Researchers Have Finally Found Human Skeletal Stem Cells

By Lacy Schley | September 21, 2018 5:56 pm
A small microscope image of a bone structure that developed from human skeletal stem cells. Blue coloring indicates cartilage, brown represents bone marrow and yellow shows bone.

A small bone structure that developed from human skeletal stem cells. Blue coloring indicates cartilage, brown represents bone marrow and yellow shows bone. (Credit: Chan and Longaker et al.)

If only we could regrow our broken bones like Harry Potter, Skele-gro style. Or, at the very least, heal up like a limb-regenerating newt. Alas, we humans possess no such abilities. Though our bodies can mend broken bones, the older we get, the shoddier that patch job gets. As for cartilage — the crucial cushioning that keeps our bones from rubbing together — once that’s gone, it’s gone for good.

But a new discovery by researchers could change that outlook. A team from Stanford University has finally discovered skeletal stem cells — the cells that give rise to bone, cartilage and the supportive, spongy inside of a bone called stroma — in humans for the first time. And the hope is that someday, doctors could use these stem cells to help people regrow broken bones and missing cartilage.

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CATEGORIZED UNDER: Health & Medicine, top posts

TESS, NASA’s Next-Gen Planet Hunter, is Already Delivering

By Alison Klesman | September 21, 2018 2:00 pm
TESS exoplanet hunter first light image of night sky

A portion of TESS’ first light image, showing the Large Magellanic Cloud (right) and the bright star R Doradus. (Credit: NASA/MIT/TESS)

NASA’s Transiting Exoplanet Survey Satellite (TESS) launched April 18, headed for an orbit that takes it out to about the distance of the Moon at its apogee. Just a few weeks later, it began science operations and a list of 50 exoplanet candidates rolled in, with researchers now expecting at least six of those first candidates to be eventually confirmed as bona-fide planets.
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CATEGORIZED UNDER: Space & Physics, top posts
MORE ABOUT: exoplanets

What’s Going on Around This Strange Neutron Star?

By Alison Klesman | September 20, 2018 5:00 pm
neutron star

Neutron stars are the hot, rapidly rotating remnants of massive stars. Many are pulsars, which send out radio signals that happen to coincide with Earth, like seeing the light from a lighthouse. (Credit: Kevin Gill)

Neutron stars, the end-stage remnants of massive stars, are high-energy objects. They’re usually studied in X-rays, some of the most energetic light in the universe. Neutron stars also give off radio emissions, most famously as pulsars. But now, infrared emission around a neutron star detected with the Hubble Space Telescope has sparked curiosity, indicating that astronomers may want to add infrared light to their neutron star-studying toolkit.
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CATEGORIZED UNDER: Space & Physics
MORE ABOUT: stars

Opioid Epidemic Part Of Decades-Long Rise in Drug Overdoses

By Roni Dengler | September 20, 2018 3:00 pm
drug overdose opioids fatal

Scientists looked at deaths in the United States going back decades and were astonished at the exponential rise in fatal drug overdoses. (Credit: Yaroslau Mikheyeu/shutterstock)

Drug overdoses kill close to 200 people everyday in the United States. And while opioids are a major contributor to those deaths today, a new analysis of nearly 600,000 accidental drug overdose deaths between 1979 and 2016 reveals the current crisis is part of a much larger trend.

“We think of [the current epidemic] starting in the ’90s, but that was gas on the flame,” said Robert Pack, a public health expert at East Tennessee State University in Johnson City, who was not involved in the new research. “The flame was already there.”
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MORE ABOUT: drugs & addiction

What’s the Maximum Gravity We Could Survive?

By Michael Allen | September 20, 2018 2:13 pm
super earth

The super-Earth Kepler 62f, estimated to be around 40% larger than Earth. (Credit: NASA/Ames/JPL-Caltech)

If we wish to colonize another world, finding a planet with a gravitational field that humans can survive and thrive under will be crucial. If its gravity is too strong our blood will be pulled down into our legs, our bones might break, and we could even be pinned helplessly to the ground.

