Category: The Conversation – USA

Source: The Conversation – USA (2) – By Robert Mitchell, Associate Professor, College of Education, University of Colorado Colorado Springs

Leaders of Colorado’s rural schools are more likely to encourage a total stranger to go into teaching than a member of their own family, according to a Colorado-based survey published in October 2025.

The results come at a time when nearly every state in the United States faces critical teacher shortages.

We collected data in the fall of 2023 with the goal of describing the perceived strengths and limitations of rural schools in Colorado as understood by the people leading them. We sent an electronic survey to the 146 rural school principals and superintendents in the state, received 100 responses and analyzed 98.

Nearly every respondent mentioned issues related to the declining number of people who want to teach, which also reflects national trends. The number of individuals completing educator preparation programs annually in the United States has declined by more than 200,000 since its high point from 2008 to 2021.

When pressed for additional detail about the primary problems affecting their local schools and districts, more than 85% of respondents identified recruiting and retaining talented teachers as one of the most important issues. This was closely followed by concerns about supporting underprepared and underperforming students and poverty’s effect on student learning.

The Colorado context

In Colorado, more than 80% of school districts are rural. They serve more than 130,000 students.

For the past decade, I have worked closely with Colorado’s rural school districts. I also worked as an administrator with the Colorado Department of Higher Education from 2013-2016. These positions have taught me a great deal about the challenges facing smaller schools throughout the state – both in Colorado’s agricultural areas and in the resort regions. Issues related to small budgets, student safety and community poverty are common challenges to schools throughout the state.

As a faculty member at the University of Colorado Colorado Springs, I routinely spend extended time at several of these small schools – even serving as a fill-in classroom teacher and principal when needed.

Colorado’s remote and rural schools remain difficult to staff. The salaries offered by these schools are consistently below state averages. Some rural districts have average salaries of $33,000. That’s far below the state average teacher’s salary of $65,838.

In addition, the challenges of living in towns that may not have a grocery store or any entertainment options is less appealing to many teachers. That’s especially true for newly certified teachers right out of college.

Multiple challenges, with a few bright spots

Our survey shows some deep concerns from the state’s rural education leaders. Only 2% of rural Colorado education leaders believe their district was very effective in working with English language learners and students who are performing below grade level. More than 13% of Colorado’s English language learners are attending school in rural areas, equating to more than 15,000 students. When working with LGBTQA+ students, only 3% believed their district was very effective in supporting these students.

In contrast, nearly 60% of school leaders think their district is either effective or very effective in supporting students performing above grade level. Half of these rural educators see their work with supporting homeless or foster students as effective or very effective.

While nearly half of respondents do not have positive feelings about the current state of education in the U.S., 76% are excited about the future of their individual school districts.

Only about 14% believe that schools today are better than at any other time, and nearly 60% reported that they believe American public schools can be fixed only with major changes.

How to fix rural school challenges

The school leaders we surveyed are very concerned about the realities associated with finding and keeping qualified teachers in their schools.

We asked respondents to rank a series of commonly stated solutions related to teachers shortages. The options ranked highest included higher wages for teachers, more respect for the teaching profession, lowering barriers that allow people to become teachers and better benefits.

Wealth of experience, depth of doubt

Despite some bright spots, rural school and district leaders in Colorado are not enthusiastic about the future of American education overall.

Many school districts consistently have unfilled positions. Some have resorted to filling vacant classroom positions by hiring retired teachers or long-term substitutes. With fewer educators per school, teacher effectiveness is reduced, reducing overall student learning.

The results of our study are exceptionally notable to me and my research team because most of the respondents in this study have 15 or more years of K-12 education experience and more than six years of experience as a rural school leader. Going into the project, we thought these dedicated educators would be more positive about the current and future state of American schools. Yet, this does not seem to be the case.

If these leaders are not optimistic, it is difficult to believe that parents or other members of rural communities would feel any differently.

Robert Mitchell 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. Colorado’s rural schools serve more than 130,000 students, and their superintendents want more pay for their teachers – https://theconversation.com/colorados-rural-schools-serve-more-than-130-000-students-and-their-superintendents-want-more-pay-for-their-teachers-268332

Source: The Conversation – USA (3) – By Jennifer Spinghart, Clinical Assistant Professor of Biomedical Sciences, University of South Carolina

Affordable health care was the primary point of contention in the longest government shutdown in U.S. history, which hit 43 days on Nov. 12, 2025.

This fight highlights a persistent concern for Americans despite passage of the landmark Affordable Care Act 15 years ago.

In 2024, 27.2 million Americans, or 8.2% of the population, lacked health insurance entirely. A significant number of Americans have trouble affording health care, even if they do have insurance. The tax and spending package signed by President Donald Trump into law in July 2025 puts a further 16 million Americans at risk of losing their health care insurance by 2034, according to the Congressional Budget Office.

Many people who lack or have insufficient health insurance seek health care from a network of safety net clinics called community health centers. Even though community health centers provide care for 1 in 10 people in the U.S. – and 1 in 5 in rural areas – many people are unaware of their role in the country’s medical system.

As an emergency physician and the director of the student-led community health program at the University of South Carolina School of Medicine in Greenville, I collaborate with the community health center in Greenville and am closely familiar with how these types of providers function.

These clinics often operate on razor-thin margins and already function under continual demands to do more with less. Slated cuts to health care spending from the tax and spending bill and funding uncertainties that were driven by the shutdown threaten to destabilize them further.

What are community health centers?

Community health centers are clinics typically located in low-income areas that provide affordable health care to everyone, regardless of their ability to pay. Their history is rooted in the Civil Rights Movement.

In 1964, as activists traveled through the South to register Black voters, a group of doctors, nurses and social workers that called themselves the Medical Committee for Human Rights formed to provide emergency first aid and to support civil rights workers, volunteers and the local communities they engaged with.

Witnessing how intimately poor health in some of these communities was tied to living in conditions of extreme poverty, the group embraced the mission of providing health care as a way to fight the injustice of racism. Their idea was that treating illnesses and chronic conditions that stemmed from poverty would enable people to rise out of poverty and shape their own destiny.

The original community health centers were called Neighborhood Health Centers, and the first two – one in Boston and the other in Mississippi – opened in 1966. They were funded as part of President Lyndon B. Johnson’s War on Poverty, which introduced legislation that launched safety net programs, including Medicare and Medicaid, designed to support Americans experiencing economic hardships.

