Learn about how quitting smoking may reawaken healthy cells; how researchers figured out how to tell the age of crime scene fingerprints to help investigators; and why you sometimes yawn while exercising or singing.
Learn about how quitting smoking may reawaken healthy cells; how researchers figured out how to tell the age of crime scene fingerprints to help investigators; and why you sometimes yawn while exercising or singing.
Quitting smoking doesn’t just slow lung damage, but can also reawaken undamaged cells by Grant Currin
It's been impossible to tell the age of crime scene fingerprints — until now by Grant Currin
Why we yawn during exercise by Ashley Hamer (Listener question from Kate in Pennsylvania)
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/quitting-smoking-may-reawaken-healthy-cells-why-you-yawn-during-exercise-and-telling-the-age-of-crime-scene-fingerprints
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about how quitting smoking may reawaken healthy cells; and how researchers figured out how to tell the age of crime scene fingerprints to help investigators. We’ll also answer a listener question about how normal it is to yawn when you’re exercising or singing.
CODY: Let’s satisfy some curiosity.
If you or someone you know has been thinking about quitting smoking, then I’ve got some good news. An international team of researchers has discovered something surprising about the lungs of people who’ve stopped smoking. It turns out they can partially regenerate themselves, thanks to certain lung cells that are somehow protected from the cancer-causing chemicals in tobacco smoke. This means that quitting smoking doesn’t just slow the accumulation of further damage — it can calso reawaken cells that have not been damaged!
Here’s the science behind this pretty compelling reason to quit cigarettes for good. There are more than 60 chemicals in tobacco smoke that cause the DNA in lung cells to mutate. We’re talking somewhere between one thousand and ten thousand mutations per cell. Some of those mutations cause cells to grow uncontrollably, and that’s what causes lung cancer. Experts used to think these mutations lasted forever, but there’s new evidence that your lungs protect a few healthy cells that can replace cells with mutated DNA — even if you smoked a pack a day for decades.
In the new study, researchers compared DNA from the lung cells of 16 people, which included current smokers, former smokers, and people who had never smoked. DNA from the former smokers contained a surprise: their lungs had recovered way more than the scientists had expected. Up to 50 percent of their lung cells looked like they’d come from people who’d never had a cigarette.
The researchers weren’t able to watch the process for themselves to see exactly how the DNA recovered. But it looks like a few healthy cells somehow avoid damage from tobacco smoke. One of the researchers said it was like they were in a nuclear bunker. When someone quits smoking, those cells apparently come out of hiding and start to grow, divide, and replace mutated cells.
One of the researchers involved in the study told the BBC, quote, “patients who had quit, even after 40 years of smoking, had regeneration of cells that were totally unscathed by the exposure to tobacco,” end quote.
This is some of the first work on this phenomenon, but these surprising results will probably inspire a wave of studies into how lungs protect themselves from DNA mutation and cancer. And maybe they’ll inspire a few smokers who needed one more reason to quit.
Researchers have found a new, far more accurate way to determine the age of a fingerprint. And this is kind of important, because up until now, it’s been impossible to tell the age of crime scene fingerprints. These new findings could help investigators put the right bad guys behind bars! So put on a funny hat and grab your magnifying glass. It’s time to go sleuthing.
When we think of what makes fingerprints unique, we usually think about their physical pattern: those arches, loops, and whorls that are distinct from person to person. But in the last decade, researchers have turned their attention to a fingerprint’s chemistry. Studies have already shown that fingerprints contain chemical signatures that offer clues about a person’s sex, ethnicity, and certain aspects of their lifestyle. And now, researchers are figuring out how those chemicals change over time.
To be fair, we weren’t completely in the dark when it comes to age; forensic scientists have known for a while how to use chemistry to tell whether a fingerprint was more than eight days old. But while that’s helpful information, it’s not exactly super precise. This new finding hinges on how the environment interacts with the oils that a fingerprint leaves behind. Specifically, the researchers studied evidence of chemical reactions between ozone in the air and lipids called unsaturated triacylglycerols [try-ASS-sull-GLISS-er-ols]. The researchers used a method of chemical analysis called mass spectrometry imaging to track how levels of the triacylglycerols changed over time. What they found was surprising.
