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10 Scientific Benefits of Kissing

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Kissing may be the most primal way we express affection with other humans. We kiss babies on their adorable chubby faces, friends on the cheeks, and lovers on the lips in demonstration of our feelings and desire for closeness. Kissing may be one of the earliest evolutionary mechanisms for social bonding. While there are plenty of obvious pleasures of smooching, there are also some remarkable health benefits, backed by science. Check out these 10 benefits of lip smacking:

1. KISSING RELEASES FEEL-GOOD HORMONES …

Kissing activates the brain’s reward system, releasing neurotransmitters like oxytocin, "the love hormone," and vasopressin, which bonds mothers with babies and romantic partners to each other. It also releases endogenous opioids, dopamine, and other helpful neurohormones to keep our moods balanced.

2. … WHICH HAVE HEALING ABILITIES.

A 2005 study in Neuroendocrinology Letters adds, "Thus, love, pleasure, and lust have a stress-reducing and health-promoting potential, since they carry the ability to heal or facilitate beneficial motivation and behavior." In other words, by reducing your stress hormones, your body can better focus on healing any physiological processes that are exacerbated by stress, and help contribute to more positive mental health and behavior.

3. IT MAKES YOU MORE ALERT.

Kissing often stimulates the release of adrenaline and noradrenaline—not only do these make you feel excited by increasing your heart rate, they make you more alert, as your body prepares for action…of any kind.

4. SMOOCH MORE FOR REDUCED STRESS …

According to affection exchange theory, as mentioned in a 2009 study in the Western Journal of Communication [PDF], physical exchanges of affection, including kissing, "buffer the individual against the physiological effects of stress." The researchers found that expressed affection, of which kissing is a prime example, was directly related to lowering the stress hormone cortisol throughout the day.

5. … WHICH MIGHT HAVE A POSITIVE AFFECT ON YOUR CHOLESTEROL.

The same study authors theorize that if affectionate behavior reduces stress, "then it is logical to predict that it will also effect improvements on physiological parameters that are exacerbated by stress" such as cholesterol. Cholesterol has a number of essential physiological functions, they write, "including maintaining membrane fluidity, producing bile, and contributing to the metabolism of fat-soluble vitamins." It’s also "largely responsible" for the production of steroid hormones, such as cortisol, aldosterone, progesterone, the estrogens, and testosterone.

6. KISSING EVEN IMPROVES ALLERGY SYMPTOMS …

Allergic responses can be aggravated by stress. Since kissing reduces stress by sending those feel-good hormones mentioned earlier to the brain, as well as alleviating cortisol, a 2003 Japanese study in Physiology and Behavior explored the relationship between the stress-lowering activity of kissing on allergic reactions. Ninety participants were evenly divided into three groups: 30 with atopic dermatitis, 30 with allergic rhinitis, and 30 in a control group. In the study, the subjects, whom the authors noted "do not kiss habitually," kissed for 30 minutes with their partner in a private room while listening to soft music. They found that at the end of their smooch sessions, the participants experienced significant relief from skin wheals (hives) and plasma neurotrophin levels (a sign of allergic reaction) associated with Japanese cedar pollen and house dust mites. In 2015, this study won an Ig Nobel prize.

7. … AND MIGHT ALSO BOOST YOUR IMMUNITY.

When you kiss someone on the lips you exchange bacteria. This can either make you sick, or it can help boost your immunity by exposing you to new germs that strengthen your immune system's ability to fight these bacteria. A 2014 study in the journal Microbiome found that couples who kissed frequently were more likely to share the same microbiota in their saliva and on the surface of the tongue. How frequently? At least nine times per day.

8. A KISS A DAY KEEPS THE DENTIST AWAY?

The act of kissing stimulates your salivary glands to produce saliva, the fluid that moistens the mouth to make swallowing easier. Saliva also helps remove cavity-causing particles that stick in your teeth after eating. So while it might be a stretch to say kissing prevents cavities, it can’t hurt.

