This blog also appears in our Age Verification Resource Hub: our one-stop shop for users seeking to understand what age-gating laws actually do, what’s at stake, how to protect yourself, and why EFF opposes all forms of age verification mandates. Head to EFF.org/Age to explore our resources and join us in the fight for a free, open, private, and yes—safe—internet.

EFF is against all mandatory age verification. Not only does it turn the internet into an age-gated cul-de-sac, but it also leaves behind many people who can’t get or don’t have proper and up-to-date documentation. While populations like undocumented immigrants and people experiencing homelessness are more obviously vulnerable groups, these restrictions also impact people with more mundane reasons for not having valid documentation on hand. Perhaps they’ve undergone life changes that impact their status or other information—such as a move, name change, or gender marker change—or perhaps they simply haven’t gotten around to updating their documents. Inconvenient events like these should not be a barrier to going online. People should also reserve the right to opt-out of unreliable technology and shady practices that could endanger their personal information.

But age restriction mandates threaten all of that. Not only do age-gating laws block adults and youth alike from freely accessing services on the web, they also force users to trade their anonymity—a pillar of online expression—for a system in which they are bound to their real-life identities. And this surveillance regime stretches beyond just age restrictions on certain content; much of this infrastructure is also connected to government plans for creating a digital system of proof of identity.

So how does age gating actually work? The age and identity verification industry has devised countless different methods platforms can purchase to—in theory—figure out the ages and/or identities of their users.  But in practice, there is no technology available that is entirely privacy-protective, fully accurate, and that guarantees complete coverage of the population. Full stop.

Every system of age verification or age estimation demands that users hand over sensitive and oftentimes immutable personal information that links their offline identity to their online activity, risking their safety and security in the process.

But in practice, there is no technology available that is entirely privacy-protective, fully accurate, and that guarantees complete coverage of the population. Full stop.

With that said, as we see more of these laws roll out across the U.S. and the rest of the world, it’s important to understand the differences between these technologies so you can better identify the specific risks of each method, and make smart decisions about how you share your own data.

Age Assurance Methods

There are many different technologies that are being developed, attempted, and deployed to establish user age. In many cases, a single platform will have implemented a mixture of methods. For example, a user may need to submit both a physical government ID and a face scan as part of a liveliness check to establish that they are the person pictured on the physical ID. 

Age assurance methods generally fall into three categories:

1. Age Attestation
2. Age Estimation
3. ID-bound Proof

Age Attestation Self-attestation 

Sometimes, you’ll be asked to declare your age, without requiring any form of verification. One way this might happen is through one-off self-attestation. This type of age attestation has been around for a while; you may have seen it when an alcohol website asks if you’re over 21, or when Steam asks you to input your age to view game content that may not be appropriate for all ages. It’s usually implemented as a pop-up on a website, and they might ask you for your age every time you enter, or remember it between site accesses. This sort of attestation provides an indication that the site may not be appropriate for all viewers, but gives users the autonomy and respect to make that decision for themselves.

An alternative proposed approach to declaring your own age, called device-bound age attestation, is to have you set your age on your operating system or on App Stores before you can make purchases or browse the web. This age or age range might then be shared with websites or apps. On an Apple device, that age can be modified after creation, as long as an adult age is chosen. It’s important to separate device-bound age attestation from methods that require age verification or estimation at the device or app store level (common to digital ID solutions and some proposed laws). It’s only attestation if you’re permitted to set your age to whatever you choose without needing to prove anything to your provider or another party—providing flexibility for age declaration outside of mandatory age verification.

Attestation through parental controls

The sort of parental controls found on Apple and Android devices, Windows computers, and video game consoles provide the most flexible way for parents to manage what content their minor children can access. These settings can be applied through the device operating system, third-party applications, or by establishing a child account. Decisions about what content a young person can access are made via consent-driven mechanisms. As the manager, the parent or guardian will see requests and activity from their child depending on how strict or lax the settings are set. This could include requests to install an app, make a purchase on an app store, communicate with a new contact, or browse a particular website. The parent or guardian can then choose whether or not to accept the request and allow the activity. 

One survey that collected answers from 1,000 parents found that parental controls are underutilized. Adoption of parental controls varied widely, from 51% on tablets to 35% on video game consoles. To help encourage more parents to make use of these settings, companies should continue to make them clearer and easier to use and manage. Parental controls are better suited to accommodating diverse cultural contexts and individual family concerns than a one-size-fits-all government mandate. It’s also safer to use native settings–or settings provided by the operating system itself–than it is to rely on third-party parental control applications. These applications have experienced data breaches and often effectively function as spyware.

Age Estimation

Instead of asking you directly, the system guesses your age based on data it collects about you.

Age estimation through photo and facial estimation

Age estimation by photo or live facial age analysis is when a system uses an image of a face to guess a person’s age.

A poorly designed system might improperly store these facial images or retain them for significant periods, creating a risk of data leakage. Our faces are unique, immutable, and constantly on display. In the hands of an adversary, and cross-referenced to other readily available information about us, this information can expose intimate details about us or lead to biometric tracking.

This technology has also proven fickle and often inaccurate, causing false negatives and positives, exacerbation of racial biases, and unprotected usage of biometric data to complete the analysis. And because it’s usually conducted with AI models, there often isn’t a way for a user to challenge a decision directly without falling back on more intrusive methods like submitting a government ID. 

Age inference based on user data and third party services

Age inference systems are normally conducted through estimating how old someone is based on their account information or querying other databases, where the account may have done age verification already, to cross reference with the existing information they have on that account.

