At least 17 Palestinians have been killed and 50 wounded in a fresh Israeli assault on Gaza City, rescuers and health officials have said, as Hamas was reported to have withdrawn from ceasefire talks.

The attacks in the early hours of Sunday morning occurred less than 24 hours after Israeli forces say the Hamas military chief, Mohammed Deif, the mastermind of the 7 October attack on southern Israel, was the target of a strike in Khan Younis, southern Gaza, which, according to the territory’s emergency services, killed more than 90 people and injured 300 more.

At least four distinct Israeli airstrikes targeted houses in various parts of the city on Sunday.

Deif, 58, who has been on Israel’s most-wanted list since 1995 and escaped multiple Israeli assassination attempts, is believed to be the chief architect of the attack that killed 1,200 people in southern Israel and triggered the Israel-Hamas war.

The Israel Defense Forces (IDF) said Rafa Salama, another top Hamas official, was also targeted in the strike.

Benjamin Netanyahu, the Israeli prime minister, said: “There is still no conclusive certainty that the two have been foiled, but I want to assure you that one way or another we will reach the top of Hamas.”

Hamas’s deputy leader, Khalil al-Hayya, told Al Jazeera TV that Deif had not been killed in the strikes and, addressing Netanyahu, said: “Deif is listening to you right now and mocking your lies.”

Another Hamas official told AFP the group’s military leader Mohammed Deif was “fine” and working despite Israel’s huge bomb.

Deif, known as “guest”, has frequently changed locations to elude Israeli detection. Engaged with Hamas from a young age, the former science student orchestrated a series of suicide bombings targeting Israeli civilians in the 1990s and then again a decade later.

On 7 October, Hamas issued a rare voice recording of Deif announcing the “Al-Aqsa Flood” operation.

Gaza’s health ministry said Israel’s strike on a camp for displaced people in Khan Younis killed at least 92 Palestinians and injured more than 300 others. Residents said they witnessed at least five “big warplanes bombing in the middle of al-Mawasi area, west of Khan Younis”.

Hamas says Israeli claims of targeting leaders of the Palestinian militant group are “false” and are aimed at “justifying” the attack. A senior Hamas official told Agence France-Presse on Sunday that the Palestinian militant group had withdrawn from talks on a ceasefire in the Gaza war because of what it called Israeli “massacres” and its attitude in negotiations.

Two Egyptian security sources told Reuters on Saturday that Gaza ceasefire talks had been halted after three days of intense negotiations failed to produce a viable outcome, blaming Israel for lacking a “genuine intent to reach agreement”. The sources, who spoke on condition of anonymity, said that the behaviour of the Israeli mediators revealed “internal discord”.

A few hours before, Hamas’s political leader, Ismail Haniyeh, accused Netanyahu of seeking to block a deal to end the war with “heinous massacres”. He said Hamas had shown “a positive and responsible response” to new proposals for a ceasefire and prisoner exchange, but “the Israeli position taken by Netanyahu was to place obstacles that prevent reaching an agreement”, Haniyeh said in a statement.

Thousands of Israelis took to the streets across the country over the weekend, accusing Netanyahu of sabotaging the negotiations. Among the demonstrators were families of hostages, who made a symbolic march from Tel Aviv to Jerusalem. Relatives of those still held captive in Gaza by Hamas fear that the recent escalation of bombings in the strip may hinder the safe return home of their loved ones.

“In light of recent events in the Gaza Strip, the families of the hostages remind Prime Minister Netanyahu that there can be no victory until all 120 hostages are returned home,” read a statement from the Hostage and Missing Families Forum. “The proposed deal is in its final stages. We have been waiting for them for 282 days. Time is of the essence; there’s not a moment more to lose.”

Israeli forces say the Hamas military chief, Mohammed Deif, the mastermind of the 7 October attack, was the target of a strike in Khan Younis, southern Gaza, which, according to the territory’s emergency services, has killed 90 people and injured hundreds more.

Deif, 58, who has been on Israel’s most-wanted list since 1995 and escaped multiple Israeli assassination attempts, is believed to be the chief architect of the attack that killed 1,200 people in southern Israel and triggered the Israel-Hamas war.

The Israel Defense Forces (IDF) said Rafa Salama, another top Hamas official, was also targeted in the strike. The IDF did not have details on whether the two were killed.

A military official later said they were “still checking and verifying the result of the strike”, and did not deny it took place inside an area the Israeli military had designated as safe for hundreds of thousands of Palestinians.

“The air force and the southern command attacked, based on accurate intelligence information, in the area where the two top targets of the Hamas terrorist organisation and other terrorists were hiding among civilians,” reads a joint statement released by IDF and Shin Bet intelligence agency. “The area that was attacked is an open and wooded area, with several buildings and sheds.”

Benjamin Netanyahu, the Israeli prime minister, said: “There is still no conclusive certainty that the two have been foiled, but I want to assure you that one way or another we will reach the top of Hamas.”

Hamas’s deputy leader, Khalil al-Hayya, told Al Jazeera TV that Deif had not been killed in the strikes and, addressing Netanyahu, said: “Deif is listening to you right now and mocking your lies.”

Gaza’s health ministry said on Saturday that Israel’s strike on a camp for displaced people in Khan Younis killed at least 90 Palestinians and injured 289 others. Residents said they witnessed at least five “big warplanes bombing in the middle of Al Mawasi area, west of Khan Younis”.

