Asian immigrants are both the fastest-growing and highest-earning immigrant ethnic group in the United States, facts that have caught the attention of many economists interested in how these groups — whether investors or residents — impact housing prices, K-12 education, and other important aspects of community life.

A new study by economists at MIT and the University of Cincinnati delves into this trend, focusing on the potential mechanisms at work behind the correlation of rising home prices and subsequent improvements in education at the county level. Their findings suggest that home prices rise not simply due to increased demand, but because the new neighbors have a positive influence on the quality of K-12 education, which in turn increases desirability.

The study focuses on 2008 to 2019, a period that saw a relative spike in US immigration from six Asian countries in particular — China, India, Japan, Korea, the Philippines, and Vietnam. Among this group, the economists focused specifically on those who arrived on non-permanent visas for study or work — a cohort that represents a distinct and growing channel of new immigrant inflow, and is often pre-selected by universities and employers.

“We’re looking at a window when the influx of Asian immigrants has a particularly strong preference for education, and who themselves were also highly educated,” says Eunjee Kwon, the West Shell, Jr. Assistant Professor of Real Estate in the Department of Finance at the University of Cincinnati, a co-author on the study published in the May issue of the Journal of Urban Economics. “This period also marks a notable shift in the socioeconomic profile of Asian immigrants to the U.S., with this cohort arriving with higher levels of education and income relative to earlier waves of Asian immigrants and, in many cases, relative to the native-born population.”

While county data is not granulated to the neighborhood or even municipality level, the researchers found that 30 to 40 percent of the rise in home values purchased in areas where Asian immigrant buyers have school-age children correlates with improved quality of education, as indicated by the average rise in standardized test scores of all children in the county.

“Maybe some Asian buyers are pure investors, but many of them become residents who buy homes for themselves and their families, and transform the neighborhoods,” says co-author Siqi Zheng, the Samuel Tak Lee Professor of Urban and Real Estate Sustainability at the MIT Center for Real Estate and the Department of Urban Studies and Planning. “We show that this is not negligible; it is a big component. We can attribute at least one-third of housing price increases to improved education.”

Amanda Ang, a postdoc in the Department of Economics at Aalto University in Helsinki, is the third co-author of the paper. The work is somewhat personal for the scientists, who undertook the study without funding in order to see for themselves what impact this particular group of immigrants had on neighborhoods.

“We wanted to understand what this group contributes to the communities where they settle," Kwon says. “We found that their presence benefits children of all other backgrounds, too."

Ang, Kwon, and Zheng use an econometric approach called an instrumental variable to home in on a causal correlation, and not just an association. To help ensure accuracy, they carefully omitted counties that have long been home to large Asian communities — such as San Francisco, Los Angeles, and New York — in order to capture the impact of recent immigrants on other counties.

“I believe that this will be a highly influential paper because it asks a very important question and uses credible statistical methods to try to disentangle selection effects from treatment effects, using a subtle analysis accounting for displacement,” says Matthew Kahn, the Provost Professor of Economics and Spatial Sciences at the University of Southern California, who was not involved with the research. 

“What really interests me about this paper is that it suggests that there can be a positive spillover effect: that U.S. areas that attract Asian immigrants also gain from improved school quality,” Kahn says. “It’s the first I’ve seen undertaken on this very important hypothesis, which certainly merits additional future research, possibly using school-level and individual-level data.”

Consider the chief difference between living systems and electronics: The first is generally soft and squishy, while the latter is hard and rigid. Now, in work that could impact human-machine interfaces, biocompatible devices, soft robotics, and more, MIT engineers and colleagues have developed a soft, flexible gel that dramatically changes its conductivity upon the application of light.

Enter the growing field of ionotronics, which involves transferring data through ions, or charged molecules. Electronics does the same, with electrons. But while the latter is well established, ionotronics is still being developed, with one huge exception: living systems. The cells in our bodies communicate with a variety of ions, from potassium to sodium.

Ionotronics, in turn, can provide a bridge between electronics and biological tissues. Potential applications range from soft wearable technology to human-machine interfaces

“We’ve found a mechanism to dynamically control local ion population in a soft material,” says Thomas J. Wallin, the John F. Elliott Career Development Professor in MIT’s Department of Materials Science and Engineering and leader of the work. “That could allow a system that is self-adaptive to environmental stimuli, in this case light.” In other words, the system could automatically change in response to changes in light, which could allow complex signal processing in soft materials.

An open-access paper about the work was published online recently in Nature Communications.

A growing field

Although others have developed ionotronic materials with high conductivities that allow the quick movement of ions, those conductivities cannot be controlled. “What we’re doing is using light to switch a soft material from insulating to something that is 400 times more conductive,” says Xu Liu, first author of the paper and former MIT postdoc in materials science and engineering who is now an incoming assistant professor at King’s College London.

Key to the work is a class of materials known as photo-ion generators (PIGs). These can become some 1,000 times more conductive upon the application of light. The MIT team optimized a way to incorporate a PIG into polyurethane rubber by first dissolving a PIG powder into a solvent, and then using a swelling method to get it into the rubber.

Much potential

In the material reported in the current work, the change in conductivity is irreversible. But Liu is confident that future versions could switch back and forth between insulating and conducting states.