Age inference includes but not limited to:

• Partnering with data brokers to gather data associated with an email, like utility use or mortgage purchases, or associated with a name, such as transaction history from a credit bureau;
• Other AI model-assisted deployments that infer age based on existing account or web activity, such as account age or “happy birthday” messages;
• Credit card ownership checks.

In order to view how old someone is via account information associated with their email, services often use data brokers to provide this information. This incentivizes even more collection of our data for the sake of age estimation and rewards data brokers for collecting a mass of data on people. Also, regulation of these age inference services varies based on a country’s privacy laws.

ID-bound Proof

ID-bound proofs, methods that use your government issued ID, are often used as a fallback for failed age estimation. Consequently, any government-issued ID backed verification disproportionately excludes certain demographics from accessing online services. A significant portion of the U.S. population does not have access to government-issued IDs, with millions of adults lacking a valid driver’s license or state-issued ID. This disproportionately affects Black Americans, Hispanic Americans, immigrants, and individuals with disabilities, who are less likely to possess the necessary identification. In addition, non-U.S. citizens, including undocumented immigrants, face barriers to acquiring government-issued IDs. The exclusionary nature of document-based verification systems is a major concern, as it could prevent entire communities from accessing essential services or engaging in online spaces.

Physical ID uploaded and stored as an image 

When an image of a physical ID is required, users are forced to upload—not just momentarily display—sensitive personal information, such as government-issued ID or biometric identifiers, to third-party services in order to gain access to age-restricted content. This creates significant privacy and security concerns, as users have no direct control over who receives and stores their personal data, where it is sent, and how it may be accessed, used, or leaked outside the immediate verification process.

Requiring users to digitally hand over government-issued identification to verify their age introduces substantial privacy risks. Once sensitive information like a government-issued ID is uploaded to a website or third-party service, there is no guarantee that it will be handled securely. The verification process typically involves transmitting this data across multiple intermediaries, which means the risk of a data breach is heightened. The misuse of sensitive personal data, such as government IDs, has been demonstrated in numerous high-profile cases, including the breach of the age verification company AU10TIX, which exposed login credentials for over a year, and the hack of the messaging application Discord. Justifiable privacy and security concerns may chill users from accessing platforms they are lawfully entitled to access.

Device-bound digital ID

Device-bound digital ID is a credential that is locally stored on your device. This comes in the form of government or privately-run wallet applications, like those offered by Apple and Google. Digital IDs are subject to a higher level of security within the Google and Apple wallets (as they should be). This means they are not synced to your account or across services. If you lose the device, you will need to reissue a new credential to the new one. Websites and services can directly query your digital ID to reveal only certain information from your ID, like age range, instead of sharing all of your information. This is called “selective disclosure."

There are many reasons someone may not be able to acquire a digital ID, preventing them from relying on this option. This includes lack of access to a smartphone, sharing devices with another person, or inability to get a physical ID. No universal standards exist governing how ID expiration, name changes, or address updates affect the validity of digital identity credentials. How to handle status changes is left up to the credential issuer.

Asynchronous and Offline Tokens

This is an issued token of some kind that doesn’t necessarily need network access to an external party or service every time you use it to establish your age with a verifier when they ask. A common danger in age verification services is the proliferation of multiple third-parties and custom solutions, which vary widely in their implementation and security. One proposal to avoid this is to centralize age checks with a trusted service that provides tokens that can be used to pass age checks in other places. Although this method requires a user to still submit to age verification or estimation once, after passing the initial facial age estimation or ID check, a user is issued a digital token they can present later to to show that they've previously passed an age check. The most popular proposal, AgeKeys, is similar to passkeys in that the tokens will be saved to a device or third-party password store, and can then be easily accessed after unlocking with your preferred on-device biometric verification or pin code.

Lessons Learned

With lessons pulled from the problems with the age verification rollout in the UK and various U.S. states, age verification widens risk for everyone by presenting scope creep and blocking web information access. Privacy-preserving methods to determine age exist such as presenting an age threshold instead of your exact birth date, but have not been mass deployed or stress tested yet. Which is why policy safeguards around the deployed technology matter just as much, if not more. 

Much of the infrastructure around age verification is entangled with other mandates, like deployment of digital ID. Which is why so many digital offerings get coupled with age verification as a “benefit” to the holder. In reality it’s more of a plus for the governments that want to deploy mandatory age verification and the vendors that present their implementation that often contains multiple methods. Instead of working on a singular path to age-gate the entire web, there should be a diversity of privacy-preserving ways to attest age without locking everyone into a singular platform or method. Ultimately, offering multiple options rather than focusing on a single method that would further restrict those who can’t use that particular path.

“Can we make tissues that are made from you, for you?” asked Jennifer Lewis ScD ’91 at the 2025 Mildred S. Dresselhaus Lecture, organized by MIT.nano, on Nov. 3. “The grand challenge goal is to create these tissues for therapeutic use and, ultimately, at the whole organ scale.”

Lewis, the Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard University, is pursuing that challenge through advances in 3D printing. In her talk presented to a combined in-person and virtual audience of over 500 attendees, Lewis shared work from her lab that focuses on enhanced function in 3D printed components for use in soft electronics, robotics, and life sciences.

“How you make a material affects its structure, and it affects its properties,” said Lewis. “This perspective was a light bulb moment for me, to think about 3D printing beyond just prototyping and making shapes, but really being able to control local composition, structure, and properties across multiple scales.”