Community health centers quickly multiplied over the following decades and became a cornerstone of the U.S. health care system. These health centers took a broad approach to patient care, focusing on preventive nutrition and health education. They also sought to help with challenges that weren’t strictly medical but also affect people’s health, such as language barriers, lack of transportation and housing insecurity.

Different types of community health centers

Most community health centers receive the majority of their funding from the federal government. These clinics, called Federally Qualified Health Centers, must fulfill some specific requirements.

For one thing, they must be strategically located to be accessible to people in low-income communities with fewer available medical professionals. They must also minimize other barriers to care – for example, by providing language interpreters and offering telehealth services if appropriate. Additionally, they must be governed by a board in which at least 51% of the members are people who live in the local community.

In 2023, such clinics received over US$5.6 billion in federal funding. In addition to direct federal government support, they often rely on reimbursements from Medicaid to cover their costs. Some also receive state funding and private funding, as well as money from private insurance of the few patients who do carry it.

People who lack Medicaid or private insurance, or who are underinsured, receive care at no cost if their income is below 200% of the poverty level, and on a sliding scale otherwise.

Another type of community health center is often referred to as a “free clinic” or a “look-alike” clinic. These clinics typically rely on private grant funding or charitable donations. They are usually run by volunteers, and they often operate on limited schedules and have limited access to specialists.

In 2024, there were more than 1,500 federally funded health clinics providing services in over 17,000 different locations and more than 775 documented free or charitable clinics across the U.S. Together, these two types of community health centers provide free care to over 30 million people.

The community health project that I direct, called Root Cause, falls into a third category of free safety net health care generally referred to as “pop-up” or makeshift medical clinics. These projects vary widely, but Root Cause, which is run by medical students, operates as a monthly health fair that provides simple screenings for high blood pressure and diabetes as well as education on preventive care and healthy lifestyles.

Pop-up projects like ours are more precarious than other types of community health centers, but through grants and partnerships with organizations in Greenville, we have managed to keep this program funded for eight years.

Compounding stressors

Community health centers are extremely cost-effective, providing primary care to more than 10% of the U.S. population at the cost of just 1% of the country’s total health care spending. But with health care costs rising and Medicaid and insurance reimbursements failing to keep up, community health centers are increasingly being asked to do more with less.

The 2025 government shutdown added further uncertainty to community health centers’ operations. Although government funding and reimbursements through Medicare and Medicaid continued, having fewer government workers to complete the administrative tasks that these clinics rely on slowed their access to funds.

In the long term, cuts to Medicaid of up to $1 trillion included in the government’s tax and spending package are likely to decrease community health centers’ funding by limiting Medicaid reimbursements.

Simultaneously, those cuts and other policy changes, such as new work requirements for Medicaid, are likely to strip millions of Americans of health coverage – pushing more people to seek free or low-cost care. Cuts to Supplemental Nutrition Assistance Program benefits would increase food insecurity as well as stress – both factors that directly affect health – and thus may have the same effect.

Given that community health centers provide a kind of long-term stopgap for health care in high-need areas, decreasing their capacity could destabilize other elements of local health care delivery systems. For example, uninsured people who can’t access care at community health centers may turn to already overburdened hospital emergency rooms, which are required by law to treat them.

As funding cuts imperil health care access, the need for safety net health care only grows. These opposing forces may be putting an untenable strain on a vital service so many Americans rely on.

Jennifer Spinghart 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. Community health centers provide care for 1 in 10 Americans, but funding cuts threaten their survival – https://theconversation.com/community-health-centers-provide-care-for-1-in-10-americans-but-funding-cuts-threaten-their-survival-267582

Source: The Conversation – USA (2) – By Golareh Jalilvand, Assistant Professor of Chemical Engineering, University of South Carolina

Picture an electric car that could go 600, 700 or even 1,000 miles on a single charge. That’s much farther than the longest-range electric vehicles on the U.S. market, according to Car and Driver magazine – and twice as far the official rating for the long-range, rear-wheel-drive Tesla Model 3, which has a maximum rated range of 363 miles.

Current EVs use lithium-ion batteries, which are also found in smartphones, laptops and even large-scale energy storage systems connected to the power grid. A standard for decades, these batteries have been tweaked and improved by generations of scientists and are now close to their physical limits. Even with the best materials and most optimized designs, there is only so much energy that can be packed into a lithium-ion battery.

I’m a materials engineer who studies these batteries and seeks alternatives with better performance, improved environmental sustainability and lower cost. One promising design uses sulfur, which could boost battery capacity significantly, though some key roadblocks remain before it can be widely used.

Lithium-sulfur vs. Lithium-ion

Any battery has three basic components: a positively charged region, called the cathode; a negatively charged region, called the anode; and a substance called the electrolyte in between, through which charged atoms, also known as ions, move between the cathode and anode.

In a lithium-ion battery, the cathode is made of a metal oxide, typically containing metals such as nickel, manganese and cobalt, bonded with oxygen. The materials are layered, with lithium ions physically between the layers. During charging, lithium ions detach from the layered cathode material and travel through the electrolyte to the anode.

The anode is usually graphite, which is also layered, with room for the lithium ions to fit between them. During discharge, the lithium ions leave the graphite layers, travel back through the electrolyte and reinsert into the layered cathode structure, recombining with the metal oxide to release electricity that powers cars and smartphones.

In a lithium-sulfur battery, the lithium ions still move back and forth, but the chemistry is different. Its cathode is made of sulfur embedded in a carbon matrix that conducts electricity, and the anode is made primarily of lithium itself, rather than graphite layers with lithium in between.

During discharging, the lithium ions travel from the anode, through the electrolyte to the cathode, where – rather than sliding in between the cathode layers – they chemically convert sulfur in sequential steps to a series of compounds called lithium sulfides. During charging, the lithium ions separate from the sulfide compounds, leave the cathode behind and travel back to the anode.

The charging and discharging process for lithium-sulfur batteries is a chemical conversion reaction that involves more electrons than the same process in lithium-ion batteries. That means a lithium-sulfur battery can theoretically store much more energy than a lithium-ion battery of the same size.

Sulfur is inexpensive and abundantly available worldwide, meaning battery manufacturers do not need to rely on scarce metals such as nickel and cobalt, which are unevenly distributed on Earth and often sourced from regions such as the Democratic Republic of Congo, which has limited worker safety regulations and fair labor practices.

Those advantages could deliver batteries with far more capacity and that are cheaper and more sustainable to produce.

Why aren’t lithium-sulfur batteries widely used yet?

