One senator called for "an unprecedented response" to defend federal action against climate change.

Rep. Jeff Van Drew, a prominent wind critic, says offshore wind developers gambled — and lost — when they chose to invest in the U.S.

Green Oceans says its mission is environmental protection, but the group's critics say it's promoting fossil energy.

“We have no time to waste in getting Revolution Wind back online,” Rhode Island's attorney general said in a statement Wednesday.

The coastal city’s lawsuit was dismissed last month. Charleston won't appeal the decision.

The state energy secretary said "patriotic communities" are supporting President Donald Trump's artificial intelligence agenda by adding clean electricity to the grid.

China’s green-energy supremacy — and the U.S. retreat from clean tech — brings geopolitical ramifications, the former vice president said.

Kapalua Resort has been dealing with drought that's affected the island's 140,000 residents.

As climate change makes the world hotter and triggers more extreme weather, including drought, thirsty expanses of groomed emerald grass are taxing freshwater supplies that are already under stress.

The report found that many companies aren’t putting enough capital toward decarbonization, and some rely too much on unproven technologies.

The last gasp of a primordial black hole may be the source of the highest-energy “ghost particle” detected to date, a new MIT study proposes.

In a paper appearing today in Physical Review Letters, MIT physicists put forth a strong theoretical case that a recently observed, highly energetic neutrino may have been the product of a primordial black hole exploding outside our solar system.

Neutrinos are sometimes referred to as ghost particles, for their invisible yet pervasive nature: They are the most abundant particle type in the universe, yet they leave barely a trace. Scientists recently identified signs of a neutrino with the highest energy ever recorded, but the source of such an unusually powerful particle has yet to be confirmed.

The MIT researchers propose that the mysterious neutrino may have come from the inevitable explosion of a primordial black hole. Primordial black holes (PBHs) are hypothetical black holes that are microscopic versions of the much more massive black holes that lie at the center of most galaxies. PBHs are theorized to have formed in the first moments following the Big Bang. Some scientists believe that primordial black holes could constitute most or all of the dark matter in the universe today.

Like their more massive counterparts, PBHs should leak energy and shrink over their lifetimes, in a process known as Hawking radiation, which was predicted by the physicist Stephen Hawking. The more a black hole radiates, the hotter it gets and the more high-energy particles it releases. This is a runaway process that should produce an incredibly violent explosion of the most energetic particles just before a black hole evaporates away.

The MIT physicists calculate that, if PBHs make up most of the dark matter in the universe, then a small subpopulation of them would be undergoing their final explosions today throughout the Milky Way galaxy. And, there should be a statistically significant possibility that such an explosion could have occurred relatively close to our solar system. The explosion would have released a burst of high-energy particles, including neutrinos, one of which could have had a good chance of hitting a detector on Earth.

If such a scenario had indeed occurred, the recent detection of the highest-energy neutrino would represent the first observation of Hawking radiation, which has long been assumed, but has never been directly observed from any black hole. What’s more, the event might indicate that primordial black holes exist and that they make up most of dark matter — a mysterious substance that comprises 85 percent of the total matter in the universe, the nature of which remains unknown.

“It turns out there’s this scenario where everything seems to line up, and not only can we show that most of the dark matter [in this scenario] is made of primordial black holes, but we can also produce these high-energy neutrinos from a fluke nearby PBH explosion,” says study lead author Alexandra Klipfel, a graduate student in MIT’s Department of Physics. “It’s something we can now try to look for and confirm with various experiments.”

The study’s other co-author is David Kaiser, professor of physics and the Germeshausen Professor of the History of Science at MIT.

High-energy tension

In February, scientists at the Cubic Kilometer Neutrino Telescope, or KM3NeT, reported the detection of the highest-energy neutrino recorded to date. KM3NeT is a large-scale underwater neutrino detector located at the bottom of the Mediterranean Sea, where the environment is meant to mute the effects of any particles other than neutrinos.

The scientists operating the detector picked up signatures of a passing neutrino with an energy of over 100 peta-electron-volts. One peta-electron volt is equivalent to the energy of 1 quadrillion electron volts.

“This is an incredibly high energy, far beyond anything humans are capable of accelerating particles up to,” Klipfel says. “There’s not much consensus on the origin of such high-energy particles.”

Similarly high-energy neutrinos, though not as high as what KM3NeT observed, have been detected by the IceCube Observatory — a neutrino detector embedded deep in the ice at the South Pole. IceCube has detected about half a dozen such neutrinos, whose unusually high energies have also eluded explanation. Whatever their source, the IceCube observations enable scientists to work out a plausible rate at which neutrinos of those energies typically hit Earth. If this rate were correct, however, it would be extremely unlikely to have seen the ultra-high-energy neutrino that KM3NeT recently detected. The two detectors’ discoveries, then, seemed to be what scientists call “in tension.”

