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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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Biden is diagnosed with 'aggressive' form of prostate cancer

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Biden is diagnosed with 'aggressive' form of prostate cancer

Former President Biden has been diagnosed with an “aggressive form” of prostate cancer, his office said Sunday, a devastating development after having dropped his bid for reelection last summer over widespread concerns over his age and health.

Biden’s personal office said he was examined last week after the president reported a series of concerning symptoms.

“Last week, President Joe Biden was seen for a new finding of a prostate nodule after experiencing increasing urinary symptoms. On Friday, he was diagnosed with prostate cancer, characterized by a Gleason score of 9 (Grade Group 5) with metastasis to the bone,” the office said in a statement.

“While this represents a more aggressive form of the disease, the cancer appears to be hormone-sensitive, which allows for effective management. The President and his family are reviewing treatment options with his physicians,” the statement added.

The former president, 82, had been making his first public appearances since leaving office in recent weeks, including a public address and a lengthy sit-down on ABC’s “The View,” and also hired a communications strategist to help burnish his legacy amid the publication of a series of books critically examining his time at the White House.

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Biden has a tragic personal history with cancer, losing his son, Beau Biden, to glioblastoma in 2015, when he was serving as vice president. At that time, he launched the “cancer moonshot,” a government-wide push for improved cancer treatments that he relaunched during his presidency.

The spread of cancer to the bones will make Biden’s cancer difficult to cure. But its receptiveness to hormone treatments could help his medical team inhibit the cancer’s growth, at least temporarily.

Biden dropped out of the 2024 race in July under immense pressure from leadership in the Democratic Party after a disastrous debate with the Republican presidential nominee, Donald Trump, laid bare concerns over his age and acuity.

Within hours of dropping out of the race, Biden endorsed his vice president, Kamala Harris, to run in his place. She quickly coalesced the party around her nomination and avoided a primary battle, but lost to Trump in November.

In a post on X, Harris said she and her husband, Doug Emhoff, were saddened to learn of Biden’s diagnosis. “We are keeping him, Dr. Biden, and their entire family in our hearts and prayers during this time,” she wrote. “Joe is a fighter — and I know he will face this challenge with the same strength, resilience, and optimism that have always defined his life and leadership. We are hopeful for a full and speedy recovery.”

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Last week on “The View,” Biden said he took responsibility for Trump’s return to power, because he was in office at the time. “I do, because, look, I was in charge and he won. So, you know, I take responsibility,” he said.

But he continued to reject criticisms that he and his team worked to conceal the effects of his age on his performance as president, saying he was not surprised by Harris’ loss and suggesting he still believes he could have beaten Trump had he stayed in the race.

“It wasn’t a slam dunk,” he said, referring to President Trump’s victory. “Let me put it this way. He’s had the worst 100 days any president’s ever had. And I would not say honesty has been his strong point.”

Trump expressed concern about Biden’s condition in a Truth Social post Sunday. “Melania and I are saddened to hear about Joe Biden’s recent medical diagnosis. We extend our warmest and best wishes to Jill and the family, and we wish Joe a fast and successful recovery,” he wrote.

California Gov. Gavin Newsom was among the many politicians from both parties who posted their warm wishes and prayers for the former president. “Our hearts are with President Biden and his entire family right now. A man of dignity, strength, and compassion like his deserves to live a long and beautiful life. Sending strength, healing and prayers his way,” Newsom wrote on X.

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House Speaker Mike Johnson (R-La.) wrote on X: “This is certainly sad news, and the Johnson family will be joining the countless others who are praying for the former President in the wake of his diagnosis.”

Biden was spending the weekend in Delaware with family, an aide said.

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Nearly half of Pasadena Unified schools have contaminated soil, district finds

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Nearly half of Pasadena Unified schools have contaminated soil, district finds

Eleven of the 23 Pasadena Unified School District schools, where students have been back on campus since January, have contaminated soil after the Eaton fire, the district found.

More than 40% of the schools had lead at levels exceeding the state’s health-based limits for residential soil, and more than 20% had arsenic levels beyond what L.A. County considers acceptable, according to the results released Wednesday.

