Mouse sperm could win awards for resilience. Sperm freeze-dried and sent into space for months of exposure to high levels of solar radiation later produced healthy babies, researchers report online May 22 in Proceedings of the National Academy of Sciences.

If humans ever embark on long-term space flights, we’ll need a way to reproduce. One potential hurdle (beyond the logistical challenges of microgravity) is the high amount of solar radiation in space — radiation exposure is 100 times as high on the International Space Station as on Earth. Those doses might cause damaging genetic mutations in banked eggs and sperm.
To test this possibility, Japanese researchers sent freeze-dried mouse sperm up to the space station, where the sperm spent nine months. When rehydrated back on Earth, the sperm showed some signs of DNA damage compared with earthly sperm.

But when the researchers used the space sperm to fertilize eggs in the lab and then injected the eggs into female mice, the mice birthed healthy pups that were able to have their own offspring. The researchers suspect that some of the initial DNA damage might have been repaired after fertilization.

If mouse sperm can survive a trip to space, perhaps human sperm can, too.

HAT-P 7b is a windy world. Stiff easterlies typically whip through the atmosphere of the distant exoplanet, but sometimes the powerful gales blow in surprisingly varied directions. Now, simulations of the planet’s magnetic field lines, illustrated here as a rainbow of scrawled marks, reveal that HAT-P 7b’s magnetic field influences the winds, even turning some into westerlies. The result, published May 15 in Nature Astronomy, could lead to a better understanding of the atmospheres of other exoplanets.
Known as a “hot Jupiter,” HAT-P 7b is a gas giant that orbits its star once every 2.2 Earth days. The exoplanet, located 1,043 light-years away, is also tidally locked: One side always faces toward its star while the other faces away. That orientation pushes temperatures to about 1,900° Celsius on the planet’s dayside compared with about 900° C on the nightside. Those extreme temperature differences tend to power strong easterly winds, according to an analysis of data from the Kepler satellite. But that analysis also revealed that over time the winds are surprisingly mercurial.

The magnetic field, which may be generated by the planet’s core, is connected to the winds because of high temperatures stripping electrons from atmospheric atoms of lithium, sodium and potassium, making them positively charged. Those particles then interact with the field, creating an electromagnetic force strong enough to disrupt the stout easterly winds, writes study author Tamara Rogers, an astrophysicist at Newcastle University in England.

In the image above, blue lines track strong magnetic field lines directed one way, while those in magenta trace powerful lines in the opposite direction. Weaker parts of the field lines are shown in green and yellow. The stronger the magnetic field, the wilder the winds — with the strongest lines completely reversing the direction the winds blow, Rogers concludes.

A monkey’s brain builds a picture of a human face somewhat like a Mr. Potato Head — piecing it together bit by bit.

The code that a monkey’s brain uses to represent faces relies not on groups of nerve cells tuned to specific faces — as has been previously proposed — but on a population of about 200 cells that code for different sets of facial characteristics. Added together, the information contributed by each nerve cell lets the brain efficiently capture any face, researchers report June 1 in Cell.
“It’s a turning point in neuroscience — a major breakthrough,” says Rodrigo Quian Quiroga, a neuroscientist at the University of Leicester in England who wasn’t part of the work. “It’s a very simple mechanism to explain something as complex as recognizing faces.”

Until now, Quiroga says, the leading explanation for the way the primate brain recognizes faces proposed that individual nerve cells, or neurons, respond to certain types of faces (SN: 6/25/05, p. 406). A system like that might work for the few dozen people with whom you regularly interact. But accounting for all of the peripheral people encountered in a lifetime would require a lot of neurons.

It now seems that the brain might have a more efficient strategy, says Doris Tsao, a neuroscientist at Caltech.

Tsao and coauthor Le Chang used statistical analyses to identify 50 variables that accounted for the greatest differences between 200 face photos. Those variables represented somewhat complex changes in the face — for instance, the hairline rising while the face becomes wider and the eyes becomes further-set.