9. IT MAY HELP YOU DETERMINE THE COMPATIBILITY OF YOUR MATE …

Perhaps the way you know you’ve found the one has nothing to do with their eyes, kind words, or the way they romance you, but very subtle cues you pick up through kissing. According to a 2013 study in the Archives of Sexual Behavior, kissing "might facilitate the subconscious appraisal of a potential mate by utilizing pheromonal cues to assess genetic … compatibility, general health, underlying genetic fitness or menstrual cycle phase and fertility." (Note the "might" here—we still haven't found evidence of human pheromones.) In fact, the authors write, in a handful of societies where mouth-to-mouth partner contact is unknown or frowned upon, such as the Mehinaku of Brazil (in fact, only 46 percent of cultures are known to kiss romantically), romantic partners still engage in "kissing traditions of close face-to-face contact involving sniffing, licking or rubbing."

10. … AND IMPROVE YOUR RELATIONSHIP SATISFACTION.

The same study authors suggest that romantic kissing, as well as other forms of physical contact, can strengthen feelings of attachment to the person you're kissing, increasing the feeling of relationship satisfaction between romantic partners. And a 2013 study in the Archives of Sexual Behavior found that more frequent kissing was linked to couples’ perceived feelings about the quality of a relationship—namely, the more kissing, the happier they were—which was not the case for more sex.

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Penn Vet Working Dog Center
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Stones, Bones, and Wrecks
New Program Trains Dogs to Sniff Out Art Smugglers
Penn Vet Working Dog Center
Penn Vet Working Dog Center

Soon, the dogs you see sniffing out contraband at airports may not be searching for drugs or smuggled Spanish ham. They might be looking for stolen treasures.

K-9 Artifact Finders, a new collaboration between New Hampshire-based cultural heritage law firm Red Arch and the University of Pennsylvania, is training dogs to root out stolen antiquities looted from archaeological sites and museums. The dogs would be stopping them at borders before the items can be sold elsewhere on the black market.

The illegal antiquities trade nets more than $3 billion per year around the world, and trafficking hits countries dealing with ongoing conflict, like Syria and Iraq today, particularly hard. By one estimate, around half a million artifacts were stolen from museums and archaeological sites throughout Iraq between 2003 and 2005 alone. (Famously, the craft-supply chain Hobby Lobby was fined $3 million in 2017 for buying thousands of ancient artifacts looted from Iraq.) In Syria, the Islamic State has been known to loot and sell ancient artifacts including statues, jewelry, and art to fund its operations.

But the problem spans across the world. Between 2007 and 2016, U.S. Customs and Border Control discovered more than 7800 cultural artifacts in the U.S. looted from 30 different countries.

A yellow Lab sniffs a metal cage designed to train dogs on scent detection.
Penn Vet Working Dog Center

K-9 Artifact Finders is the brainchild of Rick St. Hilaire, the executive director of Red Arch. His non-profit firm researches cultural heritage property law and preservation policy, including studying archaeological site looting and antiquities trafficking. Back in 2015, St. Hilaire was reading an article about a working dog trained to sniff out electronics that was able to find USB drives, SD cards, and other data storage devices. He wondered, if dogs could be trained to identify the scents of inorganic materials that make up electronics, could they be trained to sniff out ancient pottery?

To find out, St. Hilaire tells Mental Floss, he contacted the Penn Vet Working Dog Center, a research and training center for detection dogs. In December 2017, Red Arch, the Working Dog Center, and the Penn Museum (which is providing the artifacts to train the dogs) launched K-9 Artifact Finders, and in late January 2018, the five dogs selected for the project began their training, starting with learning the distinct smell of ancient pottery.

“Our theory is, it is a porous material that’s going to have a lot more odor than, say, a metal,” says Cindy Otto, the executive director of the Penn Vet Working Dog Center and the project’s principal investigator.