The district found lead at more than three times the state’s allowable limit of 80 milligrams per kilogram of soil next to Blair High School’s tennis courts and more than double the limit at four elementary schools. Lead, when inhaled through dust or ingested from dirt-covered hands, can cause permanent brain and nerve damage in children, resulting in slowed development and behavioral issues.

Arsenic, a known carcinogen, was found at a concentration of 92 mg/kg at San Rafael Elementary School. The county has used 12 mg/kg as a reference level, based on an estimate of the highest naturally occurring arsenic levels in all of Southern California. The naturally occurring background level of arsenic in Altadena and Pasadena ranges from 4 to 10 mg/kg, according to a 2019 study by the U.S. Geological Survey.

There is no safe exposure level for arsenic or lead.

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“I’m worried about her safety,” said Nicole Maccalla of her daughter, a sixth-grader at Octavia E. Butler Magnet, which is located less than a mile from the Eaton fire burn area. “I would really like to have assurances that she’s physically safe while she’s at school.”

Instead, what she got was a map of the school posted by the district showing lead levels 40% and 70% above the allowable limit in soil samples taken next to the school entrance and near the outdoor lunch tables, respectively.

“If, literally, you’ve got to walk by lead to walk up the steps to school, then how many kids are walking through that with their shoes and then walking into the classroom?” Maccalla said. “It’s not like these are inaccessible areas that are gated off.”

Maccalla made the hard decision to let her daughter return to school in January despite early fears — worrying that the trauma of changing schools directly after the fire would be too much.

Along with other concerned parents, Maccalla has been pushing for both soil and indoor testing for months at school board meetings. It was only after the L.A. County Department of Public Health announced in April that it had found 80% of properties had lead levels exceeding the state’s standards in some areas downwind that the district hired the environmental firm Verdantas to conduct testing at schools.

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“The school board has been very resistant to any request for testing from parents,” she said. “The superintendent kept saying it’s safe.” The parents’ response: “Prove it.”

The district released test results for 33 properties it owns — some with district schools and children’s centers, others with charter and private schools, some rented to nonprofits — that were all largely unscathed by the fires. On the 22 properties with public schools, students have been back in the classroom since late January. The full results with maps for each school can be seen on the school district’s website.

The district stated on its website there was “no indication that students or staff were exposed to hazardous levels of fire-related substances in the soil,” noting that any contamination found was highly localized. (For example, although seven samples at Blair High School identified elevated lead levels, 21 samples did not.)

Health agencies also advised the district that soil covered with grass or cement was unlikely to pose a health risk.

In response to the results, the district stated it would restrict access to contaminated areas, complete follow-up sampling and work on remediation over the summer. No classroom instruction would be affected.

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“We want to be abundantly clear: Safety is not negotiable,” Pasadena Unified School District Supt. Elizabeth Blanco said in a press release. “That’s why we’re moving forward with both urgency and care.”

For Maccalla, it’s too little too late. “I would like to know what their plan is for monitoring the health of the children, given you’ve got kids that have already been playing outside in that soil for four months straight,” she said. “So what’s their health crisis mitigation plan?”

The test results also found high levels of chromium — which, in some chemical configurations, is a carcinogen — on one campus. Another had high levels of a class of contaminants called polycyclic aromatic hydrocarbons, which can cause headaches, coughing, skin irritation and, over long periods of exposure, can come with an increased risk of cancer.

Three of the five properties with the district’s children’s centers also had elevated levels of heavy metals — two with lead, one with arsenic.

When Maccalla — who has spent much of her time after the fire volunteering with the community advocacy group Eaton Fire Residents United — first saw the map of her daughter’s school, she began to formulate a plan to rally volunteers to cover the contaminated areas with mulch and compost before school buses arrive again Monday morning. (That is an expert-approved remediation technique for fire-stricken soil.)

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“If the district is not going to do it, the state’s not going to do it, our county’s not going to do it, our city’s not going to do it,” she said, “well, the citizens will. We absolutely will.”