Most of the injured were sent to Nasser hospital. However, according to officials and medics, the facility is “no longer able to function” as doctors are “overwhelmed with large numbers of casualties”.

Hamas says that Israeli claims of targeting leaders of the Palestinian militant group are “false” and are aimed at “justifying” the attack.

The Israeli military said its strike on Deif was in a “fenced Hamas area” and that most people there were militants.

Earlier, a senior Hamas official called the Israeli allegations “nonsense”. “All the martyrs are civilians and what happened was a grave escalation of the war of genocide, backed by the American support and world silence,” Sami Abu Zuhri told Reuters, adding that the strike showed Israel was not interested in reaching a ceasefire deal. He did not confirm whether Deif had been present.

The targeted area of Nus Street contains more than 80,000 displaced people from across Gaza.

Witnesses said ambulances and civil defence crews were targeted after the strike, with a number of hovering Israeli aircraft “shooting and targeting directly at the ambulances and rescue teams upon their arrival”.

The Gaza health ministry said: “The number of the victims is still increasing because bodies are still being recovered beneath the rubble”.

“Rescue teams are still recovering dozens of martyrs and wounded until this moment from the site of bombing and targeting,” reads a statement by the government information office in Gaza. “This massacre comes in conjunction with the lack of hospitals that can receive this large number of martyrs and wounded, and in conjunction with the occupation’s destruction of the health system in the Gaza Strip.”

Not seen in public for years, Deif, known as “guest”, has frequently changed locations to elude Israeli detection. Engaged with Hamas from a young age, the former science student orchestrated a series of suicide bombings targeting Israeli civilians in the 1990s and then again a decade later.

Speculations suggest that Deif may have been disabled in one of the numerous Israeli attempts on his life, with his spouse and young children having died in a 2014 airstrike.

Referred to by Israeli authorities as “a dead man walking”, Deif’s actual name is Mohammed Diab Ibrahim al-Masri.

On 7 October, Hamas issued a rare voice recording of Deif announcing the “Al-Aqsa Flood” operation.

The Saudi channel Al-Hadath reported that Salama, the commander of Hamas’s Khan Younis Brigade, was killed in the strike and that Deif was seriously wounded.

The death of Deif could represent a significant victory for Israel and a devastating blow to Hamas. The operation could provide Netanyahu with a potential advantage, as he has made clear his intention to continue the war until Hamas’s military capabilities are destroyed, with Deif’s death being a significant step in that direction.

Saturday’s strikes came as US, Egyptian and Qatari mediators were actively working to narrow the divide between Israel and Hamas in a proposed three-phase ceasefire and hostage release plan.

The talks were halted after three days of intense negotiations failed to produce a viable outcome, two Egyptian security sources said on Saturday, blaming Israel for lacking a genuine intent to reach agreement.

The sources, who spoke to Reuters on condition of anonymity, said the behaviour of the Israeli mediators revealed “internal discord”.

According to the sources, the Israeli delegation would give approvals on several conditions under discussion, but then come back with amendments or introduce new conditions that risked sinking the negotiations.

The sources said the mediators viewed the “contradictions, delays in responses, and the introduction of new terms contrary to what was previously agreed” as signs the Israeli side viewed the talks as a formality aimed at influencing public opinion.

Hamas leader Ismail Haniyeh on Saturday accused Netanyahu of seeking to block a ceasefire in the Gaza war with “heinous massacres”.

He said Hamas had shown “a positive and responsible response” to new proposals for a ceasefire and prisoner exchange, but “the Israeli position taken by Netanyahu was to place obstacles that prevent reaching an agreement,” Haniyeh said in a statement.

Kenyan police said that they had found more bags filled with dismembered female body parts on Saturday, the latest macabre discovery at a rubbish dump that has horrified and angered the country.

Detectives have been scouring the site in the Nairobi slum of Mukuru since the mutilated corpses of at least six women were found on Friday in sacks floating in a sea of garbage.

The Directorate of Criminal Investigations (DCI) on Saturday said that another five bags had been retrieved from the abandoned quarry, three of them containing female body parts, including severed legs and two torsos.

“We want to assure the public that our investigations will be thorough and shall cover a wide range of areas, including but not limited to the possible activities of cultists and serial killings,” it said in a statement.

Kenya was left reeling last year by the discovery of mass graves in a forest near the Indian Ocean coast containing the bodies of hundreds of followers of a doomsday sect, one of the world’s worst cult-related massacres.

The country’s law enforcement services are also under scrutiny after dozens of people were killed during anti-government demonstrations last month, with rights groups accusing officers of using excessive force and of abducting protesters.

Police on Friday had reported finding bodies of at least six women in Mukuru, while the state-funded police watchdog said nine bodies had been found, seven of them women.

Tensions have been running high at the Mukuru site, with local media reports that police had fired into the air to try to disperse an angry crowd.

The DCI said a team of detectives and forensic experts “were impeded by agitated members of the public from accessing the scene”.

The Independent Police Oversight Authority (Ipoa) on Friday had said that it was investigating whether there was any police involvement in the gruesome saga.

“The bodies, wrapped in bags and secured by nylon ropes, had visible marks of torture and mutilation,” it said, noting that the dumpsite was less than 100 metres from a police station.

The Ipoa also said it was looking into claims of abductions of demonstrators who went missing after the deadly anti-government protests, but did not link those missing to the dumped bodies.

Some people on social media have described them as victims of femicide.

The Kenyan president, William Ruto, on Saturday said there was “no justification” for any Kenyan to lose their life.