She notes that the current material was developed using only one kind of PIG, polymer (the polyurethane rubber), and solvent, but there are many other kinds of all three. So there is great potential for creating even better light-responsive soft materials.

Liu also notes the potential for developing soft materials that respond to other environmental stimuli, such as heat or magnetism. “We’re inspired to do more work in this field by changing the driving force from light to other forms of environmental stimuli,” she says.

“Our work has the potential to lead to the creation of a subfield that we call soft photo-ionotronics,” Liu continues. “We are also very excited about the opportunities from our work to create new soft machines impacting soft wearable technology, human-machine interfaces, robotics, biomedicine, and other fields.”

Additional authors of the paper are Steven M. Adelmund, Shahriar Safaee, and Wenyang Pan of Reality Labs at Meta. 

New York's proposed 2026-2027 budget currently includes provisions that will require all 3D printers sold in the state to run print-blocking censorware—software that surveils every print for forbidden designs. This policy would also create felony charges for possessing or sharing certain design files. The vote on the state budget could happen as early as next week, so New Yorkers need to act fast and demand that their Assemblymembers and Senators strip this provision from the budget.

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State legislators across the US are rushing to regulate 3D-printed firearms under the syllogism “something must be done; there, I've done something.” The most reckless of these proposals is a mandate for manufacturers to implement print blocking on all 3D printers. We, and other experts, have already pointed out that this algorithmic print blocking is simply unfeasible and will only serve to stifle competition, free expression, and privacy. While most detrimental to the creative communities lawfully using these printers, every New Yorker will be impacted by this blow to innovation.

This policy is unfortunately buried in Part C of the New York State’s proposed budget for the 2026-2027 fiscal year (S.9005 / A.10005), which is urgently moving toward a vote after facing extensive delays. It’s also bundled with a policy that would allow felony charges to be brought against researchers and journalists for sharing design files restricted by the state.  The worst of these impacts won’t be known until after it is negotiated behind closed doors, with no safeguards for creative expression or privacy.

Researchers and Journalists Could Face Felony Charges

Part C Subpart A of the budget includes two particularly concerning provisions: §2.10 and 2.11. These threaten Class E felony charges for distributing or possessing 3D-printer files that would produce firearm parts with a 3D printer or CNC machine. 

Under these provisions merely sharing a print file with any of them could result in criminal charges

The first provision, 2.10, makes it a felony to sell or distribute files that can produce major firearm components to someone who is not a federally and NY-licensed gunsmith. Under 2.11, it’s also a felony to possess these files if you intend to illegally print a firearm or share them with someone you believe is not permitted to own or smith a firearm.

A journalist reporting on 3D-printed guns. A researcher studying printable firearms. An artist incorporating parts into a new work commenting on gun culture. Under these provisions merely sharing a print file with any of them could result in criminal charges, even if no one involved intends to assemble a firearm.

Criminalizing information doesn’t work. Someone intent on illegally printing a firearm is already subject to charges for that act. Adding felony liability for simply possessing a file or design piles on additional charges while doing nothing to stop printing. New charges for someone distributing these files won’t make them inaccessible to lawbreakers, but they will have a chilling effect on legitimate and entirely legal work. 

Unsurprisingly, a similar law was proposed and subsequently scrapped in Colorado due to First Amendment concerns. We recommend New York do the same.

Mandated Surveillance, Less Access

Part C Subpart B would require every 3D printer and CNC machine sold in New York to include algorithms that scan your design files and block prints the system identifies as producing firearm components. Furthermore, all sales and deliveries of these machines must be made face-to-face. 

Unlike other bills we have seen, there are no exceptions to this mandate. These restrictions apply to sales to researchers, commercial manufacturers, and—oddly enough—federally and state-licensed gunsmiths.

Applying these restrictions to CNC machine sellers is particularly absurd. These cousins of 3D printers, which make 3D objects by removing materials, are often tens of thousands of dollars and used by commercial manufacturers. Automotive, aerospace, medical manufacturers, and many others industries will be subject to the in-person sales, surveillance risk, and all the other problems with these print-blocking algorithms introduce.

Industries will be subject to the in-person sales, surveillance risk, and all the other problems

Even limiting the focus to individual buyers—hobbyists and artists who use these machines at home—this restriction to face-to-face sales comes with its own issues. Beyond unnecessarily complicating the use of printers in the state, this barrier to access will hit rural New Yorkers the hardest. People in rural or remote locations can stand to benefit from the saved time and costs of printing useful parts at home. With this restriction, they will need to drive to one of the few retailers who actually sell this equipment and settle for the models they stock. 

That is, if sellers continue to stock these printers despite the risk. Subpart B §§ 2.3 and 2.5 open sellers up to liability, including anyone on the second-hand market, for selling out-of-date printers. Meanwhile, buyers hoping to illegally print firearms can simply build their own printer with widely available equipment.

The Law Won’t Work as Advertised 

Here’s what makes Subpart B of the New York budget particularly reckless: the technology it mandates is not capable of doing what it is supposed to. 

There is very little detail provided about requirements for the mandated algorithms. What the bill does outline boils down to this: the algorithms must evaluate print files to determine whether they would produce a firearm or illegal firearm parts, and if so, block the print. In an attempt to enable this, New York state would also create and maintain a library of forbidden files with tightly restricted access. 

