Why Do Women Get Alzheimer’s More Than Men?

By Jennifer Walter | September 23, 2019 12:00 pm
MRI scans of patients show patients with Alzheimer’s disease. (Credit: Atthapon Raksthaput/Shutterstock)

Scientists are still unraveling why Alzheimer’s disease affects men and women disproportionately. Out of the 5 million Americans who have it, about 64 percent are women.

Once in their 60s, women are twice as likely to develop Alzheimer’s than breast cancer, and more than twice as likely to develop Alzheimer’s as their male counterparts. And when women develop the disease, the effects can be more dire than they are on men. One study found that the disease progressed twice as quickly in women, cutting their life spans even shorter from when they were diagnosed with the disease.

But the reason why women are disproportionately affected by the disease is complicated. And scientists still have miles to go before they fully understand why the disease is so widespread among senior women, and how women can best prevent getting Alzheimer’s.

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Short Sleeper ‘Syndrome’: When You Can Get By on Just a Few Hours of Sleep

By Megan Schmidt | September 20, 2019 5:03 pm
staying awake
A small segment of the population are born with superhuman sleep needs. They’re called natural short sleepers, and they wake up refreshed and wide awake on very little sleep. And these individuals share a few other quirks, too. (Credit: Shutterstock)

What do Donald Trump, Elon Musk, and Martha Stewart have in common? They’re part of the one percent.

No, not that one percent. Instead, we’re referring to the one percent of people who thrive on far less sleep than what is recommended by doctors and researchers. Scientists call them natural short sleepers.

Trump, Musk and Stewart all reportedly get by on less than six hours a night, making them part of the so-called “sleepless elite.” Most people need around seven to nine hours of sleep a night for overall health and well-being. But it seems that these guidelines don’t apply to a small segment of the population officially called natural short sleepers. 

Short sleepers wake up feeling refreshed and wide awake, despite clocking six or less hours of sleep per night. Some short sleepers say a mere few hours of shut-eye a night is all they need to feel great.  

It’s sort of like being both a night owl and early riser at the same time. And, unsurprisingly, this group has caught the interest of researchers due to their sleep efficiency.

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How Old Are Saturn’s Rings?

By Alison Klesman | September 20, 2019 3:11 pm
A recently captured view of Saturn’s rings shows them glowing brightly on June 20, 2019. Hubble took this stunning shot as part of the Outer Planets Atmospheres Legacy (OPAL) project. (Credit: NASA, ESA, A. Simon (GSFC), M.H. Wong (University of California, Berkeley) and the OPAL Team)

Saturn’s rings are one of the most striking celestial features in our solar system. The Pioneer and Voyager probes gave us our first close-up look. More recently, NASA’s Cassini mission spent more than a decade studying them and the planet they encircle, before ultimately diving between the planet and its rings to take the most detailed measurements to date.

But despite everything we’ve learned about the rings, unanswered questions abound. Chief among them is one of the simplest you can ask: How old are Saturn’s rings?

Tricky Business

Age is tricky for astronomers to measure. Researchers have to arrive at this answer indirectly — by measuring other properties, such as mass, color, or composition, and then inferring what those properties mean about the rings’ age. 

Those estimates vary wildly. That’s because they depend on the measurements taken and the assumptions made along the way, which is why the debate over whether Saturn’s rings continues to rage. 

Here’s what we do know, based on direct measurement: Overall, Saturn’s rings weigh about 33 million trillion pounds (15 million trillion kilograms), or 40 percent the mass of its 250-mile-wide (400 kilometers) moon, Mimas. They are composed of largely pure water ice — about 95 percent ice, with only about 5 percent rock and metals. Over time, they spread out and even rain material down onto Saturn

To estimate the rings’ age, researchers try to consider what’s happened to change the rings from their original appearance to how they look today. As particles within the rings collide with and gravitationally influence each other, the rings should spread out until they essentially fade away. The rings should also get darker with time, as dust and meteorites fall onto them, affecting their color and brightness. 

So, measuring the mass of the rings and the amount of light they reflect should give researchers a good starting point for estimating their age.

Old or Young?

Some models place the rings at basically the age of the solar system, stating they likely formed with Saturn and have always been there. After all, scientists have known for decades now that they’re quite massive. To form them after the planet, rather than with it, calculations show the total destruction of a Mimas-sized moon or passing comet is needed — a rare, unlikely event. 

On the other hand, the rings are still around. Even given their mass, some researchers expect they would have dissipated away and argue for a young age. And based on observations of color, Saturn’s rings do appear young. They are relatively bright, reflecting much of the light that hits them, so they don’t appear as polluted (dark) as older rings are expected to be. Based on this information, some researchers estimate that the rings are much younger: somewhere in the range of 100,000 to 1 billion years.