The biggest obstacle to mass production and use of sulfur-based batteries is durability. A good lithium-ion battery, like those in an electric vehicle, can go through thousands of cycles of discharging and recharging before its capacity starts to fade. That amounts to thousands of car rides.

But lithium-sulfur batteries tend to lose capacity much more quickly, sometimes after fewer than 100 cycles. That’s not very many trips at all.

The reason lies in the chemistry. During the chemical reactions that store and release energy in a lithium-sulfur battery, some of the lithium sulfide compounds dissolve into the liquid electrolyte of the battery.

When that happens, those amounts of both sulfur and lithium are removed from being used in any remaining reactions. This effect, known as “shuttling,” means that with each round of discharging and recharging, there are fewer elements available to release and store energy.

In the past couple of decades, research has produced improved designs. Earlier versions of these batteries lost much of their capacity within a few dozen discharge–recharge cycles, and even the best laboratory prototypes struggled to survive beyond a few hundred.

New prototypes retain more than 80% of their initial capacity even after thousands of cycles. This improvement comes from redesigning the key parts of the battery and adjusting the chemicals involved: Special electrolytes help prevent the lithium sulfides from dissolving and shuttling.

The electrodes have also been improved, using materials such as porous carbon that can physically trap the intermediate lithium sulfides, stopping them from wandering away from the cathode. This helps the discharge and recharge reactions happen without so many losses, making the reactions more efficient so the battery lasts longer.

The road ahead

Lithium-sulfur batteries are no longer fragile laboratory curiosities, but there are significant challenges before they can become serious contenders for real-world energy storage.

In terms of safety, lithium-sulfur batteries have a less volatile cathode than lithium-ion batteries, but research is continuing into other aspects of safety.

Another problem is that the more energy a lithium-sulfur battery stores, the fewer cycles of charging it can handle. That’s because the chemical reactions involved are more intense with increased energy.

This trade-off may not be a major obstacle for using these batteries in drones or grid-level energy storage, where ultrahigh energy densities are less critical. But for electric vehicles, which demand both high energy capacity and long cycle life, scientists and battery researchers still need to sort out a workable balance. That means the foundation for the next generation of lithium-sulfur batteries is likely still a few years down the road.

Golareh Jalilvand receives funding from NantG Power LLC, and the US Department of Energy for research on lithium-sulfur batteries.

– ref. Sulfur-based batteries could offer electric vehicles a greener, longer-range option – https://theconversation.com/sulfur-based-batteries-could-offer-electric-vehicles-a-greener-longer-range-option-263896

Source: The Conversation – USA (2) – By Jonathan Levy, Professor and Chair, Department of Environmental Health, Boston University

If you’ve been following recent debates about health, you’ve been hearing a lot about vaccines, diet, measles, Medicaid cuts and health insurance costs – but much less about one of the greatest threats to global public health: climate change.

Anybody who’s fallen ill during a heat wave, struggled while breathing wildfire smoke or been injured cleaning up from a hurricane knows that climate change can threaten human health. Studies show that heat, air pollution, disease spread and food insecurity linked to climate change are worsening and costing millions of lives around the world each year.

The U.S. government formally recognized these risks in 2009 when it determined that climate change endangers public health and welfare.

However, the Trump administration is now moving to rescind that 2009 endangerment finding so it can reverse U.S. climate progress and help boost fossil fuel industries, including lifting limits on greenhouse gas emissions from vehicles and power plants. The administration’s arguments for doing so are not only factually wrong, they’re deeply dangerous to Americans’ health and safety.

As physicians, epidemiologists and environmental health scientists who study these effects, we’ve seen growing evidence of the connections between climate change and harm to people’s health. More importantly, we see ways humanity can improve health by tackling climate change.

Here’s a look at the risks and some of the steps individuals and governments can take to reduce them.

Extreme heat

Greenhouse gases from vehicles, power plants and other sources accumulate in the atmosphere, trapping heat and holding it close to Earth’s surface like a blanket. Too much of it causes global temperatures to rise, leaving more people exposed to dangerous heat more often.

Most people who get minor heat illnesses will recover, but more extreme exposure, especially without enough hydration and a way to cool off, can be fatal. People who work outside, are elderly or have underlying illnesses such as heart, lung or kidney diseases are often at the greatest risk.

Heat deaths have been rising globally, up 23% from the 1990s to the 2010s, when the average year saw more than half a million heat-related deaths. Even in the U.S., the Pacific Northwest heat dome in 2021 killed hundreds of people.

Climate scientists predict that with advancing climate change, many areas of the world, including U.S. cities such as Miami, Houston, Phoenix and Las Vegas, will confront many more days each year hot enough to threaten human survival.

Extreme weather

Warmer air holds more moisture, so climate change brings increasing rainfall and storm intensity, worsening flooding, as many U.S. communities have experienced in recent years. Warm ocean water also fuels more powerful hurricanes.

Increased flooding carries health risks, including drownings, electrocution and water contamination from human pathogens and toxic chemicals. People cleaning out flooded homes also face risks from mold exposure, injuries and mental distress.

Climate change also worsens droughts, disrupting food supplies and causing respiratory illness from dust and dry conditions as well as wildfires. And rising temperatures and aridity dry out forest and grasslands, making them more vulnerable to catching fire, which creates other health risks.

Air pollution

Wildfires, along with other climate effects, are also worsening air quality around the country.

Wildfire smoke is a toxic soup of microscopic particles (known as fine particulate matter, or PM2.5) that can penetrate deep in the lungs and hazardous compounds such as lead, formaldehyde and dioxins generated when homes, cars and other materials burn at high temperatures. Smoke plumes can travel thousands of miles downwind and trigger heart attacks and elevate lung cancer risks, among other harms.

Meanwhile, warmer conditions favor the formation of ground-level ozone, a heart and lung irritant. Burning of fossil fuels also generates dangerous air pollutants that cause a host of health problems, including heart attacks, strokes, asthma flare-ups and lung cancer.

Infectious diseases

Because they are cold-blooded organisms, insects are directly influenced by temperature. So as temperatures have risen, mosquito biting rates have risen as well. Warming also shortens the development time of disease agents that mosquitoes transmit.

Mosquito-borne dengue fever has turned up in Florida, Texas, Hawaii, Arizona and California. New York state just saw its first locally acquired case of chikungunya virus, also transmitted by mosquitoes.

