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We may have found the secret ingredient to effortless 8 pack abs... In Flies and Mice. Also, a team of scientists have developed robots, made of living cells.

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Living robots:

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Exercise is an important part of staying healthy, but I'm sick of it.  What if we could get the benefits of working out without actually having to work out?  It's 2020.  Well, in a new study in Nature Communications, researcchers report a type of protein that seems to confer the healthy effects of exercise.  To be more specific, having higher levels of this protein improved things like muscle tone and endurance in flies and in mice, but the research does have important implications for human health.  It could help us better understand the exact physiological changes that exercise causes in our bodies and that knowledge could help doctors care for a lot of people.  

Just to be clear, these researchers were not trying to get me out of going to the gym.  They were searching for ways to help people stay healthy when they can't exercise, say, due to the effects of age or illness or injury.  That work led them to study a group of proteins called sestrins.  Previous research has shown that sestrins build up in muscles following exercise but it wasn't clear why or what they actually do, so the international research team designed a workout routine for fruit flies. 

They put the flies in vials and then by shifting the position of those vials, the team encouraged the flies to repeatedly climb up the sides, basically a fly treadmill.  They also used a similar technique to induce flies to fly across the vial, and some of these flies were engineered to lack sestrins.  Over weeks of exercise, the normal flies experienced several health benefits, including a faster metabolism and increased endurance.  The flies without sestrins saw no such improvements, so the researchers tried essentially the same thing with mice and it was the same story.  The mice engineered to lack sestrins didn't gain the usual benefits of a workout regimen.  Instead, they got winded when they ran on their little wheels.  

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All that made it pretty clear that sestrins were required for the benefits of exercise.  The researchers tried dialing up sestrin levels instead of lowering them, and flies engineered to overproduce sestrins not only had stronger muscles and more endurance, they got buff without doing their workouts.  The researchers suspect that sestrins are responsible for coordinating the cellular pathways that underlie the health and that might mean they can be used to help people stay toned while they can't exercise.  

For example, in a related study published this week in Nature Communications, researchers found that the muscles of mice engineered to overexpress sestrins didn't weaken and atrophy when kept from moving, so it's possible that in the future, sestrins could help people who are bedridden keep their muscles healthy, but if you're hoping to go to the store and buy some sestrin supplements, we are not anywhere close to that yet. 

None of the study animals were fed sestrins to get these effects.  Instead, the teams tinkered with their genomes to get them to overproduce sestrins where they are normally made, and sestrins are large proteins, so they may not work well as pills.  Your stomach might just chop them up and digest them like any other protein and if they're absorbed, they might not travel to where they're needed.  Besides, scientists have a lot more to learn about these proteins and how they work, especially in humans, since, you know, we are not flies or mice, but with more research, we might someday be able to use the knowledge we gain about sestrins to help people be healthier.

In other news this week, researchers have made a totally new kind of robot, one that is alive.  Seriously, as reported in a study in the journal PNAS, researchers designed and built tiny robots out of living cells.  Most machines are, of course, made with artificial materials like metal and plastic.  Those are sturdy and relatively easy to work with, but they're not perfect.  One of their big issues is that they tend to contain substances that damage the environment. 

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Robots made of live tissues might be less sturdy but they could probably do a lot of the things other machines do or even things current machines can't do because they're too big or too toxic, like performing tasks inside an organism.  So a team of researchers from the University of Vermont decided to try building robots out of living cells, but they began first with computer simulations.

They asked a supercomputer to design theoretical robots out of two types of cells: skin cells, because they're tough and relatively sturdy, and heart muscle cells, because they contract.  The computer was given information about what the cells could and couldn't do and based on that, it was told to design robots of a few hundred cells, so less than a millimeter wide that could move in a single direction.  Finally, after hundreds of simulations and refinements, the team compiled the designs that were most likely to work if they actually built them and then they built them.  They took stem cells from embryos of the African clawed frog, or xenopus laevis and with some super small forceps and a tiny electrode, they assembled them to match the designs.  

They decided to call these tiny machines xenobots after the frogs that provided the building materials and for the most part, they worked like the computer simulation said they would.  The living bots were able to explore their environment, interact with each other, and even push tiny objects from place to place.  The researchers are hopeful that with some more development, living robots like these could be designed to perform all sorts of tasks like gathering microplastics from the ocean or scraping plaque from human arteries, and unlike machines made from metal or plastic, they are completely biodegradable.  They're just skin and muscle cells.  When they're done working, if they fail to function, they just decompose.  

They are also self-healing.  When the researchers intentionally cut the robots, the cells stitched themselves back together just like your skin cells do when they're damaged.

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It's very exciting to consider all of the possible applications of living robots, but the researchers are just as excited about how much we'll learn about ourselves in the process.  They think designing and testing these robots will teach us a lot about the ways our own cells communicate and connect, and it just goes to show that amazing things can happen when you combine computer science and physics and biology. 

In fact, that's basically the entire premise behind the field of computational biology and you can learn all about that with  They have an entire course on computational biology which explains how algorithms can help with biological questions, like how a particular string of amino acids folds to make a protein, and that is just one of their courses.  They have dozens of them covering topics in science, computer science, math, and engineering, so you can brush up on classical mechanics and then dive into data structures and each is designed to be hands-on and interactive so you really learn the material and you have fun doing it.  So if you're the kind of person whose New Year's resolution is to learn more about how the world works, you might want to head over to to check out what Brilliant has to offer, and as a special thank you for being a SciShow fan, the first 200 people to sign up at that link will get 20% off an annual premium subscription, which a pretty awesome deal, plus you'll be supporting us here at SciShow, so thanks for that.