For mice, birth mode matters when it comes to weight. Within their first years of life, pups born by C-section gained more weight than mice born vaginally, researchers report. Scientists attribute this heft to different microbiomes — the communities of microorganisms that live in and on the body — in the C-section group.

The results, published October 11 in Science Advances, are the latest hint that a baby’s delivery method has important consequences for future health. By 15 months after weaning, the mice born by C-section had gained 33 percent more weight than the mice born vaginally. That number was even higher — 70 percent — when researchers compared only the female mice.

As fascinating as these results are, they’re from mice, so it’s unclear whether something similar happens among people.

Human babies (and other animal youngsters) are born germy, colonized at a tender age with their mothers’ bacteria. This bacterial transfer may begin in the womb, animal studies suggest, and continues during a trip through the birth canal. Several studies have shown that, like the mice in the new study, babies born by C-section have different compositions of bacteria than babies born vaginally.
The idea is that babies born via C-section may miss out on some of the beneficial bugs living in birth canals. Earlier work points to a possible remedy for this disparity: Wiping down newborns delivered by C-section with vaginal fluids, a controversial process known as vaginal seeding. That procedure seemed to make babies’ microbiomes more similar to that of vaginally born babies, at least temporarily. (In this case, the researchers looked at only the first month of life.)

Other experiments, however, haven’t found big, long-lasting differences among the microbiomes of babies born by C-section or vaginally. And even if those differences among babies do exist, as some studies suggest, it’s not easy to pin them on C-sections themselves.

For starters, it’s impossible to separate out the influences of conditions that might make a mom more likely to have a C-section. Take the case of obesity itself: During pregnancy, obesity increases a woman’s chances of having a C-section. It also increases a baby’s risk of obesity. These sorts of twisty complications make the situation hard to sort out in people.

Another tricky part of translating data from mice to people is that unlike women who undergo C-sections, the mice in this study didn’t receive antibiotics. It’s possible that the combined effects of antibiotics and a C-section would be even greater than those described here. During pregnancy and labor, antibiotics may change the composition of bacteria in a mother, and as a consequence, the microbiome of the baby.

Despite the lack of clear-cut answers, the steady trickle of results linking birth method, babies’ microbiomes and future health hint that there’s something going on there. But many more studies are needed before that something gets more specific.

Nature has no shortage of animal camouflage tricks. One newly recognized form of deception, used by plant-eating insects called leafhoppers, was thought to have a whole different purpose.

Leafhoppers are found worldwide in temperate and tropical regions. Most of the insects, of which there are about 20,000 described species, produce small quantities of microspheres called brochosomes — tiny soccer ball–like particles with honeycomb indentations. Researchers figured out that the brochosomes, which leafhoppers rub on their bodies, were used primarily to make the insects water-repellent. But why the bugs also used the balls to cover their eggs, which the insects lay on young leaves, was a mystery.
Now, using a novel method to manufacture brochosomes in large quantities, engineers found that the microparticles have the exact shape and size to prevent reflection of light in any direction. As a result, surfaces covered with brochosomes appear similar to a leaf in the spectrum of light that is visible to insects, mechanical engineer Tak-Sing Wong and his team at Penn State report online November 3 in Nature Communications. That suggests that the antireflective property of the spheres functions as camouflage for the eggs, protecting them from would-be predators such as birds or other insects.

The manufactured brochosomes have many potential applications, the researchers say, such as solar energy harvesting, where antireflective surfaces are needed.

A year after the Rosetta spacecraft’s rendezvous with comet 67P/Churyumov-Gerasimenko came to an end, the views are still stunning. This montage, released in September by the European Space Agency, includes 210 of the thousands of images taken by Rosetta and the Philae lander and recaps the daring mission to explore the space rock. The images are arranged chronologically (starting at the top left and moving from left to right in each row).