Finding the gravitational limit of the human body is something that’s better done before we land on a massive new planet. Now, in a paper published on the pre-print server arXiv, three physicists, claim that the maximum gravitational field humans could survive long-term is four-and-a-half times the gravity on Earth. Read More

CATEGORIZED UNDER: Space & Physics
MORE ABOUT: exoplanets

For the First Time, A Praying Mantis Has Been Caught Fishing

By Nathaniel Scharping | September 20, 2018 1:49 pm
Praying mantis eating fish

The male praying mantis (Hierodula tenuidentata) eating a guppy fish (Poecilia reticulata) starting from the tail, while the fish is still alive and breathing in the water. (Credit: Rajesh Puttaswamaiah)

There’s nowhere you can hide from the praying mantis. The ferocious insects are known to feast on a veritable buffet of living creatures, including everything from butterflies and newts to snakes, mice and hummingbirds. And now, just when you thought it was safe to live in the water, we can add fish to the mantid menu. Read More

CATEGORIZED UNDER: Living World
MORE ABOUT: animals

Sharing is Caring? Actually, it’s Just Contagious

By Anna Groves | September 20, 2018 10:00 am
An African Hadza woman with close-cropped hair and wearing colorful fabrics and beads sits in the front passenger seat of a car. She is holding two honey sticks.

A Hadza woman plays the honey stick public goods game inside the researchers’ vehicle. (Photo: Eduardo Acevedo)

Once upon a time (er, yesterday), we might have thought a character trait like generosity was something deeply ingrained by life experiences or even decided by a person’s genes.

But research today in Current Biology suggests that a person’s propensity to share is highly dependent on one thing: how much the people around them – currently – are sharing.

A person’s generosity as recent as last year has no correlation to their generosity now.

Scientists learned this while studying cooperation in the Hadza hunter-gatherer societies of Tanzania.

The Hadza live in camps of about 30 people, each made up of a few nuclear families. The camps move geographically every few weeks, and families move between camps regularly.

This structure makes Hadza society a perfect setup for investigating whether a personality trait is maintained over time, or if it changes with new social surroundings.

A Sweet Game

To look at generosity of individuals across camps and over time, the researchers used what’s called a public goods game, a concept borrowed from economists.

In these games, individuals are given an opportunity to keep or share some or all of a “good” they’re offered. Shared goods go into a pot where they will be multiplied and then distributed to the whole group. Individuals don’t know each other’s choices.

Food sharing is an important part of the Hadza’s hunter-gatherer culture, and honey is a favorite food. So the researchers used honey sticks as the good to share (or not) in the game.

To play, they’d offer each Hadza four honey sticks. They could keep any number of sticks, and contribute any number to a box. For every stick in the box, the researchers promised to add three more before distributing them to everyone in the camp after everyone had played. No one knew anyone else’s contributions to the box.

Surprising Sharing

The researchers learned that members of a camp were always similar to one another in how much they shared. But across camps, sharing varied significantly – camps were easily sorted into those with good sharers and bad.

But Hadza people had not sorted themselves into like-minded groups over time, with the good sharers seeking out other good sharers.

Instead, individuals’ generosity changed over time. How much each person shared was related only to how well members of their current camp were sharing. How much they shared in their previous camp, as recent as one year prior, was irrelevant.

In other words, a previously selfish person became generous when they joined a generous camp, and vice versa.

“The robustness of that result was really surprising,” says Kris Smith, a University of Pennsylvania scientist who led the research.

Coren Apicella, his colleague at Penn, agrees. “It was surprising, and from a scientific perspective, it was nice to have such findings year after year,” she says. “That we found it in four different years was really cool, and it was really strong.”

In the future, Smith plans to look into how the Hadza think the other people in their camp intend to behave. And many other questions remain, such as how these social norms are communicated.

This could be particularly interesting, Apicella says, because Hadza society operates without the formal institutions we might think of as keeping people in check: written laws, police or even religions with judgmental gods.

Be Excellent to Each Other

Though understanding the exact mechanism will require more research, it’s clear that a person can and does become more generous by joining a generous group.

Which leaves us with an encouraging moral.

“If you find yourself surrounded by selfish people, you don’t necessarily have to find a new crowd,” Smith said in a statement. “But by being generous yourself, you can get others to be generous as well.”

CATEGORIZED UNDER: Mind & Brain, top posts
MORE ABOUT: psychology

Gambling Monkeys Shed Light on Risky Behavior

By Anna Groves | September 20, 2018 10:00 am
Two rhesus macaques with tan and white coats.

Two rhesus macaques, though not the two shown here, have helped scientists identify a brain region important for risky decision-making. (Credit: izarizhar/shutterstock)

Researchers have identified a key brain area associated with high-risk behavior, thanks to two monkeys they trained to gamble.

Before the rhesus monkeys could start gambling, they had to learn the researchers’ system of cues. Squares of different colors signaled how big the payout – a drink of water or juice – would be.