Kaiser and Klipfel, who had been working on a separate project involving primordial black holes, wondered: Could a PBH have produced both the KM3NeT neutrino and the handful of IceCube neutrinos, under conditions in which PBHs comprise most of the dark matter in the galaxy? If they could show a chance existed, it would raise an even more exciting possibility — that both observatories observed not only high-energy neutrinos but also the remnants of Hawking radiation.

“Our best chance”

The first step the scientists took in their theoretical analysis was to calculate how many particles would be emitted by an exploding black hole. All black holes should slowly radiate over time. The larger a black hole, the colder it is, and the lower-energy particles it emits as it slowly evaporates. Thus, any particles that are emitted as Hawking radiation from heavy stellar-mass black holes would be near impossible to detect. By the same token, however, much smaller primordial black holes would be very hot and emit high-energy particles in a process that accelerates the closer the black hole gets to disappearing entirely.

“We don’t have any hope of detecting Hawking radiation from astrophysical black holes,” Klipfel says. “So if we ever want to see it, the smallest primordial black holes are our best chance.”

The researchers calculated the number and energies of particles that a black hole should emit, given its temperature and shrinking mass. In its final nanosecond, they estimate that once a black hole is smaller than an atom, it should emit a final burst of particles, including about 1020 neutrinos, or about a sextillion of the particles, with energies of about 100 peta-electron-volts (around the energy that KM3NeT observed).

They used this result to calculate the number of PBH explosions that would have to occur in a galaxy in order to explain the reported IceCube results. They found that, in our region of the Milky Way galaxy, about 1,000 primordial black holes should be exploding per cubic parsec per year. (A parsec is a unit of distance equal to about 3 light years, which is more than 10 trillion kilometers.)

They then calculated the distance at which one such explosion in the Milky Way could have occurred, such that just a handful of the high-energy neutrinos could have reached Earth and produced the recent KM3NeT event. They find that a PBH would have to explode relatively close to our solar system — at a distance about 2,000 times further than the distance between the Earth and our sun.

The particles emitted from such a nearby explosion would radiate in all directions. However, the team found there is a small, 8 percent chance that an explosion can happen close enough to the solar system, once every 14 years, such that enough ultra-high-energy neutrinos hit the Earth.

“An 8 percent chance is not terribly high, but it’s well within the range for which we should take such chances seriously — all the more so because so far, no other explanation has been found that can account for both the unexplained very-high-energy neutrinos and the even more surprising ultra-high-energy neutrino event,” Kaiser says.

The team’s scenario seems to hold up, at least in theory. To confirm their idea will require many more detections of particles, including neutrinos at “insanely high energies.” Then, scientists can build up better statistics regarding such rare events.

“In that case, we could use all of our combined experience and instrumentation, to try to measure still-hypothetical Hawking radiation,” Kaiser says. “That would provide the first-of-its-kind evidence for one of the pillars of our understanding of black holes — and could account for these otherwise anomalous high-energy neutrino events as well. That’s a very exciting prospect!”

In tandem, other efforts to detect nearby PBHs could further bolster the hypothesis that these unusual objects make up most or all of the dark matter.

This work was supported, in part, by the National Science Foundation, MIT’s Center for Theoretical Physics – A Leinweber Institute, and the U.S. Department of Energy.

Nature Climate Change, Published online: 18 September 2025; doi:10.1038/s41558-025-02451-6

Cities will face increasing risk along with intensified climate shocks but can also act as key agents for mitigation and adaptation. We hope to see more research that could lead to enhanced climate action by providing comprehensive, equitable and practical solutions.

Nature Climate Change, Published online: 18 September 2025; doi:10.1038/s41558-025-02408-9

Climate change will raise the severity and frequency of forest disturbance, damaging the economic value of timber. Researchers show Europe’s timber-based forestry could lose up to €247 billion, yet in some regions the increase in forest productivity could offset these shocks.

This posted was drafted by EFF legal intern Alexandra Halbeck

The Court of Appeals for the Ninth Circuit, which covers California and most of the Western U.S., just delivered good news for digital privacy: abandoning a phone doesn’t abandon your Fourth Amendment rights in the phone’s contents. In United States v. Hunt, the court made clear that no longer having control of a device is not the same thing as surrendering the privacy of the information it contains. As a result, courts must separately analyze whether someone intended to abandon a physical phone and whether they intended to abandon the data stored within it. Given how much personal information our phones contain, it will be unlikely for courts to find that someone truly intended to give up their privacy rights in that data.

