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Courtesy of Oliver Lucanus

The Fierce Rapids of the Congo River Create New Fish Species

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Courtesy of Oliver Lucanus

Scientists say the turbulent waters of the lower Congo River divided one fish family so thoroughly that it split into several different species. The researchers published their findings in the journal Molecular Ecology.

One 200-mile stretch of the river has a peculiar claim to fame—it’s become a sort of evolutionary playground, boasting more than 300 different species of fish alone. “In this very short section of the Congo, we find a tremendous diversity of fishes,” co-author Melanie Stiassny of the American Museum of Natural History said in a statement.

At a mere 3 to 5 million years old, Stiassny said, this segment of the river is still relatively young. “So what is it about this system that makes it such a pump for species?”

New species are formed when an existing species is split into two populations, often by some sort of insurmountable physical barrier. Over thousands of years, the different environments and pressures faced by the two populations will be so different that they’ll evolve into two separate species.

But there are currently no major dams in this section of the Congo, nor does the river branch or trickle off into lakes. The fish are all essentially swimming in the same body of water.

Stiassny and her colleagues had a theory: The behavior of the water itself had broken fish families apart. To test their hypothesis, they collected 53 fish, all members of the genus Teleogramma, from different sections of the strange 200-mile stretch. The researchers sequenced the fishes’ DNA and compared their bodies, looking for similarities and differences.

There were plenty of differences. Within those 53 fish the researchers had representatives of all five Teleogramma species [PDF]. But some of those species were practically living on top of one another—sometimes less than a mile apart. But there was always something between them: roiling river rapids.

Alter et al. 2017. Molecular Genetics.

Lead author Elizabeth Alter, of CUNY York College and AMNH, said the rapids are working the same way a wall or a mountain might, keeping the fish populations separate. “What's particularly unique about the lower Congo is that this diversification is happening over extremely small spatial scales,” she said in the statement. “There is no other river like it.”

The fish may be facing even greater barriers in the near future, as the region has been proposed as the site of a new dam—a situation that Stiassny says would "majorly disrupt" this extraordinary ecosystem.

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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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Nick Briggs/Comic Relief
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What Happened to Jamie and Aurelia From Love Actually?
May 26, 2017
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Nick Briggs/Comic Relief

Fans of the romantic-comedy Love Actually recently got a bonus reunion in the form of Red Nose Day Actually, a short charity special that gave audiences a peek at where their favorite characters ended up almost 15 years later.

One of the most improbable pairings from the original film was between Jamie (Colin Firth) and Aurelia (Lúcia Moniz), who fell in love despite almost no shared vocabulary. Jamie is English, and Aurelia is Portuguese, and they know just enough of each other’s native tongues for Jamie to propose and Aurelia to accept.

A decade and a half on, they have both improved their knowledge of each other’s languages—if not perfectly, in Jamie’s case. But apparently, their love is much stronger than his grasp on Portuguese grammar, because they’ve got three bilingual kids and another on the way. (And still enjoy having important romantic moments in the car.)

In 2015, Love Actually script editor Emma Freud revealed via Twitter what happened between Karen and Harry (Emma Thompson and Alan Rickman, who passed away last year). Most of the other couples get happy endings in the short—even if Hugh Grant's character hasn't gotten any better at dancing.

[h/t TV Guide]

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