Any credit card can offer cash back, but only discover matches all the cash back. You’Ve earned at the end of your first year, it’s like getting one of those birthday cards. That’S shaped like cash, so you already know there’s cash inside before opening it, but in this case it’s stuffed with your first year. Cash back match and you don’t even have to send a thank you note. Cash back match only by discover card learn more at match, discover something brighter hi you’re about to get smarter in just a few minutes, with curiosity daily from i’m cody gough and i’m ashley hamer. Today you learn about how a fever helps you get better. What frogs have to do with the history of pregnancy tests and a potential breakthrough in the shockingly complicated traveling salesperson problem let’s satisfy some curiosity. You probably know that getting a fever is your body’s way of fighting off illness, but here’s, something surprising it wasn’t until recently that scientists understood how fevers actually help you get better, so here’s the story of how that happened. The part that was best understood was how fevers start when a virus or bacterium invades your cells, immune cells, called macrophages, gobble up the invaders and send out proteins called cytokines to alert the rest of your body that you’re under attack one place. That alert goes is to the hypothalamus that’s, a part of your brain that controls body temperature. Among other things, the hypothalamus is the one that stokes the fires of fever, but why well for a long time, people assumed that higher temperature made it harder for bacteria and viruses to survive that’s, what i thought, but that turns out to be a small part of Fever’S power, another soldier in the fight against infection is the lymphocyte or white blood cell versions of this cell called t lymphocytes receive pieces of the invader proteins from the macrophages and use them to target and destroy the infection they move to where they’re needed.

With the help of molecules called integrins, which help them stick to blood vessels, they use to travel to the infection, they’re basically hitching a ride. Well, it turns out that both infection fighting t lymphocytes and the integrins that help them get where they’re going do much better. In toasty temperatures, a 2011 study found that virus infected mice that had their body temperature raised produced more of a certain type of t, lymphocyte that infected mice that stayed at normal temperature and a 2019 study found that fever boosts a protein that helps more integrins cluster. On the surface of the lymphocyte, which helps it move more efficiently and interestingly, this protein only kicked in at a temperature of 101.3 degrees, fahrenheit or 38.5 degrees celsius. The kind of temperature that would probably leave you bedridden for the day just goes to show how helpful a fever really is. Now, if your fever is high, you should consult a doctor who may tell you to take something to reduce it, but if not maybe write it out just know: there’s a war going on inside you and do what you can to help the good guys win today. Pregnancy tests are simple and reliable devices you can buy from your local drug store, but it hasn’t always been that way. Modern pregnancy tests only became widely available in the 1960s, but they were definitely an upgrade from the frogs we used before yeah. You heard me right. The first widely available pregnancy test was a frog.

In 1930, a british scientist was performing the scientific equivalent of throwing things against the wall to see what sticks, in his case, messing with the frog’s various glands and hormones to learn what he could about human hormones. The scientist’s name was lancelot hogben, which i’m sure is a name cody’s, definitely gon na steal. For his next d campaign level, four paladin got it. Hogman was a zoologist who had just returned from south africa, which explains why this particular study amphibian, was xenopus aka. The african clawed frog back in the uk. He was able to continue his work with his favorite study species. Anyway, our story really begins the day he decided to inject hormones from an ox’s pituitary gland into one of his frogs when he did this. Something strange happened. The frog laid eggs – in fact this happened every time he did. It. Hogman knew that the pituitary gland is involved in regulating pregnancy in humans, that’s thanks to a hormone it produces called human chorionic, gonadotropin or hcg. He wondered if this pregnancy hormone was what made the frog lay eggs. So he injected the frog with urine from a pregnant woman and sure enough. The frog laid eggs that changed everything from the 1930s until the invention of the modern pregnancy test, a woman who suspected that she might be pregnant, would go to a doctor and provide a urine sample that urine would be injected into the skin of an african clawed Frog and reliable results would arrive that day.

These so called frog tests became an industry standard worldwide. The test seems barbaric by today’s standards, but as far as animal based pregnancy testing goes, it was pretty safe. Other pregnancy tests that used animals always required killing them. So the fact that the frogs could be injected many times without causing any obvious harm was a huge step up eventually simpler animal free tests for hcg and urine became standard, and in the 1970s the first home pregnancy tests hit drugstore shelves by then the frog test Had croaked but it’s still pretty unforgettable. Well, they were totally important to the history of pregnancy. Tests like toad, like t o a d like that and like that, like yeah, yeah, cool, good, good talk, Laughter, wow you really committed to that one. We really need to go on yeah today’s episode is sponsored by linkedin. The new year marks a fresh start for your small business, whether you’re shifting hours or hiring more remote employees. One thing that remains unchanged is the importance of having the right people on your team. When your business is ready to make that next hire, linkedin jobs can help by matching your role with qualified candidates. So you can find the right person quickly and to lend a helping hand. Your first job post is free i’ve, been on both sides of the hiring process, and i know that, usually you either get too few applicants or way too many. So what i love about, linkedin jobs, is that you can post a job with targeted screening questions so that you can get the right candidates and linkedin will quickly get your role in front of more qualified candidates from their active community of professionals, with more than 722 Million members worldwide, plus, you can manage job posts and contact candidates from a single view on the familiar linkedin.