But there are some additional concerns. After all, what if the rings are old and formed with the planet, but researchers are simply overestimating how quickly they should dissipate? Or maybe they’re being rejuvenated or renewed so they look young and fresh, despite their age. Newer studies are once again suggesting that the rings are old, and factors previously ignored or unknown may be “cleaning” them to make them look brighter and younger.

Mystery Unsolved

So, that’s the heart of the debate these days: Are the rings actually young, or are there processes at play that make them look young? It all depends on how the researchers model solar system processes and the rings’ evolution over time, such as how quickly space dust contaminates the rings and how efficient the processes are that renew them. 

It may seem like an unsolvable problem, but astronomers have hope. Southwest Research Institute astronomer Luke Dones, co-author of some of the most recent studies arguing once again for old rings, said in a statement: “It’s not impossible to determine the age of the rings, but to do so we’ll need a future mission to Saturn that spends a long, intense period studying the rings themselves as well as the relationship between them and the gas giant.”

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: solar system

When Did Humans Reach North America? The Question Keeps Growing More Complex

By Megan Gannon, SAPIENS | September 19, 2019 10:30 am
Native Americans have been visiting Calvert Island off the Canadian coast for more than 10,000 years. (Credit: Pacific Northwest Sailing/Shutterstock)

Humans have long found comfort on Calvert Island, just off the coast of mainland British Columbia. For millennia, they have climbed the island’s rocky outcrops, walked through its rainy conifer forests, and waded through its chilly intertidal pools to collect crabs, mussels, and other marine life.

There, in 2014, a group of Canadian researchers uncovered human footprints pressed into a prehistoric layer of soil. The footprints, 29 in total, are the oldest found in North America. They suggest an intimate scene in which, 13,000 years ago, at least three people may have hopped out of a boat onto the damp shore. One person appears to have slipped as the group walked toward drier land. The footprints also speak to a much larger and contested story—the tale of the humans who first set foot in North America.

North and South America were relatively lonely places for our species 13,000 years ago. The continents were the last major landmasses in the world to be populated by Homo sapiens. But the explanation of how and when this peopling happened has needed to be heavily revised in the last two decades.

“This field is bonkers right now,” says anthropological geneticist Jennifer Raff of the University of Kansas. “I think there’s a new important paper coming out every three or four months.” Indeed, no tidy, new framework has arisen to take the place of older theories. Instead, new data, including genetic findings, continue to complicate the story of how these continents came to be peopled.

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CATEGORIZED UNDER: Living World, Top Posts

Misophonia, Or Why I Hate the Sound of Chewing Salad

By Nathaniel Scharping | September 18, 2019 4:00 pm
young child boy doesn't like specific sound
Misophonia is an aversive reaction to specific sounds that emerges in childhood, most often with annoyance that quickly turns to anger. (Credit: mamaza/Shutterstock)

It was the salads that got me. On nights when my parents started off dinner with some leafy greens, I left the room. The habit quickly became a ritual, and to my family’s credit – or not –  no one ever remarked on it. It was just another quirk, like biting fingernails, or sticking your tongue out when you concentrate.

You see, to me, the sounds of chewing salad were unendurable. The crisp crunching noises and the scrape and squeak of utensils on ceramic dinnerware felt like a personal affront, a stimulus manufactured to induce rosy-red rage inside. I felt an inexplicable urge to hurl plates and bowls against the walls. So, I left the table.

As I grew up and moved away, the problem faded into the background, or, at least, I learned to deal with it. Not till much later did I discover that there was a name for these irrational fits of anger, and a diagnosis to accompany it.

Misophonia is an aversive reaction to specific sounds, often in the form of annoyance that turns quickly to anger. Eating, chewing gum and typing on keyboards are all commonly listed triggers. But it varies from person to person. Human-made noises are most likely to cause the reaction, and these sounds typically come from people who misophonia sufferers are close to, like family and friends. The condition typically starts during childhood or adolescence. And while scientists don’t know exactly how many people are affected, one study of almost 500 undergraduates found some level of misophonia in 20 percent of them.

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CATEGORIZED UNDER: Mind & Brain, Top Posts

Homo heidelbergensis: The Answer to a Mysterious Period in Human History?

By Bridget Alex | September 17, 2019 11:56 am
Cranium 5 Homo heidelbergensis
Cranium 5, a skull found at Sima de los Huesos and thought to be either a late Homo heidelbergensis or an early Neanderthal. (Credit: Rept0n1x/Wikimedia Commons)

There’s a murky chapter in human evolution, one that occurs right before our species entered the scene.