This approach mirrors what EFF urged in the amicus brief we filed in Hunt, joined by the ACLU, ACLU of Oregon, EPIC, and NACDL. We argued that a person may be separated from—or even discard—a device, yet still retain a robust privacy interest in the information it holds. Treating phones like wallets or backpacks ignores the reality of technology. Smartphones are comprehensive archives of our lives, containing years of messages, photos, location history, health data, browsing habits, and countless other intimate details. As the Supreme Court recognized in Riley v. California, our phones hold “the privacies of life,” and accessing those digital contents generally requires a warrant. This is an issue EFF has worked on across the country, and it is gratifying to see such an unambiguous ruling from an influential appellate court.

The facts of Hunt underscore why the court’s distinction between a device and its contents matters. In 2017, Dontae Hunt was shot multiple times and dropped an iPhone while fleeing for medical help. Police collected the phone from the crime scene and kept it as evidence. Nearly three years later—during an unrelated drug investigation—federal agents obtained a warrant and searched the phone’s contents. Hunt challenged both the warrantless seizure and the later search, arguing he never intended to abandon either the device or its data.

The court rejected the government’s sweeping abandonment theory and drew a crucial line for the digital age: even if police have legal possession of hardware, they do not have green light to rummage through its contents. The panel emphasized that courts must treat the device and the data as separate questions under a Fourth Amendment analysis.

In this specific case, because the government ultimately obtained a warrant before searching the device, that aspect of the case survived constitutional scrutiny—but crucially, only on that basis. The court also found that police acted reasonably in initially seizing the phone during the shooting investigation and keeping it as unclaimed property until a warrant could be obtained to search it.

Under Hunt, if officers find a phone that’s been misplaced, dropped during an emergency, or otherwise separated from its owner, they cannot leap from custody of the glass-and-metal shell to unfettered access to the comprehensive digital record inside. This decision ensures that constitutional protections don’t evaporate just because someone abandons their device, and that warrants still matter in the digital age. Our constitutional rights should follow our digital lives—no matter where our devices may end up.

It's easy to keep up with the fight for digital privacy and free expression. Our EFFector newsletter delivers bite-sized updates, stories, and actions you can take to stay informed and help out.

In this latest issue, we show how libraries and schools can safeguard their computers with Privacy Badger; highlight the dangers of unaccountable corporations and billionaires buying surveillance tech for police; and share news that EFF’s Executive Director, Cindy Cohn, will be stepping down in mid-2026 after more than two decades of leadership.

EFFector isn’t just for reading—you can listen, too! In our audio companion, EFF Senior Staff Technologist Cooper Quintin explains why ICE’s contract with Paragon Solutions is so dangerous. Catch the conversation on YouTube or the Internet Archive.

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EFFECTOR 37.12 - ICE 🤝 Cyber Mercenaries

Since 1990 EFF has published EFFector to help keep readers on the bleeding edge of their digital rights. We know that the intersection of technology, civil liberties, human rights, and the law can be complicated, so EFFector is a great way to stay on top of things. The newsletter is chock full of links to updates, announcements, blog posts, and other stories to help keep readers—and listeners—up to date on the movement to protect online privacy and free expression. 

Thank you to the supporters around the world who make our work possible! If you're not a member yet, join EFF today to help us fight for a brighter digital future.

This is the second instalment in a ten-part blog series documenting EFF's findings from the Stop Censoring Abortion campaign. You can read additional posts here. 

During our Stop Censoring Abortion campaign, we set out to collect and spotlight the growing number of stories from people and organizations that have had abortion-related content removed, suppressed, or flagged by dominant social media platforms. Our survey submissions have revealed some alarming trends, including: if you don’t have a personal or second-degree connection at Meta, your chances of restoring your content or account are likely to drop significantly. 

Through the survey, we heard from activists, clinics, and researchers whose accounts were suspended or permanently removed for allegedly violating Meta’s policies on promoting or selling “restricted goods,” even when their posts were purely educational or informational. What the submissions also showed is a pattern of overenforcement, lack of transparency, and arbitrary moderation decisions that have specifically affected reproductive health and reproductive justice advocates. 

When accounts are taken down, appeals can take days, weeks, or even months (if they're even resolved at all, or if users are even given the option to appeal). For organizations and providers, this means losing access to vital communication tools and being cut off from the communities they serve. This is highly damaging since so much of that interaction happens on Meta’s platforms. Yet we saw a disturbing pattern emerge in our survey: on several occasions, accounts are swiftly restored once someone with a connection to Meta intervenes.