And it’s not just insect-borne infections. Warmer temperatures increase diarrhea and foodborne illness from Vibrio cholerae and other bacteria and heavy rainfall increases sewage-contaminated stormwater overflows into lakes and streams. At the other water extreme, drought in the desert Southwest increases the risk of coccidioidomycosis, a fungal infection known as valley fever.

Other impacts

Climate change can threaten health in numerous other ways. Longer pollen seasons can increase allergen exposures. Lower crop yields can reduce access to nutritious foods.

Mental health can also suffer, with anxiety, depression and post-traumatic stress following disasters, and increased rates of violent crime and suicide tied to high-temperature days.

Young children, older adults, pregnant women and people with preexisting medical conditions are among the highest-risk groups. Often, lower-income people are also at greater risk because of higher rates of chronic disease, higher exposures to climate hazards and fewer resources for protection, medical care and recovery from disasters.

What can people and governments do?

As an individual, you can reduce your risk by following public health advice during heat waves, storms and wildfires; protecting yourself against tick and mosquito bites; and spending time in green space that improves your mental health.

You can also make healthy choices that reduce your carbon footprint, such as:

• Walking, biking or using public transit instead of driving, since more physical activity reduces chronic disease risks.

• Rebalancing your diet from meat-heavy to plant-forward, which can cut your risk of heart disease and lower greenhouse gas emissions from meat production.

• Making your home more energy-efficient and opting for electric rather than gas- or oil-powered heating and cooking, which can reduce emissions while improving indoor air quality.

However, there are limits to what individuals can do alone.

Actions by governments and companies are also necessary to protect people from a warmer climate and stop the underlying causes of climate change.

Workplace safety can be addressed through rules to reduce heat exposure for people who work outdoors in industries such as agriculture and construction. Communities can open cooling centers during heat waves, provide early warning systems and design drinking water systems that can handle more intense rainfall and runoff, reducing contamination risks.

Governments can ensure that public transit is available and not overly expensive to reduce the number of vehicles on the road. They can promote clean energy rather than fossil fuels to cut emissions, which can also save money since the cost of solar energy has dropped spectacularly. In fact, both solar and wind energy are less expensive than fossil fuel energy.

Yet the U.S. government is currently going in the opposite direction, cutting support for renewable energy while subsidizing the fossil fuel industries that endanger public health.

To really make America healthy, in our view, the country can’t ignore climate change.

Jonathan Levy receives funding from the National Institutes of Health, the Federal Aviation Administration, the City of Boston, and the Mosaic Foundation.

Howard Frumkin has no financial conflicts of interest to report. He is a member of advisory boards (or equivalent committees) for the Planetary Health Alliance; the Harvard Center for Climate, Health, and the Global Environment; the Medical Society Consortium on Climate Change and Health; the Global Consortium on Climate and Health Education; the Yale Center on Climate Change and Health; and EcoAmerica’s Climate for Health program—all voluntary unpaid positions.

Jonathan Patz receives funding from the National Institutes of Health. He is affiliated with the Medical Society Consortium for Climate and Health, and its affiliate Healthy Climate Wisconsin.

Vijay Limaye is affiliated with the Natural Resources Defense Council.

– ref. Want to make America healthy again? Stop fueling climate change – https://theconversation.com/want-to-make-america-healthy-again-stop-fueling-climate-change-269269

Source: The Conversation – USA (2) – By Kai R. Larsen, Professor of Information Systems, University of Colorado Boulder

Technological innovations can seem relentless. In computing, some have proclaimed that “a year in machine learning is a century in any other field.” But how do you know whether those advancements are hype or reality?

Failures quickly multiply when there’s a deluge of new technology, especially when these developments haven’t been properly tested or fully understood. Even technological innovations from trusted labs and organizations sometimes result in spectacular failures. Think of IBM Watson, an AI program the company hailed as a revolutionary tool for cancer treatment in 2011. However, rather than evaluating the tool based on patient outcomes, IBM used less relevant measures – possibly even irrelevant ones, such as expert ratings rather than patient outcomes. As a result, IBM Watson not only failed to offer doctors reliable and innovative treatment recommendations, it also suggested harmful ones.

When ChatGPT was released in November 2022, interest in AI expanded rapidly across industry and in science alongside ballooning claims of its efficacy. But as the vast majority of companies are seeing their attempts at incorporating generative AI fail, questions about whether the technology does what developers promised are coming to the fore.

In a world of rapid technological change, a pressing question arises: How can people determine whether a new technological marvel genuinely works and is safe to use?

Borrowing from the language of science, this question is really about validity – that is, the soundness, trustworthiness and dependability of a claim. Validity is the ultimate verdict of whether a scientific claim accurately reflects reality. Think of it as quality control for science: It helps researchers know whether a medication really cures a disease, a health-tracking app truly improves fitness, or a model of a black hole genuinely describes how it behaves in space.

How to evaluate validity for new technologies and innovations has been unclear, in part because science has mostly focused on validating claims about the natural world.

In our work as researchers who study how to evaluate science across disciplines, we developed a framework to assess the validity of any design, be it a new technology or policy. We believe setting clear and consistent standards for validity and learning how to assess it can empower people to make informed decisions about technology – and determine whether a new technology will truly deliver on its promise.

Validity is the bedrock of knowledge

Historically, validity was primarily concerned with ensuring the precision of scientific measurements, such as whether a thermometer correctly measures temperature or a psychological test accurately assesses anxiety. Over time, it became clear that there is more than just one kind of validity.

Different scientific fields have their own ways of evaluating validity. Engineers test new designs against safety and performance standards. Medical researchers use controlled experiments to verify treatments are more effective than existing options.

Researchers across fields use different types of validity, depending on the kind of claim they’re making.

Internal validity asks whether the relationship between two variables is truly causal. A medical researcher, for instance, might run a randomized controlled trial to be sure that a new drug led patients to recover rather than some other factor such as the placebo effect.

External validity is about generalization – whether those results would still hold outside the lab or in a broader or different population. An example of low external validity is how many early studies that work in mice don’t always translate to people.

Construct validity, on the other hand, is about meaning. Psychologists and social scientists rely on it when they ask whether a test or survey really captures the idea it’s supposed to measure. Does a grit scale actually reflect perseverance or just stubbornness?

Finally, ecological validity asks whether something works in the real world rather than just under ideal lab conditions. A behavioral model or AI system might perform brilliantly in simulation but fail once human behavior, noisy data or institutional complexity enter the picture.

Across all these types of validity, the goal is the same: ensuring that scientific tools – from lab experiments to algorithms – connect faithfully to the reality they aim to explain.