“We are a democratic country guided by the rule of law. Those involved in mysterious killings in Nairobi and any other part of the country will be held to account,” he said on X.

Kenya’s feared police force is often accused of extrajudicial killings and other rights abuses, but convictions are rare.

A coalition of civil society and rights groups said the Mukuru discoveries came amid a “troubling surge” in cases of mysterious disappearances and abductions, particularly after the anti-tax protests.

“It represents a grave violation of human rights and raises serious concerns about the rule of law and security in our country,” the coalition said.

National police chief Japhet Koome resigned on Friday after being the target of much public anger over the protest deaths.

Ruto is scrambling to contain the worst crisis of his rule over the deeply unpopular plans for tax hikes, which he has now scrapped.

Crowds that gathered at the dumpsite on Friday chanted “Ruto must go”, the slogan of Gen-Z Kenyans leading the demonstrations that have now morphed into a wider campaign against the president, corruption and alleged police brutality.

On Monday, doomsday cult leader Paul Nthenge Mackenzie went on trial along with 94 co-defendants over the deaths of more than 400 followers he is accused of inciting to starve themselves to death to meet Jesus.

He and his co-accused also face charges of murder, manslaughter and child cruelty in separate cases over what has been dubbed the “Shakahola forest massacre”.

A hundred years ago, the plant scientist Arthur Watkins launched a remarkable project. He began collecting samples of wheat from all over the globe, nagging consuls and business agents across the British empire and beyond to supply him with grain from local markets.

His persistence was exceptional and, a century later, it is about to reap dramatic results. A UK-Chinese collaboration has sequenced the DNA of all the 827 kinds of wheat, assembled by Watkins, that have been nurtured at the John Innes Centre near Norwich for most of the past century.

In doing so, scientists have created a genetic goldmine by pinpointing previously unknown genes that are now being used to create hardy varieties with improved yields that could help feed Earth’s swelling population.

Strains are now being developed that include wheat which is able to grow in salty soil, while researchers at Punjab Agricultural University are working to improve disease resistance from seeds that they received from the John Innes Centre. Other strains include those that would reduce the need for nitrogen fertilisers, the manufacture of which is a major source of carbon emissions.

“Essentially we have uncovered a goldmine,” said Simon Griffiths, a geneticist at the John Innes Centre and one of the project’s leaders.

“This is going to make an enormous difference to our ability to feed the world as it gets hotter and agriculture comes under increasing climatic strain.”

Today, one in five calories consumed by humans come from wheat, and every year the crop is eaten by more and more people as the world’s population continues to grow.

“Wheat has been a cornerstone of human civilisation,” added Griffiths. “In regions such as Europe, north Africa, large parts of Asia, and subsequently North America, its cultivation fed great empires, from ancient Egypt’s to the growth of modern Britain.”

This wheat was derived from wild varieties that were originally domesticated and cultivated in the Fertile Crescent in the Middle East, 10,000 years ago. Many of these varieties and their genes have disappeared over the millennia, a process that was accelerated about a century ago as the science of plant breeding became increasingly sophisticated and varieties with properties that were then considered of no value were discarded.

“That is why the Watkins collection is so important,” said Griffiths. “It contains varieties that had been lost but which will be invaluable in creating wheat that can provide healthy yields in the harsh conditions that now threaten agriculture.”

The project’s other leader, Prof Shifeng Cheng of the Chinese Academy of Agricultural Sciences, said: “We can retrace the novel, functional and beneficial diversity that were lost in modern wheats after the ‘green revolution’ in the 20th century, and have the opportunity to add them back into breeding programmes.”

Scientists had wanted to pinpoint and study the wheat genes in the Watkins collection after the development of large-scale DNA sequencing more than a decade ago, but faced an unusual problem. The genome of wheat is huge: it is made up of 17bn units of DNA, compared with the 3bn base pairs that make up the human genome.

“The wheat genome is full of ­little retro elements and that has made it more difficult and, crucially, more expensive to sequence,” said Griffiths. “However, thanks to our Chinese colleagues who carried out the detailed sequencing work, we have overcome that problem.”

Griffiths and his colleagues sent samples from the Watkins collection to Cheng and were rewarded three months later with the arrival of a suitcase crammed with hard drives. These contained a petabyte – one million gigabytes – of data that had been decoded by the Chinese group using the Watkins collection.

Astonishingly, this data revealed that modern wheat varieties only make use of 40% of the genetic diversity found in the collection.

“We have found that the Watkins collection is packed full of useful variation which is simply absent in modern wheat,” said Griffiths.

These lost traits are now being tested by plant breeders with the aim of creating a host of new varieties that would have been forgotten if it had not been for the efforts of Arthur Watkins.

A shy pioneer

Arthur Watkins’s introduction to agriculture was unusual. At the age of 19, he was sent to fight in the trenches in the first world war. He survived, and for several months after the armistice he was ordered to remain in France to act as an assistant agricultural officer, tasked with helping local farmers feed the troops who were still waiting to be shipped home.

The post triggered his interest in agriculture and he applied to study it at Cambridge when he returned to Britain, said Simon Griffiths of the John Innes Centre. After graduating, Watkins – a shy, reserved academic – joined the university’s department of agriculture, where he began his life’s work: collecting wheat samples from across the planet.

“Crucially, Watkins had realised that, as we began breeding new wheat varieties, genes that were then thought to be of little use and which were being deleted from strains might still have future value,” said Griffiths.