“They know which (color) gives which amount,” says Veit Stuphorn, associate professor of psychological and brain sciences at Johns Hopkins University. “In the wild, they’re doing this all the time, using very small differences in visual cues. So we’re tapping into something that has ecological meaning for them. This berry is slightly better, or this root.”

But, Stuphorn says, “probability is harder to teach.”

Xiaomo Chen led the study and is now a postdoctoral fellow at Stanford University. To teach the monkeys to understand their odds, she and Stuphorn next showed the animals squares with two colors at a time. More area of a color meant higher odds of that outcome. The monkeys got that, too.

As a control, the scientists ran trials where two options had the same probabilities but different maximum payouts, plus trials that had different probabilities for the same maximum payout. The monkeys almost always chose the better option, showing that they knew what they were doing.

To add an extra layer of precision, Chen and Stuphorn trained the monkeys to play this game totally visually: they didn’t press any buttons, or use any signals other than holding their gaze on the square they wanted to choose.

Gambling Big

The monkeys, as it turned out, were highly risk-seeking, regularly choosing options with higher potential rewards at low odds.

Part of this, says Stuphorn, is likely that each trial had a relatively small amount of reward at stake, and that they knew there would be thousands of trials.

“They might have been more risk-averse if there was a risk of pain or real danger, but obviously we can’t test that,” explains Stuphorn.

Regardless, the monkeys liked the gambles, and this allowed Chen and Stuphorn to study the brain mechanisms behind the risky behavior.

Brain Freeze

Researchers have known for a while that the frontal cortex of the brain is important for decision-making. But Chen and Stuphorn wanted to know if a particular area, the Supplementary Eye Field or SEF, was associated with risky decisions.

The most straightforward way to test what a brain region controls is to turn it off. This can be done, temporarily, by cooling down the neurons until they’re too cold to fire off their action potentials.

Conveniently, the SEF is only about 1 mm deep, so the researchers could cool it off – and turn it off – with external cold.

When they did, the monkeys’ behavior changed: they became more risk-averse.

But there were other behaviors associated with gambling that were not affected; notably, that monkeys were still more likely to gamble after a win, and more likely to play it safe after a loss – a common behavior among gambling monkeys and humans.

“The specificity of the effect was exciting,” says Stuphorn. “To some extent it means you can decompose the mechanisms that overall compose the gamble.”

These findings could lead to better treatments for humans with destructively risky behaviors.

CATEGORIZED UNDER: Mind & Brain, top posts

Employees Trust Each Other More in Competitive Workplaces

By Mark Barna | September 19, 2018 4:27 pm
office workers compete on roller chairs

(Credit: g-stockstudio/shutterstock)

Firms in competitive industries are often seen as cutthroat and intense places to work. But while the work might be intense, the employees tend to trust and cooperate with each other, according to a study published Wednesday in Science Advances. The high stakes appear to bring about group cohesiveness, which might have deep evolutionary roots.

The Canadian and American researchers examined several workplace surveys for America, such as the US Census of Firms and the North American Industrial Classification System, and for Germany, they used the Herfindahl index, which measures firm size and industry competition. Within these surveys, they found statistics on the level of competitiveness in various industries based on mathematical formulas.

Researchers also looked at surveys in America and Germany with info on where people work so they could pinpoint workers in competitive and noncompetitive industries. Finally, they examined questionnaire responses from thousands of Americans and Germans in a variety of industries, looking for answers to a specific question: How much do you trust your co-workers?
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CATEGORIZED UNDER: Mind & Brain
MORE ABOUT: psychology

How AI Is Teaching Gliders to Soar

By Nathaniel Scharping | September 19, 2018 3:17 pm
glider

(Credit: Aerovista Luchtfotografie/Shutterstock)

An adult albatross can spend days without ever touching the ground. Long wings that lock into place provide enormous amounts of lift. And a keen sense for thermals and air currents lets the birds soar with little energy expenditure. Sleeping, eating, drinking and bathing all take place on the wing, over the course of journeys that can span up to 10,000 miles.

Entrepreneurs like Mark Zuckerberg wish they could fly like an albatross. The Facebook founder’s Internet.org initiative aimed to deliver wireless internet to developing countries with high-flying drones that could stay aloft for months, beaming internet to rural areas. After disappointing drone flights, among other things, the project has since been scrapped. Google, too, seemed interested in developing long-lasting drones, acquiring Titan Aerospace in 2014, a maker of near-orbital drones that could serve as satellites. Read More

CATEGORIZED UNDER: Technology
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