Category: The Conversation – USA

Source: The Conversation – USA (2) – By James R. Elliott, Professor of Sociology, Rice University

Dangerous flooding has damaged neighborhoods in almost every state in 2025, leaving homes a muddy mess. In several hard-hit areas, it wasn’t the first time homeowners found themselves tearing out wet wallboard and piling waterlogged carpet by the curb.

Wanting to rebuild after flooding is a common response. But for some people, the best way to stay in their community, adapt to the changing climate and recover from disasters is to do what humans have done for millennia: move.

Researchers expect millions of Americans to relocate from properties facing increasing risks of flood, fire and other kinds of disasters in the years ahead.

What people do with those high-risk properties can make their community more resilient or leave it vulnerable to more damage in future storms.

We study flood resilience and have been mapping the results of government buyout programs across the U.S. that purchase damaged homes after disasters to turn them into open space.

Our new national maps of who relocates and where they go after a flood shows that most Americans who move from buyout areas stay local. However, we also found that the majority of them give up their home to someone else, either selling it or leaving a rental home, rather than taking a government buyout offer. That transfers the risk to a new resident, leaving the community still facing future costly risks.

FEMA’s buyout program at risk

Government buyout programs can help communities recover after disasters by purchasing high-risk homes and demolishing them. The parcel is then converted to a natural flood plain, park or site for new infrastructure to mitigate future flood damage for nearby areas.

FEMA has been funding such efforts for decades through its property buyout program. It has invested nearly US$4 billion to purchase and raze approximately 45,000 flood-prone homes nationwide, most of them since 2001.

Those investments pay off: Research shows the program avoids an estimated $4 to $6 in future disaster recovery spending for every $1 invested. In return, homeowners receive a predisaster price for their home, minus any money they might receive from a related flood insurance payout on the property.

But this assistance is now in jeopardy as the Trump administration cuts FEMA staff and funding and the president talks about dismantling the agency. From March to September, governors submitted 42 applications for funding from FEMA’s Hazard Mitigation Grant Program, which includes buyouts – all were denied or left pending as of mid-September.

Our recommendation after studying this program is to mend it, not end it. If done right, buyouts can help maintain local ties and help communities build more sustainable futures together.

Buyouts vs. selling homes in damaged areas

Our team at Rice University’s Center for Coastal Futures and Adaptive Resilience developed an interactive mapping tool to show where buyout participants and neighbors living within a half-mile of them moved after FEMA initiates a buyout program in their area.

The maps were created using individual data, down to the address level, from 2007 to 2017, across more than 550 counties where FEMA’s buyout program operated nationally.

Zoomed out, they show just how many places the program has helped across the U.S., from coastal cities to inland towns. And, when zoomed in, they reveal the buyout locations and destinations of more than 70,000 residents who moved following FEMA-funded buyouts in their area.

The maps also show which people relocated by accepting a federal buyout and which ones relocated on their own. Nationwide, we see the vast majority of movers, about 14 out of every 15, are not participants in the federal buyout program. They are neighbors who relocated through conventional real estate transactions.

This distinction matters, because it implies that most Americans are retreating from climate-stressed areas by transferring their home’s risk to someone else, not by accepting buyouts that would take the property out of circulation.

Selling may be good for homeowners who can find buyers, but it doesn’t make the community more resilient.

Lessons for future buyout programs

Our interactive map offers some good news and insights for buyout programs going forward.

Regardless of how they occur, we find that moves from buyout areas average just 5 to 10 miles from old to new home. This means most people are maintaining local ties, even as they relocate to adapt to rising climate risks.

Nearly all of the moves also end in safer homes with minimal to minor risk of future flooding. We checked using address-level flood factors from the First Street Foundation, a nonprofit source of flood risk ratings that are now integrated into some online real estate websites.

But many homes in risky areas are still being resold or rented to new residents, leaving communities facing a game of climate roulette.

How long that can continue will vary by neighborhood. Rising insurance costs, intensifying storms and growing awareness of flood risks are already dampening home sales in some communities − and thus opportunities to simply hand over one’s risk to someone else and move on.

The U.S. can create safer communities by expanding federal, state and local voluntary buyout programs. These programs allow communities to reduce future flood damage and collectively plan for safer uses of the vacated lands that emerge.

Giving residents longer periods of time to participate after the damage could also help make the programs more attractive. This would provide property owners more flexibility in deciding when to sell and demolish their property, while still taking risky property off the market rather than handing the risk to new residents.

James R. Elliott has received funding from the National Science Foundation.

Debolina Banerjee does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. FEMA buyouts vs. risky real estate: New maps reveal post-flood migration patterns across the US – https://theconversation.com/fema-buyouts-vs-risky-real-estate-new-maps-reveal-post-flood-migration-patterns-across-the-us-262211

Source: The Conversation – USA (2) – By Tom Duszynski, Clinical Assistant Professor of Epidemiology, Indiana University

Imagine a city street at dusk, silent save for the rising sound of a collective guttural moan. Suddenly, a horde of ragged, bloodied creatures appear, their feet shuffling along the pavement, their hollow eyes locked on fleeing figures ahead.

A classic movie monster, the zombie surged in popularity in the 21st century during a time of global anxiety – the Great Recession, the specter of climate change, the lingering trauma of the 9/11 terrorist attacks and the COVID-19 pandemic.

The zombie apocalypse became a way for people to explore the terrifying concept of societal collapse, a step removed from real threats such as nuclear war or global financial disaster.

As a public health epidemiologist and an amateur zombie historian, I couldn’t help but notice the striking parallels between what epidemiologists do to stop infectious disease outbreaks and what horror movie heroes do to stop zombies. The key questions posed in any zombie narrative – how did this start, how many are infected, how to contain it – are the identical questions that epidemiologists ask during a real infectious disease outbreak or pandemic.

In 2011, in fact, the Centers for Disease Control and Prevention published a zombie apocalypse preparedness guide that explained how readying oneself for a zombie apocalypse can prepare people for any large-scale disaster. The zombie is more than just a monster; it is a powerful, public health teaching tool.

Zombies in ancient history

The idea of the reanimated dead has been part of human history for millennia, showing up across cultures and long before modern germ theory or epidemiology existed. These creatures were often a way for societies to understand and explain the natural world and disease transmission in the absence of scientific knowledge.

The oldest written reference to creatures similar to modern zombies is found in “The Epic of Gilgamesh,” which was etched on stone tablets sometime between 2000 and 1100 B.C.E. Enraged after Gilgamesh rejects her marriage proposal, the goddess Ishtar tells him, “I shall bring up the dead to consume the living, I shall the make the dead outnumber the living.” This ancient terror – the dead overwhelming the living – has a direct parallel to the concept of an out-of-control epidemic in which the sick quickly overwhelm the healthy. Hollywood has readily adopted this concept in many zombie movies.

The origins of the flesh-eating corpse on screen date back to George Romero’s 1968 classic “The Night of the Living Dead.” You won’t hear the word “zombie” in Romero’s film, however – in the script, he called the creatures “flesh eaters.” Similarly, in Danny Boyle’s 2002 film “28 Days Later,” the terrifying creatures were called the “infected.” Both these terms, “flesh eaters” and “infected,” directly echo public health concerns – specifically, the spread of disease via a bacteria or virus and the need for quarantine to contain the afflicted.