The researchers turned those variables into a 50-dimensional “face space,” with each face being a point and each dimension being an axis along which a set of features varied.
Then, Tsao and Chang extracted 2,000 faces from that map, each linked to specific coordinates. While projecting the faces one at a time onto a screen in front of two macaque monkeys, the team recorded the activity in single neurons in parts of the monkey’s temporal lobe known to respond specifically to faces. All together, the recordings captured activity from 205 neurons.

Each face cell was tuned to one of the 50 axes previously identified, Tsao and Chang found. The rate at which each cell sent electrical signals was proportional to a given face’s coordinate position along an axis. But a cell didn’t respond to changes in features not captured by that axis. For instance, a cell tuned to an axis where nose width and eye size changed wouldn’t respond to changes in lip shape.
Adding together the features conveyed by each cell’s activity creates a picture of a complete face. And like a computer creating a full-color display by mixing different proportions of red, green and blue light, the coordinate system lets a brain paint any face in a spectrum.

“It was a total surprise,” Tsao says. Even when the faces were turned in profile, the same cells still responded to the same features.

Tsao and Chang were then able to re-create that process in reverse using an algorithm. When they plugged in the activity patterns of the 205 recorded neurons, the computer spat out an image that looked almost exactly like what they had shown the monkeys.

“People view neurons as black boxes,” says Ed Connor, a neuroscientist at Johns Hopkins University who wasn’t part of the study. “This is a striking demonstration that you can really understand what the brain is doing.”

Elsewhere in the brain, though, neurons don’t use this facial coordinate system. In 2005, Quiroga discovered individual neurons attuned to particular people in the hippocampus, a part of the brain involved in memory. He found, for instance, a single neuron that fired off messages in response to a photo of Jennifer Aniston or conceptually related images, like her name written out or a picture of her Friends costar Lisa Kudrow.

The new results fit well into that picture, Tsao and Quiroga agree. Tsao compares her system to a GPS for facial identity. “These cells are coding the coordinates. And you can use these coordinates for anything you want. You can build a specific lookup table that codes these into specific identities — like Barack Obama, or your mother.”

Quiroga’s hippocampal cells, just a few neural connections away, are like the output of that table — a sort of speed dial for people and concepts previously encountered.

The different coding strategies might be tied to differences in what these brain areas do. “When we remember things, we forget details but we remember concepts,” Quiroga says. But for telling faces apart, and especially for processing unfamiliar faces, “details are key.”

Take a trip to a black hole with Stephen Hawking as a guide, watch glowing bioluminescent earthworms wriggle away from predators and discover the fascinating mathematics of origami — all while cuddled up in front of a laptop. That’s the promise of the online streaming service CuriosityStream, which offers hefty doses of science for viewers who prefer fact-based documentaries over reality TV, sports and the political bickering that dominate today’s television programming.

CuriosityStream, which recently celebrated its second birthday, operates much like Netflix. With plans starting at $2.99 per month, users can browse more than 1,700 commercial-free programs covering science, technology, history and the arts. The service works on computers, mobile devices and streaming players such as Roku and Apple TV.
CuriosityStream aims to supplement the media diet of science-starved viewers. “When you look at television … there’s very little science on anymore,” says Steve Burns, CuriosityStream’s chief programming officer. Subscribers, he says, “crave the substance that they’ve been missing on TV for so long.”

Along with a slew of documentaries from the BBC and other public broadcasters, CuriosityStream offers more than 600 original programs that you won’t find anywhere else. One standout is David Attenborough’s Light on Earth, in which the naturalist takes viewers on an engaging survey of bioluminescent life, from flickering fireflies and luminous mushrooms to eerily glowing ocean creatures.

