Author: Kate Horowitz

There’s no two ways about it: premenstrual syndrome (PMS) is awful. But for people with severe PMS (also known as premenstrual dysphoric disorder, or PMDD), “awful” is an understatement. Now scientists at the National Institutes of Health say they may have found the root of the problem: abnormal gene expression. They published their findings in the journal Molecular Psychiatry.

Experiencing PMDD symptoms is like having the volume turned up on the emotional elements of regular PMS. These extreme bouts of depression, anger, and anxiety can be so deep and persistent that they interfere with work or school, home, or relationships.

PMDD is not common; scientists estimate that it affects 2 to 5 percent of people who menstruate. But for those who have it, it can be disabling, and it sure would be nice to know what’s causing it.

Previous studies in the ’90s concluded that people with PMDD appear to be hypersensitive to ordinary, menstrual-related fluctuations in steroid hormones like estrogen and progesterone. They still couldn’t tell us where this hypersensitivity came from, but they kept looking.

Fast-forward to 2015. Technology has advanced in ways that would have blown our minds 20 years ago. Behavioral endocrinologist Peter Schmidt, who led the earlier studies, teamed up with experts in neurogenetics and psychiatry to try a new approach.

They recruited 67 women between the ages of 18 and 48. Some of these women had been diagnosed with PMDD, while others said they had no trouble with severe PMS. One subgroup of participants with PMDD were given drugs that turned off their production of estrogen and progesterone. Their symptoms abated. When the researchers stopped the treatment, the women’s symptoms returned. These changes supported the theory that even normal changes in hormone levels could trigger big emotional changes for women with the condition. In other words, PMDD is quite literally PMS on steroids.

Next, the researchers extracted cell samples from 48 participants (24 with PMDD and 24 without) and sequenced their genetic code, looking for differences. They found them, all right: A large group of genes called the ESC/E(Z) complex was working overtime in women with PMDD. This makes a lot of sense, the researchers say, as the role of the ESC/E(Z) complex is to tell our genes how to respond to changes in our internal and external environment. Hypersensitivity there could definitely cause dramatic overreaction to hormonal changes.

The authors say these findings strike at the myth of the fragile, overly emotional woman. “This is a big moment for women’s health,” co-author and neurogeneticist David Goldman said in a statement. “It establishes that women with PMDD have an intrinsic difference in their molecular apparatus for response to sex hormones—not just emotional behaviors they should be able to voluntarily control.”

Babies’ lives are tough. They can’t communicate their feelings or needs; they don’t understand why anything is happening; and their ability to perceive and interact with the world around them changes by the day. But at least now they’ll be able to eat a food that could benefit their long-term health. New guidelines published in the Annals of Allergy, Asthma & Immunology encourage parents to give their babies small amounts of peanuts, which may help prevent a deadly food allergy later in life.

As anyone with a school-aged child can tell you, food allergies are on the rise. One 2013 study from the Centers for Disease Control and Prevention found a 50 percent increase in childhood food allergies between 1997 and 2011. Scientists have yet to determine the exact cause of this enormous uptick. Until they do, pediatricians and parents have focused on treating the allergies—and preventing them wherever possible.

That used to mean keeping kids and peanuts apart for as long as possible. But doing so didn’t seem to help. Allergies continued to rise. We needed a new strategy.

If avoidance wasn’t working, experts thought, what about exposure? What we call an allergy is the immune system overreacting to an ordinarily harmless trigger. So to prevent allergies from developing, pediatricians began introducing tiny doses of potential triggers when children were still very young. The tactic worked.

“You have the potential to stop something in its tracks before it develops,” report co-author Matthew Greenhawt, of the American College of Allergy, Asthma and Immunology, told The New York Times. There’s “a window of time in which the body is more likely to tolerate a food than react to it, and if you can educate the body during that window, you’re at much lower likelihood of developing an allergy to that food.”

Evidence continues to pile up in favor of doing just that. Study after study has confirmed the safety of giving babies very small doses of peanuts, eggs, and other common food allergens, and official recommendations have begun to fall in line.

The latest recommendations, created by a panel at the National Institute of Allergy and Infectious Disease, emphasize the safety of introducing peanuts early on. Specific guidelines for each baby depend on that child’s allergy risk level. Low- and moderate-risk babies can start eating peanut foods around 6 months of age. High-risk kids should start sooner, under a doctor’s supervision.

