Spread of misfolded proteins could trigger type 2 diabetes

Type 2 diabetes and prion disease seem like an odd couple, but they have something in common: clumps of misfolded, damaging proteins.

Now new research finds that a dose of corrupted pancreas proteins induces normal ones to misfold and clump. This raises the possibility that, like prion disease, type 2 diabetes could be triggered by these deformed proteins spreading between cells or even individuals, the researchers say.

When the deformed pancreas proteins were injected into mice without type 2 diabetes, the animals developed symptoms of the disease, including overly high blood sugar levels, the researchers report online August 1 in the Journal of Experimental Medicine.
“It is interesting, albeit not super-surprising” that the deformed proteins could jump-start the process in other mice, says Bruce Verchere, a diabetes researcher at the University of British Columbia in Vancouver. But “before you could say anything about transmissibility of type 2 diabetes, there’s a lot more that needs to be done.”

Beta cells in the pancreas make the glucose-regulating hormone insulin. The cells also produce a hormone called islet amyloid polypeptide, or IAPP. This protein can clump together and damage cells, although how it first goes bad is not clear. The vast majority of people with type 2 diabetes accumulate deposits of misfolded IAPP in the pancreas, and the clumps are implicated in the death of beta cells.

Deposits of misfolded proteins are a hallmark of such neurodegenerative diseases as Alzheimer’s and Parkinson’s as well as prion disorders like Creutzfeldt-Jakob disease (SN: 10/17/15, p. 12).

Since IAPP misfolds like a prion protein, neurologist Claudio Soto of the University of Texas Health Science Center at Houston and his colleagues wondered if type 2 diabetes could be transmitted between cells, or even between individuals. With this paper, his group “just wanted to put on the table” this possibility.

The mouse version of the IAPP protein cannot clump — and mice don’t develop type 2 diabetes, a sign that the accumulation of IAPP is important in the development of the disease, says Soto. To study the disease in mice, the animals need to be engineered to produce a human version of IAPP. When pancreas cells containing clumps of misfolded IAPP, taken from an engineered diabetic mouse, were mixed in a dish of healthy human pancreas cells, it triggered the clumping of IAPP in the human cells.
The same was true when non-diabetic mice got a shot made with the diabetic mouse pancreas cells. The non-diabetic mice developed deposits of clumped IAPP that grew over time, and the majority of beta cells died. When the mice were alive, more than 70 percent of the animals had blood sugar levels beyond the healthy range.

Soto’s group plans to study if IAPP could be transmitted in a real world scenario, such as through a blood transfusion. They’ve already begun work on transfusing blood from mice with diabetes to healthy mice, to see if they can induce the disease. “More work needs to be done to see if this ever operates in real life,” Soto says.

Even if transmission of the misfolded protein occurs only within an individual, “this opens up a lot of opportunities for intervention,” Soto says, “because now you can target the IAPP.”

Verchere also believes IAPP is “a big player” in the progression of type 2 diabetes, and that therapies that prevent the clumps of proteins from forming are needed. Whether or not future research supports the idea that the disease is transmissible, the study is “good for appreciating the potential role of IAPP in diabetes.”

Normally aloof particles of light seen ricocheting off each other

Cross two flashlight beams and they pass right through one another. That’s because particles of light, or photons, are mostly antisocial — they don’t interact with each other. But now scientists have spotted evidence of photons bouncing off other photons at the Large Hadron Collider at CERN, the European particle physics lab in Geneva.

“This is a very basic process. It’s never been observed before, and here it is finally emerging from the data,” says theoretical physicist John Ellis of King’s College London who was not involved with the study. Researchers with the ATLAS experiment at the LHC report the result August 14 in Nature Physics.
Because photons have no electric charge, they shouldn’t notice one another’s presence. But there’s an exception to that rule. According to quantum mechanics, photons can briefly transform into transient pairs of electrically charged particles and antiparticles — such as an electron and a positron — before reverting back to photons. Predictions made more than 80 years ago suggest that this phenomenon allows photons to interact and ricochet away from one another.

This light-by-light scattering is extremely rare, making it difficult to measure. But photons with more energy interact more often, providing additional chances to spot the scattering. To produce such energetic photons, scientists slammed beams of lead nuclei together in the LHC. Photons flit in and out of existence in the lead nuclei’s strong electromagnetic fields. When two nuclei got close enough that their electromagnetic fields overlapped, two photons could interact with one another and be scattered away.