After a decade-long journey to catch up to a comet whizzing through space at speeds up to 135,000 kilometers per hour, Rosetta finally reached 67P in August 2014 (SN: 9/6/14, p. 8). The spacecraft began documenting the comet’s odd duck shape (SN: 2/21/15, p. 6) and zooming in to pinpoint a perfect place for Philae to park. Each craft took “farewell” images of the other before Philae’s tumultuous touchdown, when the lander got an extremely close look at the comet’s surface (fourth row).
Rosetta captured its shadow on 67P’s surface (sixth row, far left), along with evidence of outgassing from the comet. The spacecraft then drew close enough to spot Philae (second to last row, second from right) and snap extraordinary views of the surface before making its own final plunge into the comet on September 30, 2016. The last image in the mosaic shows the spot on 67P’s surface that became Rosetta’s final resting place.

MINNEAPOLIS — To destroy plastic, caterpillars go with their gut bacteria.

Caterpillars that nibble through polyethylene plastic cultivate a diverse community of digestive bacteria that process the plastic, researchers reported November 13 at the annual meeting of the Society of Environmental Toxicology and Chemistry North America. Dousing old plastic in a similar mix of bacteria might speed the breakdown of the persistent pollutant.

Polyethylene is widely used to make plastic bags and other packaging materials, but it hangs around in landfills for decades, perhaps even centuries. Recently, scientists identified several species of caterpillars that appear to eat and digest the plastic, breaking it down. But dumping old shopping bags into a den of caterpillars isn’t really a practical large-scale strategy for getting rid of the plastic. So to figure out the insects’ secret, researchers fed polyethylene to the larvae of pantry moths, Plodia interpunctella, and then looked at the bacteria in the caterpillars’ guts.
Caterpillars that ate a control diet of bran and wheat had guts mostly dominated by Turicibacter, a group of bacteria commonly found in animals’ digestive tracts. But the caterpillars that munched on the plastic had a much more diverse native microbial community. In particular, they had high levels of a few types of bacteria: Tepidimonas, Pseudomonas, Rhizobiales and Methylobacteriaceae.

Some of these bacteria have been shown to colonize and help degrade plastics in the ocean, says study coauthor Anisha Navlekar of Texas Tech University in Lubbock, so it makes sense that the microorganisms also appear to be helping the caterpillars break down plastics.

BOSTON — A decades-long debate over who once occupied a settlement located near the caves where the Dead Sea Scrolls were found has taken a chaste turn.

Analyses of 33 newly excavated skeletons of people buried at the West Bank site, Qumran, supports a view that the community consisted of a religious sect of celibate men. Anthropologist Yossi Nagar of the Israel Antiquities Authority in Jerusalem presented the findings November 16 at the annual meeting of the American Schools of Oriental Research. Preliminary radiocarbon dating of one of the Qumran bones indicates that the interred bodies are around 2,200 years old — close to the same age as the ancient texts, which are estimated to have been written between around 150 B.C. and A.D. 70.
Plus, reexamination of 53 previously unearthed human skeletons from Qumran’s cemetery, now housed in France, found that six of seven individuals formerly tagged as women were actually men, Nagar said. A small number of children have also been excavated at Qumran.

Israel Antiquities Authority anthropologists Hanania Hizmi and Yevgeny Aharonovich directed the latest excavations at Qumran in 2016. The researchers called in Nagar to study the skeletons. He identified 30 of the newly excavated individuals as definitely or probably males, based on factors that include pelvic shape and body sizes. (There was not enough evidence to assign a sex to the remaining three.) At the time of their deaths, the men ranged in age from around 20 to 50 or more, Nagar estimated.
“I don’t know if these were the people who produced the Qumran region’s Dead Sea Scrolls,” Nagar said. “But the high concentration of adult males of various ages buried at Qumran is similar to what has been found at cemeteries connected to Byzantine monasteries.” The Byzantine Empire, founded in A.D. 330, was an extension of the Roman Empire in the eastern Mediterranean.
Earlier investigations of Qumran suggested it was founded more than 2,700 years ago. Warfare led to its abandonment before it was settled again for about 200 years, up to around the year A.D. 68.
Discovery of the Dead Sea Scrolls, which include parts of the Hebrew Bible, in 11 nearby caves between 1947 and 1956 stimulated intense interest in who had occupied Qumran. In February of 2017, researchers revealed they had found another cave in the same area that possibly held scrolls or pieces of papyrus and leather intended to be written on.