The roots of the word zombie arefor the Haitian variety. thought to stretch back to West Africa and to words such as “nzambi,” which means “creator” in African Kongo, or “ndzumbi,” which means “corpse” in the Mitsogo language of Gabon. However, it was in Haitian Vodou, a religion that draws from the West African spiritual traditions among people who were enslaved on Haiti’s plantations, that the concept took its most terrifying form.

According to Vodou, when a person experiences an unnatural, early death, priests can capture and co-opt their soul. Slave owners capitalized on this belief to prevent suicide among the enslaved. To become a zombie – dead yet still a slave – was the ultimate nightmare. This cultural concept speaks not just to disease but to societal trauma and the public health crisis of forced labor.

Zombie-like creatures around the world

Across the globe, other reanimated corpses crop up in local folklore, often reflecting fears of improper burial, violent death or moral wickedness. Many tales about these eerie creatures don’t just convey how to avoid becoming one of them, but also detail how to stop or prevent them from taking over. This focus on prevention and control is at the heart of public health.

During the expansion of China’s Qing dynasty, which took place between 1644 and 1911, a creature known as the jiangshi, or “hopping zombie,” emerged amid widespread unrest and integration of non-Chinese minorities. The jiangshi were corpses suffering from rigor mortis and decomposition, reanimated when a soul couldn’t leave after a violent death. Instead of staggering, these mythological creatures would hop, and their method of attack was to steal a person’s lifeforce, or qi.

Fear of a lonely, restless afterlife led families who lost a loved one far from home to hire a Taoist priest to retrieve the body for proper burial with ancestors.

In Scandinavia, the draugr – meaning “again walker” or “ghost” – was a creature bent on revenge. According to lore, draugrs typically emerged from mean-spirited people or improperly buried corpses. Like zombies, they could turn regular people into draugrs by infecting them. They would attack their victims by devouring flesh, drinking blood or driving victims insane. Draugrs’ contagious nature is a model for disease transmission. What’s more, their seasonal activity – they most often appear at night in winter months – is similar to seasonal trends in infectious disease transmission.

In medieval times, meanwhile, legend had it that creatures called revenants – corpses that came out of their graves – stalked northern and western Europe. According to 12th-century English historian William of Newburgh, these creatures emerged from the lingering life force of people who had committed evil deeds during their lives or who experienced a sudden death. Clerics fueled people’s fears of becoming a revenant by claiming these creatures were created by Satan. The recommended but gruesome prevention method for this fate was to capture and dismember these creatures and to burn the body parts, especially the head.

Archaeological evidence from a medieval village in England suggests that communities heeded this advice. Archaeologists excavated the village’s burial grounds, and among human remains from the 11th to 13th centuries they found broken and burned bones with knife marks. They show how a community may have taken extreme measures to control a perceived contagion or threat to public safety, mirroring a modern-day quarantine or eradication protocols.

Perhaps the most striking similarity between these historical monsters and Hollywood zombies is that so many of them are created by an infectious agent of some kind. After an outbreak occurs, control is difficult to regain, underscoring the necessity of a rapid public health response.

Tom Duszynski does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Zombies, jiangshi, draugrs, revenants − monster lore is filled with metaphors for public health – https://theconversation.com/zombies-jiangshi-draugrs-revenants-monster-lore-is-filled-with-metaphors-for-public-health-261448

Source: The Conversation – USA – By Stephanie A. (Sam) Martin, Frank and Bethine Church Endowed Chair of Public Affairs, Boise State University

For decades, federal shutdowns have mostly been budget fights. The 2025 one has become bigger than that: It’s turned into a messaging war.

Official government communications, including website banners, out-of-office email replies and autogenerated responses that denounce “Senate Democrats,” “the Radical Left” or “Democrats’ $1.5 trillion wishlist” for closing the government, mark a sharp break from past practice.

These messages are more than rhetorical escalation. Many may violate the Hatch Act, the 1939 statute that limits partisan political activity by federal employees and agencies. They also represent new tests for how far a White House can push the bounds of campaign-style messaging while also claiming to govern.

In any democracy, power lies not only in who writes the laws or signs the budgets but in who shapes the story. Communication is not an afterthought or byproduct of governance. It is one of its essential instruments. Political narrative helps citizens understand who’s responsible, who’s acting in good faith and who’s to blame.

The 2025 shutdown has turned that truth into strategy. Federal communication systems – agency websites, automated emails and public information portals – are being used to persuade rather than inform. It’s a move that is both politically risky and legally perilous.

Serve the public, not a party

The Hatch Act was passed during the Great Depression, after years of concern that federal agencies were being used improperly as political machines. Its goal was simple: to ensure that public servants worked for the American people, not for the party in power.

At its core, the Hatch Act prohibits executive branch federal employees – except for the president and vice president – from engaging in partisan political activity as part of their official duties or under their official authority. Government workers may not use their positions or public resources to influence elections, coerce individual behavior or engage in political advocacy.

The law requires federal agencies to avoid the partisan fray and focus on serving the public rather than political agendas.

The Office of Special Counsel, which enforces the law, has been clear on this point. “The purpose of the Act,” says an Office of Special Counsel guide written for federal employees, “is to maintain a federal workforce that is free from partisan political influence or coersion.” Government communication can inform, but it cannot campaign.

Yet the shutdown has already produced multiple potential violations:

• The Department of Education, according to a lawsuit, altered employees’ email auto-responses – without consent – to say things like “the Democrats have shut the government down.” Such changes do more than convey impartial information. They compel employees to align themselves with institutionally imposed scripts.

• Likewise, agencies including Health and Human Services and the Small Business Administration reportedly distributed or directed staff to adopt partisan out-of-office auto-replies assigning blame to Democrats.

• The Department of Housing and Urban Development posted a banner on its official website stating that the “Radical Left are going to shut down the government.”

Taken individually, each incident might provoke a Hatch Act complaint. Collectively, they amount to a systematic campaign to transform nonpartisan federal agencies into partisan political messengers.

Why this is unprecedented

What sets the 2025 messaging apart isn’t just its volume – it’s the scale, the coordination and the brazenness of its political targeting.

In past shutdowns, partisan spin lived mostly in press conferences and campaign talking points. Agencies themselves, even under pressure, stayed neutral.

This time, the administration is using the machinery of government to deliver partisan blame.

The timing and similarity of messages across departments seems coordinated. Housing and Urban Development posted a banner blaming Democrats the day before the shutdown began. Within hours, other agencies followed using nearly identical language.

More troubling are the reported changes to federal employees’ auto-replies without their consent.

These missives forced career civil servants, many of them furloughed, to become unwilling messengers for partisan ends. Federal agencies and their workers are supposed to serve everyone, not only those who support the party in power.

And because the watchdogs who could enforce the legal boundary are also sidelined – the Office of Special Counsel is furloughed – complaints have nowhere to go, at least for now. They simply land in unattended email inboxes.