A trained materials scientist, Lewis reflected on learning to speak the language of biologists when she joined Harvard to start her own lab focused on bioprinting and biological engineering. How does one compare particles and polymers to stem cells and extracellular matrices? A key commonality, she explained, is the need for a material that can be embedded and then erased, leaving behind open channels. To meet this need, Lewis’ lab developed new 3D printing methods, sophisticated printhead designs, and viscoelastic inks — meaning the ink can go back and forth between liquid and solid form.

Displaying a video of a moving robot octopus named Octobot, Lewis showed how her group engineered two sacrificial inks that change from fluid to solid upon either warming or cooling. The concept draws inspiration from nature — plants that dynamically change in response to touch, light, heat, and hydration. For Octobot, Lewis’ team used sacrificial ink and an embedded printing process that enables free-form printing in three dimensions, rather than layer-by-layer, to create a fully soft autonomous robot. An oscillating circuit in the center guides the fuel (hydrogen peroxide), making the arms move up and down as they inflate and deflate.

From robots to whole organ engineering

“How can we leverage shape morphing in tissue engineering?” asked Lewis. “Just like our blood continuously flows through our body, we could have continuous supply of healing.”

Lewis’ lab is now working on building human tissues, primarily cardiac, kidney, and cerebral tissue, using patient-specific cells. The motivation, Lewis explained, is not only the need for human organs for people with diseases, but the fact that receiving a donated organ means taking immunosuppressants the rest of your life. If, instead, the tissue could be made from your own cells, it would be a stronger match to your own body.

“Just like we did to engineer viscoelastic matrices for embedded printing of functional and structural materials,” said Lewis, “we can take stem cells and then use our sacrificial writing method to write in perfusable vasculature.” The process uses a technique Lewis calls SWIFT — sacrificial writing into functional tissue. Sharing lab results, Lewis showed how the stem cells, differentiated into cardiac building blocks, are initially beating individually, but after being packed into a tighter space that will support SWIFT, these building blocks fuse together and become one tissue that beats synchronously. Then, her team uses a gelatin ink that solidifies or liquefies with temperature changes to print the complex design of human vessels, flushing away the ink to leave behind open lumens. The channel remains open, mimicking a blood vessel network that could have fluid actively, continuously flowing through it. “Where we’re going is to expand this not only to different tissue types, but also building in mechanisms by which we can build multi-scale vasculature,” said Lewis.

Honoring Mildred S. Dresselhaus

In closing, Lewis reflected on Dresselhaus’ positive impact on her own career. “I want to dedicate this [talk] to Millie Dresselhaus,” said Lewis. She pointed to a quote by Millie: “The best thing about having a lady professor on campus is that it tells women students that they can do it, too.” Lewis, who arrived at MIT as a materials science and engineering graduate student in the late 1980s, a time when there were very few women with engineering doctorates, noted that “just seeing someone of her stature was really an inspiration for me. I thank her very much for all that she’s done, for her amazing inspiration both as a student, as a faculty member, and even now, today.”

After the lecture, Lewis was joined by Ritu Raman, the Eugene Bell Career Development Assistant Professor of Tissue Engineering in the MIT Department of Mechanical Engineering, for a question-and-answer session. Their discussion included ideas on 3D printing hardware and software, tissue repair and regeneration, and bioprinting in space. 

“Both Mildred Dresselhaus and Jennifer Lewis have made incredible contributions to science and served as inspiring role models to many in the MIT community and beyond, including myself,” said Raman. “In my own career as a tissue engineer, the tools and techniques developed by Professor Lewis and her team have critically informed and enabled the research my lab is pursuing.”

This was the seventh Dresselhaus Lecture, named in honor of the late MIT Institute Professor Mildred Dresselhaus, known to many as the "Queen of Carbon Science.” The annual event honors a significant figure in science and engineering from anywhere in the world whose leadership and impact echo Dresselhaus’ life, accomplishments, and values. 

“Professor Lewis exemplifies, in so many ways, the spirit of Millie Dresselhaus,” said MIT.nano Director Vladimir Bulović. “Millie’s groundbreaking work, indeed, is well known; and the groundbreaking work of Professor Lewis in 3D printing and bio-inspired materials continues that legacy.”

"To really understand science policy, you have to step outside the lab and see it in action," says Jack Fletcher, an MIT PhD student in nuclear science and engineering and chair of the 15th annual Executive Visit Days (ExVD). 

Inspired by this mindset, ExVD — jointly organized by the MIT Science Policy Initiative (SPI) and the MIT Washington Office — convened a delegation of 21 MIT affiliates, including undergraduates, graduate students, and postdocs, in Washington Oct. 27-28. 

Although the government shutdown prevented the delegation’s usual visits to executive agencies, participants met with experts across the federal science and technology policy ecosystem. These discussions built connections in the nation’s capital, displayed how evidence interacts with political realities, and demonstrated how scientists, engineers, and business leaders can pursue impactful careers in public service. 

A recurring theme across meetings was that political realities and institutional constraints, not just evidence and analysis, shape policy outcomes. As Mykyta Kliapets, a PhD student at KU Leuven (Belgium) and a visiting student at the MIT Kavli Institute for Astrophysics and Space Research, reflected, “It was really helpful to hear how rarely straightforward policy environments are — sometimes, a solution that makes the most sense technically is not always politically feasible.” 

The group also heard how political forces directly impact science, from disruptions during government shutdowns to recent reductions in federal research support. Speakers underscored that effective science policy requires combined fluency in evidence, systems, and incentives.