“His thinking was incredibly ahead of its time. He realised that genetic diversity – in this case, of wheat – was being eroded and that we badly needed to halt that.

“Very few scientists were thinking of this issue in those days. Watkins was clearly thinking well ahead of his time, and we have much to be grateful for that.”

The fitness instructor Richard Simmons, who rocketed to fame in the 1980s with up-tempo neon-colored exercise videos such as Sweatin’ to the Oldies, has died.

Simmons had just thanked fans on social media for birthday wishes after he turned 76 on Friday. “I never got so many messages about my birthday in my life!” Simmons wrote on X, formerly known as Twitter. “I am sitting here writing emails. Have a most beautiful rest of your Friday.”

ABC News said Simmons’ death was confirmed by his representative on Saturday, following a 911 call made by his housekeeper. It added that Simmons appeared to have died of natural causes, citing police sources.

Born in New Orleans as Milton Teagle Simmons, Simmons rose to fame in the 1970s and captured the zeitgeist in the 1980s through a series of exercise videos, conducted in often lurid outfits. He also opened a number of gyms, promoted a range of products and became an established media presence on TV and radio over the decades.

Having long been the most recognizable face of fitness and healthy living in the US, promoting various weight-loss programs in his often flamboyant style, Simmons also became involved in aspects of political activism, such as his support for non-competitive physical education in public schools.

In the past decade, Simmons had largely retreated from public life. In March, he revealed that he had been diagnosed with skin cancer, underneath his eye. In the same month, he posted on social media that “I am … dying. The truth is we all are dying. Every day we live we are getting closer to our death.”

He later clarified that he was not actually about to die and that he intended to pass on a message for people to embrace life.

It has produced one of the most consistent sets of negative results in the history of science. For more than 60 years, researchers have tried to find a single convincing piece of evidence to support the idea that we share the universe with other intelligent beings. Despite these decades of effort, they have failed to make contact of any kind.

But the hunt for alien civilisations may be entering a new era, researchers believe. Scientists with Breakthrough Listen, the world’s largest scientific research programme dedicated to finding alien civilisations, say a host of technological developments are about to transform the search for intelligent life in the cosmos.

These innovations will be outlined at the group’s annual conference, which is to be held in the UK for the first time, in Oxford, this week. Several hundred scientists, from astronomers to zoologists, are expected to attend.

Astronomer Steve Croft, a project scientist with Breakthrough Listen, said: “There are amazing technologies that are under development, such as the construction of huge new telescopes in Chile, Africa and Australia, as well as developments in AI. They are going to transform how we look for alien civilisations.”

Among these new instruments are the Square Kilometre Array, made up of hundreds of radio telescopes now being built in South Africa and Australia, and the Vera Rubin Observatory that is being constructed in Chile. The former will become the world’s most powerful radio astronomy facility while the latter, the world’s largest camera, will be able to image the entire visible sky every three or four nights, and is expected to help discover millions of new galaxies and stars.

Both facilities are set to start observations in the next few years and both will provide data for Breakthrough Listen. Using AI to analyse these vast streams of information for subtle patterns that would reveal evidence of intelligent life will give added power to the search for alien civilisations, added Croft.

“Until now, we have been restricted to looking for signals deliberately sent out by aliens to advertise their existence. The new techniques are going to be so sensitive that, for the first time, we will be able to detect unintentional transmissions as opposed to deliberate ones and will be able to spot alien airport radar, or powerful TV transmitters – things like that.”

The importance of being able to detect civilisations from the signatures of their everyday activities is supported by astrophysicist Prof Adam Frank of the University of Rochester in New York. “By searching for signatures of an alien society’s day-to-day activities – a technosignature – we are building entirely new toolkits to find intelligent, civilisation-building life,” he writes in his new book, The Little Book of Aliens.

All sorts of technosignatures have been suggested as indicators of the presence of alien civilisations, from artificial lighting to atmospheric pollution. Some scientists have even suggested that alien civilisations could be spotted from the solar panels they have built. Solar panels absorb visible light but strongly reflect ultraviolet and infrared radiation, which could be detected using a powerful telescope.

However, this would only be possible to spot if vast tracts of a planet’s surface had been covered in solar farms and hundreds of hours of observing time were committed to such a search, says astrobiologist Lewis Dartnell, writing in the latest edition of the BBC’s Sky at Night magazine.

Other alien efforts to trap solar radiation could be even more elaborate and conspicuous, however. The US physicist Freeman Dyson once proposed that some civilisations might be advanced enough to build vast arrays of solar panels encircling their home stars. These great orbiting edifices – known as Dyson spheres – would be detectable from Earth, and several candidates have been proposed, including Boyajian’s star, in the constellation Cygnus, whose output of light is sporadic and unpredictable. Some suggested this could be being caused by a Dyson sphere, though recent observations have ruled out the possibility.

The hunt for alien civilisations has been a cornerstone of cinematic sci-fi spectaculars from E.T. to Contact, Arrival and District 9. However, extraterrestrial life forms have remained the stuff of fiction, despite efforts which began in earnest in 1960 when astronomer Frank Drake used a 26-metre radio telescope to search for possible signals from the stars Tau Ceti and Epsilon Eridani. None were detected – a state of affairs that has continued despite vast increases in the power and sophistication of modern telescopes.

Whether this stream of negative results continues remains to be seen. Croft remains optimistic that we will soon succeed in making contact. “We know that the conditions for life are everywhere, we know that the ingredients for life are everywhere.

