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The Territory Is Tiny and So Is the Newborn Caterpillar Defending It

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The Territory Is Tiny and So Is the Newborn Caterpillar Defending It

When territorial animals are confronted by intruders, they instinctively protect their turf — no matter how small.

For warty birch caterpillars, that means patrolling one of the tiniest territories on Earth: the tips of birch leaves. Scientists observed the caterpillars warding off intruders with loud vibrations that advertise they are in command of a domain that stretches a few millimeters across.

“It’s like rap battles,” said Jayne Yack, a professor of neuroethology at Carleton University in Ottawa and an author of the study, which was published on Tuesday in The Journal of Experimental Biology.

Dr. Yack’s team is the first to observe an insect defending a leaf tip, a discovery that hints at a hidden world of territorial disputes playing out on small scales. These caterpillars are kings of the tiniest castles ever identified.

The behavior of warty birch caterpillars is unconventional. These insects seek turf as soon as they hatch, settling on leaf tips in a “dragon-like” resting stance. While other caterpillar species defend ranges at later developmental stages, they are not as vulnerable to predators and exposure as the warty birches.

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“The remarkable thing about these guys is that they’re so small when they hatch, less than a millimeter,” Dr. Yack said. “The mortality rate for a small insect like that is very high, so usually they form groups to survive in that hostile world. But these guys always go to the tip of a leaf. That’s their strategy.”

Dr. Yack and her team collected eggs laid by two-lined hooktip moths, the adult form of the species, and set up new hatchlings on single birch leaves. The newborns overwhelmingly booked it to the tips.

After staking claims, the caterpillars made vibrational signals, called drums and buzz scrapes, produced by striking and scraping their bodies against the leaf. The vibrations are like a “no vacancy” sign that rumbles across nearby stems and branches.

Rival warty birch caterpillars were introduced onto occupied leaves over the course of 18 trial encounters. When confronted by intruders, the resident caterpillars dialed up the signal rate by about four times. If the intruder breached the perimeter of the leaf tip, the defenders escalated the signal rate by about 14 times.

Newborn caterpillars are too fragile to endure the sort of violent conflicts observed in other territorial animals, from ants to elephants, which can be deadly. But intruders did make body contact in eight of the trials. And such encounters highlighted why the tiny tyrants want to live on a leaf tip: It allows an easy getaway. Faced with insistent invaders they’d never defeat, the caterpillars can rappel off the tip on a silk thread, a strategy called lifelining.

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It took only a light touch to drive a leaf tip’s resident to retreat on its lifeline, leaving the caterpillar literally hanging by a thread. In the other 10 encounters, the intruders heeded the warnings and left the resident in control.

Dr. Yack and her colleagues have since conducted experiments that suggest caterpillars can distinguish signals from different sources. They might even imitate vibrations made by predators, like spiders.

“The vibroscape of insects is really unexplored,” Dr. Yack said.

The new research opens a window into caterpillar communication. But along with evidence suggesting some wasps or aphids defend territory as small as the tip of a birch leaf, the study also shows that territorial conflicts come in all shapes and sizes.

“Territorial behavior is really important to animals, including humans, and there are a lot more strategies out there than we think,” Dr. Yack said.

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China Launches Reusable Rocket in Race With SpaceX

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Video released by Chinese state media shows a state-owned aerospace company launching a rocket and recovering part of it on Friday. The successful launch of a reusable rocket was a major step for China toward challenging SpaceX’s satellite internet dominance.

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Nobel Prize winner leaving UC Berkeley for new role in China

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Nobel Prize winner leaving UC Berkeley for new role in China

Nobel Prize recipient Omar Yaghi is leaving his role at UC Berkeley to lead the development of a new artificial intelligence institute at Tsinghua University in Beijing, the Chinese university announced.

Yaghi will head the AI Chemistry and Materials Research Institute at Tsinghua, where he was appointed an honorary professor in 2022. Known as AIMATRY (AI × Materials × Chemistry), the new center will focus on material design and synthesis through artificial intelligence, according to a statement from the university.

In 2025, Yaghi shared the Nobel Prize in chemistry with Susumu Kitagawa of Kyoto University and Richard Robson of the University of Melbourne for their development of metal-organic frameworks, a type of super-porous material in which metal ions and carbon-based molecules combine to form crystals with exceptionally large surface areas.

The material has the potential to combat climate change by capturing and storing carbon or other pollutants, and by extracting water from the atmosphere in water-scarce areas. Upon awarding the prize, a member of the Nobel committee likened the technology’s ability to store enormous amounts of stuff in seemingly compact spaces to Hermione Granger’s enchanted handbag in the Harry Potter series.

Yaghi’s Irvine-based company, Atoco, has said it will start taking orders later this year for its technology that harvests water from the air.

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A representative for Yaghi said he was not yet available to respond to questions.

China is one of several countries that has been actively recruiting scientists from the U.S., where the Trump administration has slashed science funding, suspended research grants, fired science advisors and tightened immigration restrictions.