Legal challenges and limits

Whether shutdown communications truly violate the Hatch Act – or related laws – is not yet clear. The administration could argue that it’s not campaigning but merely explaining why services are suspended. As a scholar of political communication and American democracy, I believe that defense weakens when official messages explicitly assign partisan blame or name a political party.

And not every political statement is a Hatch Act violation. The law allows employees to express views off duty or in private contexts, so long as they use their own phones and computers.

Even if the Office of Special Counsel later finds violations, harm will likely persist. Once messages are posted or auto-replies sent, their effects can’t always be undone. And because ethics officials are furloughed, too, accountability will be delayed, if it comes at all.

Some employees are likely to claim their speech rights were violated by being forced to send partisan messages. This is an argument already at the heart of the lawsuit filed by the American Federation of Government Employees against the Education Department.

Why this matters

Federal agencies exist to administer laws impartially and to do so on behalf of the people.

When the government uses its own infrastructure for partisan messaging, the very neutrality on which democratic governance depends erodes. It dilutes public trust in the idea of a neutral state.

The damage also extends into the future. If the current administration succeeds in turning its administrative machinery into a political weapon, without consequence, a precedent will be created. Future presidents may be tempted to follow suit, making acceptable the use of taxpayer-funded systems as campaign tools.

And because enforcement bodies such as the Office of Special Counsel also are sidelined during a shutdown, accountability has to wait. That creates an asymmetry of power: One side gets to amplify its message through government channels in real time, while its opponents must wait for the system to restart just to file a complaint. By the time they can, the moment will have passed and the political narrative is likely to have already hardened.

Crises demand explanation, even blame. Citizens expect their leaders to tell them what went wrong. But they also expect honesty and fairness in how that story is told. The administration’s messaging strategy during this shutdown tests whether government communication remains a public service or becomes another instrument of political power.

Stephanie A. (Sam) Martin does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. When government websites become campaign tools: Blaming the shutdown on Democrats has legal and political risks – https://theconversation.com/when-government-websites-become-campaign-tools-blaming-the-shutdown-on-democrats-has-legal-and-political-risks-267086

Source: The Conversation – USA – By Andrew Guthrie Ferguson, Professor of Law, George Washington University

Police are getting a boost from artificial intelligence, with algorithms now able to draft police reports in minutes. The technology promises to make police reports more accurate and comprehensive, as well as save officers time.

The idea is simple: Take the audio transcript from a body camera worn by a police officer and use the predictive text capabilities of large language models to write a formal police report that could become the basis of a criminal prosecution. Mirroring other fields that have allowed ChatGPT-like systems to write on behalf of people, police can now get an AI assist to automate much dreaded paperwork.

The catch is that instead of writing the first draft of your college English paper, this document can determine someone’s liberty in court. An error, omission or hallucination can risk the integrity of a prosecution or, worse, justify a false arrest. While police officers must sign off on the final version, the bulk of the text, structure and formatting is AI-generated.

Who – or what – wrote it

Up until October 2025, only Utah had required that police even admit they were using an AI assistant to draft their reports. On Oct. 10, that changed when California became the second state to require transparent notice that AI was used to draft a police report.

Governor Gavin Newsom signed SB 524 into law, requiring all AI-assisted police reports to be marked as being written with the help of AI. The law also requires law enforcement agencies to maintain an audit trail that identifies the person who used AI to create a report and any video and audio footage used in creating the report. It also requires agencies to retain the first draft created with AI for as long as the official report is retained, and prohibits a draft created with AI from constituting an officer’s official statement.

The law is a significant milestone in the regulation of AI in policing, but its passage also signifies that AI is going to become a major part of the criminal justice system.

If you are sitting behind bars based on a police report, you might have some questions. The first question that Utah and California now answer is “Did AI write this?” Basic transparency that an algorithm helped write an arrest report might seem the minimum a state could do before locking someone up. And, even though leading police technology companies like Axon recommend such disclaimers be included in their reports, they are not required.

Police departments in Lafayette, Indiana and Fort Collins, Colorado, were intentionally turning off the transparency defaults on the AI report generators, according to an investigative news report. Similarly, police chiefs using Axon’s Draft One products did not even know which reports were drafted by AI and which were not because the officers were just cutting and pasting the AI narrative into reports they indicated they wrote themselves. The practice bypassed all AI disclaimers and audit trails.

Many questions

Transparency is only the first step. Understanding the risks of relying on AI for police reports is the second.

Technological questions arise about how the AI models were trained and the possible biases baked into a reliance on past police reports. Transcription questions arise about errors, omissions and mistranslations because police stops take place in chaotic, loud and frequently emotional contexts amid a host of languages.

Finally, trial questions arise about how an attorney is supposed to cross-examine an AI-generated document, or whether the audit logs need to be retained for expert analysis or turned over to the defense.

Risks and consequences

The significance of the California law is not simply that the public needs to be aware of AI risks, but that California is embracing AI risk in policing. I believe it’s likely that people will lose their liberty based on a document that was largely generated by AI and without the hard questions satisfactorily answered.

Worse, in a criminal justice system that relies on plea bargaining for more than 95% of cases and is overwhelmingly dominated by misdemeanor offenses, there may never be a chance to check whether the AI report accurately captured the scene. In fact, in many of those lower-level cases, the police report will be the basis of charging decisions, pretrial detention, motions, plea bargains, sentencing and even probation revocations.

I believe that a criminal legal system that relies so heavily on police reports has a responsibility to ensure that police departments are embracing not just transparency but justice. At a minimum, this means more states following Utah and California to pass laws regulating the technology, and police departments following the best practices recommended by the technology companies.

But even that may not be enough without critical assessments by courts, legal experts and defense lawyers. The future of AI policing is just starting, but the risks are already here.

Andrew Guthrie Ferguson does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Concerns about AI-written police reports spur states to regulate the emerging practice – https://theconversation.com/concerns-about-ai-written-police-reports-spur-states-to-regulate-the-emerging-practice-267410

Source: The Conversation – USA – By Uwe Bergmann, Professor of Ultrafast X-Ray Science, University of Wisconsin-Madison

X-ray beams aren’t used just by doctors to see inside your body and tell whether you have a broken bone. More powerful beams made up of very short flashes of X-rays can help scientists peer into the structure of individual atoms and molecules and differentiate types of elements.

But getting an X-ray laser beam that delivers super short flashes to capture the fastest processes in nature isn’t easy – it’s a whole science in itself.

Radio waves, microwaves, the visible light you can see, ultraviolet light and X-rays are all exactly the same phenomenon: electromagnetic waves of energy moving through space. What differentiates them is their wavelength. Waves in the X-ray range have short wavelengths, while radio waves and microwaves are much longer. Different wavelengths of light are useful for different things – X-rays help doctors take snapshots of your body, while microwaves can heat up your lunch.

Optical lasers are devices that emit parallel, or collimated, beams of light. They send out a beam where all the waves have the same wavelength – the red light you get from a laser pointer is one example – and oscillate in synchronicity.