Over 1 million years ago our ancestors belonged to the primitive-looking species Homo erectus. Jump to 300,000 years ago and Earth is home to at least three lineages of big-brained humans: Homo sapiens, Neanderthals and Denisovans. So what happened in the intervening 700,000 years?

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CATEGORIZED UNDER: Living World, Top Posts
MORE ABOUT: human origins

Cows Burp Out Tons of Methane. Feeding Them Seaweed Could Help

By Jennifer Walter | September 16, 2019 5:13 pm
Cows Methane
Adding seaweed to cows’ diet would help tamp down their methane emissions. (Credit: Jan K/ Shutterstock)

Every morning, Breanna Roque goes out to the barn to feed the cows. But this isn’t your typical farm – in fact, it’s a laboratory. The University of California, Davis graduate researcher spends her time among bovines, tweaking their diets so that they burp less. Why? Less burps means less methane. And less methane, on a global scale, could mean slowing down climate change.  

Roque is part of a team feeding cows a special diet, one that includes small portions of a sticky, red seaweed called Asparagopsis taxiformis. It’s not the typical fare for the grass-happy bovines, but the seaweed-infused feed serves a specific purpose – keeping the cows’ prodigious methane production in check.

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CATEGORIZED UNDER: Environment, Living World, Top Posts

9 Ways to Instantly Cut Your Environmental Impact

By Anna Funk | September 13, 2019 4:43 pm
thrift store shopping
Buying clothes and other items second hand is a great way to cut your environmental impact. (Credit: Cabeca de Marmore/Shutterstock)

Helping the environment might seem like an impossible task, especially when there are a couple billion other people out there, still doing their thing. But even just cutting your current environmental impact a little is better than doing nothing at all. So, here are a few ideas to get you started.

Buy Stuff Second Hand

What has less of an impact than buying the most sustainable new product on the market? Not buying it. Or anything new, for that matter. Any product that’s manufactured requires resources, energy, packaging and transportation. And that’s also true for products that are a “sustainable alternative” to something else.

But our world is already so full of stuff. It’s waiting for you in thrift stores. Second-hand shops. Yard sales. Used car lots. The back of your friend’s closet. In fact, the resale industry is booming: A report by First Research estimates the used merchandise industry in the U.S. hit $17.5 billion in 2019.

How many copies of Pride and Prejudice are in circulation right now? (Hint: It’s something like 20 million.) Do you really need one from Amazon that’s never been read?

But if you’re a material girl, living in a material world, and can’t imagine wearing someone else’s shoes — the least you can do is be sure to donate (or even resell) the stuff you’re done with instead of throwing it in the trash.

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CATEGORIZED UNDER: Environment, Top Posts

How the Government is Working to Combat Fake Images and Videos

By Christye Sisson, Rochester Institute of Technology | September 11, 2019 11:04 am
It can be tricky to make it look like people are doing things they never did. (Credit: Alexander Sobol/Shutterstock)

Lots of people – including Congress – are worried about fake videos and imagery distorting the truth, purporting to show people saying and doing things they never said or did.

I’m part of a larger U.S. government project that is working on developing ways to detect images and videos that have been manipulated. My team’s work, though, is to play the role of the bad guy. We develop increasingly devious, and convincing, ways to generate fakes – in hopes of giving other researchers a good challenge when they’re testing their detection methods.

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CATEGORIZED UNDER: Technology, Top Posts

Americans Commonly Eat Orange Roughy, a Fish Scientists Say Can Live to 250 Years Old

By Kate Evans | September 11, 2019 10:30 am
Orange roughy live in the deep ocean, where they’re often caught by trawling ships. (Credit: New Zealand National Institute of Water and Atmospheric Research)

Would you eat an animal if you knew it was as old as the U.S. Constitution? 

Scientists in New Zealand have aged a fish called an orange roughy at between 230 and 245 years old, making it one of the longest-lived fin-fish on record.

The ancient fish was born in the late 1700s — and then caught in 2015 by a New Zealand commercial fishing boat on the Louisville Ridge, a chain of seamounts in the South Pacific around 930 miles east of the mainland.

The spiny, scarlet creature was hauled in by a trawl net from its deep, dark home more than 3,000 feet below the surface, along with many hundreds of its schoolmates. But before it was sold and eaten, New Zealand government observers on board the ship extracted samples from inside the creature’s head to determine its age.

Orange roughy — known as “slimehead” before a marketing makeover in the 1970s  — are mainly caught off the coast of New Zealand and Australia, then sold abroad, mainly to the U.S.

Whole Foods, Trader Joes and some other retailers refuse to stock the species, citing sustainability concerns and the environmental impacts of bottom trawling. For researchers, the species’ great age highlights the need for a precautionary approach to fisheries management.

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CATEGORIZED UNDER: Environment, Living World, Top Posts
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