We’ve already gone over why this idea simply won’t work. Design files are trivially easy to modify, split into segments, or otherwise alter to evade pattern detection. Even if printers fully rendered and analyzed the print with cloud-based AI, any number of design or post-print tricks can be used to dodge detection. Meanwhile, such fuzzy AI interpretation will rapidly increase the percentage of lawful prints censored. 

Firearms aren’t a highly specific design like paper currency; these proposed algorithms are futilely attempting to block an infinite number of designs capable of—or that can be made capable of—the few simple mechanical functions that make up a firearm. 

This group has no peer review requirements, so it could easily be loaded with profiteers or incumbent manufacturers

As we’ve said before: the internet always routes around censorship. Anyone determined to print a prohibited object has straightforward workarounds. The people who get surveilled and blocked are the people trying to follow the law.

The bill aims to enforce this impossible mandate by creating a working group to define the actual technical requirements of enforcement—but only after the law passes. This group has no peer review requirements, so it could easily be loaded with profiteers or incumbent manufacturers who are already lining up to participate. These incumbents stand to profit from shutting out new competitors and locking in users to their devices, and sellers into their platform, subjecting both to the type of enshittification seen with Digital Rights Management (DRM) software. There are also no safeguards in the law to prevent the most surveillance-heavy approaches to print scanning, or to stop this censorship infrastructure from being further weaponized against lawful speech.

On the other hand, unbiased experts in open-source manufacturing in the working group can at best pause the clock by showing such algorithms are unfeasible. That is, until a new snake oil company comes along to restart it. 

New York Won't Be the Last Stop 

New York is one of the largest consumer markets in the country. When it mandates a feature in hardware, manufacturers hardly ever build a New York-only version. They build the New York version and sell it globally. A print-blocking mandate adopted in New York will become the national standard in practice.

New Yorkers deserve more than this rush job buried in a budget bill. This is an unfeasible tech solution, built without the consumer protections that would be required of any serious policy proposal, and creates new costs and inconveniences amidst a protracted annual budget process. It also threatens First Amendment protections. This policy will take shape without consumer guardrails, behind closed doors, and risks the worst outcomes for grassroots innovation and creativity enabled by these machines. Worse still, these practices can become the norm across other states and among 3D-printer manufacturers worldwide. 

Your representatives could vote on this ill-conceived measure in the next week.  If you're a New Yorker, email your legislators now, and tell them to strip this measure from the budget today. 

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A phone’s push notifications can contain a significant amount of information about you, your communications, and what you do throughout the day. They’re important enough to government investigations that Apple and Google now both require a judge’s order to hand details about push notifications over to law enforcement, and even with that requirement Apple shares data on hundreds of users. More recently, we also learned from a 404 Media report that law enforcement forensic extraction tools can unearth the text from deleted notifications, including those from secure messaging tools, like Signal. The good news is that you can mitigate some of this risk. 

There are two points where notifications may betray your privacy: when they’re transmitted over cloud servers and once they land on the device. Let’s start with the cloud. It might seem like push notifications come directly from an app, but they are typically routed through either Apple or Google’s servers first (depending on if you use iOS or Android). According to a letter sent to the Department of Justice by Senator Wyden, the content of those notifications may be visible to Apple and Google, and at the very least the companies collect some metadata about what apps send a notification and when. App providers have to make the decision to hide the content from Apple and Google and implement that functionality; Signal is one app that does this. 

Then, once the notifications land on your phone, depending on your settings, the notification content may be visible on your lock screen without needing to unlock the device. This can be dangerous if you lose your device, someone steals it, or it’s confiscated by law enforcement. 

You may clear notifications after looking at them. But it turns out the content notifications get recorded in your device’s internal storage, which then makes them susceptible to recovery with certain types of forensic tools. Notification content may even persist after the app is deleted, if the OS doesn’t fully purge the app’s notification data. 

We still have a lot of unanswered questions about how the notification databases work on devices. We do not know how long notifications are stored, or whether they’re backed up to the cloud, in which case the cloud provider could get backdoor access to the content of messages if the backups are enabled and not end-to-end encrypted. This may also make backups vulnerable to law enforcement demands for data. 

Which is all to say that there are myriad ways that law enforcement can access the content or metadata of push notifications. Let’s fix that.

Consider the Strongest Notification Protections for Your Secure Messaging Apps

Secure chat tools are designed to keep the content of the messages safe inside the app. So, for secure chat apps like WhatsApp and Signal, that means the company that makes those apps cannot see the content of your messages, and they’re only accessible on your and your recipients’ devices. Once messages land on a device, it’s still important to consider some privacy precautions, particularly with notifications. 

Signal
Signal offers three levels of information to include in notifications, all which are pretty self explanatory:

• Name, Content, and Actions (Name and message on Android) shows the entirety of a message as well as who sent it (on iPhone you can also slide to reply, mark as read, or call back). 
• Name only only shows the name of the sender. 
• No Name or Content (No name or message on Android) will only show that you have a message from Signal, not who sent it or what it’s about. 

To change your settings:

• On iPhone: Tap your profile picture, then Settings > Notifications > Show.
• On Android: Tap your profile picture, then Notifications > Show. 

WhatsApp
WhatsApp only has one option for this, and it’s currently limited to iPhone, but you can at least tell the app not to include the content of a message in the notification:

• Open WhatsApp for iPhone, tap the “You” bar, then Notifications, and disable the Show preview option.