An influential early theory held that members of an ancient, celibate Jewish sect, the Essenes, lived at Qumran and either wrote the Dead Sea Scrolls or were caretakers of these religious, legal and philosophical documents. But over the past 30 years, other possible inhabitants of Qumran have been proposed, including Bedouin herders, craftsmen and Roman soldiers.

Qumran individuals show no signs of war-related injuries and are not predominantly young adult men, as would be expected of a cemetery for soldiers, Nagar said. The Qumran skeletons can’t be confirmed as Essenes, but their identity as part of a community of celibate men appears probable, he added.

Extraction and analysis of DNA from the Qumran skeletons would help confirm that they are all, or almost all, men, said Jonathan Rosenbaum, a professor of Jewish Studies at Gratz College in Melrose Park, Pa.

Researchers removed small samples of bone from some of the newly excavated Qumran skeletons before reburying the finds in their original resting places. Nagar wasn’t sure if any attempts to retrieve DNA from bone samples would be launched.

A new twist on gene editing makes the CRISPR/Cas9 molecular scissors act as a highlighter for the genetic instruction book. Such highlighting helps turn on specific genes.

Using the new tool, researchers treated mouse versions of type 1 diabetes, kidney injury and Duchenne muscular dystrophy, the team reports December 7 in Cell. The new method may make some types of gene therapy easier and could be a boon for researchers hoping to control gene activity in animals, scientists say.
CRISPR/Cas9 is a two-part molecular scissors. A short, guide RNA leads the DNA-cutting enzyme Cas9 to specific places in the genetic instructions that scientists want to slice. Snipping DNA is the first step to making or fixing mutations. But researchers quickly realized the editing system could be even more versatile.

In the roughly five years since CRISPR/Cas9 was first wielded, researchers have modified the tool to make a variety of changes to DNA (SN: 9/3/16, p. 22). Many of those modifications involve breaking the Cas9 scissors so they cannot cut DNA anymore. Strapping other molecules to this “dead Cas9” allows scientists to alter genes or change the genes’ activities.

Gene-activating CRISPR/Cas9, known as CRISPRa, could be used to turn on dormant genes for treating a variety of diseases. For instance, doctors might be able to turn on alternate copies of genes to compensate for missing proteins or to reinvigorate genes that grow sluggish with age. So far, researchers have mostly turned on genes with CRISPRa in cells growing in lab dishes, says Charles Gersbach, a biomedical engineer at Duke University not involved in the new study.

Being able to precisely turn on genes within an animal and influence the animal’s health is a “great advance,” Gersbach says. It has been difficult to do before because CRISPR activators are too big to fit inside viruses needed to deliver the tools to body cells.
In the new study, Juan Carlos Izpisua Belmonte of the Salk Institute for Biological Studies in La Jolla, Calif., and colleagues shrank the tool. This time, the researchers “killed” and modified the guide RNA instead of the DNA-cutting enzyme. The team used short guide RNAs, just 14 or 15 units long, instead of the usual 20 to 22.
The short leash can still lead Cas9 to specific spots in DNA, but once there, the enzyme — although still capable of cutting — doesn’t snip the DNA. Another piece of RNA tacked onto the “dead” guide attracts proteins that help turn genes on. The pieces of the dead guide activators are small enough to fit in gene therapy viruses.

In one experiment, the team wanted to restore the ability of mice with a version of type 1 diabetes to make insulin, a hormone that controls blood sugar. In type 1 diabetes, the immune system destroys the pancreas, the organ that normally makes insulin. Since pancreatic cells are gone, the researchers needed a new type of cell to take over the pancreas’s job.

So Belmonte’s group infected diabetic mice with viruses carrying the dead guide activators. The researchers used the dead guide RNAs to turn on the Pdx gene in the mice’s livers, which caused the liver cells to produce insulin, reversing the mice’s diabetes. Essentially the liver cell was transformed into one that does an important job of the pancreas.

“Labs have been trying to do that for decades,” says Kirk Wangensteen, a physician scientist at the University of Pennsylvania Perelman School of Medicine. Such experiments will help scientists understand what factors determine a cell’s identity.

