Ben Franklin had nothing on trilobites.

Roughly 400 million years before the founding father invented bifocals, the now extinct trilobite Dalmanitina socialis already had a superior version (SN: 2/2/74). Not only could the sea critter see things both near and far, it could also see both distances in focus at the same time — an ability that eludes most eyes and cameras.

Now, a new type of camera sees the world the way this trilobite did. Inspired by D. socialis’s eyes, the camera can simultaneously focus on two points anywhere between three centimeters and nearly two kilometers away, researchers report April 19 in Nature Communications.
“In optics, there was a problem,” says Amit Agrawal, a physicist at the National Institute of Standards and Technology in Gaithersburg, Md. If you wanted to focus a single lens to two different points, you just simply could not do it, he says.

If a camera could see like a trilobite, Agrawal figured, it could capture high-quality images with higher depths of field. A high depth of field — the distance between the nearest and farthest points that a camera can bring into focus — is important for the relatively new technique of light-field photography, which uses many tiny lenses to produce 3-D photos.

To mimic the trilobite’s ability, the team constructed a metalens, a type of flat lens made up of millions of differently-sized rectangular nanopillars arranged like a cityscape — if skyscrapers were one two-hundredth the width of a human hair. The nanopillars act as obstacles that bend light in different ways depending on their shape, size and arrangement. The researchers arranged the pillars so some light traveled through one part of the lens and some light through another, creating two different focal points.
To use the device in a light-field camera, the team then built an array of identical metalenses that could capture thousands of tiny images. When combined, the result is an image that’s in focus closeup and far away, but blurry in between. The blurry bits are then sharpened with a type of machine learning computer program.

Achieving a large depth of field can help the program recover depth information, says Ivo Ihrke, a computational imaging scientist at the University of Siegen in Germany who was not involved with this research. Standard images don’t contain information about the distances to objects in the photo, but 3-D images do. So the more depth information that can be captured, the better.

The trilobite approach isn’t the only way to boost the range of visual acuity. Other cameras using a different method have accomplished a similar depth of field, Ihrke says. For instance, a light-field camera made by the company Raytrix contains an array of tiny glass lenses of three different types that work in concert, with each type tailored to focus light from a particular distance. The trilobite way also uses an array of lenses, but all the lenses are the same, each one capable of doing all the depth-of-focus work on its own — which helps achieve a slightly higher resolution than using different types of lenses.

Regardless of how it’s done, all the recent advances in capturing depth with light-field cameras will improve imaging techniques that depend on that depth, Agrawal says. These techniques could someday help self-driving cars to track distances to other vehicles, for example, or Mars rovers to gauge distances to and sizes of landmarks in their vicinity.

Imagine a world without insects. You might breathe a sigh of relief at the thought of mosquito-free summers, or you might worry about how agriculture will function without pollinators. What you probably won’t picture is trudging through a landscape littered with feces and rotting corpses — what a world devoid of maggots and dung beetles would look like.

That’s just a snippet of the horrifying picture of an insect-free future that journalist Oliver Milman paints in the beginning of The Insect Crisis. “The loss of insects would be an agonizing ordeal eclipsing any war and even rivaling the looming ravages of climate breakdown,” he writes. And yet, the threat of an impending “insect apocalypse” doesn’t get nearly the same level of attention as climate change.

Researchers have been observing declining insect populations for decades. For instance, a study of nearly 40 years of data from a protected rainforest in Puerto Rico found that insect biomass had decreased by 98 percent on the ground and 80 percent in the canopy since the mid-1970s.

The threats insects face are many: Light pollution, the increasing use of pesticides and climate change are just a few (SN: 8/31/21; SN: 8/17/16; SN: 7/9/15). And it’s not only rare species that are at risk — it’s also species that were once common around the globe.

The reality of the crisis isn’t as foreboding as Milman initially makes it seem. A world with no insects is unlikely, he acknowledges. Studies have found that while some species are in decline, others, such as freshwater insects, are doing fine (SN: 4/23/20). Rather than viewing the insect crisis as all insect populations on one downward-trending line on a graph, Milman suggests picturing lots of different lines — some holding steady, some sloping up or down, and some zigzagging. “Insects are being shifted to an unhappy state where there will be far more bedbugs and mosquitoes and far fewer bumblebees and monarch butterflies,” he writes.