Of course, doctors do not recommend giving babies whole peanuts, which they could choke on. Instead, they suggest foods made with peanuts or watered-down peanut butter.

“This won’t outright prevent every single case of peanut allergy,” Greenhawt told the Times, “but the number could be significantly reduced by tens of thousands.”

[h/t New York Times]

The Internet of Things is upon us. We use fitness trackers to count our steps, program our vacuums to clean our rooms, and can set the thermostat in the kitchen while sitting in a meeting at work. If all this connectivity is your jam (and you’ve got hair, or a hairy friend or pet), L’Oréal and Kérastase’s new smart hairbrush will help bring your grooming routine into the 21st century.

The theory behind the Hair Coach is familiar: The more information you have about something—in this case, your luscious locks—the better off you’ll be. The setup is also pretty standard: a smart device linked to a tracking app for mobile phones.

 
What makes Hair Coach unique is its execution: a high-quality hairbrush packed with enough gadgetry to make a spy jealous. A microphone built into the brush records the sound of your brushstrokes, then sends that information to the app for analysis. Movement sensors track and count your strokes, while load sensors monitor how hard you’re brushing. Conductivity sensors inside the brush’s bristles note whether your hair is wet or dry, while the app pulls in local weather data to consider how humidity and temperature could be affecting your ‘do. The net result is a personalized analysis of brushing technique and hair quality, which is used to generate recommendations and tips for better hair care.

Because this is a L’Oréal/Kérastase collaboration, you can expect advertisements and recommendations like “buy this serum.” But if you’ve got a passion for beauty products and some cash to burn—the Hair Coach will retail for $200 in autumn 2017—you’re probably already their ideal customer.

[h/t Gizmodo]

Why did the chicken cross the road? We don’t know, but it probably had its reasons. A new paper published in the journal Animal Cognition reports that the barnyard birds’ intelligence and social skills are far more complex than we thought.

Lori Marino is senior scientist for The Someone Project, which aims to challenge popular misconceptions about chickens, cows, pigs, and other farm animals. Her report, which was partially funded by the ASPCA, describes experiment after experiment showing that chickens are, in fact, very complex animals with rich inner and outer lives.

Last year was a big year for bird intelligence research. in 2016, scientists reported that some birds are at least as smart as apes. They found tool-making crows and clever pigeons and puzzle-solving bullfinches. The phrase “birdbrain” began to lose its meaning.

But amid the myth-shattering, some birds got more attention than others. “There’s not a lot of scientific work being done on chicken cognition,” Marino tells mental_floss, “because if you assume an animal doesn’t have a given trait, you aren’t going to study it. But what research there has been is very, very compelling.”

For example: Studies have found that chickens have object permanence—that is, they understand that when you cover something, it does not go away—a skill humans develop around age one. They’re also capable of counting and basic arithmetic, even as chicks. They understand logic and simple reasoning, including some concepts we don’t understand until we’re six or seven years old. They have some sense of time and complex social relationships. They have distinct personalities and show one another empathy.

“Chickens have a mind. They have a life,” Marino says. “They’re not just these dumb, inert objects scratching in the dust. It is like something to be a chicken.”

Why is that so hard for us to believe? “It’s a perfect storm,” Marino explains. The first problem is our longstanding skepticism of avian cognitive ability—the “birdbrain” idea. We’re getting over that, but “the history is there,” she says. “The other thing is that, well, we eat them.”

People have a vested interest in thinking of farm animals as inanimate commodities, Marino says, because otherwise we’d start feeling bad about killing and eating them. Instead, we focus on turning them into better meat—a strategy that she believes dulls our scientific rigor and robs us of the chance to learn more about our fellow organisms. 

“Most of the work that’s done on chickens, fish, and cows tends to involve trying to figure out how to make them lay more eggs or grow faster or not peck each other,” she said. “It’s all very applied, and it misses the whole point. These are animals who have an evolutionary and adaptive history just like a chimpanzee or a dog or a human being. They’re animals. And at the very least, we need to approach them as animals in their own right.”

The sounds of the Stone Age may have been even less dignified than we thought. A vocal expert working with the BBC suggests that Neanderthal vocalizations may have sounded less like low grunts and more like high-pitched shrieks.