But to do the gene therapy in humans, scientists would need to tackle another problem. In the diabetes experiment, they could use mice already engineered to make their own Cas9. But people don’t naturally make Cas9, and the entire dead guide activator and Cas9 system won’t fit in a single virus. So Belmonte’s team wanted to know if two viruses could be used at once to deliver all the pieces to target cells.

The Salk researchers tested their system in mice with a muscle-wasting disease that mimics Duchenne muscular dystrophy. Duchenne muscular dystrophy is caused by mutations in a huge gene called dystrophin. There’s no way to cram the dystrophin gene into a virus to do traditional replacement gene therapy, but researchers have found that turning on other genes can compensate and bulk up muscles. So in the dual-virus experiment, the scientists turned on a muscle-building gene called follistatin.

This time, the dead guide activator for turning on the follistatin gene was packaged in one virus and Cas9 in another virus. Both viruses were used to infect muscle cells in the hind legs of mice that had muscular dystrophy. Treated mice had more muscle mass in their hind legs than untreated mice did.

Much higher levels of gene activity were triggered in these experiments than scientists have achieved before, says Michael Hemann, a cancer biologist at MIT. High levels of activity are probably needed to produce enough protein to correct diseases.

Hemann and others say the new activator system will be useful for research, but some challenges remain before the therapy can be used in people. Researchers always have a challenge getting the therapy to the right place in the body, he says. The technology’s safety and efficacy must also be demonstrated.

2017 was a good year for worrying about nutrient losses that might come with a changing climate.

The idea that surging carbon dioxide levels could stealthily render some major crops less nutritious has long been percolating in plant research circles. “It’s literally a 25-year story, but it has come to a head in the last year or so,” says Lewis Ziska, a plant physiologist with the U.S. Agricultural Research Service in Beltsville, Md.

Concerns are growing that wheat, rice and some other staple crops could, pound for pound, deliver less of some minerals and protein in decades to come than those crops do today. In 2017, three reports highlighted what changes in those crops could mean for global health. Also this year, an ambitious analysis made an almost-global assessment of sources of selenium, a trace element crucial for health, and warned of regions where climate change might cut the element’s availability (SN: 4/1/17, p. 14).
Crop responses to rising CO2 might affect nutrition and health for billions of people, Ziska says, but the idea has been difficult to convey to nonspecialists. One complication is that though plants certainly need CO2 to grow, providing more of it doesn’t mean that all aspects of plant biology change in sync. In hoping for a farming bonus, Ziska warns, people often overlook the disproportionate zest of weeds. An outdoor experiment wafting extra CO2 through a forest has already shown, for example, that poison ivy grew faster than the trees.

In the 2017 Annual Review of Public Health, Samuel Myers of Harvard University and colleagues wrote that global shortfalls in human nutrition are already “staggering.” More than a billion people aren’t getting enough zinc now, raising risks of premature birth, stunted childhood growth and weak immune systems. To estimate future shortfalls, Myers and colleagues turned to nutrient data they published in 2014 in Nature.

That report compared staple crops grown in various outdoor setups on three continents at either ambient or enhanced atmospheric CO2 concentrations. Fancy research piping boosted ambient levels of 363 to 386 parts per million to 546 and 584 ppm. (A moderate scenario puts late-century levels at 580 to 720 ppm.)
Decreases in zinc concentrations, including in rice and wheat, could plunge an additional 150 million to 200 million people into zinc deficiency, the researchers calculate. Likewise, predicted declines in iron content in some grains and legumes look worrisome for countries with anemia rates already higher than 20 percent, such as India and Algeria, Myers and colleagues reported in August in GeoHealth. Such high-anemia nations have a lot of people especially at risk, including 1.4 billion young children and women of childbearing age.

An expanded set of experiments suggested that protein content in rice and wheat could sink by roughly 8 percent, Myers and colleagues wrote in the August Environmental Health Perspectives. Thus, rising CO2 could add some 148 million people worldwide to the roughly 1.4 billion expected to be short of protein by 2050.

