECRETS
QUIZZES
WORLD WAR 1
SMART SHOPPING
STONES, BONES, & WRECKS
#TBT
THE PRESIDENTS
WORDS
RETROBITUARIES