For the first time, ExVD visited the Delegation of the European Union to the United States to meet with Francesco Maria Graziani, climate and energy counselor. He described E.U.-U.S. cooperation on energy and climate as “active and vital, but complex,” noting that the E.U. can struggle to navigate a diverse, multilevel, and variable U.S. policy landscape. “The E.U. and the U.S. share many goals, but we often operate on different timelines and with different tools,” said Graziani. He identified nuclear power, geothermal energy, and supply chain security as areas of continued E.U. and U.S. collaboration. 

Graziani also discussed ongoing collaborations like the Destination Earth project, which improves global climate models using U.S. state-level data. “As a European, hearing differences in how the U.S. navigates science policy gave me a new lens on how two advanced democracies balance innovation, regulation, and the urgency of scientific challenges,” said Sofia Karagianni, an MBA student at the MIT Sloan School of Management. 

The ExVD delegation also met with three MIT alumni at the Science and Technology Policy Institute (STPI). A federally funded research and development center, STPI provides technical and analytical support on science and technology issues to inform policy decisions by the White House Office of Science and Technology Policy (OSTP) and other federal sponsors. Recently, STPI’s research reports have focused on a number of topics including quantum computing, biotechnology, and artificial intelligence. The discussion at STPI emphasized the importance of conducting  objective analyses that have relevance for policymakers. Director Asha Balakrishnan explained how it is often useful to provide “options” in their reports, rather than “recommendations,” because policymakers benefit from understanding the advantages and disadvantages of potential policy actions.

Participants found the speakers’ reflections on career development and fellowships particularly valuable. Several speakers discussed their experiences with the AAAS Science and Technology Policy Fellowship, which places scientists and engineers in federal agencies and congressional offices for a year. 

“In speaking with former fellows, I learned just how transformative these fellowships can be for scientists seeking to apply their academic research backgrounds to a wide range of careers at the intersection of science and policy,” said Amanda Hornick, a recent doctoral graduate of the Harvard-MIT Program in Health Sciences and Technology. Eli Duggan, a graduate student in MIT's Technology and Policy Program, added that “seeing how the speakers’ work makes a real impact got me excited to apply my technical and policy background for the public good.”

The lessons from these conversations reflect the broader mission of the MIT Science Policy Initiative: to help the MIT community understand and engage with the policymaking process. SPI is a student- and postdoc-led organization dedicated to strengthening dialogue between MIT and the broader policy ecosystem. Each year, SPI organizes multiple trips to Washington, giving members the chance to meet directly with federal agencies and policymakers while exploring careers at the intersection of science, technology, and policy. These trips also spark connections and conversations that participants bring back to campus, enriching policy dialogue within the MIT community. 

SPI is grateful to the individuals and organizations who shared their time and insights at this year’s ExVD, giving participants a foundation to draw on as they explore career opportunities and the many ways technical expertise can shape public decision-making.

Students enrolled in MIT’s New Engineering Education Transformation (NEET) program recently collaborated across academic disciplines to design and construct a solar-powered charging station. Positioned in a quiet campus courtyard, the station provides the MIT community with climate-friendly power for phones, laptops, and tablets.

Its installation marked the “first time a cross-departmental team of undergraduates designed, created, and installed on campus a green technology artifact for the public good, as part of a class they took for credit,” says Amitava “Babi” Mitra, NEET founding executive director.

The project was very on-brand for the NEET program, which centers interdisciplinary, cross-departmental, and project-centric scholarship with experiential learning at its core. Launched in 2017 as an effort to reimagine undergraduate engineering education at MIT, NEET seeks to empower students to tackle complex societal challenges that straddle disciplines.

The solar-powered charging station project class is an integral part of NEET’s decarbonization-focused Climate and Sustainability Systems (CSS) “thread,” one of four pathways of study offered by the program. The class, 22.03/3.0061 (Introduction to Design Thinking and Rapid Prototyping), teaches the design and fabrication techniques used to create the station, such as laser cutting, 3D printing, computer-aided design (CAD), electronics prototyping, microcontroller programming, and composites manufacturing.

The project team included students majoring in chemical engineering, materials science and engineering, mechanical engineering, and nuclear science and engineering.

“What I really liked about this project was, at the beginning, it was really about ideation, about design, about brainstorming in ways that I haven’t seen before,” says NEET CSS student Aaron De Leon, a nuclear science and engineering major focused on clean energy development. 

During these brainstorming sessions, the team considered how their subjective design choices for the charging station would shape user experience, something De Leon, who enrolled in the class as a sophomore, says is often overlooked in engineering classes.

The team’s forest-inspired station design — complete with “tree trunks,” oyster mushroom-shaped desk space, and four solar panels curved to mimic the undulation of the forest canopy — was intended to evoke a sense of organic connectivity. The tree trunks were crafted from novel flax fiber-based composite layups the team developed through experiments designed to identify more sustainable alternatives to traditional composites.

The group also discussed how a dearth of device charging options made it difficult for students to work outside, according to NEET CSS student Celestina Pint, who enrolled in the class as a sophomore. The desk space was added to help MIT students work comfortably outdoors while also charging their devices with renewable energy.

Pint joined NEET because she wanted to “keep an open approach to climate and sustainability,” as opposed to relying on her materials science and engineering major alone, she says. “I like the interdisciplinary aspect.”

The project class presented abundant interdisciplinary learning opportunities that couldn’t be replicated in a purely theory-based curriculum, says Nathan Melenbrink, NEET lecturer, who teaches the project class and is the lead instructor for the NEET CSS thread.

For example, the team got a crash course in navigating real-world bureaucracy when they discovered that the installation of their charging station had to be approved by more than a dozen entities, including campus police, MIT’s insurance provider, and the campus facilities department.