Check your other apps to see if they offer similar settings.

Limit Your Notifications Device-Wide

Since Apple and Google manage push notifications for their respective devices, they also have some visibility into certain data. Push notification data can include certain types of metadata, like which app sent a notification and when, as well as the account ID associated with the phone. In some cases, Apple and Google may have access to unencrypted content, including the content of the text in a notification or other information from the app itself. 

For most app notifications, there’s no simple way to easily figure out what metadata might be gleaned from a notification, or if the notification is unencrypted or not. But some app developers have described details along these lines. For example, Signal president Meredith Whittaker explained on social media how the Signal app handles notifications entirely on-device. Searching online for an app name along with “notification privacy,” “notification encryption” or “notification metadata” may help answer your questions, or you may need to dig around in support forums for the app.

It’s also good to reconsider whether any app should be sending you notifications to begin with. Aside from a potential decrease in the number of distractions you endure throughout the day, or the level of chaos on display on your lockscreen, limiting the apps that can send notifications and what content is visible in them can improve your privacy with respect to the sorts of metadata that may be gathered by the companies, as well as any content that may be viewable if someone has physically accessed your device.

To check and change your settings on iPhone

• Open Settings > Notifications.
• On the Show Previews option, you can choose whether to show the content of notifications on the lock screen, “Always,” which doesn’t require unlocking the device, “When Unlocked,” which does, and “Never,” which means notifications won’t have any details, just that you have a notification in an app. 
• Alternatively, you can scroll down and change these settings per app. Just tap the app name, then the Show Previews menu, and choose how you’d like them to appear. Or, if you’ve decided you don’t want notifications from that app at all, uncheck the Allow Notifications option.

To check and change your settings on Android
The core version of Android relies on app developers to develop specific settings more than controlling them on a platform-wide level.

• Open Settings > Notifications > App notifications to disable notifications from any app completely. Some apps may also offer internal notification options for specific types of notices, like new messages, that you can control in the app itself. Tap an app name, then tap the Addition settings in the app option to potentially customize it more.
• You can also experiment with the sensitive content setting. This is up to the developer to set properly, but when done so, most notifications will require at least unlocking the device to see them. Open Settings > Notifications > Notifications on lock screen and disable “Show sensitive content.”

Control What Notifications AI Tools Can Access

In an attempt to make notifications easier to skim, both Android and iOS offer optional ways to get notification summaries using their AI tools that summarize the content of notifications. On an individual app level, WhatsApp offers this as well. Some of these summarization tools, like Apple’s, run on the device, while others, like WhatsApp’s, do not. This can all be a lot to keep track of, and sending data off device may create some level of risk for some messages.

Since this is a bit more complicated, we have another blog post that walks through the steps to take to protect messaging from accidentally ending up in AI tools built into Apple and Google's devices. For WhatsApp specifically, we have a blog detailing when you might want to turn on the app’s “Advanced Chat Privacy” feature, which can disable summaries for both yourself and others in the chat.

Balancing security, privacy, and usability with something like push notifications is a complicated task. At the very least, Apple and Google should better ensure that the content of these notifications isn’t transmitted over their servers in plain text. The companies need to also make sure that device operating systems don’t back up the notification database to the cloud, and when an app is deleted, that all notification data is purged.

We appreciate that apps like Signal allow you to control what’s visible with notifications on a per-app basis, and we’d like to see this level of granularity of choices in other secure messaging tools, like WhatsApp. Likewise, more apps should handle push notifications similarly to the way Signal does, where a ping is sent to wake up the app to check for messages, and the content of that message is never sent across servers.

Granular convection takes place everywhere: candy in a box, sand on the beach, foam in a cushion. Often referred to as the “Brazil nut effect,” granular convection occurs when solid, independent, irregularly shaped particles reorder themselves following agitation. One might think, intuitively, that the larger pieces fall to the bottom, but it is their size, and not their density, that alters their location, and the larger pieces end up on the top.

In the world of competitive running, elite athletes have their footwear individually designed for needs such as foot shape and pressure points. Comfortable and supportive footwear can assist optimal performance. However, most footwear is standardized and doesn’t offer a personalized performance. 

MIT associate professor of architecture Skylar Tibbits, founder and co-director of the Self-Assembly Lab in the MIT School of Architecture and Planning, along with various MIT colleagues, have been developing tests surrounding the phenomenon of granular convection within the midsole — or middle layer, between the outsole (bottom) and insole (top) — of running shoes to create a shoe that evolves over time to provide an individualized product. As we approach the running of the 130th Boston Marathon — one of the world's most prominent displays of footwear supporting athletes — Tibbits answers three questions about bead-based technologies as applied to running shoes. 

Q. What are the advantages of an adaptive midsole over the current bead-based midsole technology?

A. Currently, the standard midsoles in running shoes are static. They aren’t customized to the shape of our foot or the force we deliver when running or walking. They also don’t change or improve over time as we run in them. Some products — blue jeans, baseball gloves, and hats, for example — get more comfortable as you wear them. We were exploring how this could be taken even further with a running shoe so that you would have the cushion, support, and stiffness where you need it and have it improve these features as you use it so that, over time, the actual performance of the shoe gets better. It’s not a personalized fit; it’s a performance-driven adaptation.