The Case Studies: An Abortion Clinic

The Red River Women's Clinic is an abortion clinic in Moorhead, MN. It was originally located in Fargo, North Dakota, and for many years was the only abortion clinic in North Dakota. In early January, the clinic’s director heard from a patient that she thought they only offered procedural/surgical abortions and not medication abortion. To clarify for other patients, they posted on the clinic’s page that they offered both procedural and medication abortions—attaching an image of a box of mifepristone. When they tried to boost the post, the ad was flagged and their account was suspended.

They appealed the decision and initially got the ad approved, yet the page was suspended again shortly after. But this time, multiple appeals and direct emails went unanswered, until they reached out to a digital rights organization that was able to connect with staff at Meta that stepped in. Only then was their page restored, with Meta noting that their post did not violate the policies but warning that future violations could lead to permanent removal.

While this may have been a glitch in Meta’s systems or a misapplication of policy, the suspension of the clinic’s Facebook account was detrimental for them. “We were unable to update our followers about dates/times we were closed, we were unable to share important information and news about abortion that would have kept our followers up to date, there was a legislative session happening and we were unable to share events and timely asks for reaching out to legislators about issues,” shared Tammi Kromenaker, Director of Red River Women's Clinic. The clinic was also prevented from starting an Instagram page due to the suspension. “Facebook has a certain audience and Instagram has another audience,” said Kromenaker, “we are trying to cater to all of our supporters so the loss of FB and the inability to access and start an Instagram account were really troubling to us.” 

The Case Studies: RISE at Emory University

RISE, a reproductive health research center at Emory University, launched an Instagram account to share community-centered research and combat misinformation related to reproductive health. In January of this year, they posted educational content about mifepristone on their instagram. “Let's talk about Mifepristone + its uses + the importance of access”, read the post. Two months later, their account was suddenly suspended, flagging the account under its policy against selling illegal drugs. Their appeal was denied, which led to the account being permanently deleted. 

Screenshot submitted by RISE to EFF

“As a team, this was a hit to our morale” shared Sara Redd, Director of Research Translation at RISE. “We pour countless hours of person-power, creativity, and passion into creating the content we have on our page, and having it vanish virtually overnight took a toll on our team.” For many organizational users like RISE, their social media accounts are a repository for resources and metrics that may not be stored elsewhere. “We spent a significant amount of already-constrained team capacity attempting to recover all of the content we’d created for Instagram that was potentially going to be permanently lost. [...] We also spent a significant amount of time and energy trying to understand what options we might have available from Meta to appeal our case and/or recover our account; their support options are not easily accessible, and the time it took to navigate this issue distracted from our existing work.”  

Meta restored the account only after RISE was able to connect with someone there. Once RISE logged back in, they confirmed that the flagged post was the one about mifepristone. The post never sold or directed people where to buy pills, it simply provided accurate information about the use and efficacy of the drug. 

This Shouldn’t Be How Content Moderation Works

Meta spokespersons have admitted to instances of “overenforcement” in various press statements, noting that content is sometimes incorrectly removed or blurred even when it doesn’t actually violate policy. Meta has insisted to the public that they care about free speech, as a spokesperson mentioned to The New York Times: “We want our platforms to be a place where people can access reliable information about health services, advertisers can promote health services and everyone can discuss and debate public policies in this space [...] That’s why we allow posts and ads about, discussing and debating abortion.” In fact, their platform policies directly mention this: 

Note that advertisers don’t need authorization to run ads that only:

• Educate, advocate or give public service announcements related to prescription drugs

Additionally: 

Note: Debating or advocating for the legality or discussing scientific or medical merits of prescription drugs is allowed. This includes news and public service announcements. 

Meta also has policies specific to “Health and Wellness,” where they state: 

When targeting people 18 years or older, advertisers can run ads that:

• Promote sexual and reproductive health and wellness products or services, as long as the focus is on health and the medical efficacy of the product or the service and not on the sexual pleasure or enhancement. And these ads must target people 18 years or older. This includes ads for: [...]
• Family planning methods, such as:
  • Family planning clinics
  • In Vitro Fertilization (IVF) or any other artificial insemination procedures
  • Fertility awareness
  • Abortion medical consultation and related services

But these public commitments don’t always match users’ experiences. 

Take the widely covered case of Aid Access, a group that provides medication abortion by mail. This year, several of their Instagram posts were blurred and removed on Instagram, including one with tips for feeling safe and supported at home after taking abortion medication. But only after multiple national media outlets contacted Meta for comment on the story were the posts and account restored.