The team also gained valuable experience with troubleshooting unanticipated design implementation challenges during the project’s fabrication phase.

“Adjustments had to be made,” Pint says. Once the station was installed, “it was interesting to see what was the same and what was different” from the team’s initial design.

This underscores a unique value of the project, according to NEET CSS student Tyler Ea, a fifth-year mechanical engineering major who joined the project team last year and is now a teaching assistant for the class.

Students “are able to take ownership of something physical, like a physical embodiment of their ideas, and something that they can point towards and say, ‘here’s something that I thought about, and this is how I went about building it, and then here’s the final result,’” he says.

While students only become eligible to join NEET in their second year, first-year students interested in the program were also able to learn from the solar-powered charging station project in the first-year discovery class SP.248 (The NEET Experience). After learning fundamental concepts in systems engineering, the class analyzed the station and suggested changes they thought would improve its design.

Melenbrink says student-built campus installations were once a hallmark of MIT’s academic culture, and he sees the NEET CSS solar-powered charging station project as an opportunity to help revive this tradition.

“What I hear from the old guard is that there was always somebody … lugging some giant, odd-looking prototype of something across campus,” Melenbrink says.

More collaborative, hands-on, student-led climate projects would also help the Institute meet its commitment to become a leading source of meaningful climate solutions, according to Elsa Olivetti, the Jerry McAfee (1940) Professor of Materials Science and Engineering and strategic advisor to the MIT Climate and Sustainability Consortium (MCSC).

“This local renewable energy project demonstrates that our campus community can learn through solution development,” she says. “Students don’t have to wait until they graduate or enter the job market to make a contribution.”

Students enrolled in this year’s Introduction to Design Thinking and Rapid Prototyping class will fabricate and install a new solar-powered charging station with a unique design. De Leon says he appreciates the latitude NEET students have to make the project their own.

“There was never the case of a professor saying, ‘We need to do it this way,’” he says. “I really liked that ability to learn as many things as you wanted to, and also have the autonomy to make your own design decisions along the way.”

“I just can’t make it tonight. You have fun without me.” Across much of the animal kingdom, when infection strikes, social contact shuts down. A new study details how the immune and central nervous systems implement this sickness behavior.

It makes perfect sense that when we’re battling an infection, we lose our desire to be around others. That protects others from getting sick and lets us get much-needed rest. What hasn’t been as clear is how this behavior change happens.

In new research published Nov. 25 in Cell, scientists at MIT’s Picower Institute for Learning and Memory and collaborators used multiple methods to demonstrate causally that when the immune system cytokine interleukin-1 beta (IL-1β) reaches the IL-1 receptor 1 (IL-1R1) on neurons in a brain region called the dorsal raphe nucleus, that activates connections with the intermediate lateral septum to shut down social behavior.

“Our findings show that social isolation following immune challenge is self-imposed and driven by an active neural process, rather than a secondary consequence of physiological symptoms of sickness, such as lethargy,” says study co-senior author Gloria Choi, associate professor in MIT’s Department of Brain and Cognitive Sciences and a member of the Picower Institute.

Jun Huh, Harvard Medical School associate professor of immunology, is the paper’s co-senior author. The lead author is Liu Yang, a research scientist in Choi’s lab.

A molecule and its receptor

Choi and Huh’s long collaboration has identified other cytokines that affect social behavior by latching on to their receptors in the brain, so in this study their team hypothesized that the same kind of dynamic might cause social withdrawal during infection. But which cytokine? And what brain circuits might be affected?

To get started, Yang and her colleagues injected 21 different cytokines into the brains of mice, one by one, to see if any triggered social withdrawal the same way that giving mice LPS (a standard way of simulating infection) did. Only IL-1β injection fully recapitulated the same social withdrawal behavior as LPS. That said, IL-1β also made the mice more sluggish.

IL-1β affects cells when it hooks up with the IL-1R1, so the team next went looking across the brain for where the receptor is expressed. They identified several regions and examined individual neurons in each. The dorsal raphe nucleus (DRN) stood out among regions, both because it is known to modulate social behavior and because it is situated next to the cerebral aqueduct, which would give it plenty of exposure to incoming cytokines in cerebrospinal fluid. The experiments identified populations of DRN neurons that express IL-1R1, including many involved in making the crucial neuromodulatory chemical serotonin.

From there, Yang and the team demonstrated that IL-1β activates those neurons, and that activating the neurons promotes social withdrawal. Moreover, they showed that inhibiting that neural activity prevented social withdrawal in mice treated with IL-1β, and they showed that shutting down the IL-1R1 in the DRN neurons also prevented social withdrawal behavior after IL-1β injection or LPS exposure. Notably, these experiments did not change the lethargy that followed IL-1β or LPS, helping to demonstrate that social withdrawal and lethargy occur through different means.

“Our findings implicate IL-1β as a primary effector driving social withdrawal during systemic immune activation,” the researchers wrote in Cell.

Tracing the circuit

With the DRN identified as the site where neurons receiving IL-1β drove social withdrawal, the next question was what circuit they effected that behavior change through. The team traced where the neurons make their circuit projections and found several regions that have a known role in social behavior. Using optogenetics, a technology that engineers cells to become controllable with flashes of light, the scientists were able to activate the DRN neurons’ connections with each downstream region. Only activating the DRN’s connections with the intermediate lateral septum caused the social withdrawal behaviors seen with IL-1β injection or LPS exposure.

In a final test, they replicated their results by exposing some mice to salmonella.