“I think it would be deeply weird if it turned out we were the only inhabited planet in the galaxy or in the universe. But you know, it’s possible.”

It has produced one of the most consistent sets of negative results in the history of science. For more than 60 years, researchers have tried to find a single convincing piece of evidence to support the idea that we share the universe with other intelligent beings. Despite these decades of effort, they have failed to make contact of any kind.

But the hunt for alien civilisations may be entering a new era, researchers believe. Scientists with Breakthrough Listen, the world’s largest scientific research programme dedicated to finding alien civilisations, say a host of technological developments are about to transform the search for intelligent life in the cosmos.

These innovations will be outlined at the group’s annual conference, which is to be held in the UK for the first time, in Oxford, this week. Several hundred scientists, from astronomers to zoologists, are expected to attend.

Astronomer Steve Croft, a project scientist with Breakthrough Listen, said: “There are amazing technologies that are under development, such as the construction of huge new telescopes in Chile, Africa and Australia, as well as developments in AI. They are going to transform how we look for alien civilisations.”

Among these new instruments are the Square Kilometre Array, made up of hundreds of radio telescopes now being built in South Africa and Australia, and the Vera Rubin Observatory that is being constructed in Chile. The former will become the world’s most powerful radio astronomy facility while the latter, the world’s largest camera, will be able to image the entire visible sky every three or four nights, and is expected to help discover millions of new galaxies and stars.

Both facilities are set to start observations in the next few years and both will provide data for Breakthrough Listen. Using AI to analyse these vast streams of information for subtle patterns that would reveal evidence of intelligent life will give added power to the search for alien civilisations, added Croft.

“Until now, we have been restricted to looking for signals deliberately sent out by aliens to advertise their existence. The new techniques are going to be so sensitive that, for the first time, we will be able to detect unintentional transmissions as opposed to deliberate ones and will be able to spot alien airport radar, or powerful TV transmitters – things like that.”

The importance of being able to detect civilisations from the signatures of their everyday activities is supported by astrophysicist Prof Adam Frank of the University of Rochester in New York. “By searching for signatures of an alien society’s day-to-day activities – a technosignature – we are building entirely new toolkits to find intelligent, civilisation-building life,” he writes in his new book, The Little Book of Aliens.

All sorts of technosignatures have been suggested as indicators of the presence of alien civilisations, from artificial lighting to atmospheric pollution. Some scientists have even suggested that alien civilisations could be spotted from the solar panels they have built. Solar panels absorb visible light but strongly reflect ultraviolet and infrared radiation, which could be detected using a powerful telescope.

However, this would only be possible to spot if vast tracts of a planet’s surface had been covered in solar farms and hundreds of hours of observing time were committed to such a search, says astrobiologist Lewis Dartnell, writing in the latest edition of the BBC’s Sky at Night magazine.

Other alien efforts to trap solar radiation could be even more elaborate and conspicuous, however. The US physicist Freeman Dyson once proposed that some civilisations might be advanced enough to build vast arrays of solar panels encircling their home stars. These great orbiting edifices – known as Dyson spheres – would be detectable from Earth, and several candidates have been proposed, including Boyajian’s star, in the constellation Cygnus, whose output of light is sporadic and unpredictable. Some suggested this could be being caused by a Dyson sphere, though recent observations have ruled out the possibility.

The hunt for alien civilisations has been a cornerstone of cinematic sci-fi spectaculars from E.T. to Contact, Arrival and District 9. However, extraterrestrial life forms have remained the stuff of fiction, despite efforts which began in earnest in 1960 when astronomer Frank Drake used a 26-metre radio telescope to search for possible signals from the stars Tau Ceti and Epsilon Eridani. None were detected – a state of affairs that has continued despite vast increases in the power and sophistication of modern telescopes.

Whether this stream of negative results continues remains to be seen. Croft remains optimistic that we will soon succeed in making contact. “We know that the conditions for life are everywhere, we know that the ingredients for life are everywhere.

“I think it would be deeply weird if it turned out we were the only inhabited planet in the galaxy or in the universe. But you know, it’s possible.”

Toxic PFAS “forever chemicals” used in lithium ion batteries essential to the clean energy transition present a dangerous source of chemical pollution that new research finds threatens the environment and human health as the nascent industry scales up.

The multipronged, peer-reviewed study zeroed in on a little-researched and unregulated subclass of PFAS called bis-FASI that are used in lithium ion batteries.

Researchers found alarming levels of the chemicals in the environment near manufacturing plants, noted their presence in remote areas around the world, found they appear to be toxic to living organisms, and discovered that waste from batteries disposed of in landfills was a major pollution source.

The nation faces “two critical challenges – to minimize aquatic pollution and increase our use of clean and sustainable energy, and both are worthy causes”, said Jennifer Guelfo, a Texas Tech University researcher and study co-author.

“But there’s a bit of tug-of-war between the two, and this study highlights that we have an opportunity now as we scale up this energy infrastructure to do a better job of incorporating environmental risk assessments,” she added.

PFAS are a class of about 16,000 human-made compounds most often used to make products resistant to water, stains and heat. They are called “forever chemicals” because they do not naturally break down and have been found to accumulate in humans. The chemicals are linked to cancer, birth defects, liver disease, thyroid disease, plummeting sperm counts and a range of other serious health problems.

Public health advocates are increasingly sounding the alarm over the need to find alternatives to the toxic chemicals for clean energy technology, such as batteries and wind turbines, as the transition progresses.