Over the past 15 years, scientists have built X-ray free-electron lasers, which instead of emitting beams of visible light emit X-rays. They are housed in large facilities where electrons travel through a long accelerator – depending on the facility, between a few hundred meters and 1,700 yards – and after passing through a series of thousands of magnets they generate extremely short and powerful X-ray pulses.

The pulses are used kind of like flash photography, where the flash – the X-ray pulse – is short enough to capture the fast movement of an object. Researchers have used them as cameras to study how atoms and molecules move and change inside materials or cells.

But while these X-ray free-electron laser pulses are very short and powerful, they’re not the shortest pulses that scientists can make with lasers. By using more advanced technology and taking advantage of the properties some materials have, researchers can create even shorter pulses: in the attosecond region.

One attosecond is one-billionth of a billionth of a second. An attosecond is to one second about what one second is to the 14 billion-year age of the universe. The fastest processes in atoms and molecules happen at the attosecond scale: For instance, it takes electrons attoseconds to move around inside a molecule.

We’re physicists who work with X-ray free-electron lasers. We study what happens when we put different types of materials in the X-ray free-electron pulses’ path. In a new experiment we put copper and manganese samples in the path of highly focused X-ray free-electron laser pulses. We knew the interactions between these elements and the X-ray free-electron laser pulses would generate new X-ray laser pulses.

Originally, we wanted to find out how different chemical forms of the element manganese – for example, manganese-II and manganese-VII – would create small changes in the wavelengths of these newly generated X-ray laser pulses.

But along the way, we found some unexpected results that made the newly generated X-ray laser pulses act strangely. At first, we did not understand why, but when we eventually figured it out, we realized that we had discovered two unique laser phenomena, and that these effects had helped us generate X-ray laser pulses that where much shorter than we’d expected – shorter than the fastest X-ray pulses ever previously generated.

Filamentation – irregular spurts

We found that our new X-ray laser pulses weren’t always shooting out in the forward direction, as we expected. When we increased the intensity of the X-ray free-electron laser pulses, the resulting new X-ray laser pulses spurted out irregularly, in slightly different directions.

For optical lasers, these irregular spurts – or filamentation – result from the index of refraction changing in the laser material. But we didn’t expect to see this effect for X-rays, since materials – including the manganese and copper we used – don’t refract X-rays very much.

However, the high intensity X-ray free-electron laser pulses we used generated the fluctuations at the quantum level in our materials that led to these irregular spurts.

Rabi cycling – a broad spectrum of light

Even more surprising than the filamentation effects we saw was the fact that the X-ray pulses we generated contained a variety of different wavelengths that were more spread out than what we expected to see with the materials we used.

Seventy years ago – five years before the first optical laser was built – physicists Stanley Autler and Charles Townes discovered a strange phenomenon in microwaves known as Rabi cycling. And the spread of wavelengths we saw looked just like Rabi cycling.

Autler and Townes knew that when light hit an atom, the atom would absorb its energy by exciting an electron from one energy level to a higher one. The hole left by that missing electron is filled by an electron that’s coming down from a higher energy level in the atom and releasing – or emitting – this energy difference as light.

What Autler and Townes found was that when the microwaves are very intense, the strong electric field can split each of these energy levels into two distinct levels, called doublets, which have slightly different energies.

These doublets are separated by an energy, or a frequency, known as the Rabi frequency. The Rabi frequency depends on the intensity of the new light. The stronger it is, the larger is the energy separation.

In Autler and Townes’ discovery of Rabi cycling, they used microwaves. The energy splitting was so small that the Rabi frequency was very low, at radio wave frequencies.

In this new study we used X-rays, which have 100 million times shorter wavelengths than microwaves and 100 million times more energy. This meant the resulting new X-ray laser pulses were split into different X-ray wavelengths corresponding to Rabi frequencies in the extreme ultraviolet region. Ultraviolet light has a frequency 100 million times higher than radio waves.

This Rabi cycling effect allowed us to generate the shortest high-energy X-ray pulses to date, clocking in at 60-100 attoseconds.

Future directions and applications

While the pulses that X-ray free-electron lasers currently generate allow researchers to observe atomic bonds forming, rearranging and breaking, they are not fast enough to look inside the electron cloud that generates such bonds. Using these new attosecond X-ray laser pulses could allow scientists to study the fastest processes in materials at the atomic-length scale and to discern different elements.

In the future, we also hope to use much shorter X-ray free-electron laser pulses to better generate these attosecond X-ray pulses. We are even hoping to generate pulses below 60 attoseconds by using heavier materials with shorter lifespans, such as tungsten or hafnium. These new X-ray pulses are fast enough to eventually enable scientists to answer questions such as how exactly an electron cloud moves around and what a chemical bond actually is.

Uwe Bergmann receives funding from the Department of Energy and has previously worked at SLAC and Lawrence Berkeley National Laboratory.

Thomas Linker receives funding from the Department of Energy and works at SLAC National Accelerator Laboratory.

– ref. Our team of physicists inadvertently generated the shortest X-ray pulses ever observed – https://theconversation.com/our-team-of-physicists-inadvertently-generated-the-shortest-x-ray-pulses-ever-observed-258776

Source: The Conversation – USA – By Randy Stein, Associate Professor of Marketing, California State Polytechnic University, Pomona

Why do some people endorse claims that can easily be disproved? It’s one thing to believe false information, but another to actively stick with something that’s obviously wrong.

Our new research, published in the Journal of Social Psychology, suggests that some people consider it a “win” to lean in to known falsehoods.

We are social psychologists who study political psychology and how people reason about reality. During the pandemic, we surveyed 5,535 people across eight countries to investigate why people believed COVID-19 misinformation, like false claims that 5G networks cause the virus.

The strongest predictor of whether someone believed in COVID-19-related misinformation and risks related to the vaccine was whether they viewed COVID-19 prevention efforts in terms of symbolic strength and weakness. In other words, this group focused on whether an action would make them appear to fend off or “give in” to untoward influence.

This factor outweighed how people felt about COVID-19 in general, their thinking style and even their political beliefs.

Our survey measured it on a scale of how much people agreed with sentences including “Following coronavirus prevention guidelines means you have backed down” and “Continuous coronavirus coverage in the media is a sign we are losing.” Our interpretation is that people who responded positively to these statements would feel they “win” by endorsing misinformation – doing so can show “the enemy” that it will not gain any ground over people’s views.

When meaning is symbolic, not factual

Rather than consider issues in light of actual facts, we suggest people with this mindset prioritize being independent from outside influence. It means you can justify espousing pretty much anything – the easier a statement is to disprove, the more of a power move it is to say it, as it symbolizes how far you’re willing to go.

When people think symbolically this way, the literal issue – here, fighting COVID-19 – is secondary to a psychological war over people’s minds. In the minds of those who think they’re engaged in them, psychological wars are waged over opinions and attitudes, and are won via control of belief and messaging. The U.S. government at various times has used the concept of psychological war to try to limit the influence of foreign powers, pushing people to think that literal battles are less important than psychological independence.

By that same token, vaccination, masking or other COVID-19 prevention efforts could be seen as a symbolic risk that could “weaken” one psychologically even if they provide literal physical benefits. If this seems like an extreme stance, it is – the majority of participants in our studies did not hold this mindset. But those who did were especially likely to also believe in misinformation.