To measure the interaction, ATLAS scientists sifted through their data to find collisions in which only two photons — the two that scattered away from the collision — appeared in the aftermath. “That’s the trickiest part of the whole thing,” says physicist Peter Steinberg of Brookhaven National Laboratory in Upton, N.Y., a member of the ATLAS collaboration. The scientists had to ensure that, in their enormous, highly sensitive particle detector, only two photons appeared, and convince themselves that no other particles had gone unaccounted for. The researchers found 13 such events over 19 days of data collection. Although other processes can mimic light-by-light scattering, the researchers predict that only a few such events were included in the sample.

The number of scattering events the researchers found agrees with the predictions of the standard model, physicists’ theory of particle physics. But a more precise measurement of the interaction might differ from expectations. If it does, that could hint at the existence of new, undiscovered particles.

These chip-sized spacecraft are the smallest space probes yet

Spacecraft have gone bite-sized. On June 23, Breakthrough Starshot, an initiative to send spacecraft to another star system, launched half a dozen probes called Sprites to test how their electronics fare in outer space. Each Sprite, built on a single circuit board, is a prototype of the tiny spacecraft that Starshot scientists intend to send to Alpha Centauri, the trio of stars closest to the sun. Those far-flung probes would be the smallest working spacecraft yet.

“We’re talking about launching things that are a thousand times lighter than any previous spacecraft,” says Avi Loeb, an astrophysicist at Harvard University who is part of the committee advising the initiative. A Sprite is only 3.5 centimeters square and weighs four grams, but packs a solar panel, radio, thermometer, magnetometer for compass capabilities and gyroscope for sensing rotation.

These spacecraft are designed to fly solo, but for this test, they hitched a ride into low Earth orbit on satellites named Max Valier and Venta-1. Each satellite has one Sprite permanently riding sidecar, and the Max Valier craft has another four it could fling out into space. Unfortunately, as of August 10, ground controllers haven’t yet been able to reach the Max Valier satellite to send a “Release the Sprites!” command. One of the permanently attached Sprites — probably the one on Venta-1 — is in radio contact.

Before sending next-gen Sprites off to Alpha Centauri, scientists plan to equip them with cameras, actuators for steering and other tools. “This was really just the first step in a long journey for Starshot,” Loeb says.

This sea snake looks like a banana and hunts like a Slinky

With its bright hue, this snake was bound to stand out sooner or later.

A newly discovered subspecies of sea snake, Hydrophis platurus xanthos, has a narrow geographic range and an unusual hunting trick. The canary-yellow reptile hunts at night in Golfo Dulce off Costa Rica’s Pacific coast. With its body coiled up at the sea surface, the snake points its head under the water, mouth open. That folded posture “creates a buoy” that stabilizes the snake so it can nab prey in choppy water, says study coauthor Brooke Bessesen, a conservation biologist at Osa Conservation, a biodiversity-focused nonprofit in Washington, D.C. In contrast, typical Hydrophis platurus, with a black back and yellow underbelly, hunts during the day, floating straight on calm seas.
The newly described venomous snake has been reported only in a small, 320-square-kilometer area of Golfo Dulce. After analyzing 154 living and preserved specimens, the researchers described the reptile’s characteristics July 24 in Zookeys. The scientists hope that the subspecies designation will enable the Costa Rican government to protect the sunny serpent, which they worry is already at risk from overzealous animal collectors.

This newfound hermit crab finds shelter in corals, not shells

A new species of hermit crab discovered in the shallow waters of southern Japan has been enjoying the perks of living like a peanut worm. Like the worms, the 7- to 8-millimeter-long hermit crab uses corals as a covering, researchers report September 20 in PLOS ONE.