There are three advantages to this technology. The first is that customization is not only for elite athletes. Most elite athletes are already getting gear personalized for their specific needs by their sponsoring brands. Now, customized gear can be available for everyone. Second, customized gear currently does not adapt to an athlete’s performance. But you need your footwear to evolve because your needs as a runner evolve. You need to get the comfort, cushioning, and protection, to support your performance.

A third advantage is the manufacturability of this type of shoe. Custom shoes are now made in a factory for the specifications of a single athlete. That doesn’t scale. You can’t produce a manufacturing process where every single person’s shoe is going to be custom-made for them. We’ve shown that every shoe can be the same and mass produced, but, over time, the shoe will evolve to your personal needs. That is a way to get customization without having to change the manufacturing process.

Q: Why the interest in granular systems, and granular convection in particular?

A: We’ve worked on reversible construction techniques with granular jamming over the years, which is at the opposite end of the spectrum. Granular convection promotes the movement of particles; the more they are mixed, the more they separate. Our vision was looking at footwear that adapts with you over time. We thought we could use granular convection as a mechanism for the footwear to evolve.

We put particles with different stiffness, different material properties, and unique sizes, so that over time, we know the softer particles, which are the larger particles, will rise to the top, and the stiffer particles that are smaller will sink to the bottom, towards the outsole. We designed how these particles moved based on the vibration and the impact of walking and running.

We also designed the container. We had three different particle sizes; we conducted tests to try to dial it into the right number of steps for it to evolve over the course of about 20,000 steps. About the length of a marathon. We could either speed up or slow down that process.

Q. Are there future applications of customization for granular convection? If so, where do you see your research going next?

A: Any products that need cushioning systems that improve over time would benefit from this technology. With custom packaging, you have molded foam that fits around a product — a flat-screen television, for example — that is tossed out after it has been shipped from factory to distributor to customer. I worked with a furniture company that wrapped blankets around chairs for transport, but there were still some chairs that sustained damage. Maybe we could develop a blanket or some kind of material that adapts over the journey so that it creates just the right amount of cushion for the shape and property of that product and, once it’s delivered, its shape could be “released” and then reused. How can we reset this product in a timely manner so it can be used again?

Wheelchairs are another product where we would want seat cushions that can adapt to how a person sits, the force distribution, and the environment in which they are being used, such as a sidewalk or a gravel path. We considered this as it relates to footwear. You might want to reset your shoes because you’re going to be running road races on a given day and trail races another day. How can we empty and refill the midsole with different particles so it can adapt again? More importantly, how can we upgrade or change our shoes without throwing them away? This is exciting future work for us to explore.

SunZia has quietly begun sending enormous amounts of wind power to California, as President Donald Trump works to thwart the wind industry.

The U.S. Supreme Court is expected to make a final ruling in 2027, which could resolve or limit California’s bid to recoup climate damages from the oil and gas industry.

U.S. climate pollution stayed nearly the same as the year before, according to a University of Maryland report that filled a gap left by the Trump administration.

The Trump administration says emission regs are "contrary to the national and foreign policy interests of the United States."

The City Council is considering a petition to remove the mayor while elected officials gear up for an election in November.

Sen. Ted Cruz is leading the probe into the Federal Judicial Center — which is chaired by Chief Justice John Roberts — over its inclusion of climate science in a judicial manual.

A new report found that ESG filings fell 47 percent as rule changes limit the ability of smaller investors to pressure corporations publicly.

Lawmakers’ intense focus on the California Air Resources Board and the cost of climate policy has only increased since President Donald Trump reclaimed the White House on a platform of lowering the cost of living.

That detail could have significant impacts on the utility's ability to get building permits and federal funding.

Momentum in the negotiations has eroded in recent years as the U.S. retreated on climate action and nations fought over green finance.

The flooding also destroyed a bridge, dozens of roads and crops.

Interesting research: “Humans expect rationality and cooperation from LLM opponents in strategic games.”

Abstract: As Large Language Models (LLMs) integrate into our social and economic interactions, we need to deepen our understanding of how humans respond to LLMs opponents in strategic settings. We present the results of the first controlled monetarily-incentivised laboratory experiment looking at differences in human behaviour in a multi-player p-beauty contest against other humans and LLMs. We use a within-subject design in order to compare behaviour at the individual level. We show that, in this environment, human subjects choose significantly lower numbers when playing against LLMs than humans, which is mainly driven by the increased prevalence of ‘zero’ Nash-equilibrium choices. This shift is mainly driven by subjects with high strategic reasoning ability. Subjects who play the zero Nash-equilibrium choice motivate their strategy by appealing to perceived LLM’s reasoning ability and, unexpectedly, propensity towards cooperation. Our findings provide foundational insights into the multi-player human-LLM interaction in simultaneous choice games, uncover heterogeneities in both subjects’ behaviour and beliefs about LLM’s play when playing against them, and suggest important implications for mechanism design in mixed human-LLM systems...

Often hailed as the most successful international environmental agreement of all time, the 1987 Montreal Protocol continues to successfully phase out the global production of chemicals that were creating a growing hole in the ozone layer, causing skin cancer and other adverse health effects.