The paper notes that few end-of-life standards for PFAS battery waste exist, and the vast majority ends up in municipal dumps where it can leach into waterways, accumulate locally or be transported long distances.

It looked at the presence of the chemicals in historical leachate samples and found none in those from prior to the mid-1990s, when the chemical class was commercialized.

The study noted previous research that bis-FASI can be reused, though as little as 5% of lithium batteries are recycled. That could yield a projected 8m tons of battery waste by 2040 if battery recycling is not dramatically scaled up with demand.

“This says that we should be taking a closer look at this class of PFAS,” Guelfo said.

Since very little toxicological data on bis-FASI exists, the study also checked for effects on invertebrates and zebrafish. It found effects at low exposure levels, which suggests toxicity in line with other PFAS compounds known to be dangerous.

Researchers also sampled water, soil and air around a 3M plant in Minnesota and other large facilities known to make the chemicals. The soil and water levels were concerning, Guelfo said, and detection of the chemicals in snow suggests the chemicals easily move through the atmosphere.

That may help explain why the chemicals have been found in Chinese seawater and other remote areas not close to production plants.

While the most commonly used PFAS definitions globally include bis-FASI, one division of the EPA does not consider it to belong to the chemical class, so it was not included on a list of compounds to be monitored in US water. The EPA has drawn criticism for using a narrow definition of PFAS that public health advocates say has excluded some chemicals at the industry’s behest.

However, the new research, taken with previous evidence, shows bis-FASI are persistent, mobile and toxic like most other PFAS, noted Lee Ferguson, a Duke University researcher and co-author.

“That classification combined with the huge ramp-up in clean energy storage that we’re seeing should at least ring some alarm bells,” he said.

What can we say to make you go, Joe? It is the question that more and more Democrats – elected members and ordinary voters – are asking as the rumbling crisis over Joe Biden’s presidential candidacy, sparked by a pitiful display in the debate in Atlanta, degenerates into a war of attrition.

Last Thursday, the president’s fate appeared perched on the edge of an abyss, as Congress members deserted him, senators poured out their heartfelt fears at a tearful meeting with White House staff, and even his own close aides and advisers briefed reporters that he should stand aside.

Then Biden gave a rare press conference to close Nato’s 75th anniversary summit in Washington. With the exception of the now half-expected flubs – referring to Kamala Harris as “Vice-President Trump” (having earlier introduced Ukraine’s president, Volodymyr Zelenskiy, as “President Putin”) – the feared Atlanta-style disaster did not materialise; instead, the 81-year-old Biden seemed to confound his advanced years as he expounded on foreign policy with an authority that would certainly have eluded Donald Trump, even if several thoughts trailed off unfinished.

Consequently, the president is now locked in a battle of wills with key segments of his party, with the campaign to coax him to step aside and avert a possible catastrophic election defeat boiling down to who has the greater conviction.

Campaigning in the vital swing state of Michigan on Friday, Biden made plain how strong his will was, evoking scenes that would have fitted a Trump rally.

“They hammer me because I sometimes confuse names. I say that’s Charlie instead of Bill,” Biden told a rally in Detroit, blaming his predicament on the media. “But guess what? Donald Trump has gotten a free pass.”

His broadside prompted boos from the crowd, some of whom turned to point accusingly at watching reporters in a scene with striking Trumpian parallels, the New York Times reported, while mention of Trump, his presumed Republican opponent, provoked chants of “lock him up” resembling those aimed at Hillary Clinton by the former president’s own supporters in the 2016 campaign.

The scenes unfolded after Mike Levin, a California Democrat, became the party’s first member of Congress to tell Biden to his face that he should step aside and “pass the torch” in a virtual meeting with the Congressional Hispanic Caucus. Unmoved, the president replied that voters should “touch me, poke me, ask me questions” if they think he is too old to serve or beat Trump, as polls suggesta significant majority doesmany do.

“I think I know what I’m doing, because the truth of the matter is – I’m going to say something outrageous – no president in three years has done what we have in three years other than Franklin Roosevelt,” he reportedly said.

Where does the Democratic party go in the face of this obduracy, with its own national convention little more than a month away?

The default answer may be to hope for the worst as a means of hoping for the best, according to Larry Sabato of the University of Virginia’s Center for Politics. That means waiting for Biden to undergo another crack-up reminiscent of the debate fiasco during the rash of public appearances he has promised to re-establish his credibility.

“I asked one member of Congress what extra pressure they could bring and he answered, ‘that’s all we got unless there’s another episode’,” said Sabato. “Does he freeze at the podium, does he start babbling? This member of Congress correctly pointed out to me that Trump has done the very same thing a number of times and has gotten away with it. But Biden can’t now get away with it – and he’s done it to himself.”

Another imagined scenario – widely touted, yet far from inevitable – is of party elders visiting the White House and persuading Biden to stand aside in the wider interest, as Republican grandees did with Richard Nixon in 1974 at the denouement of Watergate, telling him he would be impeached if he did not resign.

Speculation is rife that similar moves are afoot with Biden. “I think that there will be a visit to the White House by elder statesmen, probably Barack Obama, possibly Bill Clinton, John Kerry – contemporaries of Biden’s – who just say: ‘“Look at the party, look at yourself. You just can’t continue’,” said John Zogby, a veteran US pollster.

Without such dramatic symbolism Democrats face a “daunting task”, he argued, in persuading Biden to surrender a political prize he spent half a century of public service coveting and preparing for.