Evaluating technology claims

We developed a method to help researchers across disciplines clearly test the reliability and effectiveness of their inventions and theories. The design science validity framework identifies three critical kinds of claims researchers usually make about the utility of a technology, innovation, theory, model or method.

First, a criterion claim asserts that a discovery delivers beneficial outcomes, typically by outperforming current standards. These claims justify the technology’s utility by showing clear advantages over existing alternatives.

For example, developers of generative AI models such as ChatGPT may see higher engagement with the technology the more it flatters and agrees with the user. As a result, they may program the technology to be more affirming – a feature called sycophancy – in order to increase user retention. The AI models meet the criterion claim of users considering them more flattering than talking to people. However, this does little to improve the technology’s efficacy in tasks such as helping resolve mental health issues or relationship problems.

Second, a causal claim addresses how specific components or features of a technology directly contribute to its success or failure. In other words, it is a claim that shows researchers know what makes a technology effective and exactly why it works.

Looking at AI models and excessive flattery, researchers found that interacting with more sycophantic models reduced users’ willingness to repair interpersonal conflict and increased their conviction of being in the right. The causal claim here is that the AI feature of sycophancy reduces a user’s desire to repair conflict.

Third, a context claim specifies where and under what conditions a technology is expected to function effectively. These claims explore whether the benefits of a technology or system generalize beyond the lab and can reach other populations and settings.

In the same study, researchers examined how excessive flattery affected user actions in other datasets, including the “Am I the Asshole” community on Reddit. They found that AI models were more affirming of user decisions than people were, even when the user was describing manipulative or harmful behavior. This supports the context claim that sycophantic behavior from an AI model applies across different conversational contexts and populations.

Measuring validity as a consumer

Understanding the validity of scientific innovations and consumer technologies is critical for scientists and the general public. For scientists, it’s a road map to ensure their inventions are rigorously evaluated. And for the public, it means knowing that the tools and systems they depend on – such as health apps, medications and financial platforms – are truly safe, effective and beneficial.

Here’s how you can use validity to understand the scientific and technological innovations happening around you.

Because it is difficult to compare every feature of two technologies against each other, focus on which features you value most from a technology or model. For example, do you prefer a chatbot to be accurate or better for privacy? Examine claims for it in that area, and check that it is as good as claimed.

Consider not only the types of claims made for a technology but also which claims are not made. For example, does a chatbot company address bias in its model? It’s your key to knowing whether you see untested and potentially unsafe hype or a genuine advancement.

By understanding validity, organizations and consumers can cut through the hype and get to the truth behind the latest technologies.

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. New technologies like AI come with big claims – borrowing the scientific concept of validity can help cut through the hype – https://theconversation.com/new-technologies-like-ai-come-with-big-claims-borrowing-the-scientific-concept-of-validity-can-help-cut-through-the-hype-259030

Source: The Conversation – USA (2) – By Michael Luchs, JS Mack Professor of Business, William & Mary

Every fall I anticipate the winter holidays with almost childlike joy. I look forward to familiar traditions with friends and family, eggnog in my coffee, and the sense that everyone is feeling a little lighter and more connected.

At the same time, I feel anxious and annoyed by the manufactured sense of urgency around gift giving: the endless searching and second-guessing shaped by advertisers, retailers and cultural expectations.

Don’t get me wrong, I mostly love giving – and, yes, receiving – gifts during the holidays. But as a researcher who studies consumer psychology, I see how those same forces, amplified by constant buying opportunities and frictionless online payments, make us especially vulnerable and often unwise this time of year.

Buying behavior, including gift giving, doesn’t just reflect needs and wants but also our values. Frequently, the values we talk about are more akin to aspirational ideals. Our actual values are revealed in the seemingly inconsequential choices we make day after day – including shopping.

The cumulative effects of our spending behaviors carry enormous implications for society, the environment and everyone’s well-being – from the purchaser and recipient to people working throughout the supply chain. This makes consumer behavior an especially important place to apply the emerging social science research on wisdom. While wisdom is defined in different ways, it can be understood as seeing decisions through a broader, values-informed perspective and acting in ways that promote well-being.

Over the past decade, consumer psychology researcher David Mick and I have studied what that means when it comes to consumption. “Consumer wisdom?” you may wonder. Isn’t that an oxymoron?

But there are vast differences in how we consume – and as our research shows, this can lead to very different effects on individual well-being.

Defining consumer wisdom

Building on some of David’s earlier work, I began my own research on consumer wisdom in the summer of 2015, interviewing dozens of people across the U.S. whom others in their communities had identified as models of wisdom. Previous research guided me to settings where I could easily find people who represented different aspects of wisdom: practicality on farms in upstate New York; environmental stewardship in Portland, Oregon; and community values in Tidewater, Virginia.

I didn’t use the term “wisdom,” though. It can be intimidating, and people often define it narrowly. Instead, I spoke with people whose peers described them as exemplary decision-makers – people leading lives that considered both the present and the future, and who balanced their needs with others’ needs.

From those conversations, David and I developed a theory of consumer wisdom. With the help of a third co-author, Kelly Haws, we validated this framework through national surveys with thousands of participants, creating the consumer wisdom scale.

The scale shows how consumer wisdom is not some lofty ideal but a set of practical habits. Some are about managing money. Some are about goals and personal philosophy, and others are about broader impact.

We have found that six dimensions capture the vast majority of what we would call consumer wisdom:

1. Responsibility: managing resources to support a rewarding yet realistic lifestyle.
2. Purpose: prioritizing spending that supports personal growth, health and relationships.
3. Perspective: drawing on past experiences and anticipating future consequences.
4. Reasoning: seeking and applying reliable, relevant information; filtering out the noise of advertising and pop culture.
5. Flexibility: being open to alternatives such as borrowing, renting or buying used.
6. Sustainability: spending in ways that support the buyer’s social or environmental goals and values.

These are not abstract traits. They are everyday ways of aligning your spending with your goals, resources and values.

Importantly, people with higher scores on the scale report greater life satisfaction, as well as better health, financial security and sense of meaning in life. These results hold even after accounting for known determinants of well-being, such as job satisfaction and supportive relationships. In other words, consumer wisdom makes a distinctive and underappreciated contribution to well-being.

Putting it in practice

These six dimensions offer a different lens on holiday norms – one that can reframe how to think about gifts.

Interestingly, the English word “gift” traces back to the Old Norse rune gyfu, which means generosity. It’s a reminder that true giving is not about checking boxes on referral, revenue-generating gift guides or yielding to slick promotions or fads. Generosity is about focusing on another person’s well-being and our relationship with them.