MIT-led studies have since shown the subsequent reduction in ozone-depleting substances is helping stratospheric ozone to recover. (It could return to 1980 levels by as early as 2040, according to some estimates.) But the Montreal Protocol made an exception in its rules for the use of ozone-depleting substances as feedstocks in the production of other materials. That’s because it was thought that only a small amount — just 0.5 percent — of the ozone-depleting substances used for this purpose would leak into the atmosphere.

In recent years, however, scientists have observed more ozone-depleting substances in the atmosphere than expected, and have increased their estimates of leakage from feedstocks.

Now an international group of scientists, including researchers from MIT, has calculated the impact of different feedstock leakage rates on the ozone’s fragile recovery. They find the higher leakage rates, if not addressed by the Montreal Protocol, could delay ozone recovery by about seven years.

“We’ve realized in the last few years that these feedstock chemicals are a bug in the system,” says author Susan Solomon, the Lee and Geraldine Martin Professor of Environmental Studies and Chemistry, who was part of the original research team that linked the chemicals to the ozone hole. “Production of ozone-depleting substances has pretty much ceased around the world except for this one use, which is when you have a chemical you convert into something else.”

The paper, which was published in Nature Communications today, is the first to comprehensively quantify the impact of leaked feedstocks, which are currently used to make plastics and nonstick chemicals. They are also used to make substitute chemicals for the ones regulated under the Montreal Protocol. The researchers say it shows the importance of curbing use and preventing leakage of such feedstocks, especially as the production of their end products, like plastic, is projected to grow.

“We’ve gotten to the point where, if we want the protocol to be as successful in the future as it has been in the past, the parties really need to think about how to tighten up the emissions of these industrial processes,” says first author Stefan Reimann of the Swiss Federal Laboratories for Materials Science and Technology.

“To me, it’s only fair, because so many other things have already been completely discontinued. So why should this exemption exist if it’s going to be damaging?” says Solomon.

Joining Reimann on the paper are his colleagues Martin K. Vollmer and Lukas Emmenegger; Luke Western and Susan Solomon of the MIT Center for Sustainability Science and Strategy and the Department of Earth, Atmospheric and Planetary Sciences; David Sherry of Nolan-Sherry and Associates Ltd; Megan Lickley of Georgetown University; Lambert Kuijpers of the A/gent Consultancy b.v.; Stephen A. Montzka and John Daniel of the National Oceanic and Atmospheric Administration; Matthew Rigby of the University of Bristol; Guus J.M. Velders of Utrecht University; Qing Liang of the NASA Goddard Space Flight Center; and Sunyoung Park of Kyungpook National University.

Repairing the ozone

In 1985, scientists discovered a growing hole in the ozone layer over Antarctica that was allowing more of the sun’s harmful ultraviolet radiation to reach Earth’s surface. The following year, researchers including Solomon traveled to Antarctica and discovered the cause of the ozone deterioration: a class of chemicals called chlorofluorocarbons, or CFCs, which were then used in refrigeration, air conditioning, and aerosols.

The revelations led to the Montreal Protocol, an international treaty involving 197 countries and the European Union restricting the use of CFCs. The subsequent decision to exempt the use of ozone-depleting substances for use as feedstocks was based partially on industry estimates of how much of their feedstocks leaked.

“It was thought that the emissions of these substances as a feedstock were minor compared to things like refrigerants and foams,” Western says. “It was also believed that leakage from these sources was minor — around half a percent of what went in — because people would essentially be leaking their profits if their feedstocks were released into the atmosphere.”

Unfortunately, some of those assumptions are no longer true. Western and Reimann are part of the Advanced Global Atmospheric Gases Experiment (AGAGE), a global monitoring network co-founded by Ronald Prinn, MIT’s TEPCO Professor of Atmospheric Science. AGAGE monitors emissions of ozone-depleting substances around the world, and in recent years researchers have revised their estimates of feedstock leakage upwards, to about 3.6 percent. For some chemicals, the number was even higher.

In the new paper, the researchers estimated a 3.6 percent feedstock leakage as the baseline for most chemicals. They compared that with a scenario where 0.5 percent of feedstocks are leaked from 2025 onward and a scenario with zero feedstock-related emissions. The researchers also looked at production trends between 2014 and 2024 to project how much of each specific ozone-depleting chemical would be used as feedstock between 2025 and 2100.

The analysis shows that until 2050, total ozone-depleting chemical emissions decrease in all scenarios as rising feedstock emissions are offset by declining uses enforced by the Montreal Protocol. In the scenario with continued 3.6 percent leakage, however, emissions level off around 2045, and total emissions only decrease by 50 percent overall by 2100.

The researchers then evaluated the impact of feedstock-related emissions on stratospheric ozone depletion. In the scenario where feedstock leakage is 0.5 percent, the ozone returns to its 1980 status by 2066. In the scenario with zero feedstock leakage, the ozone reclaims its 1980 health in 2065. But in the baseline scenario, the recovery is delayed about seven years, to 2073.

“This paper sends an important message that these emissions are too high and we have to find a way to reduce them,” Reimann says. “Either that means no longer using these substances as feedstocks, swapping out chemicals, or reducing the leakage emissions when they are used.”

A global response

Solomon is confident industries will be able to adjust to the latest findings.

“There are a lot of innovators in the chemical industry,” Solomon says. “They make new chemicals and improve chemicals for a living. It’s true they can perhaps get too entrenched with certain chemicals, but it doesn’t happen that often. Actually, they’re usually quite willing to consider alternatives. There are thousands of other chemicals that could be used instead, so why not switch? That’s been the attitude.”