Other kinds of hermit crabs live in coral reefs, but typically move in and out of a series of mollusk shells as the crabs grow. Diogenes heteropsammicola is the first hermit crab known to form a mutually beneficial relationship with two species of mobile corals called walking corals. Unlike more familiar coral species, these walking corals don’t grow in colonies and aren’t attached to the seafloor. Instead, each host coral grows with and around a crab, forming a cavity in the coral skeleton that provides a permanent home for the crustacean. In exchange, the crab helps the coral “walk.”
Walking corals are already known to be in a symbiotic relationship with a different sea creature — flexible, marine peanut worms called sipunculids. A symbiotic shift between such distantly related species as the worms and the crab is rare because organisms in a mutualistic relationship tend to be specialized and completely dependent on one other, says study coauthor Momoko Igawa, an ecologist at Kyoto University in Japan.
But similar to the worms, D. heteropsammicola appears to be well-adapted to live in the corals. Its extra slim body can slip inside the corals’ narrow cavity. And unlike other hermit crabs — whose tails curve to the right to fit into spiral shells — D.heteropsammicola’ s tail is symmetrical and can curl either way, just like the corals’ opening.
“Being able to walk around in something that is going to grow larger as you grow larger, that’s a big plus,” says Jan Pechenik, a biologist at Tufts University in Medford, Mass., who was not involved in the study. A typical hermit crab that can’t find a larger shell to move into “really is in trouble.”

D. heteropsammicola’s relationship with walking corals may begin in a similar way as it does with sipunculan worms, Igawa says. A walking coral larva latches onto a tiny mollusk shell containing a juvenile hermit crab and starts to grow. When the hermit crab outgrows the shell, the crustacean moves into the readily available host coral’s crevice, and the shell remains encapsulated in the coral.

By observing the hermit crab in an aquarium, Igawa and coauthor Makoto Kato, also an ecologist at Kyoto University, determined that the crab provides the corals with the same services as the worms: transportation and preventing the corals from being overturned by currents or buried in sediment.

Igawa hopes to search for this new hermit crab in Indonesia, a region where walking corals are normally found. Plus, because walking coral fossils are easy to come by in Japan, she also wants “to reveal the evolutionary history of the symbioses of walking corals [with] sipunculans and hermit crabs by observing these fossils.”

New setup for image recognition AI lets a program think on its feet

Artificial intelligence is getting some better perspective. Like a person who can read someone else’s penmanship without studying lots of handwriting samples, next-gen image recognition AI can more easily identify familiar sights in new situations.

Made from a new type of virtual building block called capsules, these programs may cut down the enormous amount of data needed to train current image-identifying AI. And that could boost such technology as machine-made medical diagnoses, where example images may be scarce, or the responsiveness of self-driving cars, where the view is constantly shifting. Researchers with Google will present this new version of an artificial neural network at the Neural Information Processing Systems conference in Long Beach, Calif., on December 5.
Neural networks are webs of individual virtual nerve cells, or neurons, that learn to pick out objects in pictures by studying labeled example images. These networks largely classify pictures based on whether they contain certain features. For instance, a program trained on a series of head shots might conclude that a face has two eyes, a nose and a mouth. Show that program a face in profile with only one eye visible, though, and it may not recognize the photo as a face, explains Roland Memisevic, a computer scientist at the University of Montreal who was not involved in the work.

To overcome that limitation, researchers can train a neural network on millions of photos from myriad angles, and the program memorizes all the different ways a face might look. Compared with the human brain, which doesn’t need anywhere near a million examples to know what a face looks like, this system is wildly inefficient. “It’s a disaster,” Memisevic says. “Capsules try to fix that.”

Instead of webs of individual artificial neurons, these new programs have webs of clusters of neurons, called capsules. These teams of neurons can provide more information than one neuron by itself. Each capsule is designed to track not only whether a certain feature is in an image, but also properties of that feature — say, a nose’s size, orientation and position. This spatial awareness helps the program better recognize objects in previously unseen scenarios.

A capsule-containing network trained on head shots could see a face in profile and deduce — based on the appearance of the visible eye, nose and mouth — that the other eye is simply obscured, and the picture depicts a face. Since capsule networks are better at applying what they know to new situations, these neural networks need less training data to achieve the same performance as their predecessors, says Sara Sabour, a computer scientist with Google Brain in Toronto.
Sabour and her colleagues trained one capsule network on images of handwritten numbers and tested it on pictures where each number was slightly distorted. The capsule network recognized the warped images with 79 percent accuracy; a typical neural network trained on the same amount of data only got 66 percent right.