Those changes in biodiversity come with consequences. Farmers may have to fend off more pests that attack soybeans, for instance, and insect-pollinated fruits and vegetables will become hard to grow at scale. Some insect-eating animals will decline as their food disappears, which has already happened to some birds (SN: 7/11/14), or even vanish. Water and soil quality could also be in jeopardy.
Milman investigates the crisis by sharing his own adventures with insects, along with those of researchers, taking readers from the United States to Mexico, across the Atlantic to Europe and all the way to Australia. By sharing scientists’ stories, he makes the plight of insects personal. There’s a researcher in Denmark who has spent 25 years surveying insect populations by driving his old Ford Anglia down the same country roads and counting the number of bugs squashed against the windshield. Back when he started, he’d regularly have to clean insect guts off his car. But in recent years, he has experienced a lot of “zero insect days.” As I read that, I struggled to remember the last time I had to scrape any dead insects off my car. Another researcher recalls the joy of catching fireflies on his family ranch in Texas as a child. I felt a wave of sadness as I thought about how I don’t see fireflies as much as I did when I was a kid. With more streetlights and the switch to LED bulbs, it’s becoming harder for fireflies to spot potential mates.

Amid the doom and gloom, the book still manages to spark awe and delight with fun facts about insects. Bumblebee wings, for instance, vibrate so fast that they can produce gravitational forces of up to 50 g’s — five times greater than what fighter jet pilots experience. Milman also offers hope, sharing how certain insects are adapting to the threats and how some people are fighting to protect the critters through political campaigns and changing farming habits.

By the book’s end, readers may find that their attitude toward some insects has shifted from loathing to love, or at the very least, appreciation. (I, for one, never cared much for flies — until I learned we wouldn’t have chocolate without them.) Milman makes clear how much we benefit from insects, and what we stand to lose without them. As one researcher puts it, our deeply woven reliance on insects is like the internet: When parts of the network are removed, the less internet there is, “until eventually it doesn’t work anymore.”

A world without the internet would be difficult but livable. The same can’t be said for a world without insects.

More of the ingredients for life have been found in meteorites.

Space rocks that fell to Earth within the last century contain the five bases that store information in DNA and RNA, scientists report April 26 in Nature Communications.

These “nucleobases” — adenine, guanine, cytosine, thymine and uracil — combine with sugars and phosphates to make up the genetic code of all life on Earth. Whether these basic ingredients for life first came from space or instead formed in a warm soup of earthly chemistry is still not known (SN: 9/24/20). But the discovery adds to evidence that suggests life’s precursors originally came from space, the researchers say.
Scientists have detected bits of adenine, guanine and other organic compounds in meteorites since the 1960s (SN: 8/10/11, SN: 12/4/20). Researchers have also seen hints of uracil, but cytosine and thymine remained elusive, until now.

“We’ve completed the set of all the bases found in DNA and RNA and life on Earth, and they’re present in meteorites,” says astrochemist Daniel Glavin of NASA’s Goddard Space Flight Center in Greenbelt, Md.

A few years ago, geochemist Yasuhiro Oba of Hokkaido University in Sapporo, Japan, and colleagues came up with a technique to gently extract and separate different chemical compounds in liquified meteorite dust and then analyze them.

“Our detection method has orders of magnitude higher sensitivity than that applied in previous studies,” Oba says. Three years ago, the researchers used this same technique to discover ribose, a sugar needed for life, in three meteorites (SN: 11/22/19).

In the new study, Oba and colleagues combined forces with astrochemists at NASA to analyze one of those three meteorite samples and three additional ones, looking for another type of crucial ingredient for life: nucleobases.

The researchers think their milder extraction technique, which uses cold water instead of the usual acid, keeps the compounds intact. “We’re finding this extraction approach is very amenable for these fragile nucleobases,” Glavin says. “It’s more like a cold brew, rather than making hot tea.”