Solomon says the fact that AGAGE can detect the impact of feedstock emissions is a testament to the progress the world has made in reducing emissions from other sources up to this point. She believes raising awareness of the feedstock problem is the first step.

“This isn’t the first time that the AGAGE Network has made measurements that have allowed the world to see we need to do a little better here or there,” Western says. “Often, it’s just a mistake. Sometimes all it takes is making people more aware of these things to tighten up some processes.”

Members of the Montreal Protocol meet every year. In those meetings, they split into working groups around different topics. Feedstock emissions are already one of those topics, so participants will review the evidence together. Typically, they release a statement about mitigation strategies if needed.

“We wanted to raise the warning flag that something is wrong here,” Reimann says. “We could reduce the period of ozone depletion by years. It might not sound like a long time, but if you could count the skin cancer cases you’d avoid in that time, it would seem quite significant.”

The work was supported, in part, by the U.S. National Science Foundation, the U.S. National Aeronautics and Space Administration (NASA), the Swiss Federal Office for the Environment, the VoLo Foundation, the United Kingdom Natural Environment Research Council, and the Korea Meteorological Administration Research and Development Program.

A new study from MIT suggests that a carcinogen that has been found in medications and in drinking water contaminated by chemical plants may have a much more severe impact on children than adults.

In a study of mice, the researchers found that juveniles exposed to drinking water containing this compound, known as NDMA, showed dramatically higher rates of DNA damage and cancer than adults.

The findings may help to explain an epidemiological association between childhood cancer and prenatal exposure to NDMA in people living near a contaminated site in Wilmington, Massachusetts, the researchers say. The study also suggests that it is critical to evaluate the impact of potential carcinogens across all ages.

“We really hope that groups that do safety testing will change their paradigm and start looking at young animals, so that we can catch potential carcinogens before people are exposed,” says Bevin Engelward, an MIT professor of biological engineering. “As a solution to cancer, cancer prevention is clearly much better than cancer treatment, so we hope we can spot dangerous chemicals before people are exposed, and therefore prevent extensive cancer risk.”

MIT postdoc Lindsay Volk is the lead author of the paper. Engelward is the senior author of the study, which appears in Nature Communications.

From DNA damage to cancer

NDMA (N-Nitrosodimethylamine) can be generated as a byproduct of many industrial chemical processes, and it is also found in cigarette smoke and processed meats. In recent years, NDMA has been detected in some formulations of the drugs valsartan, ranitidine, and metformin. It was also found in drinking water in Wilmington, Massachusetts, in the 1990s, as a result of contamination from the Olin Chemical site.

In 2021, a study from the Massachusetts Department of Health suggested a link between that water contamination and an elevated incidence of childhood cancer in Wilmington. Between 1990 and 2000, 22 Wilmington children were diagnosed with cancer. The contaminated wells were closed in 2003.

Also in 2021, Engelward and others at MIT published a study on the mechanism of how NDMA can lead to cancer. In the new Nature Communications paper, Engelward and her colleagues set out to see if they could determine why the compound appears to affect children more than adults.

Most studies that evaluate potential carcinogens are performed in mice that are at least 4 to 6 weeks old, and often older. For this study, the researchers studied two groups of mice — one 3 weeks old (juvenile), and one 6 months old (adult). Each group was given drinking water with low levels of NDMA, about five parts per million, for two weeks.

Inside the body, NDMA is metabolized by a liver enzyme called CYP2E1. This produces toxic metabolites that can damage DNA by adding a small chemical group known as a methyl group to DNA bases, creating lesions known as adducts.

When the researchers examined the livers of the mice, they found that juveniles and adults showed similar levels of DNA adducts. However, there were dramatic differences in what happened after that initial damage. In juvenile mice, DNA adducts led to significant accumulation of double-stranded DNA breaks, which occur when cells try to repair adducts. These breaks produce mutations that eventually lead to the development of liver cancer.

In the adult mice, the researchers saw essentially no double-stranded breaks and significantly fewer mutations compared to juveniles. Furthermore, the livers did not develop severe pathology, including tumors, even though they experienced the same initial level of DNA adducts.

“The initial structural changes to the DNA had very different consequences depending on age,” Engelward says. “The double-stranded breaks were exclusively observed in the young.”

Further experiments revealed that these differences stem from differences in the rates of cell proliferation. Cells in the juvenile liver divide rapidly, giving them more opportunity to turn DNA adducts into mutations, while cells of the adult liver rarely divide.

“This really emphasizes the overall problem that we’re trying to highlight in the paper,” Volk says. “With toxicological studies, oftentimes the standard is to use fully grown mice. At that point, they’re already slowing down cell division, so if we are testing the harmful effects of NDMA in adult mice, then we’re completely missing how vulnerable particular groups are, such as younger animals.”

While most of these effects were seen in the liver, because that is where NDMA is metabolized, a few of the mice developed other types of cancer, including lung cancer and lymphoma.

Adult risk is not zero

For most of these studies, the researchers used mice that had two of their DNA repair systems knocked out. This speeds up the mutation process, allowing the researchers to see the effects of NDMA exposure more easily, without needing to study a large population of mice.