In an additional study we ran that focused on attitudes around cryptocurrency, we measured whether people saw crypto investment in terms of signaling independence from traditional finance. These participants, who, like those in our COVID-19 study, prioritized a symbolic show of strength, were more likely to believe in other kinds of misinformation and conspiracies, too, such as that the government is concealing evidence of alien contact.

In all of our studies, this mindset was also strongly associated with authoritarian attitudes, including beliefs that some groups should dominate others and support for autocratic government. These links help explain why strongman leaders often use misinformation symbolically to impress and control a population.

Why people endorse misinformation

Our findings highlight the limits of countering misinformation directly, because for some people, literal truth is not the point.

For example, President Donald Trump incorrectly claimed in August 2025 that crime in Washington D.C. was at an all-time high, generating countless fact-checks of his premise and think pieces about his dissociation from reality.

But we believe that to someone with a symbolic mindset, debunkers merely demonstrate that they’re the ones reacting, and are therefore weak. The correct information is easily available, but is irrelevant to someone who prioritizes a symbolic show of strength. What matters is signaling one isn’t listening and won’t be swayed.

In fact, for symbolic thinkers, nearly any statement should be justifiable. The more outlandish or easily disproved something is, the more powerful one might seem when standing by it. Being an edgelord – a contrarian online provocateur – or outright lying can, in their own odd way, appear “authentic.”

Some people may also view their favorite dissembler’s claims as provocative trolling, but, given the link between this mindset and authoritarianism, they want those far-fetched claims acted on anyway. The deployment of National Guard troops to Washington, for example, can be the desired end goal, even if the offered justification is a transparent farce.

Is this really 5-D chess?

It is possible that symbolic, but not exactly true, beliefs have some downstream benefit, such as serving as negotiation tactics, loyalty tests, or a fake-it-till-you-make-it long game that somehow, eventually, becomes a reality. Political theorist Murray Edelman, known for his work on political symbolism, noted that politicians often prefer scoring symbolic points over delivering results – it’s easier. Leaders can offer symbolism when they have little tangible to provide.

The authors do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.

– ref. Winning with misinformation: New research identifies link between endorsing easily disproven claims and prioritizing symbolic strength – https://theconversation.com/winning-with-misinformation-new-research-identifies-link-between-endorsing-easily-disproven-claims-and-prioritizing-symbolic-strength-265652

Source: The Conversation – USA (2) – By Andrew Muhammad, Professor of Agriculture and Resource Economics, University of Tennessee

Lumber, especially softwood lumber like pine and spruce, is critical to U.S. home construction. Its availability and price directly affect housing costs and broader economic activity in the building sector. The U.S. imports about 40% of the softwood lumber the nation uses each year, more than 80% of that from Canada.

President Donald Trump says that the U.S. has the capacity to meet 95% of softwood lumber demand and directed federal officials to update policies and regulatory guidelines to expand domestic timber harvesting and curb the arrival of foreign lumber.

On Sept. 29, 2025, he announced new tariffs on imported timber and wood products, including an additional 10% tariff on Canadian lumber. Those were added to 35% tariffs imposed on Canadian lumber in August. It was the latest phase in a long-standing dispute over the supply of lumber to builders in the U.S., which dates back to the 1980s, when U.S. producers began arguing that Canadian companies were benefiting from unfair subsidies from their government. Starting on Oct. 15, Canadian softwood lumber imports could face tariffs exceeding 45%.

As researchers studying the forestry sector and international trade, we recognize that the U.S. has ample forest resources. But replacing imports with domestic lumber isn’t as simple as it sounds.

There are differences in tree species and quality, and U.S. lumber often comes at a higher cost, even with tariffs on imports. Challenges like limited labor and manufacturing capacity require long-term investments, which temporary tariffs and uncertain trade policies often fail to encourage. In addition, the amount of lumber imported tends to mirror the boom-and-bust cycles of housing construction, a dynamic that tariffs alone are unlikely to change.

Trump’s moves

To boost U.S. logging, in March, Trump issued an executive order telling the departments of Interior and Agriculture to ease what he called “heavy-handed” regulations on timber harvesting. The executive order and a follow-up memo from Agriculture Secretary Brooke Rollins do not spell out specifics, but officials say more details are in the works that will simplify the timber harvesting process, with the goal of boosting domestic timber production by 25%.

That same month, Trump ordered the Commerce Department to assess how imports of timber, lumber and related wood products affect U.S. national security.

While that assessment was underway, in July, the Commerce Department published findings from a trade review of 2023 Canadian lumber imports. That inquiry alleged that Canadian companies were selling lumber to the U.S. at unfairly low prices, potentially leaving U.S. producers with lower sales or depressed prices. That finding was cited as the basis for the 35% August tariff announcement.

In its national security investigation initiated in March, the Commerce Department concluded that an overreliance on imported wood products means “the United States may be unable to meet demands for wood products that are crucial to the national defense and critical infrastructure.” The September tariff announcement is based on those findings.

Canadian lumber in the US market

In 1991, the U.S. imported 11.5 billion board feet (27 million cubic meters) of Canadian lumber. Those imports rose to a high of 22 billion board feet (52 million cubic meters) by 2005.

But as housing construction declined – especially during the Great Recession from 2007 to 2009 – imports dropped sharply, to less than 8.4 billion board feet (20 million cubic meters) in 2009. The current volume has not recovered to prerecession levels, rising only to 12 billion board feet (28 million cubic meters) in 2024.

The value of Canadian lumber has also fluctuated. Historically, prices for Canadian lumber have averaged about US$330 per thousand board feet ($140 per cubic meter). During and after the COVID-19 pandemic, import prices soared to almost $800 per thousand board feet ($340 per cubic meter). But since peaking in 2021 and 2022, prices have dropped significantly to $436 per thousand board feet ($185 per cubic meter) by 2024.

In total, in 2024, the U.S. imported more than $11 billion in forest and wood products from Canada. Softwood lumber accounted for almost half of that.

Lumber and housing

As personal income rises and populations grow, people seek to build new homes. As new home construction – called “housing starts” in economic data – increases, so does demand for softwood lumber to build those homes. And when housing starts slow, so does lumber demand.

For instance, housing starts fell during the Great Recession. They declined from a January 2006 peak of 2.3 million to less than 500,000 in January 2009 – a decrease of nearly 80%. In that same period, imports of Canadian lumber fell by more than 60%. Domestic softwood lumber production fell by more than 40%.

Both domestic and imported lumber prices can directly influence the overall cost of building homes, which in turn affects housing affordability. That said, lumber used for framing usually accounts for less than 10% of the total cost to build a new home. The effects of tariffs on new home construction may be significantly less than other factors, such as rising labor costs.

A matter of choice

The U.S. has a lot of potential lumber available. Especially in the South, the inventory of harvestable lumber has grown significantly over many years.