Short of that, Nancy Pelosi, the 84-year-old former speaker of the House of Representatives, and the former president, Barack Obama, are reported to have conferred privately about their concerns. Obama was apparently told in advance by George Clooney, a major Democratic fundraiser, about an opinion article the actor had written for the New York Times calling on the president to end his campaign – and did nothing to stop it.

In a drama-laden report following Biden’s Nato press conference, the Axios website described an unofficial “committee to un-elect the president” consisting of figures who had served in the administrations of Obama and Bill Clinton, that was “plotting hourly” to push Biden out of the race. These individuals were reported to be commissioning polls, lobbying ex-presidents and organising donors – with some effect on Friday when it was announced that $90m of donations had been frozen while Biden heads the ticket.

Yet signs persist that Biden’s camp may have fiercer convictions than their more numerous doubters. At Thursday’s meeting with White House staffers, the pro-Biden Pennsylvania senator John Fetterman – who revived his political career after suffering a stroke – crudely dismissed colleagues arguing that the president risked shredding his legacy if he stayed in the race only to lose to Trump.

“You have legacies, too, if you fuck over a great president over a bad debate,” he said, according to the Politico website.

Faced with that fervour, does the Democratic party’s elite – derided and blamed by Biden last week for his plight – have the stomach to apply the coup de grace and say time’s up, as GOP leaders once did with Nixon?

Sabato is not hopeful. “I guarantee you they won’t do it,” he said. “The Democrats have a talent for blowing races they could win. This may be another one.”

OpenAI whistleblowers have urged the US financial watchdog to investigate non-disclosure agreements at the startup after claiming the contracts included restrictions such as requiring employees to seek permission before contacting regulators.

Non-disclosure agreements (NDAs) typically bar an employee from sharing company information with outside parties but a group of whistleblowers are arguing that OpenAI’s agreements could have led to workers being punished for raising concerns about the company to federal authorities.

San Francisco-based OpenAI is the developer of the ChatGPT chatbot and a key player in the artificial intelligence boom, which has been accompanied by expressions of concern from experts about the potential dangerous capabilities of the technology.

“Given the well-documented potential risks posed by the irresponsible deployment of AI, we urge the Commissioners to immediately approve an investigation into OpenAI’s prior NDAs, and to review current efforts apparently being undertaken by the company to ensure full compliance with SEC rules,” the letter to Gary Gensler, the chair of the US Securities and Exchange Commission (SEC), said.

The letter from whistleblower representatives was sent on 1 July and published by the Washington Post on Saturday after the news organisation obtained it from the office of the US senator Chuck Grassley. The letter states that a formal complaint has been filed with the SEC alleging “systemic” legal violations at the startup. The whistleblowers’ names are redacted.

“Artificial intelligence is rapidly and dramatically altering the landscape of technology as we know it,” Senator Grassley told Reuters, adding that “OpenAI’s policies and practices appear to cast a chilling effect on whistleblowers’ right to speak up and receive due compensation for their protected disclosures”.

Allegations in the letter include claiming that employees have been required to sign agreements that waive their federal rights to whistleblower compensation.

The whistleblowers claim OpenAI’s employment contracts, severance agreements and non-disclosure agreements violate SEC rules, including requiring employees to notify the company if they communicate with regulators.

“There is an urgent need to ensure that employees working on this technology understand that they can raised complaints or address concerns to federal regulatory or law enforcement authorities,” they wrote.

The whistleblowers call on SEC commissioners to investigate OpenAI’s past non-disclosure agreements, which they argue broke the law by requiring employees to sign “illegally restrictive” contracts.

The letter added that restrictive NDAs are “particularly egregious” given the potential for advanced AI systems to threaten humanity. It urged the SEC to take four actions: to make OpenAI produce every NDA it has issued and ensure none of the signatories have had their rights affected; remind past and present OpenAI employees that they have the right to whistleblow; fine OpenAI for each improper NDA; and to order OpenAI to correct the “chilling effect” of its past practices.

An OpenAI spokesperson said: “Our whistleblower policy protects employees’ rights to make protected disclosures. Additionally, we believe rigorous debate about this technology is essential and have already made important changes to our departure process to remove nondisparagement terms.”

The SEC has been contacted for comment.

To screenwriters in the 1950s, she was a major power player, fighting for pay rises and striking rights. To the Hollywood studio heads, she was “the meanest bitch in town”.

Now, a new book aims to restore Mary C McCall Jr’s reputation as one of the film industry’s most important figures, a trailblazer who was airbrushed from history after getting on the wrong side of movie moguls.

Prof J E Smyth, whose book, Mary C McCall Jr: The Rise and Fall of Hollywood’s Most Powerful Screenwriter, will be published in September, said: “[McCall] was targeted by right-wing men who didn’t like the amount of power she had had during the 1930s and 1940s and they were going after her …

“The Hollywood blacklist cleaned a lot of women out of the industry, and she was one. Then historians and film critics erased her, because all they’ve ever cared about is great male directors … At McCall’s death in 1986, aged 81, archives did not even want her papers, and she has simply been forgotten. Material relating to women was just deemed not worthwhile.”

Smyth, professor of history at the University of Warwick, discovered material in the archives of Warner Bros, the Academy of Motion Picture Arts and Sciences and the Writers Guild Foundation, as well as private collections, that shed new light on McCall, who became the first female president of the Screen Writers Guild in 1942.