Also this year, grazing cattle joined the list of animals facing a protein downturn in their food. (Ziska and colleagues raised the issue for bees in 2016.) For cattle, 22 years and more than 36,000 fecal measurements suggest that plants on U.S. grazing lands have grown poorer in protein, ecologist Joseph Craine of Jonah Ventures, in Boulder, Colo., and colleagues reported April 10 in Environmental Research Letters. For every kilogram of plants that cattle ate in 2015, there were 10.6 grams less protein than there had been 22 years before. The yearly loss is equivalent to the protein available in $1.9 billion worth of soy meal — and rising CO2 is a possible culprit.

Plant reactions will be varied and complex, Ziska points out. An Artemisia plant’s anti-malarial compound, artemisinin, can get more concentrated as CO2 increases, possibly good news for plant-based medicine. But the mix of urushiols, oils that put the itch in poison ivy, can become more allergy-provoking when exposed to extra CO2, a test suggested. Ziska is now looking into how much caffeine will turbocharge future coffee beans.

Whatever the changes, concern is growing, says mathematical biologist Irakli Loladze of Bryan College of Health Sciences in Lincoln, Neb. He, Ziska and nine coauthors included nutritional erosion in the 2016 U.S. scientific assessment of the impacts of climate change on human health. To raise the public profile of the issue, though, Myers says, “We have a ways to go.”

An itinerant interstellar asteroid may actually be a comet in disguise.

Known as ‘Oumuamua, the object was detected in October and is the first visitor from another star spotted touring our solar system (SN: 11/ 25/17, p. 14). Early observations suggested the vagabond was rocky. But after additional analysis, a team of researchers suggests December 18 in Nature Astronomy that the object might have an icy core.

In general, comets are icy and asteroids are rocky. Ice gives comets their characteristic tails: As a comet passes near the sun, the heat warms the ice, causing it to sublimate, releasing gas and dust. Because no tail appeared despite ‘Oumuamua’s passage by the sun, the mysterious visitor was dubbed an asteroid — a surprising conclusion since the vast majority of objects ejected from star systems are expected to be icy.
“Everybody’s been assuming that this is just a lump of rock,” says astronomer Alan Fitzsimmons of Queen’s University Belfast in Northern Ireland. “This may not be the case.” So ‘Oumuamua might not be as odd as originally thought.

Fitzsimmons and colleagues used the Very Large Telescope in Chile and the William Herschel Telescope in La Palma, Spain to capture the object’s spectrum — its light sliced up according to wavelength. “It’s an impressive piece of work,” says astronomer Olivier Hainaut of the European Southern Observatory in Garching, Germany, who was not involved with the research. “It was a very faint object and to observe such a faint moving target is horribly difficult.”

The object’s spectrum revealed a reddish hue with no signs of ice. But ‘Oumuamua could have an exterior crust — about half a meter thick or thicker — which hid the ice and insulated it from the sun’s heat, the researchers calculated. “You could have a lot of ice in this thing and really not know it,” says astronomer Jessica Sunshine of the University of Maryland in College Park, who was not involved with the research. Such a crust could have formed as energetic particles known as cosmic rays bombarded the object over its lifetime, creating an ice-free surface rich in organic compounds. ‘Oumuamua’s spectrum is similar to those of other objects in the solar system suspected of concealing such icy interiors.
Studies of ‘Oumuamua continue — with some researchers looking for evidence of even more surprising hypotheses. Using the Green Bank Telescope in West Virginia, scientists with the Breakthrough Listen project are searching for signatures of artificial origin — that is, aliens — on the off chance that the object might be an interstellar spacecraft. Sorry, X-Files fans: So far no such signals have been detected.

Some reports from 2017 hint at potentially big discoveries — if the research holds up to additional scientific scrutiny.