Another enjoyable original is Stephen Hawking’s Favorite Places, in which the famed physicist tours a black hole, exoplanet Gliese 832c, Saturn and other cosmic locales. Computer-generated imagery of the turbulent region around a black hole, for example, provides a brilliant visual background to Hawking’s explanations of relevant research. One episode is currently available, and two new ones are slated to go online later in the year.

Some shows are more engaging than others. Another original, The Hunt for Dark Matter, takes a deep dive into the technology behind the search for the invisible substance thought to pervade the universe. But the show will likely fall flat for many viewers, as its introduction lacks some of the background on the physics of dark matter that is necessary to grasp the relevance of the work.

CuriosityStream provides a wealth of options to choose from, including a variety of shorter shows, each 10 or 15 minutes long. With new programs added regularly, the service should provide enough binge-worthy fodder to keep even the most avid documentary lovers busy

Premature babies, who often develop jaundice because of an excess of bile pigment called bilirubin, can be saved from this dangerous condition by the use of fluorescent light.… The light alters the chemistry of bilirubin so it can be excreted with the bile. Exchange transfusion is the usual treatment when jaundice occurs but this drastic procedure carries a … risk of death. —Science News, June 17, 1967

Update
Preemies aren’t the only babies at risk for jaundice. About 60 percent of full-term infants also develop the condition. Severe cases can cause brain damage if untreated. But today, some researchers warn that light therapy, now widely used, may not work for babies whose bilirubin levels are very high. And studies have begun to suggest a link between the therapy and certain childhood cancers (SN Online: 1/30/15). Though the risk of developing cancer is small, doctors should be cautious about prescribing the treatment, researchers wrote in 2016 in Pediatrics.

On June 18, 4-year-old Bentley Thomas Koch fatally shot himself in the face. A few weeks earlier, Harmony Warfield, age 7, was shot and killed by her 2-year-old cousin. And teens Shadi Najjar and Artem Ziberov, both on the eve of graduating from high school, died in a hail of gunfire. Stories like these of kids dying from gunshot wounds are devastating, but, sadly, they aren’t an anomaly.

The most comprehensive look at fatal and nonfatal firearm injuries among children in the United States makes that abundantly clear. Every day, roughly 19 children die or are medically treated in an emergency department for gun-inflicted wounds, a study published June 19 in Pediatrics finds.

The statistics, based on data from 2002 to 2014, are stark:

Nearly 1,300 children, from birth to age 17, die from gunshot wounds each year on average and another 5,790 kids are wounded;
Of the deaths, 53 percent are homicides, 38 percent are suicides and 6 percent are accidents;
Boys ages 13 to 17 make up the bulk of gunshot victims;
Cause of death varies by race — African-Americans are overwhelmingly more likely to die from homicide than suicide; white kids are nearly three times as likely to die from suicide as from homicide; and for American Indian and Asian-American kids, it’s 50-50.
But this study doesn’t just lay out the numbers. It starts to dig deeper into the whys. And those whys can have important implications, laying the framework for policies that could ultimately lead to a drop in the numbers.

For the numbers, Katherine Fowler, a behavioral scientist at the U.S. Centers for Disease Control and Prevention, and colleagues started with data from the National Vital Statistics System and the National Electronic Injury Surveillance System.

For the whys, her team looked at cases described in the National Violent Death Reporting System, or NVDRS. That let the researchers fill in details like where an incident took place and whether it involved multiple victims — for instance, a homicide followed by suicide or a multiple victim homicide. The database also includes demographic information about the shooter, evidence of alcohol or drugs at the time of death, and whether the incident was gang-related or involved a boyfriend or girlfriend or parents. Clues to whether relationship, financial or school issues were part of the problem also come to light, as does evidence of depression, anxiety, any previous suicide attempt, treatment for mental health problems and physical health problems. Notes about playing with a gun or thinking the gun was a toy, as well as hunting accidents are also included.
This tally of circumstances led Fowler and colleagues to conclude that firearm homicides of younger children, up through age 12, often involve conflict between parents, intimate partners or among family. “This highlights how children can be caught in the cross fire in cases of domestic violence and points to the importance of addressing the intersection of these forms of violence,” she says.