“For many, many years, our funding was very competitive; if you worked hard and you were doing good research, you would get funding,” Yaghi said of the U.S. in an interview with Scientific American earlier this year. “The current state is not so encouraging because of the cutting back on grants and support of science by the very agencies that many university researchers rely on.”

Yaghi was born in Jordan to Palestinian refugees, and immigrated to the U.S. when he was 15 to study.

“We’ve learned over and over in human civilization that scholars can move across borders,” Yaghi told the New York Times last year. “This is how knowledge spread and how vast regions of the world lifted themselves out of poverty.”

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Trump administration seeks to limit federal funding that doesn’t ‘advance’ presidential policies

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Trump administration seeks to limit federal funding that doesn’t ‘advance’ presidential policies

A new rule proposed by the White House Office of Management and Budget would fundamentally overhaul the way federal grants are awarded and overseen — a sweeping change that one scientific society said “would all but end the use of scientific merit in the selection of grants and programs across the government.”

Proposed in late May, the rule would give political appointees unprecedented control over federal grants for research, education and infrastructure, and specifies that government funds can only be spent on projects “aligned with administration policies and priorities,” according to a copy of the proposed rule.

The rule would also restrict research topics, limit U.S. scientists’ ability to collaborate with colleagues in other countries and make it easier for the government to suspend or cancel grants at any time.

The changes are intended to improve “transparency, accountability, and oversight for Federal awards” while “ensuring that American tax dollars are not wasted or misused,” according to the White House office.

But critics say that if the rule is implemented, the final sign-off for grants will no longer be in the hands of subject-matter experts within individual agencies, but in those of political appointees.

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“This touches all parts of American life,” said Dr. Eric Rafla-Yuan, a psychiatrist who practices at the Veterans Administration and San Diego County’s psychiatric hospital.

“Control of how all of the federal grants and programs are funded will fall under a small group of highly partisan individuals who would have very few limits on how they spend these billions of taxpayer dollars,” said Rafla-Yuan, who also chairs the Committee to Protect Public Mental Health advocacy group. “This touches everyone’s life, even if they don’t realize it.”

OMB published the proposed rule May 29, opening a 45-day comment period that closes July 13.

Opposition to the proposed rule has mobilized multiple sectors of society. Professional groups representing cancer researchers, civil engineers, county governments, medical schools, housing agencies, city and municipal governments, nonprofits and others have publicly expressed concerns about potential consequences.

By midday Thursday, the Federal Register logged nearly 100,000 comments about the proposal, many of them expressing concern.

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“I understand the need for oversight, fiscal responsibility, and accountability. That is not the issue,” wrote Jack Feldman, a neuroscientist who holds the David Geffen School of Medicine Chair in Neuroscience at UCLA. “The issue is whether scientific research is to be judged by scientific merit, or whether it can be approved, denied, or terminated according to broad political criteria that may change from one administration to the next.”

Crucially, the rule converts policies governing federal grants from “guidance” into binding regulations that all agencies would be required to follow. It would give political appointees power to override federal agencies’ merit-based reviews and mandate that a political appointee review decisions to ensure that all awards “demonstrably advance the President’s policy priorities.”

The elevation of political appointees in what were previously merit-based decisions has alarmed many scientists.

“The proposed rule changes would all but end the use of scientific merit in the selection of grants and programs across the government,” read a statement from the Planetary Society, a nonprofit dedicated to space research.

Researchers and science groups have also expressed concern about a section of the rule prohibiting the promotion of “theories of disparate-impact liability” — a legal concept that refers to policies that appear neutral but cause disproportionate harm to certain groups.

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The section’s vague language and many loopholes could have a chilling effect on any research that studies the effects of a disease, policy or public health intervention on any specific group of people, Rafla-Yuan said.

As an example, he said, “if there’s a specific age range that is at higher risk for suicide, and we want to figure out, well, what’s going on with people that are aged 14 to 19 … we can’t do that under the wording in this rule.”

New restrictions on collaborations with scientists in other countries would hinder opportunities for U.S. researchers and limit innovation, said Joanne Padrón Carney, chief government relations officer for the American Assn. for the Advancement of Science.

“Science is a global enterprise. Especially in biomedical and public health fields, diseases don’t care about borders or government policies,” she said.

California’s congressional delegation sent a letter Wednesday asking OMB to rescind the proposal, outlining concerns about its impact on scientific innovation, U.S. competitiveness and the fiscal stability of local governments, many of which rely on federal grants for local services.

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The proposed rule grants the federal government broad powers to suspend or cancel grants for any reason, introducing “unprecedented unpredictability into local governance,” the lawmakers wrote, “leaving vital infrastructure projects unfinished and abandoning vulnerable populations who rely on these services.”

Republican Sen. Susan Collins has also asked the White House to withdraw certain parts of the letter and extend the public comment period, saying the proposed rule as written would “harm small and rural communities, undermine scientific and biomedical research, and conflict with Congress’ control over the federal funding process.”

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