From the perspective of consumer wisdom, that means asking what will genuinely contribute to the recipient’s life. One of the most important dimensions of consumer wisdom is “purpose”: the idea that thoughtful spending can nurture personal growth, health, enjoyment and sense of connection. Out with trendy gadgets, fast fashion and clutter-creating décor or knickknacks – things that feel exciting in the moment but are quickly forgotten. In with quality headphones, a shared cooking class, a board game, and a workshop or tools to support a hobby – gifts that can spark growth, joy and deeper connection.

In my ongoing research, people have described wise gifts as those that define value from the recipient’s perspective – gifts that stay meaningful and useful over time. The wisest gifts, respondents say, also affirm the recipient’s identity, showing that the giver truly understands and values them.

Wiser consumption is learnable, measurable and consequential. By choosing gifts that reflect purpose and the original spirit of “gyfu” – true generosity – we can make the holidays less stressful. More importantly, we can make them more meaningful: strengthening relationships in ways that bring joy long after.

Michael Luchs received funding from the Templeton Foundation through a grant from the University of Chicago School of Divinity.

– ref. Turn shopping stress into purposeful gift giving by cultivating ‘consumer wisdom’ during the holidays – https://theconversation.com/turn-shopping-stress-into-purposeful-gift-giving-by-cultivating-consumer-wisdom-during-the-holidays-265564

Source: The Conversation – USA – By Ashley Brandebura, Assistant Professor of Neuroscience, University of Virginia

Delivering a connection-building protein to star-shaped cells in the brain could reverse changes to neural circuits seen in Down syndrome, according to new research my colleagues and I published in the journal Cell Reports.

Down syndrome is caused by an error in cell division during development. Individuals receive three copies of chromosome 21 instead of the typical two copies, resulting in duplicates of the genes encoded on chromosome 21. This trisomy leads to a multitude of changes to heart and immune function as well as neurodevelopmental impairments.

Changes to the structure of neurons in people with Down syndrome alter how they connect with each other. One major type of brain cell called astrocytes helps form connections between neurons. These star-shaped cells have many thin arms that extend into the spaces between neurons. They also secrete various proteins that are vital to forming the proper neural connections necessary for brain function.

Researchers have found that mouse models of several neurodevelopmental disorders, including Down syndrome, have altered levels of astrocyte proteins during development. My colleagues and I hypothesized that these changes might contribute to the changes in neural connections seen in Down syndrome. Could restoring the proper levels of some of these astrocyte proteins “rewire” the brain?

Identifying an astrocyte protein

First, we needed to pick a candidate astrocyte protein to test our hypothesis. A previous study had identified a list of astrocyte proteins that were altered in a mouse model of Down syndrome. We focused on proteins present in lower levels in Down syndrome astrocytes compared to astrocytes without the condition. We thought there might not be enough of these proteins available to help form neural connections.

Among the top 10 proteins we identified was a molecule called pleiotrophin, or Ptn. This protein is known to help guide axons – long extensions that neurons use to send information to each other – to their targets during development. So it made sense that it might also help neurons form the branching arms they use to receive information.

We found that mice unable to produce Ptn had neurons with fewer branching arms, similar to what we saw in mice with Down syndrome. This correlation implies that proper Ptn levels are necessary to affect neuron branching during brain development.

Restoring neurons in Down syndrome

Next, we wanted to know if delivering Ptn to astrocytes changes neural connections in mice with Down syndrome.

To answer that question, we packaged the gene for Ptn into a small virus with its replication genes removed. Called adeno-associated viruses, these tools allow researchers to deliver genetic material to specific targets in the body and are used for applications like gene therapy. We delivered the Ptn gene into astrocytes throughout the entire brain of adult mice with Down syndrome so we could evaluate its effects.

We focused on the visual cortex and the hippocampus, areas of the brain involved in vision and memory that are both critically affected in Down syndrome. After enhancing the ability of astrocytes to produce Ptn, we found that both regions recovered levels of neural branching density similar to those of mice without Down syndrome.

Finally, we wanted to see if we could actually restore electrical activity levels in the hippocampus by increasing astrocyte Ptn levels. Measuring electrical activity can indicate whether neurons are functioning properly. After delivering the Ptn gene to the astrocytes of mice with Down syndrome, we found the electrical activity of their hippocampus restored to levels no different from mice without Down syndrome.

Together, our findings show that delivering Ptn to the astrocytes of mice can reverse changes to neuron structure and function seen in Down syndrome. While our findings are far from ready to be used in the clinic, more research could help us understand whether and how Ptn could help improve the health of human patients.

Rewiring the brain

More broadly, our findings suggest that astrocyte proteins have the potential to rewire the brain in other neurodevelopmental conditions.

Typically, adult brains have low plasticity, meaning they have a decreased capacity to form new connections between neurons. This means it can be difficult to change neural circuits in adults. Our hope is that further exploration on how astrocyte proteins can alter the adult brain could lead to new treatments for neurodevelopmental disorders like Fragile X syndrome or Rett syndrome, or to neurodegenerative diseases like Parkinson’s disease.

Ashley Brandebura receives funding from NIH NINDS and NIA.

– ref. Star-shaped cells make a molecule that can ‘rewire’ the brains of mice with Down syndrome – understanding how could lead to new treatments – https://theconversation.com/star-shaped-cells-make-a-molecule-that-can-rewire-the-brains-of-mice-with-down-syndrome-understanding-how-could-lead-to-new-treatments-268739

Source: The Conversation – USA (3) – By Paul L. Morgan, Director, Institute for Social and Health Equity, University at Albany, State University of New York

Black, Hispanic and Native American students are more likely than white or Asian students to struggle with reading – and that gap emerges early, according to our new research. During kindergarten, they are more likely to score in the lowest 10% on assessments measuring skills such as letter recognition, vocabulary and recognizing common sight words. Large racial and ethnic differences in the risks for reading difficulties continue as students move through elementary school – a pattern largely explained by family income and early academic skills.

Our study, published online in November 2025 in the Journal of School Psychology, finds that about 15% of Black, Hispanic and Native American kindergartners score in the lowest 10% of reading scores, compared to 6% and 8% of white and Asian students, respectively. By fifth grade, 18%, 16% and 10% of Black, Hispanic and Native American students are struggling. The contrasting rate for white and Asian students is about 5%.