So the question becomes: If Meta admits its enforcement isn’t perfect, why does it still take knowing someone, or having the media involved, to get a fair review? When companies like Meta claim to uphold commitments to free speech, those commitments should materialize in clear policies that are enforced equally, not only when it is escalated through leveraging relationships with Meta personnel.

“Facebook Jail” Reform

There is no question that the enforcement of these content moderation policies on Meta platforms and the length of time people are spending in “content jail” or “Facebook/Instagram jail” has created a chilling effect. 

“I think that I am more cautious and aware that the 6.1K followers we have built up over time could be taken away at any time based on the whims of Meta,” Tammi from Red River Women’s Clinic told us. 

RISE sees it in a slightly different light, sharing that “[w]hile this experience has not affected our fundamental values and commitment to sharing our work and rigorous science, it has highlighted for us that no information posted on a third-party platform is entirely one’s own, and thus can be dismantled at any moment.”

At the end of the day, clinics are left afraid to post basic information, patients are left confused or misinformed, and researchers lose access to their audiences. But unless your issue catches the attention of a journalist or you know someone at Meta, you might never regain access to your account.

These case studies highlight the urgent need for transparent, equitable, and timely enforcement that is not dependent on insider connections, as well as accountability from platforms that claim to support open dialogue and free speech. Meta’s admitted overenforcement should, at minimum, be coupled with efficient and well-staffed review processes and policies that are transparent and easily understandable. 

It’s time for Meta and other social media platforms to implement the reforms they claim to support, and for them to prove that protecting access to vital health information doesn’t hinge on who you know.

This is the second post in our blog series documenting the findings from our Stop Censoring Abortion campaign. Read more in the series: https://www.eff.org/pages/stop-censoring-abortion   

The Mexican government passed a package of outrageously privacy-invasive laws in July that gives both civil and military law enforcement forces access to troves of personal data and forces every individual to turn over biometric information regardless of any suspicion of crime.   

The laws create a new interconnected intelligence system dubbed the Central Intelligence Platform, under which intelligence and security agencies at all levels of government—federal, state and municipal—have the power to access, from any entity public or private, personal information for “intelligence purposes,” including license plate numbers, biometric information, telephone details that allow the identification of individuals, financial, banking, and health records, public and private property records, tax data, and more. 

You read that right. Banks’ customer information databases? Straight into the platform. Hospital patient records? Same thing. 

The laws were ostensively passed in the name of gathering intelligence to fight high-impact crime. Civil society organizations, including our partners RD3 and Article 19 Mexico, have raised alarms about the bills—as R3D put it, these new laws establish an uncontrolled system of surveillance and social control that goes against privacy and free expression rights and the presumption of innocence.  

In a concept note made public recently, RD3 breaks down exactly how bad the bills are. The General Population Act forces every person in Mexico to enroll in a mandatory biometric ID system with fingerprints and a photo. Under the law, public and private entities are required to ask for the ID for any transaction or access to services, such as banking, healthcare, education, and access to social programs. All data generated through the ID mandate will feed into a new Unique Identity Platform under the Disappeared Persons Act.  

The use of biometric IDs creates a system for tracking activities of the population—also accessible through the Central Intelligence Platform.  

The Telecommunications Act requires telecom companies to create a registry that connects people’s phone numbers with their biometric ID held by the government and cut services off to customers who won’t go along with the practice.  

It gets worse. 

The Intelligence Act explicitly guarantees the armed forces, through the National Guard, legal access to the Central Intelligence Platform, which enables real-time consultation of interconnected databases across sectors.  

Companies, both domestic and international, must either interconnect their databases or hand over information on request. Mexican authorities can share that information even with foreign governments. It also exempts judicial authorization requirements for certain types of surveillance and classifies the entire system as confidential, with criminal penalties for disclosure. All of this is allowed without any suspicion of a crime or prior judicial approval.  

We urge everyone to pay close attention to and support efforts to hold the Mexican government accountable for this egregious surveillance system. RD3 challenged the laws in court and international support is critical to raise awareness and push back.  As R3D put it, "collaboration is vital for the defense of human rights," especially in the face of uncontrolled powers set by disproportionate laws.  

We couldn’t agree more and stand with our Mexican allies. 

The field of tissue engineering aims to replicate the structure and function of real biological tissues. This engineered tissue has potential applications in disease modeling, drug discovery, and implantable grafts.

3D bioprinting, which uses living cells, biocompatible materials, and growth factors to build three-dimensional tissue and organ structures, has emerged as a key tool in the field. To date, one of the most-used approaches for bioprinting relies on additive manufacturing techniques and digital models, depositing 2D layers of bio-inks, composed of cells in a soft gel, into a support bath, layer-by-layer, to build a 3D structure. While these techniques do enable fabrication of complex architectures with features that are not easy to build manually, current approaches have limitations.