Under pressure
Putting the squeeze on hydrogen gas turned it into a long-elusive metal that may superconduct, Harvard University physicists claimed (SN: 2/18/17, p. 14). A diamond vise, supercold temperatures and intense pressure made the element reflective — a key property of metals. But other researchers in the field don’t buy it; one experiment with a slew of caveats isn’t enough to confirm the claim, those scientists say.
Woman warrior?
The skeleton of a 10th century Viking woman buried in full warrior regalia has scientists sparring over women’s roles in Viking society (SN: 10/14/17, p. 6). Researchers who confirmed the skeleton’s sex through DNA analysis contend that the woman was a high-ranking Viking warrior, the first Viking woman warrior known. But other archaeologists argue that the bones — with no obvious signs of injury or strenuous physical activity — are too pristine to have seen battle.
A far-flung star’s extra wink, spotted in data from the Kepler space telescope and further probed by the Hubble Space Telescope, may be the first evidence for an exomoon — a moon orbiting a planet orbiting a distant star. If it exists, the Neptune-sized candidate moon (dubbed Kepler 1625b i) is roughly 4,000 light-years away and orbits a planet a tad larger than Jupiter (SN: 8/19/17, p. 15).

Rooting out hominid origins
The first members of the human evolutionary family may have originated in Europe, not Africa. New analyses of a fossilized jaw (shown) and teeth from Graecopithecus, a chimpanzee-sized primate that lived in southeastern Europe roughly 7 million years ago, suggest that it may be the earliest known hominid (SN: 6/24/17, p. 9). But more complete fossils are needed to determine whether Graecopithecus was truly a hominid.

In December, astronomers and space enthusiasts received an early present: 86 newly official star names.

Such designations are often derived from Arabic, Greek or Latin origins. But the new monikers also draw inspiration from ancient mythologies and historical star names from indigenous cultures around the world, including in China, Australia and southern Africa. The star names were officially recognized by the International Astronomical Union, which oversees the naming of objects in space, and announced on December 11. Here are some of the names we thought shined the brightest.
Xamidimura
Constellation: Scorpius
According to South African lore, the indigenous Khoikhoi people nicknamed the pair of stars just before the end of the scorpion’s tail “xami di mura,” meaning “eyes of the lion.”

Fafnir
Constellation: Draco
Fafnir is a dwarf from Norse mythology who became a dragon to guard his treasure. He was slain by the hero Sigurd.
Pipirima
Constellation: Scorpius
Pipirima is named for a pair of fraternal twins, the boy Pipiri and his sister Rehua, from a Tahitian legend. When their parents didn’t share a meal of fish one night, the two kids ran away. As the parents came closer to finding them, the twins climbed onto the back of a passing stag beetle and were carried into the sky.

Chalawan
Constellation: Ursa Major
Chalawan, a villainous crocodile king from a Thai folktale, lived in an underwater cave. A man named Krai Thong fell in love with one of Chalawan’s two wives and killed the crocodile king.

Ran
Constellation: Eridanus
Ran, a Norse goddess of the sea, created peril by capturing sailors in her net.

Unurgunite
Constellation: Canis Major
In stories from Australia’s aboriginal people, Unurgunite has two wives, which are represented by stars on either side of the named star. When Mityan, who represents the moon in the stories, fell in love with one of the wives, Unurgunite fought Mityan and won. Mityan has been wandering the universe ever since.

Alsephina
Constellation: Vela
Alsephina is the brightest star in this new list. “Al-safinah” in Arabic means “the ship,” referring to the ancient Greek constellation Argo Navis (named for the Argonauts’ ship and now split into three modern constellations). The bright star, located in one of those constellations called Vela, has been unofficially called Alsephina since at least 1660, when the Dutch-German mapmaker Andreas Cellarius illustrated the star in Harmonia Macrocosmica, a book about the cosmos.

Tianguan
Constellation: Taurus
Tianguan is a binary star that was unofficially named roughly 2,000 years ago during China’s Han period in the Tianguan shu, the first Chinese systematic description of the stars. In 1898, Édouard Chavannes translated the text to French, introducing Chinese constellations in their proper astrological positions to the western world.

Cervantes
Constellation: Ara
Cervantes is named after Miguel de Cervantes, a Spanish writer who wrote the famous novel Don Quixote. The star is orbited by an exoplanet named Quijote, referring to the story’s protagonist.

Titawin
Constellation: Andromeda
Titawin is named after Medina of Tétouan, a UNESCO World Heritage Site in northern Morocco that was a central point of contact between Spaniards and Arabs beginning in the 8th century.