We analyzed data collected by the U.S. Department of Education’s National Center for Education Statistics from 2010-2016. This data includes direct academic assessments as well as surveys of the students and their parents, teachers and school administrators.

We used standard statistical methods to explore how a wide range of factors across homes and schools – measured during kindergarten – helped explain whether students later experienced reading difficulties. A key factor, according to our analysis, is the family’s socioeconomic status: a measure including household income and parental education levels and occupations.

Kindergartners who struggled with initial reading, math and science skills, as well as more general learning abilities such as working memory, were also at higher risk for reading difficulties throughout elementary school.

Why it matters

U.S. elementary students’ reading achievement has been declining in recent years. The gap between the highest- and lowest-scoring readers is increasing too.

Supporting these children is important. Students who wrestle with reading are more likely to later experience anxiety and depression. Adults with reading difficulties are also more likely to be incarcerated and unemployed. In one study, for example, about half of Texas prisoners were poor readers.

Because our findings suggest Black, Hispanic and Native American students are at higher risk for reading difficulties by kindergarten, students from these groups may have greater needs for early reading interventions that provide extra help with phonics, vocabulary and reading fluency. Some of these students may also have unrecognized learning disabilities.

Yet students of color are less likely to be identified with disabilities, including dyslexia – even when the students are experiencing early and significant reading difficulties.

What still isn’t known

How economic and educational policies and practices can best help lower the risks of reading difficulties is poorly understood. There is some evidence that cash transfers to financially struggling families may increase children’s later reading achievement. Poverty is also associated with lower exposure to age-appropriate books and other early literacy materials and fewer opportunities to acquire a larger vocabulary.

Our longitudinal research adds to the very limited understanding of the early economic, environmental, cognitive, academic and behavioral factors that help shape elementary students’ reading abilities. Most other studies have focused on a single grade and examined a limited set of specific skills – such as how children process sounds – instead of multiple grades and a more general set of risk factors.

More research is needed to identify the full range of reasons why elementary students begin to struggle in reading and what can be done to best help them.

The Research Brief is a short take on interesting academic work.

Paul L. Morgan receives funding from the National Science Foundation, the National Institute of Child Health and Human Development, and the Institute of Education Sciences.

Eric Hengyu Hu 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. Students of color are at greater risk for reading difficulties – even in kindergarten – https://theconversation.com/students-of-color-are-at-greater-risk-for-reading-difficulties-even-in-kindergarten-249429

Source: The Conversation – USA – By Austin Sarat, William Nelson Cromwell Professor of Jurisprudence and Political Science, Amherst College

After years of steady decline in the number of people executed in the United States, there has been a sharp reversal in 2025.

So far this year, 41 people have been killed in 11 states, with five more executions scheduled before the end of the year.

If all the scheduled executions are carried out, that would make 2025 the year with the most executions since 2010, when 46 inmates were put to death. That year, Texas led the way with 17 executions, while Florida carried out only one.

But this year, the Sunshine State is leading the charge. Florida has executed 15 prisoners in 2025 – the most ever in a single year since 1976, when a brief national moratorium on the death penalty was lifted. Two of the five remaining executions scheduled for 2025 are set to happen in Florida. Texas and Alabama are tied for a distant second, with five executions each.

As someone who has studied the death penalty for decades, what is happening in Florida right now seems to me to be especially important. While in some ways the state is distinctive, in many others it is a microcosm of America’s death penalty system.

The history of the death penalty in Florida

According to the Death Penalty Information Center, Florida carried out its first execution in 1827, 18 years before it became a state.

Almost 100 years later, in 1923, Florida replaced hanging with the electric chair as its method of execution. After a brief pause in the use of capital punishment in the 1970s, it was one of the first states to get back in the death penalty business.

In the 1990s, the state had several gruesome botched electrocutions. In three cases, the condemned man caught on fire before dying in the chair. To this day, the electric chair remains legal in Florida, though in 2000 the state Legislature enacted a law whereby prisoners may choose between the electric chair and lethal injection.

Over the years, the U.S. Supreme Court has taken the state to task for various constitutional defects in its death penalty laws and practices. In its 1982 decision in Enmund v. Florida, the court ruled that Florida could not use the death penalty to punish people who were minor participants in a crime that led to a murder. And in 2014, the Supreme Court found that Florida was unconstitutionally denying the kind of intellectual disability claims by people with low IQ scores that made them ineligible to be given death sentences.

But these rulings have not stopped the state from continuing to go its own way in death penalty cases. In 2020, the Florida Supreme Court ended the practice of having a court review capital sentences. This review was meant to ensure that those sentences met the U.S. Constitution’s requirements that they be meted out only in cases that truly warrant them and that they be proportional. To determine proportionality, the court undertaking such a review would compare the case in front of them with similar cases in the same jurisdiction in which the death penalty had been imposed.

Then in 2023, Florida enacted legislation ending the requirement of jury unanimity in death cases. Now, it takes only eight out of 12 jurors to send someone to death row. Only three other death penalty states do not require jury unanimity. In Missouri and Indiana, a judge may decide if the jury’s decision isn’t unanimous, and in Alabama, a 10-2 decision is sufficient.

Racial inequality on death row

As in the rest of the country, racial discrimination has long been a feature of Florida’s death penalty system.

Thirty-five percent of the 278 people currently on Florida’s death row are Black. But Black people make up only about 17% of Florida’s overall population.

This is actually lower than the approximately 40% of inmates on death row who are Black nationwide, despite the fact that Black people make up just 14% of the U.S. population.

Across the nation, 13 of the 41 inmates executed so far in 2025 have been Black or Latino men.

Florida leads the nation in the number of people – 30 – who have been sentenced to death only to be exonerated later. Of those, 57% were Black.

A record-setting year

Today, Florida has the second-largest death row population in the United States, with 256 inmates awaiting executions. Only California has more, with 580 inmates on death row, but it has had a moratorium on executions since 2006.

As Florida’s governor, Ron DeSantis is responsible for issuing death warrants. In 2025, he has signed a record-setting 15 so far. That’s the most death warrants in the state in a single year since 2014, when Gov. Rick Scott signed off on putting eight people to death.

Though he is Catholic, DeSantis does not subscribe to the church’s staunch opposition to the death penalty. The Florida Catholic Conference of Bishops has been outspoken in taking him to task for his position on capital punishment and for presiding over an execution spree. But that has not stopped him.

Indeed, on Nov. 3, 2025, the governor said that capital punishment is “an appropriate punishment for the worst offenders.” He added that it could be a “strong deterrent” if the state carried out executions more quickly.