However, the types of wood available in the U.S. are not always the same as what’s available from Canadian imports. For framing, contractors may prefer spruce, northern pines and fir, naturally abundant in Canada, because they are lighter and less likely to warp than southern yellow pine, which is abundant in the southern U.S. Southern yellow pine is more commonly used to make utility poles and preservative-treated lumber for outdoor construction projects, such as decks.

Lumber from Idaho, eastern Oregon and eastern Washington, however, does share characteristics with Canadian species and could take the place of at least some Canadian lumber.

As the Trump administration seeks to boost domestic lumber, buyers will be looking not only at where their lumber came from, but what it costs and what type of lumber is best for what they need to accomplish.

Andrew Muhammad received funding from the U.S. Department of Agriculture to research timber demand in Vietnam.

Adam Taylor does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Why higher tariffs on Canadian lumber may not be enough to stimulate long-term investments in US forestry – https://theconversation.com/why-higher-tariffs-on-canadian-lumber-may-not-be-enough-to-stimulate-long-term-investments-in-us-forestry-265713

Source: The Conversation – USA (2) – By Christine Keiner, Chair, Department of Science, Technology, and Society, Rochester Institute of Technology

If you visit the Erie Canal today, you’ll find a tranquil waterway and trail that pass through charming towns and forests, a place where hikers, cyclists, kayakers, bird-watchers and other visitors seek to enjoy nature and escape the pressures of modern life.

However, relaxation and scenic beauty had nothing to do with the origins of this waterway.

When the Erie Canal opened 200 years ago, on Oct. 26, 1825, the route was dotted with decaying trees left by construction that had cut through more than 360 miles of forests and fields, and life quickly sped up.

Mules on the towpath along the canal could pull a heavy barge at a clip of 4 miles per hour – far faster than the job of dragging wagons over primitive roads. Boats rushed goods and people between the Great Lakes heartland and the port of New York City in days rather than weeks. Freight costs fell by 90%.

As many books have proclaimed, the Erie Canal’s opening in 1825 solidified New York’s reputation as the Empire State. It also transformed the surrounding environment and forever changed the ecology of the Hudson River and the lower Great Lakes.

For environmental historians like me, the canal’s bicentennial provides an opportunity to reflect upon its complex legacies, including the evolution of U.S. efforts to balance economic progress and ecological costs.

Human and natural communities ruptured

The Haudenosaunee Confederacy, the Indigenous nations that the French called the Iroquois, engaged in canoe-based trade throughout the Great Lakes and Hudson River valley for centuries. In the 1700s, that began to change as American colonists took the land through brutal warfare, inequitable treaties and exploitative policies.

That Haudenosaunee dispossession made the Erie Canal possible.

After the Revolutionary War, commercial enthusiasm for a direct waterborne route to the West intensified. Canal supporters identified the break in the Appalachian Mountains at the junction of the Mohawk River and the Hudson as a propitious place to dig a channel to Lake Erie.

Yet cutting a 363-mile-long waterway through New York’s uneven terrain posed formidable challenges. Because the landscape rises 571 feet between Albany and Buffalo, a canal would require multiple locks to raise and lower boats.

Federal officials refused to finance such “internal improvements.” But New York politician DeWitt Clinton was determined to complete the project, even if it meant using only state funds. Critics mocked the $7 million megaproject, worth around US$170 million today, calling it “DeWitt’s Ditch” and “Clinton’s Folly.” In 1817, however, thousands of men began digging the 4-foot-deep channel using hand shovels and pickaxes.

The construction work produced engineering breakthroughs, such as hydraulic cement made from local materials and locks that lifted the canal’s water level about 60 feet at Lockport, yet it obliterated acres of wetlands and forests.

After riding a canal boat between Utica and Syracuse, the writer Nathaniel Hawthorne described the surroundings in 1835 as “now decayed and death-struck.”

However, most canalgoers viewed the waterway as a beacon of progress. As a trade artery, it made New York City the nation’s financial center. As a people mover, it fueled religious revivals, social reform movements and the growth of Great Lakes cities.

The Erie Canal’s socioeconomic benefits came with more environmental costs: The passageway enabled organisms from faraway places to reach lakes and rivers that had been isolated since the end of the last ice age.

An invasive species expressway

On Oct. 26, 1825, Gov. Clinton led a flotilla aboard the Seneca Chief from Buffalo to New York City that culminated in a grandiose ceremony.

To symbolize the global connections made possible by the new canal, participants poured water from Lake Erie and rivers around the world into the Atlantic at Sandy Hook, a sand spit off New Jersey at the entrance to New York Harbor. Observers at the time described the ritual of “commingling the waters of the Lakes with the Ocean” in matrimonial terms.

Clinton was an accomplished naturalist who had researched the canal route’s geology, birds and fish. He even predicted that the waterway would “bring the western fishes into the eastern waters.”

Biologists today would consider the “Wedding of the Waters” event a biosecurity risk.

The Erie Canal and its adjacent feeder rivers and reservoirs likely enabled two voracious nonnative species, the Atlantic sea lamprey and alewife, to enter the Great Lakes ecosystem. By preying on lake trout and other highly valued native fish, these invaders devastated the lakes’ commercial fisheries. The harvest dropped by a stunning 98% from the previous average by the early 1960s.

Tracing their origins is tricky, but historical, ecological and genetic data suggest that sea lampreys and alewives entered Lake Ontario via the Erie Canal during the 1860s. Later improvements to the Welland Canal in Canada enabled them to reach the upper Great Lakes by the 1930s.

Protecting the $5 billion Great Lakes fishery from these invasive organisms requires constant work and consistent funding. In particular, applying pesticides and other techniques to control lamprey populations costs around $20 million per year.

The invasive species that has inflicted the most environmental and economic harm on the Great Lakes is the zebra mussel. Zebra mussels traveled from Eurasia via the ballast water of transoceanic ships using the St. Lawrence Seaway during the 1980s. The Erie Canal then became a “mussel expressway” to the Hudson River.

The hungry invading mussels caused a nearly tenfold reduction of phytoplankton, the primary food of many species of the Hudson River ecosystem. This competition for food, along with pollution and habitat degradation, led to the disappearance of two common species of the Hudson’s native pearly mussels.

Today, the Erie Canal remains vulnerable to invasive plants, such as water chestnut and hydrilla, and invasive animals such as round goby. Boaters, kayakers and anglers can help reduce bioinvasions by cleaning, draining and drying their equipment after each use to avoid carrying invasive species to new locations.

A recreational treasure

During the Gilded Age in the late 1800s, the Erie Canal sparked a utilitarian sense of environmental concern. Timber cutting in the Adirondack Mountains was causing so much erosion that the eastern canal’s feeder rivers were filling up with silt.

To protect these waterways, New York created Adirondack Park in 1892. Covering 6 million acres, the park balances forest preservation, recreation and commercial use on a unique mix of public and private lands.

Erie Canal shipping declined during the 20th century with the opening of the deeper and wider St. Lawrence Seaway and competition from rail and highways. The canal still supports commerce, but the Erie Canalway National Heritage Corridor now provides an additional economic engine.

In 2024, 3.84 million people used the Erie Canalway Trail for cycling, hiking, kayaking, sightseeing and other adventures. The tourists and day-trippers who enjoy the historic landscape generate over $300 million annually.

