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7 More Zombie Animals

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Last week's post Invasion of the Zombie Animals proved to be "interesting" for many, even those who were grossed out. Further research has yielded even more interesting parasites that take over and change the body, mind, and life of their victims.

1. A Big Red Butt

A parasitic nematode named Myrmeconema neotropicum targets the gliding ant Cephalotes atratus in the Central and South America rain forests on its way to infecting birds. The nematodes travel to the ant's abdomen, and as they mature, cause the abdomen to grow round and bright red! The ants will hold their abdomens, or gasters, high as if to draw attention -which they do. The red gasters look like berries and are eaten by birds who normally don't eat insects. The nematodes then live in the bird's digestive tract.

2. A New Web Design

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Hymenoepimecis argyraphaga is a parasitic wasp found in Costa Rica. It infects one particular spider species, Plesiometa argyra. An adult wasp lays an egg on the spider's abdomen. When it hatches, it attaches itself to the spider and sucks its blood. When the right time comes, it releases a chemical into the spider that causes it to spin a web unlike any it would naturally spin. This web is designed to protect the wasp instead of feeding the spider. When the web is ready, the wasp larvae will kill the spider, eat it, and set up a cocoon in the safety of the web the spider built under the wasp larva's control.

3. Back to the Cat

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Toxoplasma gondii is a protozoa that is normally parasitic to cats, but can survive in other species of mammals or birds, including humans. It causes the disease Toxoplasmosis, which is usually mild or even asymptomatic in humans, but can be dangerous for a fetus or those with compromised immune systems. Toxoplasma gondii affects the behavior of rats in a curious way -it makes them less afraid of, and even friendly to cats! Therefore, a rat with the infection is more likely to be eaten by a cat, which is the preferred victim as T. gondii reproduce inside cats. Does the parasite change human behavior, too?

Some scientists believe that Toxoplasma changes the personality of its human hosts, bringing different shifts to men and women. Parasitologist Jaroslav Flegr of Charles University in Prague administered psychological questionnaires to people infected with Toxoplasma and controls. Those infected, he found, show a small, but statistically significant, tendency to be more self-reproaching and insecure. Paradoxically, infected women, on average, tend to be more outgoing and warmhearted than controls, while infected men tend to be more jealous and suspicious.

How this benefits the parasite is anyone's guess, but it may be chemically linked to the way T. gondii has evolved to get from the rat to the cat.

4. Fire Ant Foe

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The phorid fly (Phoridae) is also called a humpback fly due to its appearance, a scuttling fly due to its tendency to run instead of fly when disturbed, or a decapitating fly due to its habit of feeding on the brains of fire ants. Some species of phorid fly attack and then lay eggs in the body of a fire ant. The eggs hatch, and the larva make its way to the ant's head where it eats it from the inside out. The ant does not immediately die, but will walk around with no direction or purpose once its brains are gone. When the larva matures, it causes the ant's head to fall off so it can emerge as an adult fly.

Fire ants are an invasive non-native species in the US, and phorid flies have been introduced in the south as a method of controlling the fire ant population, most recently in Texas. Phorid flies have been in use in Alabama for fire ant control since 1998. Other species of phorid fly are called coffin flies. They lay eggs in human remains and can survive several generations inside a sealed coffin. Forensic pathologists study phorid fly infestations to determine how long a body has been dead.

5. A Fungus Among Us

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Cordyceps unilateralis infects ants for travel purposes in order to spread its spores. Oh, it eats them, too, but first the fungus will enter the brain and alter the ant's behavior over several days, making it climb to the top of a blade of grass. The ant will bite the grass for a secure hold. Only then will the fungus kill the ant and explode out of the head. The spores are then borne on the wind to parts unknown. See a video of Cordyceps in action.

6. Shrimp and Duck for Dinner

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Thorny-headed worms (Acanthocephala) are 1150 species of parasite with hooks on their probosces (they don't have real mouths). They use these hooks to latch onto a victim. A couple of species target the crustacean Gammarus lacustris, or blue shrimp. Once inside, the worm changes the shrimp's chemistry, possibly affecting serotonin levels. The shrimp loses interest in mating and swims dangerously close to the surface. It will bite onto and cling to plants at the water's surface, which makes it easy prey for hungry ducks. When a ducks eats the shrimp, the thorny-headed worm has found its home. It lays its eggs inside the duck, completing its life cycle.

7. Take Me To The Liver

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Dicroelium dentriticum or Lancet Liver Fluke work in much the same way the thorny-headed worm does, only on different animals. The fluke infects three species in order, snails, ants, and sheep or cattle during its life cycle, but it only controls the behavior of the ant. One the fluke has settled in the ant's nervous system, the ant will go about its regular duties during the heat of the day, but crawl up to the top of a blade of grass in the cool mornings and evenings when it is most likely to be eaten by a sheep or cow. It will then spend its adult life inside the animal's liver.

Special thanks to Carl Zimmer for help on this post.

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iStock // Ekaterina Minaeva
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Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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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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iStock
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Here's How to Change Your Name on Facebook
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iStock

Whether you want to change your legal name, adopt a new nickname, or simply reinvent your online persona, it's helpful to know the process of resetting your name on Facebook. The social media site isn't a fan of fake accounts, and as a result changing your name is a little more complicated than updating your profile picture or relationship status. Luckily, Daily Dot laid out the steps.

Start by going to the blue bar at the top of the page in desktop view and clicking the down arrow to the far right. From here, go to Settings. This should take you to the General Account Settings page. Find your name as it appears on your profile and click the Edit link to the right of it. Now, you can input your preferred first and last name, and if you’d like, your middle name.

The steps are similar in Facebook mobile. To find Settings, tap the More option in the bottom right corner. Go to Account Settings, then General, then hit your name to change it.

Whatever you type should adhere to Facebook's guidelines, which prohibit symbols, numbers, unusual capitalization, and honorifics like Mr., Ms., and Dr. Before landing on a name, make sure you’re ready to commit to it: Facebook won’t let you update it again for 60 days. If you aren’t happy with these restrictions, adding a secondary name or a name pronunciation might better suit your needs. You can do this by going to the Details About You heading under the About page of your profile.

[h/t Daily Dot]

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