“A major drawback of current 3D bioprinting approaches is that they do not integrate process control methods that limit defects in printed tissues. Incorporating process control could improve inter-tissue reproducibility and enhance resource efficiency, for example limiting material waste,” says Ritu Raman, the Eugene Bell Career Development Chair of Tissue Engineering and an assistant professor of mechanical engineering.

She adds, “given the diverse array of available 3D bioprinting tools, there is a significant need to develop process optimization techniques that are modular, efficient, and accessible.”

The need motivated Raman to seek the expertise of Professor Bianca Colosimo of the Polytechnic University of Milan, also known as Polimi. Colosimo recently completed a sabbatical at MIT, which was hosted by John Hart, Class of 1922 Professor, co-director of MIT’s Initiative for New Manufacturing, director of the Center for Advanced Production Technologies, and head of the Department of Mechanical Engineering.

“Artificial Intelligence and data mining are already reshaping our daily lives, and their impact will be even more profound in the emerging field of 3D bioprinting, and in manufacturing at large,” says Colosimo. During her MIT sabbatical, she collaborated with Raman and her team to co-develop a solution that represents a first step toward intelligent bioprinting.

“This solution is now available in both our labs at Polimi and MIT, serving as a twin platform to exchange data and results across different environments and paving the way for many new joint projects in the years to come,” Colosimo says.

A new paper by Raman, Colosimo, and lead authors Giovanni Zanderigo, a Rocca Fellow at Polimi, and Ferdows Afghah of MIT published this week in the journal Device presents a novel technique that addresses this challenge. The team built and validated a modular, low-cost, and printer-agnostic monitoring technique that integrates a compact tool for layer-by-layer imaging. In their method, a digital microscope captures high-resolution images of tissues during printing and rapidly compares them to the intended design with an AI-based image analysis pipeline.

“This method enabled us to quickly identify print defects, such as depositing too much or too little bio-ink, thus helping us identify optimal print parameters for a variety of different materials,” says Raman. “The approach is a low-cost — less than $500 — scalable, and adaptable solution that can be readily implemented on any standard 3D bioprinter. Here at MIT, the monitoring platform has already been integrated into the 3D bioprinting facilities in The SHED. Beyond MIT, our research offers a practical path toward greater reproducibility, improved sustainability, and automation in the field of tissue engineering. This research could have a positive impact on human health by improving the quality of the tissues we fabricate to study and treat debilitating injuries and disease.”

The authors indicate that the new method is more than a monitoring tool. It also ‎serves as a foundation for intelligent process control in embedded bioprinting. By enabling real-‎time inspection, adaptive correction, and automated parameter tuning, the researchers anticipate that the approach can improve ‎reproducibility, reduce material waste, and accelerate process optimization‎ for real-world applications in tissue engineering.

A genome-editing technique known as prime editing holds potential for treating many diseases by transforming faulty genes into functional ones. However, the process carries a small chance of inserting errors that could be harmful.

MIT researchers have now found a way to dramatically lower the error rate of prime editing, using modified versions of the proteins involved in the process. This advance could make it easier to develop gene therapy treatments for a variety of diseases, the researchers say.

“This paper outlines a new approach to doing gene editing that doesn’t complicate the delivery system and doesn’t add additional steps, but results in a much more precise edit with fewer unwanted mutations,” says Phillip Sharp, an MIT Institute Professor Emeritus, a member of MIT’s Koch Institute for Integrative Cancer Research, and one of the senior authors of the new study.

With their new strategy, the MIT team was able to improve the error rate of prime editors from about one error in seven edits to one in 101 for the most-used editing mode, or from one error in 122 edits to one in 543 for a high-precision mode.

“For any drug, what you want is something that is effective, but with as few side effects as possible,” says Robert Langer, the David H. Koch Institute Professor at MIT, a member of the Koch Institute, and one of the senior authors of the new study. “For any disease where you might do genome editing, I would think this would ultimately be a safer, better way of doing it.”

Koch Institute research scientist Vikash Chauhan is the lead author of the paper, which appears today in Nature.

The potential for error

The earliest forms of gene therapy, first tested in the 1990s, involved delivering new genes carried by viruses. Subsequently, gene-editing techniques that use enzymes such as zinc finger nucleases to correct genes were developed. These nucleases are difficult to engineer, however, so adapting them to target different DNA sequences is a very laborious process.