However, a small study in mice with normal DNA repair showed that juveniles experienced NDMA-induced double-strand breaks, regenerative proliferation, and large-scale mutations that were completely absent in adults. This occurs because the fast-growing juveniles possess highly active DNA replication machinery that encounters the DNA adducts before the cell has time to repair them.

The researchers also found that if they treated adult mice with thyroid hormone, which stimulates proliferation of liver cells, those cells began accumulating mutations as quickly as the juvenile liver cells. Previous work done in the Engelward laboratory has shown that inflammation can also stimulate cell proliferation-driven vulnerability to DNA damage, so the findings of this study suggest that anything that causes liver inflammation could make the adult liver more vulnerable to damage caused by agents such as NDMA.

“We certainly don’t want to say that adults are completely resistant to NDMA,” Volk says. “Everything impacts your susceptibility to a carcinogen, whether that’s your genetics, your age, your diet, and so forth. In adults, if they have a viral infection, or a high fat diet, or chronic binge alcohol drinking, this can impact proliferation within the liver and potentially make them susceptible to NDMA.”

The researchers are now investigating how a high-fat diet might influence cancer development in mice that also have exposure to NDMA.

This collaborative effort across several MIT labs was funded by the National Institutes of Environmental and Health Sciences (NIEHS) Superfund Research Program, a NIEHS Core Center Grant, a National Institutes of Health Training Grant, and the Anonymous Fund for Climate Action. 

Cells are enveloped by a lipid membrane that gives them structure and provides a barrier between the cell and its environment. However, evidence has recently emerged suggesting that these membranes do more than simply provide protection — they also influence the behavior of the protein receptors embedded in them.

A new study from MIT chemists adds further support to that idea. The researchers found that changing the composition of the cell membrane can alter the function of a membrane receptor that promotes proliferation.

Epidermal growth factor receptor (EGFR) can be locked into an overactive state when the cell membrane has a higher than normal concentration of negatively charged lipids, the researchers found. This may help to explain why cancer cells with high levels of those lipids enter a highly proliferative state that allows them to divide uncontrollably.

“The longstanding dogma of what a membrane does is that it’s just a scaffold, an organizational structure. However, there have been increasing observations that suggest that maybe these membrane lipids are actually playing a role in receptor function,” says Gabriela Schlau-Cohen, the Robert T. Haslam and Bradley Dewey Professor of Chemistry at MIT and the senior author of the study.

The findings open up the possibility of discovering new ways to treat tumors by neutralizing the negative charge, which might turn down EGFR signaling, she adds.

Shwetha Srinivasan PhD ’22 is the lead author of the paper, which appears in the journal eLife. Other authors include former MIT postdocs Xingcheng Lin and Raju Regmi, Xuyan Chen PhD ’25, and Bin Zhang, an associate professor of chemistry at MIT.

Receptor dynamics

The EGF receptor, which is found on cells that line body surfaces and organs, is one of many receptors that help control cell growth. Some types of cancer, especially lung cancer and glioblastoma, overexpress the EGF receptor, which can lead to uncontrolled growth.

Like most receptor proteins, EGFR spans the entire cell membrane. Until recently, it has been challenging to study how signals are conveyed across the entire receptor, because of the difficulty of creating membranes that have proteins going all the way through them and then studying both ends of those proteins.

To make it easier to study these signaling processes, Schlau-Cohen’s lab uses nanodiscs, a special type of self-assembling membrane that mimics the cell membrane. When making these discs, the researchers can embed receptors in them, allowing the team to study the function of the full-length receptor.

Using a technique called single molecule FRET (fluorescence resonance energy transfer), the researchers can study how the shape of the receptor changes under different conditions. Single molecule FRET allows them to measure the distance between different parts of the protein by labeling them with fluorescent tags and then measuring how fast energy travels between the tags.

In previous work, Schlau-Cohen and Zhang used single molecule FRET and molecular dynamics simulations to reveal what happens when EGFR binds to EGF. They found that this binding causes the transmembrane section of the receptor to change shape, and that shape-shift triggers the section of the receptor that extends inside the cell to activate cellular machinery that stimulates growth.

Stuck in an overactive state

In the new study, the researchers used a similar approach to investigate how altering the composition of the membrane affects the function of the receptor. First, they explored how elevated levels of negatively charged lipids would affect the cell membrane and EGFR function.

Normally, about 15 percent of the cell membrane is made up of negatively charged lipids. The researchers found that membranes with negatively charged lipids in the range of 15 to 30 percent behaved normally, but if that level reached 60 percent, then the EGFR receptor would become locked into an active state.

In that state, the pro-growth signaling pathway is turned on all the time, even when no EGF is bound to the receptor. Many cancer cells show increased levels of these lipids, and this mechanism could help to explain why those cells are able to grow unchecked, Schlau-Cohen says.

“If the membrane has high levels of negatively charged lipids, then it’s always in that open conformation. It doesn’t matter if ligand is bound or unbound,” she says. “It’s always in the conformation that’s telling the cell to grow, not just when EGF binds.”

The researchers also used this system to explore the role of cholesterol in EGFR function. When the researchers created nanodiscs with elevated cholesterol levels, they found that the membranes became more rigid, and this rigidity suppressed EGFR signaling.

The research was funded by the National Institutes of Health and MIT’s Department of Chemistry.