In another experiment, Sabour and colleagues trained a similar capsule network on tens of thousands of photos of toys, and then asked it to recognize the toys from new viewpoints. In this challenge, reported in a paper submitted to the 2018 International Conference on Learning Representations in Vancouver, the capsule network was wrong only about 1.4 percent of the time. A conventional neural network made almost twice as many errors.

Mini brains may wrinkle and fold just like ours

PHILADELPHIA — Flat brains growing on microscope slides may have revealed a new wrinkle in the story of how the brain folds.

Cells inside the brains contract, while cells on the outside grow and push outward, researchers at the Weizmann Institute of Science in Rehovot, Israel, discovered from working with the lab-grown brains, or organoids. This push and pull results in folds in the organoids similar to those found in full-size brains. Orly Reiner reported the results December 5 at the joint meeting of the American Society for Cell Biology and the European Molecular Biology Organization.
Reiner and her colleagues sandwiched human brain stem cells between a glass microscope slide and a porous membrane. The apparatus allowed the cells access to nutrients and oxygen while giving the researchers a peek at how the organoids grew. The cells formed layered sheets that closed up at the edges, making the organoids resemble pita bread, Reiner said. Wrinkles began to form in the outer layers of the organoids about six days after the mini brains started growing.

These brain organoids may help explain why people with lissencephaly — a rare brain malformation in which the ridges and folds are missing — have smooth brains. The researchers used the CRISPR/Cas9 gene-editing system to make a mutation in the LIS1 gene. People with lissencephaly often have mutations in that gene. Cells carrying the mutation didn’t contract or move normally, the team found.

Reiner and her colleagues aren’t the first to propose the push-pull idea for how brains fold. But the researchers were able to show the concept at work in their experimental system, says biophysicist Xavier Trepat of the Institute for Bioengineering of Catalonia in Barcelona, who was not involved in the study. “They really were able to reproduce the shape of what we all imagine the brain should look like,” he says. “It’s not a brain, but they see structures that look like it.”

U.S. religion is increasingly polarized

There’s both inspiring and troubling news for holiday worshippers.

Unlike other historically Christian Western nations, the United States is not losing its religion, say sociologists Landon Schnabel of Indiana University Bloomington and Sean Bock of Harvard University. But America is becoming as polarized religiously as it is politically, the researchers report online November 27 in Sociological Science.

Intense forms of religion, such as Christian evangelicalism, have maintained their popularity for nearly 30 years, Schnabel and Bock find after analyzing almost 30 years of U.S. survey data. At the same time, moderate forms of religion, such as mainline Protestantism, have consistently lost followers.
Religious moderates’ exodus from their churches stems partly from a growing link between religion and conservative politics, exemplified by the rise of the religious right in the late 1980s, the researchers suspect. Political liberals and moderates who already felt lukewarm toward the religion of their parents increasingly report identifying with no organized religion, especially if leaders of their childhood churches have taken conservative stances on social issues. Many Americans still report that they believe in God and pray, so they haven’t turned to atheism, the scientists say.

Population trends also favor intense forms of religion, Schnabel holds. Mainline Protestantism’s decline from 35 percent of the U.S. population in 1972 — about 73.5 million people — to 12 percent in 2016 — nearly 39 million people — reflects low fertility rates among these Protestants and limited numbers of new adherents from immigration and conversion. Opposite trends among U.S. evangelicals helped their form of intense Christianity surge from 18 percent of the population in 1972 to a steady level of about 28 percent from 1989 to 2016.

“More moderate forms of organized religion could become increasingly irrelevant in the United States,” Schnabel says.
The new findings play into an academic debate about the fate of religion in modern societies. Some scholars argue that in wealthy nations marked by scientific advances, religion inevitably withers. National surveys in 13 other Western, historically Christian nations show a general weakening of religious beliefs, even among intense believers, since 1991, the researchers find. But Schnabel and Bock are among those who view the United States as an exception where intense religion holds steady and even many of those leaving churches keep their faith.

The researchers examined data from nationally representative surveys on religion and other topics conducted from 1989 to 2016 by the General Social Survey, or GSS, a project of the National Opinion Research Center at the University of Chicago. GSS surveys include approximately 1,500 people annually.

