Signs and flags are pictured at a pro-Palestinian encampment on the lawn of the Stratton Student Center campus at the Massachusetts Institute of Technology (MIT) in Cambridge, Massachusetts, on May 9, 2024.
| Photo Credit: AFP

Police dismantled a pro-Palestinian tent encampment at the Massachusetts Institute of Technology early Friday and moved to clear protesters from University of Pennsylvania’s campus in Philadelphia, hours after police tear-gassed protesters and took down an encampment at the University of Arizona.

In Cambridge, Massachusetts, video showed police roaming through the MIT encampment. Police in riot gear arrived around 4 a.m., encircled the camp and gave protesters about 15 minutes to leave. Ten students who remained were arrested, the university’s president said. A crowd outside the camp began gathering and chanting pro-Palestinian slogans but were dispersed by 6 a.m.

Also Read | Police clear pro-Palestinian protest camp, arrest 33 at university in Washington DC

At the University of Arizona in Tucson, campus police in riot gear fired tear gas late Thursday at protesters before tearing down an encampment that included wood and plastic barriers on campus. In statement, the University of Arizona said it made the decision because the encampment violated school policy.

“A structure made from wooden pallets and other debris was erected on campus property after 5 p.m. in violation of the policy,” the school said in a statement. “University officials issued warnings to remove the encampment and disperse. The warnings were ignored.”

The school also said that police vehicles were spiked, and rocks and water bottles thrown at officers and university staff.

In Philadelphia early Friday, police detained people who were at an encampment that has been in place at the University of Pennsylvania for more than two weeks. Officers moved in after giving protesters a warning to leave campus or face possible arrest.

Tensions have ratcheted up in standoffs with protesters on campuses across the United States and in Europe. Some colleges cracked down immediately, while others have tolerated the demonstrations. Some have begun to lose patience and call in the police over concerns about disruptions to campus life and safety.

The protest movement began nearly three weeks ago at Columbia University in New York City. It has since swept college campuses nationwide, with demonstrators generally seeking to draw attention to the deaths in the Israel-Hamas war or calling for their schools to stop doing business with Israel or companies that support its war efforts. More than 2,500 people have been arrested.

The move at MIT comes several days after police first attempted to clear the camp only to see protesters storm past barriers and restore the encampment, which includes about a dozen tents in the heart of the campus in Cambridge.

Before removing the encampment, MIT earlier in the week had started suspending dozens of students involved in the encampment, meaning they wouldn’t be able to take part in academic activities nor commencement.

Protesters insisted the move would not stop them from demanding that MIT end all ties to the Israeli military. They encampment had been up for at least weeks and especially angered Jewish students, who have held counterprotests near the camp.

“This is only going to make us stronger. They can’t arrest the movement,” Quinn Perian, an undergraduate student at MIT and organiser for MIT Jews for Ceasefire, said. “We are going to continue and won’t back down until MIT agrees to cut ties with the Israeli military. MIT would rather arrest and suspend some students than they would end their complicity with the genocide going in Gaza.”

The encampment had been up for at least two weeks and especially angered Jewish students, who have held counterprotests nearby. They covered a lawn with small Israeli flags and put up posters of some of the people abducted by the militants in the attack that ignited the war in Gaza.

MIT President Sally Kornbluth, working to strike a balance between recognising the suffering in Gaza and concerns about the “safety of our community,” had warned Monday the encampment would have be removed.

In a letter acknowledging Friday’s arrests, she wrote that her responsibility is “to make sure that the campus is physically safe and functioning for everyone … and that everyone feels free to express their views.” The encampment, she wrote, “increasingly made it impossible to meet all these obligations.”

The various species of whales inhabiting Earth’s oceans employ different types of vocalisations to communicate. Sperm whales, the largest of the toothed whales, communicate using bursts of clicking noises — called codas — sounding a bit like Morse code.

A new analysis of years of vocalisations by sperm whales in the eastern Caribbean has found that their system of communication is more sophisticated than previously known, exhibiting a complex internal structure replete with a “phonetic alphabet.” The researchers identified similarities to aspects of other animal communication systems — and even human language.

Like all marine mammals, sperm whales are very social animals, with their calls an integral part of this. The new study has provided a fuller understanding of how these whales communicate.

“The research shows that the expressivity of sperm whale calls is much larger than previously thought,” said Pratyusha Sharma, a Massachusetts Institute of Technology doctoral student in robotics and machine learning and lead author of the study published on May 7 in the journal Nature Communications.

“We do not know yet what they are saying. We are studying the calls in their behavioral contexts next to understand what sperm whales might be communicating about,” said Ms. Sharma.

Sperm whales, which can reach about 60 feet (18 metres) long, have the largest brain of any animal. They are deep divers, feeding on giant squid and other prey.

The researchers are part of the Project CETI (Cetacean Translation Initiative) Machine Learning Team. Using traditional statistical analysis and artificial intelligence, they examined calls made by about 60 whales recorded by the Dominica Sperm Whale Project, a research program that has assembled a large dataset on the species.

“Why are they exchanging these codas? What information might they be sharing?” asked study co-author Shane Gero, Project CETI’s lead biologist and Dominica Sperm Whale Project founder, also affiliated with Carleton University in Canada.

“I think it’s likely that they use codas to coordinate as a family, organize babysitting, foraging and defense,” Mr. Gero said.

Variations in the number, rhythm and tempo of the clicks produced different types of codas, the researchers found. The whales, among other things, altered the duration of the codas and sometimes added an extra click at the end, like a suffix in human language.

“All of these different codas that we see are actually built by combining a comparatively simple set of smaller pieces,” said study co-author Jacob Andreas, an MIT computer science professor and Project CETI member.

People combine sounds — often corresponding to letters of the alphabet — to produce words that carry meaning, then produce sequences of words to create sentences to convey more complex meanings.

For people, Ms. Sharma said, “There are two levels of combination.” The lower level is sounds to words. The higher level is words to sentences.

Sperm whales, Ms. Sharma said, also use a two-level combination of features to form codas, and codas are then sequenced together as the whales communicate. The lower level has similarities to letters in an alphabet, Ms. Sharma said.

“Every communication system is tailored to the environment and animal society in which it has evolved,” Ms. Sharma added.

The communication system used by sperm whales differs, for example, from the “songs” of humpback whales — and, for that matter, from the whistles, chirps, croaks and assorted other vocalizations by various animals.

“Human language is unique in many ways, yes,” Mr. Gero said. “But I suspect we will find many patterns, structures and aspects thought to be unique to humans in other species, including whales, as science progresses — and perhaps also features and aspects of animal communications which humans do not possess.”

If scientists can decipher the meaning of what the sperm whales are “saying,” should people try to communicate with them?

“I think there’s a lot more research that we have to do before we know whether it’s a good idea to try to communicate with them, or really even to have a sense of whether that will be possible,” Mr. Andreas said.

“At the same time, I’m optimistic that we’re going to be able to learn a lot more about what information is actually encoded in these vocalizations that we’re listening to, what sort of information is contained in these clicks and these codas, as we start to understand the behavioral context in which this occurs,” Mr. Andreas added.