The results also reveal something important about child suicides involving guns. “While mental health factors are important, the findings also show that firearm suicides were also frequently related to situational life stressors and relationship problems with an intimate partner, friend or family member,” Fowler notes.

It’s these kinds of details that can help researchers and lawmakers create more effective policies to prevent such tragic deaths and injuries. It’s worked in other cases. Statistics have shown that tweaks to laws regulating the times of day teens can drive lead to injury prevention. Ditto for access to free swimming lessons when it comes to stopping accidental drownings. But similar data on gun deaths and injuries and the effectiveness of policy to prevent them are harder to come by thanks to lack of funding and political support (SN: 5/14/16, p. 16).

Even so, “we know kids are killing themselves and others with guns,” says David Hemenway, a Harvard University economist and an expert in gun research. When it comes to combatting the problem, “the circumstances help narrow down the policy.”

Fowler says the findings “highlight the need for evidence-based solutions to address this public health problem.” She’s armed with a laundry list of potential policies that could have an impact on the whys of gun violence and make a dent in the stats. School counseling programs could help kids manage their emotions and develop skills to resolve problems in relationships and with peers, she says. Along with therapy, those programs could help to reduce suicidal behavior and youth violence. Street outreach programs may also reduce gang-related violence. Parents and pediatricians talking about storing guns safely — a policy touted by the American Academy of Pediatrics, but one that has met resistance in some states — is another option.

There’s another big need, too: more data.

Despite a better picture of what’s happening when kids get a hold of guns, the data are fragmentary and incomplete, says pediatrician Eliot Nelson of the University of Vermont Children’s Hospital in Burlington. For instance, information from the NVDRS was limited to 17 states, so the numbers aren’t nationally representative. Last year, the database was expanded to 42 states and could eventually be expanded to all 50, but that will take additional funding from Congress.

The way gun injury and death data are coded in databases is another issue. Many unintentional deaths, such as when a child accidentally shoots and kills a sibling or friend, are labeled homicides, Hemenway says. Such misclassifications make it more difficult to create a policy, he says. Take, for instance, encouraging parents to lock up guns in the house. Without correctly coded data to say that younger kids are more likely to be killed by a gun at home while older kids are more likely to be killed by guns at a friend’s house, it’s harder to know how to talk to parents. For parents of young kids, the message might be to lock up their own guns; for parents of older kids, it might be to inquire about guns at the homes of their children’s friends. “We don’t always know who best to target our message to,” Nelson says.

Studies such as Fowler’s are slowly filling in the gaps. But not fast enough for kids like Bentley, Harmony, Shadi and Artem. “We want to keep growing our knowledge to prevent problems,” Nelson says. But, he says, it’s hard to do when money and politics hamper research into the problem. Gun-related deaths ranks third as the leading cause of death in 1- to 17-year-olds in the United States. “Gun death in kids is such a common problem,” Nelson says. “We can’t continue to ignore it.”

In Carl Sagan’s 1985 sci-fi novel Contact, a radio astronomer battles naysayers and funding setbacks to persist in her audacious plan — scanning the skies for signals from aliens. Sagan had real-life inspiration for his book (and the 1997 movie of the same name): astronomer Jill Tarter, who spearheaded the search for extraterrestrial intelligence, or SETI, for decades.

In Sagan’s story, the protagonist, Ellie Arroway, detects mysterious chatter from the cosmos. Tarter had no such luck. But her story, told by journalist Sarah Scoles in Making Contact, still provides insights into what it means to be human in a vast universe potentially harboring other life.
Tarter began her career as a typical radio astronomer, studying mainstream topics like stars and galaxies as a Ph.D. student. But after graduating in 1975, she began to focus on SETI, poring over data from radio telescopes, searching for unnatural blips that could be a sign of an intelligent civilization. SETI researchers typically focus on radio waves because those long wavelengths can travel through our galaxy’s dust without being absorbed.
Writings about SETI are prone to dreamy romanticism, but Making Contact admirably steers clear of excessive sentimentality. As a child gaping at the stars, Tarter wondered if creatures in the heavens were looking in our direction. Of course, Scoles notes, plenty of kids have wondered the same thing. Though Tarter’s childhood musings might seem special in retrospect, they aren’t what make her stand out.