“Collectively, these results reveal a role for IL-1R1-expressing DRN neurons in mediating social withdrawal in response to IL-1β during systemic immune challenge,” the researchers wrote.

Although the study revealed the cytokine, neurons, and circuit responsible for social withdrawal in mice in detail and with demonstrations of causality, the results still inspire new questions. One is whether IL-1R1 neurons affect other sickness behaviors. Another is whether serotonin has a role in social withdrawal or other sickness behaviors.

In addition to Yang, Choi, and Huh, the paper’s other authors are Matias Andina, Mario Witkowski, Hunter King, and Ian Wickersham.

Funding for the research came from the National Institute of Mental Health, the National Research Foundation of Korea, the Denis A. and Eugene W. Chinery Fund for Neurodevelopmental Research, the Jeongho Kim Neurodevelopmental Research Fund, Perry Ha, the Simons Center for the Social Brain, the Simons Foundation Autism Research Initiative, The Picower Institute for Learning and Memory, and The Freedom Together Foundation.

In the brand new Planet Hollywood Poker Room, 48 digital rights supporters played No-Limit Texas Hold’Em in the 4th Annual EFF Benefit Poker Tournament at DEF CON, raising $18,395 for EFF.

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The tournament was hosted by EFF board member Tarah Wheeler and emceed by lintile, lending his Hacker Jeopardy hosting skills to help EFF for the day.

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Every table had two celebrity players with special bounties for the player that knocked them out of the tournament. This year featured Wendy Nather, Chris “WeldPond” Wysopal, Jake “MalwareJake” Williams, Bryson Bort, Kym “KymPossible” Price, Adam Shostack, and Dr. Allan Friedman.

Excellent poker player and teacher Jason Healey, Professor of International Affairs at Columbia University’s School of International and Public Affairs noted that “the EFF poker tournament is where you find all the hacker royalty in one room."

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The day started at with a poker clinic run by Tarah’s father, professional poker player Mike Wheeler. The hour-long clinic helped folks get brushed up on their casino literacy before playing the big game.

Mike told the story of first teaching Tarah to play poker with jellybeans when she was only four. He then taught poker noobs how to play and when to check, when to fold, and when to go all-in.

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After the clinic, lintile roused the crowd to play for real, starting the tournament off by announcing “Shuffle up and deal!”

The first hour saw few players get knocked out, but after the blinds began to rise, the field began to thin, with a number of celebrity knock outs.
At every knockout, lintile took to the mic to encourage the player to donate to EFF, which allowed them to buy back into the tournament and try their luck another round.

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Jay Salzberg knocked out Kym Price to win a l33t crate.

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Kim Holt knocked out Mike Wheeler, collecting the bounty on his head posted by Tarah, and winning a $250 donation to EFF in his name. This is the second time Holt has sent Mike home.

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Tarah knocked out Adam Shostack, winning a number of fun prizes, including a signed copy of his latest book, Threats: What Every Engineer Should Learn From Star Wars.

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Bryson Bort was knocked out by privacy attorney Marcia Hofmann.

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Play continued for three hours until only the final table of players remained: Allaen Friedman, Luke Hanley, Jason Healey, Kim Holt, Igor Ignatov, Sid, Puneet Thapliyal, Charles Thomas and Tarah Wheeler herself.

As blinds continues to rise, players went all-in more and more. The most exciting moment was won by Sid, tripling up with TT over QT and A8s, and then only a few hands later knocking out Tarah, who finished 8th.

For the first time, the Jellybean Trophy sat on the final table awaiting the winner. This year, it was a Seattle Space Needle filled with green and blue jellybeans celebrating the lovely Pacific Northwest where Tarah and Mike are from.

The final three players were Allen Friedman, Kim Holt and Syd. Sid doubled up with KJ over Holt’s A6, and then knocked Holt out with his Q4 beating Holt’s 22.

Friedman and Sid traded blinds until Allan went all in with A6 and Syd called with JT. A jack landed on the flop and Syd won the day!

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Sid becomes the first player to win the tournament more than once, taking home the jellybean trophy two years in a row.

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It was an exciting afternoon of competition raising over $18,000 to support civil liberties and human rights online. We hope you join us next year as we continue to grow the tournament. Follow Tarah and EFF to make sure we have chips and a chair for you at DEF CON 34.

Be ready for this next year’s special benefit poker event: The Digital Rights Attack Lawyers Edition! Our special celebrity guests will all be our favorite digital rights attorneys including Cindy Cohn, Marcia Hofmann, Kurt Opsahl, and more!

Photo Gallery

Concrete was the foundation of the ancient Roman empire. It enabled Rome’s storied architectural revolution as well as the construction of buildings, bridges, and aqueducts, many of which are still used some 2,000 years after their creation.

In 2023, MIT Associate Professor Admir Masic and his collaborators published a paper describing the manufacturing process that gave Roman concrete its longevity: Lime fragments were mixed with volcanic ash and other dry ingredients before the addition of water. Once water is added to this dry mix, heat is produced. As the concrete sets, this “hot-mixing” process traps and preserves the highly reactive lime as small, white, gravel-like features. When cracks form in the concrete, the lime clasts redissolve and fill the cracks, giving the concrete self-healing properties.

There was only one problem: The process Masic’s team described was different from the one described by the famed ancient Roman architect Vitruvius. Vitruvius literally wrote the book on ancient architecture. His highly influential work, “De architectura,” written in the 1st century B.C.E., is the first known book on architectural theory. In it, Vitruvius says that Romans added water to lime to create a paste-like material before mixing it with other ingredients.