With this technique, Glavin, Oba and their colleagues measured the abundances of the bases and other compounds related to life in four samples from meteorites that fell decades ago in Australia, Kentucky and British Columbia. In all four, the team detected and measured adenine, guanine, cytosine, uracil, thymine, several compounds related to those bases and a few amino acids.

Using the same technique, the team also measured chemical abundances within soil collected from the Australia site and then compared the measured meteorite values with that of the soil. For some detected compounds, the meteorite values were greater than the surrounding soil, which suggests that the compounds came to Earth in these rocks.

But for other detected compounds, including cytosine and uracil, the soil abundances are as much as 20 times as high as in the meteorites. That could point to earthly contamination, says cosmochemist Michael Callahan of Boise State University in Idaho.

“I think [the researchers] positively identified these compounds,” Callahan says. But “they didn’t present enough compelling data to convince me that they’re truly extraterrestrial.” Callahan previously worked at NASA and collaborated with Glavin and others to measure organic materials in meteorites.

But Glavin and his colleagues point to a few specific detected chemicals to support the hypothesis of an interplanetary origin. In the new analysis, the researchers measured more than a dozen other life-related compounds, including isomers of the nucleobases, Glavin says. Isomers have the same chemical formulas as their associated bases, but their ingredients are organized differently. The team found some of those isomers in the meteorites but not in the soil. “If there had been contamination from the soil, we should have seen those isomers in the soil as well. And we didn’t,” he says.

Going directly to the source of such meteorites — pristine asteroids — could clear up the matter. Oba and colleagues are already using their extraction technique on pieces from the surface of the asteroid Ryugu, which Japan’s Hayabusa2 mission brought to Earth in late 2020 (SN: 12/7/20). NASA’s OSIRIS-REx mission is expected to return in September 2023 with similar samples from the asteroid Bennu (SN: 1/15/19).

“We’re really excited about what stories those materials have to tell,” Glavin says.

Taking antibiotics in the first two years of life can prevent babies from developing a robust immune response to certain vaccines. The new finding provides another cautionary tale against overusing antibiotics, researchers say.

Babies get immunized in their first six months, and receive booster doses in their second year, to protect against certain infectious diseases. Antibiotic use during that time was associated with subpar immune responses to four vaccines babies receive to ward off whooping cough, polio and other diseases, researchers report online April 27 in Pediatrics.

And the more rounds of antibiotics a child received, the more antibody levels to the vaccines dropped below what’s considered protective. Levels induced by the primary series of shots for the polio, diphtheria-tetanus-pertussis, Haemophilus influenzae type b and pneumococcal vaccines fell 5 to 11 percent with each antibiotic course. In the children’s second year, antibody levels generated by booster shots of these vaccines dropped 12 to 21 percent per course.
“If anyone needed yet another reason why overprescription of antibiotics is not a good thing, this paper offers that reason,” says immunologist Bali Pulendran of Stanford University School of Medicine, who was not involved in the study.

Taking antibiotics disrupts the population of bacteria that live in the gut. That’s well known, but researchers are still learning about how that disruption can affect a person’s health. The new study adds to evidence that diminishing the amount and diversity of gut bacteria impacts vaccination. In studies in mice, antibiotics hampered the immune system’s response to vaccines. And a small study in humans found that antibiotics dampened adults’ response to the flu vaccine in those whose prior immune memory for influenza had waned, Pulendran and colleagues reported in 2019.

The study in Pediatrics is the first to report an association between antibiotic use and compromised vaccine responses in children. Michael Pichichero, a pediatric infectious diseases specialist at the Rochester General Hospital Research Institute in New York, and colleagues collected blood samples taken from 560 children during routine visits with their pediatricians. Of those, 342 children had been prescribed close to 1,700 courses of antibiotics and 218 children had not gotten the drugs. The team analyzed whether antibody levels induced by the four vaccines met the threshold considered protective and found levels more often fell short for the kids who had gotten antibiotics.

The type and length of antibiotic treatment also made a difference. Broad spectrum drugs were associated with antibody levels below what is protective, while a more targeted antibiotic was not. Furthermore, a 10-day course, but not a five-day course, reduced vaccine-induced antibody levels.