Patsy Rodenburg has dedicated her career to understanding and exploring the sounds we make. As vocal coach for Judi Dench, Ian McKellen, Nicole Kidman, and Daniel Day-Lewis, Rodenburg is used to coaxing round vowels and resonance out of the human body. But Neanderthal noises required something a little different.

Working from a Neanderthal’s skeletal remains, a team of scientists created physical and virtual models of our prehistoric relative. They used these to extrapolate measurements and estimates of the Neanderthals’ abilities and traits. They also created a model of a Neanderthal throat and showed it, along with the skeleton, to Rodenburg.

She concluded that the shape of the throat, combined with the dimensions of the Neanderthal’s skull and chest, would have produced some very unusual (and “very, very loud”) noises indeed. Check out the video below to see one patient actor re-creating these bizarre sounds.

Rodenburg’s hypothesis has yet to be supported by additional research, but the shrieking-Neanderthal theory is not out of the question. This certainly wouldn’t be the first time we’ve been wrong about Neanderthals. Recent studies have shown they were at least as intelligent as any Homo sapiens they encountered, and that the two species intermixed. They buried their dead and taught their children how to make tools. (All, presumably, while screaming at each other.)

[h/t Atlas Obscura]

Getting out of bed in the morning is pretty much the worst. Who wants to leave a cozy, warm bubble and face the cold, harsh light of day? Not us—and apparently not baby dinosaurs, either. Experts say the little tykes may have spent between three and six months curled up in their eggs. The findings were published in the Proceedings of the National Academy of Sciences.

Dinosaur embryos are very rare, which means their journey from fertilized egg to baby thunder-lizard is something of a black box. We do know they had a great deal in common with modern reptiles and with birds, and while both groups lay eggs, the length of their incubation periods vary immensely. Bird babies typically take a few weeks to hatch; reptiles can take months. Because dinosaur eggs were so huge, scientists believed they were probably more bird-like than lizard-like, hatching relatively quickly. It seemed probable that birds inherited their speedy incubation period from their prehistoric ancestors.

To find out for sure, the research team examined fossilized embryos from two dinosaur species: the sheep-sized Protoceratops and the gargantuan Hypacrosaurus, whose eggs were roughly the size of bowling balls. 

The researchers used computed tomography (CT) scanners and microscopes to get a closer look at near-invisible growth lines on the embryos’ teeth. “These are the lines that are laid down when any animal’s teeth develops,” lead author Gregory Erickson said in statement. “They’re kind of like tree rings, but they’re put down daily. We could literally count them to see how long each dinosaur had been developing.”

As it turns out, they’d been developing for quite a long time. Little Protoceratops had been in its egg for almost three months; Hypacrosaurus, twice that long.

This long incubation period suggests two things: first, that dinosaurs were closer to modern reptiles than we thought, and second, that those eggs were vulnerable as heck. The longer an embryo sits around in its egg, the more protection and resources it requires, and the slower its development may be once it hatches.

And that sluggish development may have contributed to the dinosaurs’ downfall. The faster a species can mature, develop, and reproduce, the faster it can evolve—a crucial factor in a world buffeted by dramatic climate change like that faced by the dinosaurs.

“We suspect our findings have implications for understanding why dinosaurs went extinct at the end of the Cretaceous period,” Erickson said, “whereas amphibians, birds, mammals, and other reptiles made it through and prospered.”

 
The human body is an amazing and expansive place, full of strange twists and turns. It’s likely we’ll never discover all its secrets, but we do have a pretty solid grasp on the major parts. So even though new research has convincingly made the case for reclassifying the mesentery—a folded membrane that connects your intestines to the wall of your abdominal cavity and keeps everything snugly in place—as a single, continuous organ, scientists have not, as some headlines proclaim, discovered a “brand-new organ.” In fact, we’ve known about the existence of the mesentery (pronounced MEH-zun-terry) for centuries; Leonardo da Vinci even included it in his anatomical notes.

The mesentery has historically been seen as a series of unimportant attachments to the abdominal lining. But researcher J. Calvin Coffey of the University Hospital Limerick in Ireland suspected that there might be more to it. He and his colleagues examined the membrane and surrounding tissue under a microscope in 2012. They found that, rather than a group of disconnected but similar pieces, the mesentery was actually all one piece. The researchers published their findings in The Lancet Gastroenterology & Hepatology.