“Having a lot of respect for Vitruvius, it was difficult to suggest that his description may be inaccurate,” Masic says. “The writings of Vitruvius played a critical role in stimulating my interest in ancient Roman architecture, and the results from my research contradicted these important historical texts.”

Now, Masic and his collaborators have confirmed that hot-mixing was indeed used by the Romans, a conclusion he reached by studying a newly discovered ancient construction site in Pompeii that was exquisitely preserved by the volcanic eruption of Mount Vesuvius in the year 79 C.E. They also characterized the volcanic ash material the Romans mixed with the lime, finding a surprisingly diverse array of reactive minerals that further added to the concrete’s ability to repair itself many years after these monumental structures were built.

“There is the historic importance of this material, and then there is the scientific and technological importance of understanding it,” Masic explains. “This material can heal itself over thousands of years, it is reactive, and it is highly dynamic. It has survived earthquakes and volcanoes. It has endured under the sea and survived degradation from the elements. We don’t want to completely copy Roman concrete today. We just want to translate a few sentences from this book of knowledge into our modern construction practices.”

The findings are described today in Nature Communications. Joining Masic on the paper are first authors Ellie Vaserman ’25 and Principal Research Scientist James Weaver, along with Associate Professor Kristin Bergmann, PhD candidate Claire Hayhow, and six other Italian collaborators.

Uncovering ancient secrets

Masic has spent close to a decade studying the chemical composition of the concrete that allowed Rome’s famous structures to endure for so much longer than their modern counterparts. His 2023 paper analyzed the material’s chemical composition to deduce how it was made.

That paper used samples from a city wall in Priverno in southwest Italy, which was conquered by the Romans in the 4th century B.C.E. But there was a question as to whether this wall was representative of other concrete structures built throughout the Roman empire.

The recent discovery by archaeologists of an active ancient construction site in Pompeii (complete with raw material piles and tools) therefore offered an unprecedented opportunity.

For the study, the researchers analyzed samples from these pre-mixed dry material piles, a wall that was in the process of being built, completed buttress and structural walls, and mortar repairs in an existing wall.

“We were blessed to be able to open this time capsule of a construction site and find piles of material ready to be used for the wall,” Masic says. “With this paper, we wanted to clearly define a technology and associate it with the Roman period in the year 79 C.E.”

The site offered the clearest evidence yet that the Romans used hot-mixing in concrete production. Not only did the concrete samples contain the lime clasts described in Masic’s previous paper, but the team also discovered intact quicklime fragments pre-mixed with other ingredients in a dry raw material pile, a critical first step in the preparation of hot-mixed concrete.

Bergman, an associate professor of earth and planetary sciences, helped develop tools for differentiating the materials at the site.

“Through these stable isotope studies, we could follow these critical carbonation reactions over time, allowing us to distinguish hot-mixed lime from the slaked lime originally described by Vitruvius,” Masic says. “These results revealed that the Romans prepared their binding material by taking calcined limestone (quicklime), grinding them to a certain size, mixing it dry with volcanic ash, and then eventually adding water to create a cementing matrix.”

The researchers also analyzed the volcanic ingredients in the cement, including a type of volcanic ash called pumice. They found that the pumice particles chemically reacted with the surrounding pore solution over time, creating new mineral deposits that further strengthened the concrete.

Rewriting history

Masic says the archaeologists listed as co-authors on the paper were indispensable to the study. When Masic first entered the Pompeii site, as he inspected the perfectly preserved work area, tears came to his eyes.

“I expected to see Roman workers walking between the piles with their tools,” Masic says. “It was so vivid, you felt like you were transported in time. So yes, I got emotional looking at a pile of dirt. The archaeologists made some jokes.”

Masic notes that calcium is a key component in both ancient and modern concretes, so understanding how it reacts over time holds lessons for understanding dynamic processes in modern cement as well. Towards these efforts, Masic has also started a company, DMAT, that uses lessons from ancient Roman concrete to create long-lasting modern concretes.

“This is relevant because Roman cement is durable, it heals itself, and it’s a dynamic system,” Masic says. “The way these pores in volcanic ingredients can be filled through recrystallization is a dream process we want to translate into our modern materials. We want materials that regenerate themselves.”

As for Vitruvius, Masic guesses that he may have been misinterpreted. He points out that Vitruvius also mentions latent heat during the cement mixing process, which could suggest hot-mixing after all.

The work was supported, in part, by the MIT Research Support Commmittee (RSC) and the MIT Concrete Sustainability Hub.

Two competing arguments are making the rounds. The first is by a neurosurgeon in the New York Times. In an op-ed that honestly sounds like it was paid for by Waymo, the author calls driverless cars a “public health breakthrough”:

In medical research, there’s a practice of ending a study early when the results are too striking to ignore. We stop when there is unexpected harm. We also stop for overwhelming benefit, when a treatment is working so well that it would be unethical to continue giving anyone a placebo. When an intervention works this clearly, you change what you do...

The administration said it will no longer fight a legal claim that DOE broke transparency laws to support repeal of the endangerment finding.

The agency revamped its webpages to feature natural causes of rising temperatures such as the Earth’s orbit.

The decision called the president's order unlawful, as the administration failed to explain why it halted onshore and offshore wind authorizations.

Traffic and air pollution both have decreased, new research shows.

Both candidates have criticized a multimillion-dollar effort to protect the city from flooding.

The Commerce, Science and Transportation Committee also approved President Donald Trump's Coast Guard pick.

Repurposing fossil fuel subsidies and pricing carbon pollution are among the steps called for in the major report.

An EU proposal would prohibit the use of labels such as “veggie burger” or “vegan sausage” for plant-based and lab-grown dishes.