As you might imagine, museum curators may not be keen on exposing fragile ancient materials to four Labrador retrievers and a German shepherd, and the Working Dog Center didn’t want to take any risks with the Penn Museum’s priceless artifacts. So instead of letting the dogs have free rein to sniff the materials themselves, the project is using cotton balls. The researchers seal the artifacts (broken shards of Syrian pottery) in airtight bags with a cotton ball for 72 hours, then ask the dogs to find the cotton balls in the lab. They’re being trained to disregard the smell of the cotton ball itself, the smell of the bag it was stored in, and ideally, the smell of modern-day pottery, eventually being able to zero in on the smell that distinguishes ancient pottery specifically.

A dog looks out over the metal "pinhweel" training mechanism.
Penn Vet Working Dog Center

“The dogs are responding well,” Otto tells Mental Floss, explaining that the training program is at the stage of "exposing them to the odor and having them recognize it.”

The dogs involved in the project were chosen for their calm-but-curious demeanors and sensitive noses (one also works as a drug-detection dog when she’s not training on pottery). They had to be motivated enough to want to hunt down the cotton balls, but not aggressive or easily distracted.

Right now, the dogs train three days a week, and will continue to work on their pottery-detection skills for the first stage of the project, which the researchers expect will last for the next nine months. Depending on how the first phase of the training goes, the researchers hope to be able to then take the dogs out into the field to see if they can find the odor of ancient pottery in real-life situations, like in suitcases, rather than in a laboratory setting. Eventually, they also hope to train the dogs on other types of objects, and perhaps even pinpoint the chemical signatures that make artifacts smell distinct.

Pottery-sniffing dogs won’t be showing up at airport customs or on shipping docks soon, but one day, they could be as common as drug-sniffing canines. If dogs can detect low blood sugar or find a tiny USB drive hidden in a house, surely they can figure out if you’re smuggling a sculpture made thousands of years ago in your suitcase.

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Medicine
New Cancer-Fighting Nanobots Can Track Down Tumors and Cut Off Their Blood Supply
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Scientists have developed a new way to cut off the blood flow to cancerous tumors, causing them to eventually shrivel up and die. As Business Insider reports, the new treatment uses a design inspired by origami to infiltrate crucial blood vessels while leaving the rest of the body unharmed.

A team of molecular chemists from Arizona State University and the Chinese Academy of Sciences describe their method in the journal Nature Biotechnology. First, they constructed robots that are 1000 times smaller than a human hair from strands of DNA. These tiny devices contain enzymes called thrombin that encourage blood clotting, and they're rolled up tightly enough to keep the substance contained.

Next, researchers injected the robots into the bloodstreams of mice and small pigs sick with different types of cancer. The DNA sought the tumor in the body while leaving healthy cells alone. The robot knew when it reached the tumor and responded by unfurling and releasing the thrombin into the blood vessel that fed it. A clot started to form, eventually blocking off the tumor's blood supply and causing the cancerous tissues to die.

The treatment has been tested on dozen of animals with breast, lung, skin, and ovarian cancers. In mice, the average life expectancy doubled, and in three of the skin cancer cases tumors regressed completely.

Researchers are optimistic about the therapy's effectiveness on cancers throughout the body. There's not much variation between the blood vessels that supply tumors, whether they're in an ovary in or a prostate. So if triggering a blood clot causes one type of tumor to waste away, the same method holds promise for other cancers.

But before the scientists think too far ahead, they'll need to test the treatments on human patients. Nanobots have been an appealing cancer-fighting option to researchers for years. If effective, the machines can target cancer at the microscopic level without causing harm to healthy cells. But if something goes wrong, the bots could end up attacking the wrong tissue and leave the patient worse off. Study co-author Hao Yan believes this latest method may be the one that gets it right. He said in a statement, "I think we are much closer to real, practical medical applications of the technology."

[h/t Business Insider]

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