Smyth unearthed letters and an unpublished memoir that McCall wrote for her children about her career, as well as records of the work she did for female screenwriters who were having difficulty maintaining credit, or getting paid equally by producers. She said: “The material was there, but … none of the people who were writing about the Hollywood studio system wanted to actually deal with it.”

Smyth added: “We’re so wedded to the narrative of the golden age of Hollywood being about gorgeous women who do what they’re told, and the male moguls who were running the show, that between 1920 and 1960 women were only ever talked about if they were objectified on screen … There was also an assumption that most of the scripts were written by men. “But it’s total rubbish. Half of all cinematic employees within Hollywood were female and they could do just about anything in the business, including being producers. A quarter of all screenwriters were women – more than now.”

As a screenwriter, McCall wrote for Warner Bros, Columbia Pictures and Metro-Goldwyn-Mayer. Her films included Craig’s Wife, a 1936 box-office success about a woman who marries for money not love – a nuanced critique of marriage and sexual inequality – and she was friends with actors including Bette Davis and Humphrey Bogart.

She also launched the successful Maisie series in 1939, writing or co-writing eight of the 10 films about a wise-cracking working-class showgirl, played by comedian Ann Sothern, a role that turned her into one of the biggest stars of the 1940s.

Smyth said: “It was an early franchise that became really popular. While major Hollywood films – for example, Gone with the Wind from 1939 – played primarily in lavish cinemas in big cities, Maisie played primarily in small-town cinemas and had a loyal fanbase, driven by women who finally were seeing a woman on screen who was like them.

“Maisie didn’t wear designer clothes, she didn’t have a top hairdresser, she didn’t have perfect makeup. She had to put up with a lot of crap from men – and women loved it.” McCall also campaigned for fellow writers, said Smyth.

“She [led] a fight to unionise the industry’s writers and secure the first contract guaranteeing a minimum wage, credit protection and pay raises, as well as the right to strike. She was a power player. To studio heads she was, in the words of Jack Warner, ‘the meanest bitch in town’.”

In a legal case against mogul Howard Hughes, the head of RKO Pictures studio, McCall defended a writer he had fired for being subpoenaed to appear before the House Committee on Un-American Activities, which conducted investigations during the 1940s and 1950s into alleged communist activities.

McCall said: “I did not intend to permit Mr Hughes to trample on a labour agreement with muddy tennis shoes.” But in 1979, she spoke of her belief that Hughes had played a part in destroying her career, persuading other producers not to hire her. “As a consequence … I was unable to find work.”

Smyth hopes to put McCall back in her rightful place in the history books. “Historians that started to write about Hollywood in the 1960s were the ones who really cut women out of the story of Hollywood,” she said.

A court in Pakistan has acquitted the former prime minister Imran Khan and his wife on charges of unlawful marriage, just a day after his party won the majority of reserved seats in the supreme court.

Syed Zulfi Bukhari, an adviser to Imran Khan on international affairs and media, said: “The court has not only thrown out the case but the judge has ordered for the immediate release of Imran Khan and his wife.”

Bukhari said there is not a single pending case against Khan to keep him in prison. Imran Khan’s Pakistan Tehreek-e-Insaf (PTI) party asked for the immediate release of Khan and his wife, Bushra Bibi.

Khan and Bibi were sentenced to seven years days before the general elections in February by a local court in Pakistan, which found them guilty of breaking Islamic law and failing to observe the required interval between Bibi’s divorce and their marriage.

Khan was sentenced in four big cases including the unlawful marriage and another involving allegations of leaking state secrets and has been imprisoned since last August. He has been acquitted in all cases or granted bail.

Khan’s supporters and close aides were celebrating the acquittal of the unlawful marriage allegations, known as the Iddat case, hoping it would pave the way for his release. But minutes after Khan’s acquittal order, local media reported that an anti-terrorism court in Pakistan had issued written orders for the arrest and questioning of Khan in cases related to 9 May violence during his arrest last year.

Soon after his arrest, violence erupted across Pakistan when Khan’s supporters attacked military installations and buildings in protest. Khan has been accused of being the mastermind of the unrest.

Bukhari said: “Now all of sudden we are just hearing that Khan has to be questioned in cases related to 9 May violence and also his wife in a corruption case. It is a mockery of justice but we know these fake cases won’t stand in the court of law.

“The courts are releasing Imran Khan but the administration and military establishment are putting fake cases one after another to put him in prison. Why were these cases not brought before?”

Khan had accused Pakistan’s powerful military and its chief of harbouring a personal grudge against him and ordering his arrest. For decades, Pakistan has been ruled by military dictators, and the powerful military still plays a huge role in politics.

Fawad Chaudhry, the former information minister and a former close aide of Khan, said he is behind bars because of politics not criminal activity.

“[The] arrest of Imran Khan is [a] continuation of [a] political vendetta against Pakistan’s most popular political leader,” Chaudhry said. “The authorities are too scared of freeing Imran Khan hence [a] series of fake criminal cases are put together to keep him in jail.”

Zahid Hussain, a political analyst and author, said Khan’s acquittal in the Iddat case was very much expected as it was frivolous and had no legal standing.

Hussain said: “It was also expected that the military establishment does not want Khan to be out of prison and he will be arrested in another concocted case. But it will not be easy for the military to keep Khan in the prison for quite long now as the judiciary is asserting itself, we have seen yesterday in the major reserved seats case, and the pressure from the military and government is not working.”