Over the past 200 years, the Erie Canal has both shaped, and been shaped by, ecological forces and changing socioeconomic priorities. As New York reimagines the canal for its third century, the artificial river’s environmental history provides important insights for designing technological systems that respect human communities and work with nature rather than against it.

Christine Keiner does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

– ref. Erie Canal’s 200th anniversary: How a technological marvel for trade changed the environment forever – https://theconversation.com/erie-canals-200th-anniversary-how-a-technological-marvel-for-trade-changed-the-environment-forever-263320

Source: The Conversation – USA (3) – By Carol Mathews, Professor of Psychiatry, University of Florida

Many news outlets have reported an increase – or surge – in attention-deficit/hyperactivity disorder, or ADHD, diagnoses in both children and adults. At the same time, health care providers, teachers and school systems have reported an uptick in requests for ADHD assessments.

These reports have led some experts and parents to wonder whether ADHD is being overdiagnosed and overtreated.

As researchers who have spent our careers studying neurodevelopmental disorders like ADHD, we are concerned that fears about widespread overdiagnosis are misplaced, perhaps based on a fundamental misunderstanding of the condition.

Understanding ADHD as one end of a spectrum

Discussions about overdiagnosis of ADHD imply that you either have it or you don’t.

However, when epidemiologists ask people in the general population about their symptoms of ADHD, some have a few symptoms, some have a moderate level, and a few have lots of symptoms. But there is no clear dividing line between those who are diagnosed with ADHD and those who are not, since ADHD – much like blood pressure – occurs on a spectrum.

Treating mild ADHD is similar to treating mild high blood pressure – it depends on the situation. Care can be helpful when a doctor considers the details of a person’s daily life and how much the symptoms are affecting them.

Not only can ADHD symptoms be very different from person to person, but research shows that ADHD symptoms can change within an individual. For example, symptoms become more severe when the challenges of life increase.

ADHD symptoms fluctuate depending on many factors, including whether the person is at school or home, whether they have had enough sleep, if they are under a great deal of stress or if they are taking medications or other substances. Someone who has mild ADHD may not experience many symptoms while they are on vacation and well rested, for example, but they may have impairing symptoms if they have a demanding job or school schedule and have not gotten enough sleep. These people may need treatment for ADHD in certain situations but may do just fine without treatment in other situations.

This is similar to what is seen in conditions like high blood pressure, which can change from day to day or from month to month, depending on a person’s diet, stress level and many other factors.

Can ADHD symptoms change over time?

ADHD symptoms start in early childhood and typically are at their worst in mid-to late childhood. Thus, the average age of diagnosis is between 9 and 12 years old. This age is also the time when children are transitioning from elementary school to middle school and may also be experiencing changes in their environment that make their symptoms worse.

Classes can be more challenging beginning around fifth grade than in earlier grades. In addition, the transition to middle school typically means that children move from having all their subjects taught by one teacher in a single classroom to having to change classrooms with a different teacher for each class. These changes can exacerbate symptoms that were previously well-controlled.

Symptoms can also wax and wane throughout life. For most people, symptoms improve – but may not completely disappear – after age 25, which is also the time when the brain has typically finished developing.

Psychiatric problems that often co-occur with ADHD, such as anxiety or depression, can worsen ADHD symptoms that are already present. These conditions can also mimic ADHD symptoms, making it difficult to know which to treat. High levels of stress leading to poorer sleep, and increased demands at work or school, can also exacerbate or cause ADHD-like symptoms.

Finally, the use of some substances, such as marijuana or sedatives, can worsen, or even cause, ADHD symptoms. In addition to making symptoms worse in someone who already has an ADHD diagnosis, these factors can also push someone who has mild symptoms into full-blown ADHD, at least for a short time.

The reverse is also true: Symptoms of ADHD can be minimized or reversed in people who do not meet full diagnostic criteria once the external cause is removed.

How prevalence is determined

Clinicians diagnose ADHD based on symptoms of inattention, hyperactivity and impulsivity. To make an ADHD diagnosis in children, six or more symptoms in at least one of these three categories must be present. For adults, five or more symptoms are required, but they must begin in childhood. For all ages, the symptoms must cause serious problems in at least two areas of life, such as home, school or work.

Current estimates show that the strict prevalence of ADHD is about 5% in children. In young adults, the figure drops to 3%, and it is less than 1% after age 60. Researchers use the term “strict prevalence” to mean the percentage of people who meet all of the criteria for ADHD based on epidemiological studies. It is an important number because it provides clinicians and scientists with an estimate on how many people are expected to have ADHD in a given group of people.

In contrast, the “diagnosed prevalence” is the percentage of people who have been diagnosed with ADHD based on real-world assessments by health care professionals. The diagnosed prevalence in the U.S. and Canada ranges from 7.5% to 11.1% in children under age 18. These rates are quite a bit higher than the strict prevalence of 5%.

Some researchers claim that the difference between the diagnosed prevalence and the strict prevalence means that ADHD is overdiagnosed.

We disagree. In clinical practice, the diagnostic rules allow a patient to be diagnosed with ADHD if they have most of the symptoms that cause distress, impairment or both, even when they don’t meet the full criteria. And much evidence shows that increases in the diagnostic prevalence can be attributed to diagnosing milder cases that may have been missed previously. The validity of these mild diagnoses is well-documented.

Consider children who have five inattentive symptoms and five hyperactive-impulsive symptoms. These children would not meet strict diagnostic criteria for ADHD even though they clearly have a lot of ADHD symptoms. But in clinical practice, these children would be diagnosed with ADHD if they had marked distress, disability or both because of their symptoms – in other words, if the symptoms were interfering substantially with their everyday lives.

So it makes sense that the diagnosed prevalence of ADHD is substantially higher than the strict prevalence.

Implications for patients, parents and clinicians

People who are concerned about overdiagnosis commonly worry that people are taking medications they don’t need or that they are diverting resources away from those who need it more. Other concerns are that people may experience side effects from the medications, or that they may be stigmatized by a diagnosis.

Those concerns are important. However, there is strong evidence that underdiagnosis and undertreatment of ADHD lead to serious negative outcomes in school, work, mental health and quality of life.

In other words, the risks of not treating ADHD are well-established. In contrast, the potential harms of overdiagnosis remain largely unproven.

It is important to consider how to manage the growing number of milder cases, however. Research suggests that children and adults with less severe ADHD symptoms may benefit less from medication than those with more severe symptoms.

This raises an important question: How much benefit is enough to justify treatment? These are decisions best made in conversations between clinicians, patients and caregivers.

Because ADHD symptoms can shift with age, stress, environment and other life circumstances, treatment needs to be flexible. For some, simple adjustments like classroom seating changes, better sleep or reduced stress may be enough. For others, medication, behavior therapy or a combination of these interventions may be necessary. The key is a personalized approach that adapts as patients’ needs evolve over time.

Carol Mathews receives funding from the National Institutes of Health and the International OCD Foundation. She is affiliated with the International OCD Foundation, and the Family Foundation for OCD Research. She acts as a consultant for the Office of Mental Health for the State of New York.