There were 52 wildfires burning across New South Wales on Monday, and nine remained out of control.

Asian nations will need $4 trillion for water and sanitation between 2025 and 2040 — about $250 billion a year, says one report.

The Pointe-au-Chien Indian Tribe and other Indigenous people are fighting to adapt as the coastline retreats.

When it comes to brain function, neurons get a lot of the glory. But healthy brains depend on the cooperation of many kinds of cells. The most abundant of the brain’s non-neuronal cells are astrocytes, star-shaped cells with a lot of responsibilities. Astrocytes help shape neural circuits, participate in information processing, and provide nutrient and metabolic support to neurons. Individual cells can take on new roles throughout their lifetimes, and at any given time, the astrocytes in one part of the brain will look and behave differently than the astrocytes somewhere else.

After an extensive analysis by researchers at MIT, neuroscientists now have an atlas detailing astrocytes’ dynamic diversity. Its maps depict the regional specialization of astrocytes across the brains of both mice and marmosets — two powerful models for neuroscience research — and show how their populations shift as brains develop, mature, and age. 

The open-access study, reported in the Nov. 20 issue of the journal Neuron, was led by Guoping Feng, the James W. (1963) and Patricia T. Poitras Professor of Brain and Cognitive Sciences at MIT. This work was supported by the Hock E. Tan and K. Lisa Yang Center for Autism Research, part of the Yang Tan Collective at MIT, and the National Institutes of Health’s BRAIN Initiative.

“It’s really important for us to pay attention to non-neuronal cells’ role in health and disease,” says Feng, who is also the associate director of the McGovern Institute for Brain Research and the director of the Hock E. Tan and K. Lisa Yang Center for Autism Research at MIT. And indeed, these cells — once seen as mere supporting players — have gained more of the spotlight in recent years. Astrocytes are known to play vital roles in the brain’s development and function, and their dysfunction seems to contribute to many psychiatric disorders and neurodegenerative diseases. “But compared to neurons, we know a lot less — especially during development,” Feng adds.

Probing the unknown

Feng and Margaret Schroeder, a former graduate student in his lab, thought it was important to understand astrocyte diversity across three axes: space, time, and species. They knew from earlier work in the lab, done in collaboration with Steve McCarroll’s lab at Harvard University and led by Fenna Krienen in his group, that in adult animals, different parts of the brain have distinctive sets of astrocytes.

“The natural question was, how early in development do we think this regional patterning of astrocytes starts?” Schroeder says.

To find out, she and her colleagues collected brain cells from mice and marmosets at six stages of life, spanning embryonic development to old age. For each animal, they sampled cells from four different brain regions: the prefrontal cortex, the motor cortex, the striatum, and the thalamus.

Then, working with Krienen, who is now an assistant professor at Princeton University, they analyzed the molecular contents of those cells, creating a profile of genetic activity for each one. That profile was based on the mRNA copies of genes found inside the cell, which are known collectively as the cell’s transcriptome. Determining which genes a cell is using, and how active those genes are, gives researchers insight into a cell’s function and is one way of defining its identity.

Dynamic diversity

After assessing the transcriptomes of about 1.4 million brain cells, the group focused in on the astrocytes, analyzing and comparing their patterns of gene expression. At every life stage, from before birth to old age, the team found regional specialization: astrocytes from different brain regions had similar patterns of gene expression, which were distinct from those of astrocytes in other brain regions.

This regional specialization was also apparent in the distinct shapes of astrocytes in different parts of the brain, which the team was able to see with expansion microscopy, a high-resolution imaging method developed by McGovern colleague Edward Boyden that reveals fine cellular features.

Notably, the astrocytes in each region changed as animals matured. “When we looked at our late embryonic time point, the astrocytes were already regionally patterned. But when we compare that to the adult profiles, they had completely shifted again,” Schroeder says. “So there’s something happening over postnatal development.” The most dramatic changes the team detected occurred between birth and early adolescence, a period during which brains rapidly rewire as animals begin to interact with the world and learn from their experiences.

Feng and Schroeder suspect that the changes they observed may be driven by the neural circuits that are sculpted and refined as the brain matures. “What we think they’re doing is kind of adapting to their local neuronal niche,” Schroeder says. “The types of genes that they are up-regulating and changing during development points to their interaction with neurons.” Feng adds that astrocytes may change their genetic programs in response to nearby neurons, or alternatively, they might help direct the development or function of local circuits as they adopt identities best suited to support particular neurons.

Both mouse and marmoset brains exhibited regional specialization of astrocytes and changes in those populations over time. But when the researchers looked at the specific genes whose activity defined various astrocyte populations, the data from the two species diverged. Schroeder calls this a note of caution for scientists who study astrocytes in animal models, and adds that the new atlas will help researchers assess the potential relevance of findings across species.

Beyond astrocytes

With a new understanding of astrocyte diversity, Feng says his team will pay close attention to how these cells are impacted by the disease-related genes they study and how those effects change during development. He also notes that the gene expression data in the atlas can be used to predict interactions between astrocytes and neurons. “This will really guide future experiments: how these cells’ interactions can shift with changes in the neurons or changes in the astrocytes,” he says.

The Feng lab is eager for other researchers to take advantage of the massive amounts of data they generated as they produced their atlas. Schroeder points out that the team analyzed the transcriptomes of all kinds of cells in the brain regions they studied, not just astrocytes. They are sharing their findings so researchers can use them to understand when and where specific genes are used in the brain, or dig in more deeply to further to explore the brain’s cellular diversity.