DeSantis has served as governor since 2019, and prior to 2025, he had signed nine death warrants. He says that he was focused on other priorities early in his term and during the COVID-19 pandemic.

The governor, who is term limited, is in his second and last term. DeSantis’ critics allege that the recent uptick in executions is an attempt to garner attention and prove his tough-on-crime bona fides to a national audience.

Florida: Setting the trend, or bucking it?

The total number of executions in the U.S. went from a high of 98 executions in 1999 to a low of 11 in 2021. But that number has increased every year since.

While only one state, Indiana, has resumed executions after a long hiatus, no other state has increased its use of the death penalty as quickly as Florida has. Elsewhere, the common pattern of allowing people to languish on death row for decades, and in some states seemingly permanently, has held.

And although the problems that have long plagued Florida’s death penalty system remain unaddressed, it now stands alone in dramatically escalating its own pace of executions and is leading America to its own 2025 execution revival.

Read more stories from The Conversation about Florida.

Austin Sarat 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. Under Ron DeSantis’ leadership, Florida leads the nation in executions in 2025 – https://theconversation.com/under-ron-desantis-leadership-florida-leads-the-nation-in-executions-in-2025-269125

Source: The Conversation – USA – By Daniel K. Schwartz, Professor of Chemical and Biological Engineering, University of Colorado Boulder

In the home, the lab and the factory, electric fields control technologies such as Kindle displays, medical diagnostic tests and devices that purify cancer drugs. In an electric field, anything with an electrical charge – from an individual atom to a large particle – experiences a force that can be used to push it in a desired direction.

When an electric field pushes charged particles in a fluid, the process is called electrophoresis. Our research team is investigating how to harness electrophoresis to move tiny particles – called nanoparticles – in porous, spongy materials. Many emerging technologies, including those used in DNA analysis and medical diagnostics, use these porous materials.

Figuring out how to control the tiny charged particles as they travel through these environments can make them faster and more efficient in existing technologies. It can also enable entirely new smart functions.

Ultimately, scientists are aiming to make particles like these serve as tiny nanorobots. These could perform complex tasks in our bodies or our surroundings. They could search for tumors and deliver treatments or seek out sources of toxic chemicals in the soil and convert them to benign compounds.

To make these advances, we need to understand how charged nanoparticles travel through porous, spongy materials under the influence of an electric field. In a new study, published Nov. 10, 2025, in the Proceedings of the National Academy of Sciences, our team of engineering researchers led by Anni Shi and Siamak Mirfendereski sought to do just that.

Weak and strong electric fields

Imagine a nanoparticle as a tiny submarine navigating a complex, interconnected, liquid-filled maze while simultaneously experiencing random jiggling motion. While watching nanoparticles move through a porous material, we observed a surprising behavior related to the strength of the applied electric field.

A weak electric field acts only as an accelerator, boosting the particle’s speed and dramatically improving its chance of finding any exit from a cavity, but offering no directional guidance – it’s fast, but random.

In contrast, a strong electric field provides the necessary “GPS coordinates,” forcing the particle to move rapidly in a specific, predictable direction across the network.

This discovery was puzzling but exciting, because it suggested that we could control the nanoparticles’ motion. We could choose to have them move fast and randomly with a weak field or directionally with a strong field.

The former allows them to search the environment efficiently while the latter is ideal for delivering cargo. This puzzling behavior prompted us to look more closely at what the weak field was doing to the surrounding fluid.

By studying the phenomenon more closely, we discovered the reasons for these behaviors. A weak field causes the stagnant liquid to flow in random swirling motions within the material’s tiny cavities. This random flow enhances a particle’s natural jiggling and pushes it toward the cavity walls. By moving along walls, the particle drastically increases its probability of finding a random escape route, compared to searching throughout the entire cavity space.

A strong field, however, provides a powerful directional push to the particle. That push overcomes the natural jiggling of the particle as well as the random flow of the surrounding liquid. It ensures that the particle migrates predictably along the direction of the electric field. This insight opens the door for new, efficient strategies to move, sort and separate particles.

Tracking nanoparticles

To conduct this research, we integrated laboratory observation with computational modeling. Experimentally, we used an advanced microscope to meticulously track how individual nanoparticles moved inside a perfectly structured porous material called a silica inverse opal.

We then used computer simulations to model the underlying physics. We modeled the particle’s random jiggling motion, the electrical driving force and the fluid flow near the walls.

By combining this precise visualization with theoretical modeling, we deconstructed the overall behavior of the nanoparticles. We could quantify the effect of each individual physical process, from the jiggling to the electrical push.

Devices that move particles

This research could have major implications for technologies requiring precise microscopic transport. In these, the goal is fast, accurate and differential particle movement. Examples include drug delivery, which requires guiding “nanocargo” to specific tissue targets, or industrial separation, which entails purifying chemicals and filtering contaminants.

Our discovery – the ability to separately control a particle’s speed using weak fields and its direction using strong fields – acts as a two-lever control tool.

This control may allow engineers to design devices that apply weak or strong fields to move different particle types in tailored ways. Ultimately, this tool could improve faster and more efficient diagnostic tools and purification systems.

What’s next

We’ve established independent control over the particles’ searching using speed and their migration using direction. But we still don’t know the phenomenon’s full limits.

Key questions remain: What are the upper and lower sizes of particles that can be controlled in this way? Can this method be reliably applied in complex, dynamic biological environments?

Most fundamentally, we’ll need to investigate the exact mechanism behind the dramatic speedup of these particles under a weak electric field. Answering these questions is essential to unlocking the full precision of this particle control method.

Our work is part of a larger scientific push to understand how confinement and boundaries influence the motion of nanoscale objects. As technology shrinks, understanding how these particles interact with nearby surfaces will help design efficient, tiny devices. And when moving through spongy, porous materials, nanoparticles are constantly encountering surfaces and boundaries.

The collective goal of our and others’ related research is to transform the control of tiny particles from a process of trial and error into a reliable, predictable science.

Daniel K. Schwartz receives funding from the US Department of Energy, the National Science Foundation, and the National Institutes of Health.

Ankur Gupta receives funding from the National Science Foundation and the Air Force Office of Scientific Research.

– ref. Electric fields steered nanoparticles through a liquid-filled maze – this new method could improve drug delivery and purification systems – https://theconversation.com/electric-fields-steered-nanoparticles-through-a-liquid-filled-maze-this-new-method-could-improve-drug-delivery-and-purification-systems-268553