It wasn’t that hard to figure out how quickly triacylglycerols reacted with ozone and degraded into other compounds, but it turned out that the rate was different from person to person. This was a small exploratory study, so the researchers only used fingerprints from 3 volunteers. Two of those volunteers’ fingerprints degraded at about the same rate, but the third volunteer’s fingerprints degraded more slowly. They aren’t exactly sure why, but it looks like the third person had higher levels of lipids in their fingerprints. This suggests that in addition to having a unique fingerprint pattern, people might also have distinctive triacylglycerol signatures.
That means investigators using field tests based on this research will probably have to know who left a fingerprint if they want to figure out how old it is. But soon, suspects won’t be able to lie and say they visited a victim weeks before the murder — thanks to this research, investigators will already know when they were there. They just have to analyze their fingerprints.
CODY: Today’s episode is sponsored by Purple Mattress. Here’s a question – how did you sleep last night?
ASHLEY: You can sleep easy knowing that we’re getting better at crime scene analysis so we can track down criminals. But even with one more reason to sleep easy, you could end up tossing and turning all night if your bed isn’t comfortable. And if you’re struggling to get a good night’s sleep, then you’ve gotta try a Purple Mattress.
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CODY: The ONLY way to get this free pillow, is to text CURIOUS to 84-888. That’s C-U-R-I-O-U-S to 8-4-8-8-8. Message and data rates may apply.
We got a listener question from Kate in Pennsylvania, who writes, “I always yawn while trying to sing and while exercising. I was wondering if this is common and, if so, why does it happen?” Great question, Kate!
The short answer is yes, your issue is fairly common. I personally yawn ALL THE TIME when I’m at the gym, regardless of the hour. And if you ask my singer friends, yawning while singing is also a known issue. But why does it happen? Let’s dig into the science.
The most common belief about why we yawn is that it boosts our supply of oxygen. That makes intuitive sense, since when you yawn you take in a big gulp of air, and even seems to explain why yawning is contagious: if there’s a drop in oxygen, yawning signals that to the people around you so that they can yawn too. Except...that’s been entirely debunked. For a study back in 1987, scientists had people breathe air with different mixtures of oxygen and carbon dioxide. None of the air mixtures had any effect on the participants’ yawning. The researchers concluded that breathing and yawning must be controlled by separate mechanisms.
The strongest theory for why we yawn, if you ask scientists? This is gonna sound weird, but it’s to cool your brain. Here’s the logic: yawning consists of two basic components. First, you open your mouth, which stretches the jaw muscles and boosts blood flow to the area — which is, y’know, part of your head. You also take a deep breath, and when all that cool air hits your tissues it cools the blood flowing through them, and that cool blood travels to your brain and turns down the temperature. I know what you’re thinking: I yawn when I’m tired, or when I wake up in the morning, or when I’m bored, not when my brain is hot! Well, all of those things are linked to an increase in brain temperature. Physical stressors like exercise boost your core temperature, which also heats your brain. Yawning helps bring your brain temperature back to baseline. But only if the ambient temperature is right: you actually yawn less when it’s very hot and very cold.
As far as singing? The science is less clear on that, but it could be a few things. You might just be working really hard and raising your core temperature. There’s also the fact that a good throat position for singing is super similar to the beginning of a yawn — in fact, that’s how many teachers will instruct their students to sing. That starting-yawn position might just be going over the edge into a full-blown yawn. Thanks for your question, Kate! If you have a question, send it in to podcast at curiosity dot com or leave a voicemail at 312-596-5208.
CODY: Before we recap what we learned today, here’s a sneak peek at what you’ll hear next week on Curiosity Daily.
ASHLEY: Next week, you’ll learn about how to tap into your friends to help you exercise better self control;
Why a rising robot workforce could make humans less prejudiced;
How to beat procrastination not by managing your time, but by managing your emotions;
What researchers learned in the largest-ever study of cancer genomes;
And more!
CODY: You’ll also hear the first part of our series of interviews with author David Owen, who’ll tell us about how your sense of hearing works — and why it’s so important to protect. Okay, so now, let’s recap what we learned today.
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CODY: Today’s stories were written by Ashley Hamer and Grant Currin, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Special thanks to Sarah, Danielle, and Hai-Ting for their singing help. Today’s episode was produced and edited by Cody Gough.
CODY: Have a great weekend, and join us again Monday to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!