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The proportion of the U.S. population citing strong ties to any religion held steady at around 36 percent during the study period. But the share of adults identifying themselves as religiously unaffiliated rose from around 9 percent to around 20 percent of the population, the researchers report. In another sign of loosening religious ties, those who never attended religious services rose from around 14 percent to around 25 percent of the population. Occasional attendance dropped from about 80 percent to about 70 percent.

Still, those who rarely or never prayed remained at about 24 percent of the population from 1989 to 2016. People who prayed several times a day rose from around 24 percent to about 30 percent of the total.

A belief in the Bible as God’s literal word held steady at roughly one-third of Americans. A view of the Bible as inspired by a higher power but not literal fell slightly to just under half of the population. Those tagging the Bible as a book of fables rose from around 15 percent to around 22 percent.

The new findings underscore the growing polarization of U.S. religion, say Michael Hout of New York University and Claude Fischer of the University of California, Berkeley. In a 2014 report based on GSS data, the two sociologists found that most political liberals and some political moderates who weakly identified with their parents’ religion have increasingly said that they prefer no particular religion. That trend was most pronounced for those reporting that the church they grew up with had become an advocate of politically conservative positions. Many of those people expressed a qualified belief in God, endorsing neither atheism nor absolute certainty in a higher power’s existence. Political conservatives, including those who seldom attended services or had doubts about church doctrine, had no complaints about religious leaders’ conservative political pronouncements.

Members of the millennial generation born since 1990 report low levels of religious involvement regardless of their politics, Hout adds. Millennials are skeptical of institutions in general although most still believe in God, he says. “Millennials are more comfortable with do-it-yourself religion than none at all.”

Sociologists David Voas of University College London and Mark Chaves of Duke University disagree. Millennials are part of a larger U.S. trend in which each successive generation over nearly the last century has reported slightly less intensity of religious belief than the one before, Voas and Chaves reported in a 2016 analysis of GSS data. For instance, in 2014, only 45 percent of U.S. adults ages 18 to 30 had no doubts that God exists versus 68 percent of those age 65 or over.

“The proportion of intensely religious Americans is being eroded, albeit very slowly,” Voas contends.

The sun’s outer atmosphere is far more complex than previously thought

NEW ORLEANS — Despite its smooth appearance, the sun’s wispy outer atmosphere is surprisingly full of knots, whorls and blobs.

Newly analyzed observations from NASA’s STEREO spacecraft show that the sun’s outer corona is just as complicated as the highly structured inner corona, solar physicists reported December 12 at the fall meeting of the American Geophysical Union. That previously unseen structure could help solve some of the sun’s biggest puzzles, including how the solar wind is born and why the corona is so much hotter than the solar surface.
The corona is made up of charged plasma, which roils in famous loops and fans that follow magnetic field lines emerging from the surface of the sun (SN Online: 8/17/17). At a certain distance from the sun, though, that plasma escapes the corona and streams through the solar system as the solar wind, a constant flow of charged particles that pummels the planets, including Earth (SN Online: 8/18/17).

But solar physicists don’t know where the plasma gets enough energy to accelerate away from the massive, magnetic sun. And they don’t understand why the corona, which sizzles at several million degrees Celsius, has such higher temperatures than the solar surface, which chills at a mere 5,500° C (SN Online: 8/20/17).

Both problems might be cleared up by better understanding an energetic process called reconnection, which happens when magnetic field lines merge when they get too close to each other. Reconnection releases energy and helps move plasma around, so the process could be important to heating the corona and driving solar wind.

But in the best observations until now, the outer corona appeared smooth and uniform. To explain that smoothness, field lines would have to keep their distance from each other without a lot of reconnection. What’s more, physicists couldn’t tell where the boundary between the corona and the solar wind began, which might help to find that missing energy source.
“That’s changed,” solar physicist Craig DeForest of the Southwest Research Institute in Boulder, Colo., said at the AGU meeting. “Using STEREO, we’ve recently been able to drill in deeply enough to see the transition at the outer edge of the corona, where the dynamics change from what we might call coronal plasma to what we might call the young solar wind plasma.”

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DeForest and colleagues collected data for three days with STEREO in 2014 to gain more detail about small-scale changes in the outer corona than previously obtained. The researchers also processed the resulting images in a new way to bring those changes into focus.