Many years later, the CRISPR genome-editing system was discovered in bacteria, offering scientists a potentially much easier way to edit the genome. The CRISPR system consists of an enzyme called Cas9 that can cut double-stranded DNA at a particular spot, along with a guide RNA that tells Cas9 where to cut. Researchers have adapted this approach to cut out faulty gene sequences or to insert new ones, following an RNA template.

In 2019, researchers at the Broad Institute of MIT and Harvard reported the development of prime editing: a new system, based on CRISPR, that is more precise and has fewer off-target effects. A recent study reported that prime editors were successfully used to treat a patient with chronic granulomatous disease (CGD), a rare genetic disease that affects white blood cells.

“In principle, this technology could eventually be used to address many hundreds of genetic diseases by correcting small mutations directly in cells and tissues,” Chauhan says.

One of the advantages of prime editing is that it doesn’t require making a double-stranded cut in the target DNA. Instead, it uses a modified version of Cas9 that cuts just one of the complementary strands, opening up a flap where a new sequence can be inserted. A guide RNA delivered along with the prime editor serves as the template for the new sequence.

Once the new sequence has been copied, however, it must compete with the old DNA strand to be incorporated into the genome. If the old strand outcompetes the new one, the extra flap of new DNA hanging off may accidentally get incorporated somewhere else, giving rise to errors.

Many of these errors might be relatively harmless, but it’s possible that some could eventually lead to tumor development or other complications. With the most recent version of prime editors, this error rate ranges from one per seven edits to one per 121 edits for different editing modes.

“The technologies we have now are really a lot better than earlier gene therapy tools, but there’s always a chance for these unintended consequences,” Chauhan says.

Precise editing

To reduce those error rates, the MIT team decided to take advantage of a phenomenon they had observed in a 2023 study. In that paper, they found that while Cas9 usually cuts in the same DNA location every time, some mutated versions of the protein show a relaxation of those constraints. Instead of always cutting the same location, those Cas9 proteins would sometimes make their cut one or two bases further along the DNA sequence.

This relaxation, the researchers discovered, makes the old DNA strands less stable, so they get degraded, making it easier for the new strands to be incorporated without introducing any errors.

In the new study, the researchers were able to identify Cas9 mutations that dropped the error rate to 1/20th its original value. Then, by combining pairs of those mutations, they created a Cas9 editor that lowered the error rate even further, to 1/36th the original amount.

To make the editors even more accurate, the researchers incorporated their new Cas9 proteins into a prime editing system that has an RNA binding protein that stabilizes the ends of the RNA template more efficiently. This final editor, which the researchers call vPE, had an error rate just 1/60th of the original, ranging from one in 101 edits to one in 543 edits for different editing modes. These tests were performed in mouse and human cells.

The MIT team is now working on further improving the efficiency of prime editors, through further modifications of Cas9 and the RNA template. They are also working on ways to deliver the editors to specific tissues of the body, which is a longstanding challenge in gene therapy.

They also hope that other labs will begin using the new prime editing approach in their research studies. Prime editors are commonly used to explore many different questions, including how tissues develop, how populations of cancer cells evolve, and how cells respond to drug treatment.

“Genome editors are used extensively in research labs,” Chauhan says. “So the therapeutic aspect is exciting, but we are really excited to see how people start to integrate our editors into their research workflows.”

The research was funded by the Life Sciences Research Foundation, the National Institute of Biomedical Imaging and Bioengineering, the National Cancer Institute, and the Koch Institute Support (core) Grant from the National Cancer Institute.

George Tynan followed a nonlinear path to fusion.

Following his undergraduate degree in aerospace engineering, Tynann's work in the industry spurred his interest in rocket propulsion technology. Because most methods for propulsion involve the manipulation of hot ionized matter, or plasmas, Tynan focused his attention on plasma physics.

It was then that he realized that plasmas could also drive nuclear fusion. “As a potential energy source, it could really be transformative, and the idea that I could work on something that could have that kind of impact on the future was really attractive to me,” he says.

That same drive, to realize the promise of fusion by researching both plasma physics and fusion engineering, drives Tynan today. It’s work he will be pursuing as the Norman C. Rasmussen Adjunct Professor in the Department of Nuclear Science and Engineering (NSE) at MIT.

An early interest in fluid flow

Tynan’s enthusiasm for science and engineering traces back to his childhood. His electrical engineer father found employment in the U.S. space program and moved the family to Cape Canaveral in Florida.

“This was in the ’60s, when we were launching Saturn V to the moon, and I got to watch all the launches from the beach,” Tynan remembers. That experience was formative and Tynan became fascinated with how fluids flow.