Stephen V. Faraone receives research funding from the National Institutes of Health, the European Union, the Upstate Foundation and Supernus Pharmaceuticals. With his institution, he holds US patent US20130217707 A1 for the use of sodium-hydrogen exchange inhibitors in the treatment of ADHD. His continuing medical education programs are supported by The Upstate Foundation, Corium Pharmaceuticals, Tris Pharmaceuticals and Supernus Pharmaceuticals. He acts as a consultant to multiple pharmaceutical companies.

– ref. Yes, ADHD diagnoses are rising, but that doesn’t mean it’s overdiagnosed – https://theconversation.com/yes-adhd-diagnoses-are-rising-but-that-doesnt-mean-its-overdiagnosed-257108

Source: The Conversation – USA (3) – By Richard J. Price, Professor of Biomedical Engineering, University of Virginia

Sound waves at frequencies above the threshold for human hearing are routinely used in medical care. Also known as ultrasound, these sound waves can help clinicians diagnose and monitor disease, and can also provide first glimpses of your newest family members.

And now, patients with conditions ranging from cancer to neurodegenerative diseases like Alzheimer’s may soon benefit from recent advances in this technology.

I am a biomedical engineer who studies how focused ultrasound – the concentration of sound energy into a specific volume – can be fine-tuned to treat various conditions. Over the past few years, this technology has seen significant growth and use in the clinic. And researchers continue to discover new ways to use focused ultrasound to treat disease.

A brief history of focused ultrasound

Ultrasound is generated with a probe containing a material that converts electrical current into vibrations, and vice versa. As ultrasound waves pass through the body, they reflect off the boundaries of different types of tissue. The probe detects these reflections and converts them back into electrical signals that computers can use to create images of those tissues.

Over 80 years ago, scientists found that focusing these ultrasonic waves into a volume about the size of a grain of rice can heat up and destroy brain tissue. This effect is analogous to concentrating sunlight with a magnifying glass to ignite a dry leaf. Early investigators began testing how focused ultrasound could treat neurological disorders, pain and even cancer.

Yet, despite these early findings, technical hurdles stood in the way of applying focused ultrasound in the clinic. For example, because the skull absorbs ultrasound energy, sending focusing beams with high enough energy to reach damaged brain tissue proved difficult. Researchers eventually overcame this problem by integrating large arrays of ultrasound transducers – the probes that convert between electrical signals and vibrations – with image-based information about skull shape and density. This change allowed researchers to better fine-tune the beams to their targets.

It is only after scientists made key advances in imaging technology and acoustic physics in recent years that the promise of ultrasound is being realized in the clinic. Hundreds of clinical trials aimed at treating dozens of conditions have been completed or are ongoing. Researchers have found notable success on a condition called essential tremor, which leads to uncontrolled shaking, usually of the hands. Focused ultrasound treatments for essential tremor are now performed routinely at many locations around the world.

I believe some of the most exciting applications for focused ultrasound include improving drug delivery to the brain, stimulating immune responses against cancer, and treating rare diseases of the central nervous system.

Delivering drugs to the brain

The blood-brain barrier is evolution’s exquisite solution to keeping noxious substances away from this most critical organ. The blood-brain barrier is comprised of very tightly connected cells lining the inside of blood vessels. It only allows certain types of molecules to enter the brain, protecting against pathogens and toxins. However, the blood-brain barrier is problematic when it comes to treating disease because it blocks therapies from reaching their intended target.

More than 20 years ago, pioneering studies determined that sending low-intensity pulses of focused ultrasound could temporarily open the blood-brain barrier by causing microbubbles in blood vessels to oscillate. This oscillation pushes and pulls on the surrounding vessel walls, briefly opening tiny pores that allow drugs in the bloodstream to penetrate into the brain. Critically, the blood-brain barrier opens only where the focused ultrasound is applied.

After many years of testing the safety of this technique and improving control of ultrasound energy, researchers have developed several devices using focused ultrasound to open the blood-brain barrier for treatment. Clinical trials testing the ability of these devices to deliver drugs to the brain to treat conditions like glioblastoma, brain metastases and Alzheimer’s disease are underway.

In parallel, there has been significant progress in developing gene therapies for numerous brain diseases. Gene therapy involves fixing or replacing faulty genetic material to treat a specific disease. Applying gene therapy to the brain is especially challenging because such therapies typically do not cross the blood-brain barrier.

Animal studies have shown that using focused ultrasound to open the blood-brain barrier can facilitate the delivery of gene therapies to their intended targets in the brain, opening doors to testing this technique in people.

Stimulating immune responses against cancer

Cancer immunotherapy instructs the patient’s own immune system to fight the disease. However, many patients – especially those afflicted with breast cancer, pancreatic cancer and glioblastoma – have tumors that are immunologically “cold,” meaning they are unresponsive to traditional immunotherapies.

Researchers have learned that focused ultrasound can destroy solid tumors in ways that allow the immune system to better recognize and destroy cancer cells. One way focused ultrasound does this is by turning tumors into debris that then literally flows to the lymph nodes. Once immune cells in the lymph nodes encounter this debris, they can initiate an immune response specifically against the cancer.

Inspired by these breakthroughs, the University of Virginia started the world’s first focused ultrasound immuno-oncology center in 2022 to support research in this area and push the most promising approaches to the clinic. For example, my colleagues are running a clinical trial at the center to test the use of focused ultrasound and immunotherapy to treat patients with advanced melanoma.

Treating rare diseases with focused ultrasound

Research on focused ultrasound has primarily focused on the most devastating and prevalent diseases, such as cancer and Alzheimer’s disease. However, I believe that further developments in, and increased use of, focused ultrasound in the clinic will eventually benefit patients with rare diseases.

One rare disease of particular interest for my lab is cerebral cavernous malformation, or CCM. CCMs are lesions in the brain that occur when the cells that make up blood vessels undergo uncontrolled growth. While uncommon, when these lesions grow and hemorrhage, they can cause debilitating neurological symptoms. The most common treatment for CCM is surgical removal of the brain lesions; however, some CCMs are located in brain areas that are difficult to access, creating a risk of side effects. Radiation is another treatment option, but it, too, can lead to serious adverse effects.

We found that using focused ultrasound to open the blood-brain barrier can improve drug delivery to CCMs. Additionally, we also observed that focused ultrasound treatment itself could stop CCMs from growing in mice, even without administering a drug. While we don’t yet understand how focused ultrasound is stabilizing CCMs, abundant research on the safety of using this technique in patients treated for other conditions has allowed neurosurgeons to begin designing clinical trials testing the use of this technique on people with CCM.

With further research and advancements, I am hopeful that focused ultrasound can become a viable treatment option for many devastating rare diseases.

Richard J. Price receives funding from the National Institutes of Health and the UVA Focused Ultrasound Cancer Immunotherapy Center.

– ref. Focused sound energy holds promise for treating cancer, Alzheimer’s and other diseases – https://theconversation.com/focused-sound-energy-holds-promise-for-treating-cancer-alzheimers-and-other-diseases-262622