Why Is It So Hard to Sleep in a New Place?

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iStock

Maybe you’re away on a business trip and you’ve got a big presentation in the morning. Maybe it’s your first night in a new home after a long day hauling boxes. Whatever the circumstances, you could really use a good night’s rest—but, given that you're sleeping in a new place, that may be easier said than done. Now, a team of scientists at Brown University say they’ve found a cause for this first-night effect: constant, animal-like vigilance. They published their findings in the journal Current Biology.

Sleep is something of a puzzle for scientists. Most animals do it, but it’s not entirely clear why it’s necessary. In survival terms, it’s pretty inconvenient for an animal to be off its guard for several hours every day. But rather than evolving to live without rest, some animals have developed the ability to literally sleep with one eye open. Bottlenose dolphins, southern sea lions, domesticated chickens, and beluga whales are among species that practice unihemispheric slow-wave sleep (USWS), in which just one half of the brain sleeps at a time.

You can see this yourself in a line of snoozing ducks: the duck at the end of the line will have its outward-facing eye open. That eye is linked to the brain hemisphere that’s still awake. That way, even in sleep, the sight of a predator could trigger alarms in the brain, cueing the duck to take action.

This may look like an angry pirate, but it’s actually a young house sparrow in USWS. Image credit: Hussain Kaouri via Wikimedia Commons // CC BY-SA 4.0

As you can imagine, this vigilant half-sleep is a real asset in dangerous and unpredictable environments. Unfortunately, your brain might count hotel rooms and new apartments as dangerous. That’s right: Scientists have found USWS in people. Or, rather, they’ve found what amounts to USWS Lite.

Sleep researchers are well aware of the first-night effect (FNE), and frequently throw out the results from a sleep study subject’s first night in the lab. Rather than working around the FNE, a team of researchers decided to identify its cause. They recruited 35 healthy volunteers and brought them into a sleep lab for two nights of sleep with a one-week break in between. The volunteers were hooked up to machines that measured their heart rates, blood oxygen levels, breathing, eye and leg movements, as well as activity in both sides of the brain.

The scientists focused on slow-wave activity (SWA), a type of brain behavior that can indicate how deeply someone is sleeping. They looked at SWA in four different brain pathways in both sleep sessions, tracking how sleep depth was affected by disturbances in the room.

They weren’t looking for differences between the brain hemispheres, but they found them. On the first night of sleep, subjects consistently showed more wakefulness in the left half of their brains. The left hemisphere was also more sensitive to strange (and thus potentially threatening) sounds. One week later, when the subjects returned to the sleep lab, there was more symmetry in the subjects’ brain activity, suggesting they had become accustomed to the now familiar environment. Their SWA showed equal levels of wakefulness, or lack thereof, in both brain hemispheres.

While the study results suggest we are participating in USWS, co-author Yuka Sasaki says in a press statement that "our brains may have a miniature system of what whales and dolphins have."

Sasaki noted that frequent travelers may subconsciously train their brains to bypass the FNE. Our brains are “very flexible,” she said. “Thus, people who often are in new places may not necessarily have poor sleep on a regular basis."

The team’s future experiments will include trying to shut off the FNE so people can get a better (first) night’s sleep. 

What Is the Shelf Life of Donated Eyes?

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iStock.com/Pedro_Turrini

Zoe-Anne Barcellos:

I can only answer for cornea and eye donation.

The FDA does all oversight (no pun intended) of organ disposition.

The main organs—heart, liver, pancreas, lungs, etc.—are transplanted within hours. They are just not viable if they are not being perfused constantly.

The other tissues—like bone, skin, tendons, etc.—do not need to be transplanted immediately. But I am not sure on the regulations of when they need to be transplanted.

With the eyes, there are four tissues that can be recovered.

We recover whole eyes for research and education purposes. These usually go much faster, but we can hold them up to a year.

Conjunctiva can also be recovered; conjunctiva is a clear covering over most of the eye (it is what gets irritated when you have pink eye). I have been working as a recovery tech for five years, and our office has not had a request for "conj" in all that time. I believe it is mostly used for research, but I could be wrong.

Sclera is the white area of your eye. It is fairly thick and flexible. If you have ever touched a reptile egg, that is what it reminds me of. We recover sclera for transplant. They use it for several things, but mainly to patch punctures. Similar to if you pop the inner tube of your bike and repair it. Sclera can also be used to repair ear drums. We can hold on to this for up to a year.

The main thing we recover is corneas. In the U.S., we must transplant these within seven days of recovery. (Recovery is usually within hours of death, but we can push it up to 20 hours after if needed.) Sometimes we have more corneas than we need, and then they are shipped overseas and transplanted up to 14 days after recovery. There is no real different outcome with the later transplant time, but the FDA in the U.S. made the rules. (You can sign up to be an organ, tissue, and eye donor here.)

This post originally appeared on Quora. Click here to view.

Why Are There No Snakes in Ireland?

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iStock

Legend tells of St. Patrick using the power of his faith to drive all of Ireland’s snakes into the sea. It’s an impressive image, but there’s no way it could have happened.

There never were any snakes in Ireland, partly for the same reason that there are no snakes in Hawaii, Iceland, New Zealand, Greenland, or Antarctica: the Emerald Isle is, well, an island.

Eightofnine via Wikimedia Commons // Public Domain

Once upon a time, Ireland was connected to a larger landmass. But that time was an ice age that kept the land far too chilly for cold-blooded reptiles. As the ice age ended around 10,000 years ago, glaciers melted, pouring even more cold water into the now-impassable expanse between Ireland and its neighbors.

Other animals, like wild boars, lynx, and brown bears, managed to make it across—as did a single reptile: the common lizard. Snakes, however, missed their chance.

The country’s serpent-free reputation has, somewhat perversely, turned snake ownership into a status symbol. There have been numerous reports of large pet snakes escaping or being released. As of yet, no species has managed to take hold in the wild—a small miracle in itself.

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