“I would stick my hand out the window and pretend it was an airplane wing and tilt it with oncoming wind flow and see how the force would change on my hand,” Tynan laughs. The interest eventually led to an undergraduate degree in aerospace engineering at California State Polytechnic University in Pomona.

The switch to a new career would happen after work in the private sector, when Tynan discovered an interest in the use of plasmas for propulsion systems. He moved to the University of California at Los Angeles for graduate school, and it was here that the realization that plasmas could also anchor fusion moved Tynan into this field.

This was in the ’80s, when climate change was not as much in the public consciousness as it is today. Even so, “I knew there’s not an infinite amount of oil and gas around, and that at some point we would have to have widespread adoption of nuclear-based sources,” Tynan remembers. He was also attracted by the sustained effort it would take to make fusion a reality.

Doctoral work

To create energy from fusion, it’s important to get an accurate measurement of the “energy confinement time,” which is a measure of how long it takes for the hot fuel to cool down when all heat sources are turned off. When Tynan started graduate school, this measure was still an empirical guess. He decided to focus his research on the physics of observable confinement time.

It was during this doctoral research that Tynan was able to study the fundamental differences in the behavior of turbulence in plasma as compared to conventional fluids. Typically, when an ordinary fluid is stirred with increasing vigor, the fluid’s motion eventually becomes chaotic or turbulent. However, plasmas can act in a surprising way: confined plasmas, when heated sufficiently strongly, would spontaneously quench the turbulent transport at the boundary of the plasma

An experiment in Germany had unexpectedly discovered this plasma behavior. While subsequent work on other experimental devices confirmed this surprising finding, all earlier experiments lacked the ability to measure the turbulence in detail.

Brian LaBombard, now a senior research scientist at MIT’s Plasma Science and Fusion Center (PSFC), was a postdoc at UCLA at the time. Under LaBombard’s direction, Tynan developed a set of Langmuir probes, which are reasonably simple diagnostics for plasma turbulence studies, to further investigate this unusual phenomenon. It formed the basis for his doctoral dissertation. “I happened to be at the right place at the right time so I could study this turbulence quenching phenomenon in much more detail than anyone else could, up until that time,” Tynan says.

As a PhD student and then postdoc, Tynan studied the phenomenon in depth, shuttling between research facilities in Germany, Princeton University’s Plasma Physics Laboratory, and UCLA.

Fusion at UCSD

After completing his doctorate and postdoctoral work, Tynan worked at a startup for a few years when he learned that the University of California at San Diego was launching a new fusion research group at the engineering school. When they reached out, Tynan joined the faculty and built a research program focused on plasma turbulence and plasma-material interactions in fusion systems. Eventually, he became associate dean of engineering, and later, chair of the Department of Mechanical and Aerospace Engineering, serving in these roles for nearly a decade.

Tynan visited MIT on sabbatical in 2023, when his conversations with NSE faculty members Dennis Whyte, Zach Hartwig, and Michael Short excited him about the challenges the private sector faces in making fusion a reality. He saw opportunities to solve important problems at MIT that complemented his work at UC San Diego.

Tynan is excited to tackle what he calls, “the big physics and engineering challenges of fusion plasmas” at NSE: how to remove the heat and exhaust generated by burning plasma so it doesn’t damage the walls of the fusion device and the plasma does not choke on the helium ash. He also hopes to explore robust engineering solutions for practical fusion energy, with a particular focus on developing better materials for use in fusion devices that will make them longer-lasting, while  minimizing the production of radioactive waste.

“Ten or 15 years ago, I was somewhat pessimistic that I would ever see commercial exploitation of fusion in my lifetime,” Tynan says. But that outlook has changed, as he has seen collaborations between MIT and Commonwealth Fusion Systems (CFS) and other private-sector firms that seek to accelerate the timeline to the deployment of fusion in the real world.

In 2021, for example, MIT’s PSFC and CFS took a significant step toward commercial carbon-free power generation. They designed and built a high-temperature superconducting magnet, the strongest fusion magnet in the world.

The milestone was especially exciting because the promise of realizing the dream of fusion energy now felt closer. And being at MIT “seemed like a really quick way to get deeply connected with what’s going on in the efforts to develop fusion energy,” Tynan says.

In addition, “while on sabbatical at MIT, I saw how quickly research staff and students can capitalize on a suggestion of a new idea, and that intrigued me,” he adds.

Tynan brings his special blend of expertise to the table. In addition to extensive experience in plasma physics, he has spent a lot more time on hardcore engineering issues like materials, as well. “The key is to integrate the whole thing into a workable and viable system,” Tynan says.