com, with functions streamlined onto one simple screen, and now you can do it all from your mobile device, when your business is ready to make that next hire find The right person with linkedin jobs, and now you can post a job for free, just visit, curiositydaily, again that’s, curiositydaily to post a job for free terms and conditions apply. Computer scientists may have made a breakthrough in a math problem. That’S been unsolved for nearly 200 years i’m talking about the traveling salesman problem, also known as the traveling salesperson problem and it’s a lot more complex than you might think. We explained the problem on an episode of curiosity daily in 2019, so here’s a quick refresher in case you missed it. If you’ve ever been on a cross country, road trip, the traveling salesman problem should feel familiar. If you have a given number of cities what’s the most efficient route, you can take to visit each city and land back where you started. It may sound like an easy problem to solve, especially if you have a computer, just check the distance of every round trip route possible and the shortest one is your answer right, but think about it. If you’re only dealing with, say five cities, that’s 12 round trips, to check once you add more cities, those round trips skyrocket, a trip between 10 cities has more than 180 000 routes. A trip between 15 cities has more than 43 billion with enough cities.

The number of routes to check could easily overwork the most powerful computers that way of solving the problem is known as the naive solution. For perhaps obvious reasons. In the 1970s mathematician richard carp published a paper calling the problem np hard, which means there will never be an algorithm to solve it. A few algorithms have been developed or proposed to figure out which routes are more efficient than others, but not to solve. For the single most efficient one, this nearly two century old problem still has plenty of mystery for experts to uncover just another example of a deceptively difficult problem. Okay, so the leading computer algorithm to solve this problem was developed in 1976 by mathematician nicos christofides. His algorithm won’t necessarily find the best trip, but it can find round strips that are at most fifty percent longer than the best rounds trip. So a lot of computer scientists agreed that nobody would ever be able to find a better algorithm, and that was true for 44 years. But just last year a graduate student and two advisors at the university of washington proposed an algorithm that they say can do a little bit better and i mean a little bit. Their proposed solution beats christopher diese’s, 50 factor by 0.2 billionth of a trillionth of a trillionth of a percent that might seem insignificant, especially since it took them two years to finalize the 80 page paper. That explains their findings, but experts say this is still a huge deal because it tests the limits of efficient computation.

We don’t have time to dig deep into the actual math involved, but you can find a link in today’s show notes to a great write up in quanta magazine with all the details, and we should note that quanta reports, the paper itself, is yet to be peer. Reviewed, but that quote, experts are confident that it’s, correct, unquote, really. The big takeaway here is that sometimes research moves forward in baby steps, but even the tiniest finding can make a world of difference all right. Well, let’s recap what we learned today, starting with the fact that a fever helps you get better, not just because bacteria and viruses don’t thrive that well at high temperatures, but also high temperatures help your white blood cells travel to the spots that they’re needed, where they Can fight the infection just remember to talk to your doctor if your fever is high, because you don’t want to let that last, if it’s harmful, it’s definitely possible to have too much of a good thing. And if your fever is really raging, you could always get a prescription for more cowbell. That is that’s dated very dated that we’re gon na say a very dated reference that’s fine. We also learned that the first reliable and widely available pregnancy test was literally a frog. The african clawed frog would lay eggs if injected with a hormone called human chorionic gonadotropin, imagine walking into a drugstore and having to buy that over the counter.

You know because they did the same thing at the time with rabbits, but like we mentioned, they actually had to kill the rabbit and look at its ovaries to see if they were enlarged to know if the urine was from a pregnant woman, but at the time That’S why people would say we killed the rabbit as a way to say i’m pregnant, whoa, yeah every so often you’ll hear that these days, but it’s it’s, not very common yeah, and this is just a continuation of a long standing tradition of women peeing on things To figure out whether they’re pregnant i mean really, the earliest documented folk pregnancy test came from the ancient egyptians who would just urinate on barley and see if it sprouts, but in this case hcg makes it so barley, doesn’t sprout. And so, if the barley didn’t sprout, then you were pregnant and an experiment in the 1940s actually found that that works 70 of the time, so pretty good odds. Ah, we also learned that the traveling salesperson problem asks you to calculate the shortest round trip route between a list of cities when you’re, given the distances between each pair of cities, and it took 44 years before researchers found a way to improve on it. That was only by 0.2 billionth of a trillionth of a trillionth of a percent, but hey rome, wasn’t built in a day right. So like baby steps to this story is written by ashley, hamer cameron duke and cody goth that’s me and edited by ashley hammer who’s.

The managing editor for curiosity, daily script – writing was by cody goff and sonia hodgin. Today’S episode was produced and edited by cody gough plan. Your next road trip.