Instead, Scoles — who has clear affection for her subject — highlights Tarter’s tenacity. In the face of numerous obstacles, Tarter pushed the field forward, seemingly by force of will.

In a detailed portrait of how the science sausage gets made, the book follows Tarter as she faced numerous funding woes. The field of SETI, which has at various points in its history received money through NASA, is an easy target for funding cuts, with some politicians deriding it as a wasteful hunt for “little green men.” Tarter, like the fictional Arroway, fought with Congress for taxpayer dollars SETI received, then scrambled for cash from other sources to keep telescopes and other equipment in operation. Wealthy donors kept SETI afloat — and still do. To maximize their ability to accept funding, Tarter and other SETI pioneers founded the nonprofit SETI Institute, in Mountain View, Calif., in 1984.
Throughout, Tarter somehow managed to maintain her passion for a long shot search.

Although it’s a compelling story, the book stumbles in a few places, mainly minor sloppiness with physics facts, which may bother the most astute readers. (Scoles writes, for example, “Light is the only way we can learn about the universe,” neglecting gravitational waves and neutrinos, both of which have revealed secrets of cosmic objects.)

Now retired, Tarter has lost her chance to follow in Arroway’s fictional footsteps — she will never find any alien communiqués. But even if astronomers never hear from E.T., Tarter sees benefits in the search: SETI is an opportunity to make humankind less selfish. Just the thought that other creatures might inhabit the universe can make human squabbles seem less significant.

A strange property of spider silk helps explain how the arachnids avoid twirling wildly at the end of their ropes.

Researchers from China and England harvested silk from two species of golden orb weaver spiders, Nephila edulis and Nephila pilipes, and tested it with a torsion pendulum. The device has a hanging weight that rotates clockwise or counterclockwise, twisting whatever fiber it hangs from. When a typical fiber is twisted, the weight spins back and forth around an equilibrium point, eventually returning to its original orientation.
But unlike several fibers the scientists tested — copper wires, carbon fibers and even human hair — the spider silk deformed when twisted. That distortion changed the silk’s equilibrium point and cut down on the back-and-forth spinning, the scientists report in the July 3 Applied Physics Letters. Eventually, scientists might design spin-resistant ropes for mountain climbers, who, like spiders, should avoid doing the twist.

A new type of soft robot can go under the knife and make a full recovery in about a day.

Researchers fashioned a robotic hand, gripper and muscle from self-healing rubbery material. To test their robots’ resilience, the engineers sliced each with a scalpel, then put them in an oven. After cranking up the heat to 80° Celsius, baking the bots for 40 minutes, then cooling them to room temperature, the researchers found that all three bots’ cuts had completely closed up. Twenty-four hours later, the machines had regained at least 98 percent of their original strength and flexibility, the researchers report online August 16 in Science Robotics.
Incisions broke bonds between two chemical ingredients that make up the material, furan and maleimide. At higher temperatures, these chemical compounds can also split up, as well as move around more easily. So as the researchers cooled the material, the compounds were able to re-bond with those on the other side of an incision.
“This material could heal, in theory, an infinite number of times,” says study coauthor Bram Vanderborght, an engineer at Vrije University Brussels.

The work helps address a major limitation of squishy, flexible robots — which are better suited than their traditional, rigid counterparts for navigating rough terrain and handling fragile objects, but are vulnerable to punctures and tears. Self-healing machines could pave the way for creating more durable, reusable soft bots.