The researchers didn’t look at whether children in the study with diminished antibody levels were more likely to develop vaccine-preventable diseases. But there has been concern about outbreaks of whooping cough, says Pichichero, which have occurred in the the United States despite vaccination (SN: 4/4/14). Perhaps antibiotic use can help explain these outbreaks, he says.

To see what kinds of changes are occurring in the gut bacteria, Pichichero and colleagues are beginning a study with a new group of children. The researchers will collect stool samples along with blood draws and antibiotic use records. They’d like to follow the children past age 5, beyond the time kids receive another round of booster shots, to learn whether antibiotics also interfere with this next opportunity to develop antibodies.

“Antibiotics are miracle medicines,” says Pichichero. “In no way does this study imply that children who need an antibiotic shouldn’t get it.” But if possible, it should be a narrowly targeted antibiotic for a shorter course, he says. Along with the risk of antibiotic resistance that comes with overuse of the drugs (SN: 1/24/22), the impact antibiotics could have on vaccine-induced immunity “has clinical implications for every individual child.”

Leonardo da Vinci was wrong about trees.

The multitalented, Renaissance genius wrote down his “rule of trees” over 500 years ago. It described the way he thought that trees branch. Though it was a brilliant insight that helped him to draw realistic landscapes, Leonardo’s rule breaks down for many types of trees. Now, a new branching rule — dubbed “Leonardo-like” — works for virtually any leafy tree, researchers report in a paper accepted April 13 in Physical Review E.

“The older Leonardo rule describes the thickness of the branches, while the length of the branch was not taken into account,” says physicist Sergey Grigoriev of the Petersburg Nuclear Physics Institute in Gatchina, Russia. “Therefore, the description using the older rule is not complete.”
Leonardo’s rule says that the thickness of a limb before it branches into smaller ones is the same as the combined thickness of the limbs sprouting from it (SN: 6/1/11). But according to Grigoriev and his colleagues, it’s the surface area that stays the same.

Using surface area as a guide, the new rule incorporates limb widths and lengths, and predicts that long branches end up being thinner than short ones. Unlike Leonardo’s guess, the updated rule works for slender birches as well as it does for sturdy oaks, the team reports.

The connection between the surface area of branches and overall tree structure shows that it’s the living, outer layers that guide tree structure, the researchers say. “The life of a tree flows according to the laws of conservation of area in two-dimensional space,” the authors write in their study, “as if the tree were a two-dimensional object.” In other words, it’s as if just two dimensions — the width of each limb and the distance between branchings on a limb — determine any tree’s structure. As a result, when trees are rendered in two dimensions in a painting or on a screen, the new rule describes them particularly well.
The new Leonardo-like rule is an improvement, says Katherine McCulloh, a botanist at the University of Wisconsin–Madison who was not involved with this study. But she has her doubts about the Russian group’s rationale for it. In most trees, she says, the living portion extends much deeper than the thin surface layer.

“It’s really species-dependent, and even age-dependent,” McCulloh says. “A giant, old oak tree might have a centimeter of living wood … [but] there are certainly tropical tree species that have very deep sapwood and may have living wood for most of their cross sections.”

Still, the fact that the Leonardo-like rule appears to hold for many trees intrigues McCulloh. “To me, it drives home the question of why are [trees] conserving this geometry for their external tissue, and how is that related to the microscopic level differences that we observe in wood,” she says. “It’s a really interesting question.”

To test their rule, Grigoriev and colleagues took photographs of trees from a variety of species and analyzed the branches to confirm that the real-world patterns matched the predictions. The photos offer “a direct measurement of the characteristics of a tree without touching it, which can be important when dealing with a living object,” Grigoriev says.

Though the team hasn’t studied evergreens yet, the rule holds for all of the deciduous trees that the researchers have looked at. “We have applied our methodology to maple, linden, apple,” Grigoriev says, in addition to oak, birch and chestnut. “They show the same general structure and obey the Leonardo-like rule.”

While it’s possible to confirm the rule by measuring branches by hand, it would require climbing into trees and checking all the limbs — a risky exercise for trees and scientists alike. “Note,” the researchers write, “that not a single tree was harmed during these experiments.”