 
Inspired by this realization, Coffey initiated a campaign to reclassify the mesentery as a separate organ. He believes that full organ status is the key to understanding what’s going on in our guts.

“Up to now there was no such field as mesenteric science,” he said in a statement. “Now we have established anatomy and the structure. The next step is the function. If you understand the function you can identify abnormal function, and then you have disease.”

His lobbying paid off; the latest edition of Gray’s Anatomy categorizes the mesentery as an organ.

Coffey’s new paper, written with his colleague D. Peter O’Leary, makes a strong case for initiating the mesentery into the organ club. “The mesentery should be subjected to the same investigatory focus that is applied to other organs and systems,” they write.

“This is relevant universally,” Coffey added in the statement. “It affects all of us.”

Every generation thinks they were the ones to invent the fart joke. The truth is that people have been laughing about bodily functions—and other low-hanging humor fruit—for a long, long time, even in the margins of medieval texts. (Fair warning: Some of these images are legitimately R-rated.)

1. POOPING

Contradictory though it may seem, the margins of religious texts were a perfect and popular place for crude humor during the Middle Ages. If the scripture was king, the margins were its jester, poking holes in the text’s (or author’s) grandeur and commenting pointedly on issues of the day. Some of that commentary was nuanced or couched in metaphors. The poop drawings … a little less so.

2. ATTACK SNAILS

Art and religious historians have debated this one for centuries. Some theorize that the snail and its trail of slime represent death; others think it signifies the Resurrection. Some believe it’s a metaphor for the lower class and their struggle against the armored aristocracy. Still others think scribes liked snails because, well, they kind of look like penises. Which brings us to our next item …

3. GENITALS

So. Many. Penises.

4. THE ANIMAL-ON-ANIMAL CAROUSEL

Margin art was a complex, labor-intensive game for both reader and scribe, as symbolic as any family crest. Lions had one meaning and monkeys another, as did their behavior and placement on the page. Illuminators swiped existing symbols and appropriated them for new, bizarre uses. If all this sounds familiar, it’s because we’re still doing it.

5. BUTT TRUMPETS

Monty Python may have made illuminated butt trumpets famous, but they certainly didn’t invent them. No, those very special instruments came straight from the borders of religious texts, where they lay for centuries, amplifying and directing farts right into the holy gospels.

(Need more marginal mayhem? Check out Discarding Images on tumblr.)

This thing all things devours;
Birds, beasts, trees, flowers;
Gnaws iron, bites steel;
Grinds hard stones to meal;
Slays king, ruins town,
And beats mountain down.

Gollum may have said it best: Time comes for us all. But our reckoning of time is far less objective and a lot more human. Why do we divide our days into 24 hours and not, say, 10?

Find out in the above Big Questions video from host Craig Benzine, who offers a brief history of time, conjectures about ancient Egyptian modes of transportation, and even manages to squeeze in the word sexagesimal.

Tardigrades—a.k.a. moss piglets or water bears—are the scientific gift that just keeps on giving. Everything about these microscopic animals is extreme. They’ve been on Earth since long before the dinosaurs. They can withstand blistering cold, intense heat, years without food or water, and hanging out in the vacuum of space. They’re practically unkillable. So it makes sense that their sex lives would also be interesting.

That’s why scientists have produced a video of two moss piglets having sex. The researchers/cinematographers responsible for the tape described the tender-yet-disgusting process in an article in the Zoological Journal.

The sex you’re about to watch is not representative of all tardigrades, just one species, Isohypsibius dastychi. There are more than 1000 different tardigrade species out there, and not all of them reproduce sexually. But I. dastychi certainly does.

For those of us unaccustomed to watching tardigrade sex (we’re going to assume that’s mostly everyone), here’s what’s happening. The female (L) has molted and laid eggs inside her discarded old skin. The male (R, perpendicular) has curled himself around her and is stroking her as he ejaculates onto the eggs.*

The researchers write that the action was “much more complex than expected,” and note that this “mutual stimulation” went on for at least an hour.

Not bad, little tardigrades. Not bad.

*We did warn you that this would be disgusting.