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California board voted to nix a controversial hazardous waste proposal

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California board voted to nix a controversial hazardous waste proposal

A state environmental oversight board voted unanimously to rescind a controversial proposal that would have permitted California municipal landfills to accept contaminated soil that is currently required to be dumped at sites specifically designated and approved for hazardous waste.

Earlier this year, the California Department of Toxic Substances Control (DTSC) released a draft of its first-ever Hazardous Waste Management Plan, a document intended to guide the state’s strategy on dangerous waste.

The draft plan included a recommendation to weaken California’s disposal rules for contaminated soil — typically the largest segment of hazardous waste produced each year. The potential change would have allowed contaminated soil from heavily polluted sites to be dumped at landfills that were not designed to handle hazardous waste.

Environmental advocates and community members expressed concerns that the rollback could result in toxic dust blowing into communities near local landfills or dangerous chemicals leaching into groundwater. State officials countered by saying that contaminated soil would only go to landfills equipped with liners that would prevent toxic substances from seeping into local aquifers.

At a public meeting on the plan held on Thursday evening, the Board of Environmental Safety — a five-member panel established to provide oversight of DTSC — unanimously voted to remove that recommendation from the state’s draft plan. That followed months of intense scrutiny from residents and environmental groups directed toward the plan. DTSC officials present at the meeting also signaled that they would support the board’s decision to nix the revision.

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“I heard you talk about the pollution burdens you already face,” DTSC deputy director Mandi Bane said to the crowd of a few dozen who had gathered at the department’s offices in Cypress. “The worry that DTSC is taking steps that will endanger your community by making that pollution burden worse, and [the] outrage that these steps will be taken without consultation and discussion. As a public health professional, the stress, the fear, the anger that I heard from folks was very concerning … and I do want to apologize that this plan had that impact.”

Heavily polluting industries have tainted soil across California. More than 560,000 tons of hazardous soil are produced each year in California as environmental regulators endeavor to prevent residents from coming in contact with chemical-laced soil and developers build on land in industrial corridors.

However, the vast majority of this soil is not considered hazardous outside of California. The state has hazardous waste regulations that are more stringent than the federal government and most states in the country.

There are only two waste facilities in California that meet the state’s rigorous guidelines for hazardous materials, both in the San Joaquin Valley. Any hazardous dirt in California must be trucked there, or exported to landfills in neighboring states that rely on the more lenient federal standards.

State officials argued the current rules make it difficult and expensive to dispose of contaminated soil, noting that the average distance such waste is trucked right now is about 440 miles, according to the draft plan.

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Ahead of the board vote, environmental advocates rallied outside of the DTSC offices in Cypress, calling on state officials to uphold California’s hazardous waste standards for contaminated soil. Angela Johnson Meszaros, an attorney with Earthjustice, said the proposal would effectively forgo California’s regulatory authority and rely on the federal environmental rules — at a time when the Trump administration is repealing environmental policy.

“This plan is a travesty, and I’m calling on DTSC to be better than this,” Johnson Meszaros said at Thursday’s meeting. “If we don’t draw the line with this massive deregulatory effort, there is no line. We will be swept up in the insanity we see at the national level.”

The discussion of hazardous waste disposal has been thrust into the public spotlight recently as the U.S. Army Corps of Engineers continues to remove toxic ash and contaminated soil from properties destroyed in the Eaton and Palisades wildfires. Because disaster debris is traditionally considered not hazardous, federal contractors have been hauling this material to several nonhazardous local landfills without testing it.

In response to the federal cleanup plans, residents in unincorporated Agoura and the Granada Hills neighborhood in Los Angeles staged protests near local landfills.

Melissa Bumstead, an environmental advocate and San Fernando Valley resident, urged the Board of Environmental Safety to consider factoring disaster debris into the hazardous waste plan. With climate change fueling increasingly destructive wildfires, this will continue to be an issue for years to come, she said.

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“This is an opportunity, not just with hazardous waste that is manufactured,” Bumstead said, “but also hazardous waste that is created by wildfires on how to create a plan that is going to protect Californians in the future.”

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