Surprisingly, the team found that the outer corona is full of moving blobs and fine streams of plasma that vary in density by a factor of 10, suggesting that the magnetic field lines there are moving and merging more than scientists thought. “It turns out the apparent smoothness is a reflection of our instruments, not the corona itself,” DeForest says. “There’s almost certainly reconnection in the outer corona.”

The researchers also found that the corona probably fades into the solar wind between 14 million and 56 million kilometers away from the sun — about 10 to 40 times the sun’s diameter. That’s still a big range, but NASA’s Parker Solar Probe spacecraft, scheduled to launch in 2018, will fly right through that boundary. The probe will swoop within 6.4 million kilometers of the sun and take the first direct measurements of the corona — and perhaps figure out more precisely where the corona becomes the solar wind.

For now, the STEREO observations “are just tantalizing hints at an entire new set of phenomena,” DeForest says. Understanding the details of those processes “is going to require both careful analysis from Parker Solar Probe and also new, better imaging instruments.”

Solar physicist Steven Cranmer of the University of Colorado Boulder, who has made simulations of magnetic reconnection in the outer corona, finds the results exciting. Questions about the sun’s hot corona and the acceleration of the solar wind are still unsolved “not because of a lack of ideas, but because there are too many ideas,” he says. “I think we’re getting close to having the data that will let us rule out a good swath of these proposed ideas.”

The science behind kids’ belief in Santa

Over the past week, my little girls have seen Santa in real life at least three times (though only one encounter was close enough to whisper “yo-yo” in his ear). You’d think that this Santa saturation might make them doubt that each one was the real deal. For one thing, they looked quite different. Brewery Santa’s beard was a joke, while Christmas-tree-lighting Santa’s beard was legit. Add to that variations in outfits and jolliness levels.

But as I delved into the Santa-related research, I found I was wrong to think his omnipresence might throw my kids off. It turns out that the more kids see real, live Santa Clauses, the more likely they are to think he’s real. More exposure actually tracked with stronger belief, scientists reported in Cognitive Development in 2016.

That got me wondering about this belief. Like many parents, I feel a little hint of unease when it comes to telling my trusting, innocent children a lie. But lots of parents conspire to tell this lie to their children. An AP survey from 2011 (the most recent I could find on this pressing issue) revealed that 84 percent of adult respondents believed in Santa as a child.

Many of these former children had their Christmas beliefs shattered around age 8, other studies suggest. A fascinating paper from 1978 found that 85 percent of 4-year-olds believed in Santa. Five percent didn’t, and 10 percent were still thinking about it. But only 25 percent of 8-year-olds believed in Santa, with 20 percent not believing and 55 percent transitioning in their beliefs. Funnily enough, 60 percent of these same 8-year-olds still believed in the tooth fairy.
This shift in belief from age 4 to 8 has some psychology behind it. The influential child psychologist Jean Piaget proposed that around age 8 children enter the “concrete operational stage” of thinking — a critical, observant phase of questioning impossible things. (To be clear, it is impossible for Santa to fly around the world and deliver toys to all the houses, even with the 48 hours he’d have thanks to the Earth’s time zones, and other time-warping assists. Physicists have looked into it.)

Eight-year-olds’ discerning mindset was detected in a study that prodded children to list not toys, but questions for Santa. Young children tended to ask clarifying sorts of questions, such as “Is the North Pole cold?” “What are your elves’ names?” and “What do your reindeer do during the summer?” Those questions get at minor details without coming close to the central mysteries at the heart of a magical Santa. Older kids, however, were more likely to ask the toughies: “How do you fit inside a chimney?” and “How can you see everyone in the whole wide world?”

Once these questions start coming from your kid, the end may be in sight. But take heart, from yet another scientific study of Santa. Children are a sturdy bunch, and do pretty well after they find out the truth, interviews showed. In fact, it’s probably a relief when the entire world stops gaslighting kids and they finally get their hunches confirmed. The bad news is that the parents didn’t fare so well, describing themselves as predominantly sad after their children learned the truth.

For parents, their children’s discovery is an end of an era, a loss of a ritual tied up in family, tradition and treats. But sadder to me, I think, is that when that reckoning comes to my little girls, it will be a vivid reminder that my time with my small children is scant. These moments of magical thinking fly by faster than Santa would need to travel to complete his furious dash around the world.