Nearly 70% of U.S. children in car crashes with a fatality were not using proper child passenger restraints, study finds

Improper child passenger restraints included premature transition to a less protective seat, riding in the front seat and riding without a seatbelt

Ann & Robert H. Lurie Children's Hospital of Chicago

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Despite national guidelines, state laws and known safety benefits of child passenger restraint systems (CRS), suboptimal practices were found in nearly 70% of children under 13 years old who were involved in car crashes with a fatality from 2011 to 2021, according to a study published in the journal Traffic Injury Prevention.

“Given the continued problem of suboptimal child passenger safety practices among children across the country, there is a need for innovative, targeted programs to promote correct and consistent use of age-appropriate car seats, restraints and seating locations,” said lead author Arthi Kozhumam, MScGH, a PhD candidate in the Medical Scientist Training Program in the Macy Lab at Stanley Manne Children’s Research Institute at Ann & Robert H. Lurie Children’s Hospital of Chicago.

An average of three child fatalities and an estimated 429 child injuries occur each day as the result of motor vehicle crashes in the United States.

The study found that inappropriate child passenger safety practices were more common in children who were 4-7 and 8-12 years old, traveling with drivers from under-resourced communities (ie, with low or very low Child Opportunity Index), and across 75 county-level hotspots throughout the country.

“A novel contribution of this research is our finding of geographic concentrations of suboptimal child passenger safety practices. These areas can be targeted for interventions, especially in the most vulnerable age groups,” said senior author Michelle Macy, MD, MS, Director, Mary Ann & J. Milburn Smith Child Health Outcomes, Research and Evaluation Center at Manne Research Institute at Lurie Children’s and Professor of Pediatrics (Emergency Medicine) at Northwestern University Feinberg School of Medicine.

“The Child Opportunity Index also may provide a lens for targeted prioritization of educational interventions and deployment of passenger safety resources,” added Dr. Macy.

The study analyzed passenger safety practices in 50,000 children involved in a car crash with at least one fatality recorded in the national Fatality Analysis Reporting System (FARS) database – the largest available dataset. Researchers found that 36% of these children were prematurely transitioned to a less protective restraint, 20% were riding unrestrained and 15% were riding in the front seat. Additionally, 9% of children sitting in the front seat were also unrestrained.

The study furthermore revealed that stricter CRS laws and larger fines for first seat belt offense are significantly associated with lower odds of suboptimal child passenger safety practices.

“In addition to identifying individual factors and geographic areas that can be targeted for interventions, we show that state policy makes a huge difference in promoting safer transportation practices for child passengers,” said Dr. Macy.

At Lurie Children’s, the Buckle Up Program helps families stay informed and confident about car seat safety through education, resources and personalized support.

Dr. Macy holds the Mary Ann and J. Milburn Smith Research Professorship for the Director of Child Health Research at Lurie Children’s.

Ann & Robert H. Lurie Children’s Hospital of Chicago is a nonprofit organization committed to providing access to exceptional care for every child. It is the only independent, research-driven children’s hospital in Illinois and one of less than 35 nationally. This is where the top doctors go to train, practice pediatric medicine, teach, advocate, research and stay up to date on the latest treatments. Exclusively focused on children, all Lurie Children’s resources are devoted to serving their needs. Research at Lurie Children’s is conducted through Stanley Manne Children’s Research Institute, which is focused on improving child health, transforming pediatric medicine and ensuring healthier futures through the relentless pursuit of knowledge. Lurie Children’s is the pediatric training ground for Northwestern University Feinberg School of Medicine. It is ranked as one of the nation’s top children’s hospitals by U.S. News & World Report.

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Journal

Traffic Injury Prevention

DOI

10.1080/15389588.2025.2526615 

 

Do you want to freeze a cloud? Desert dust might help

ETH Zurich researchers uncover a subtle force in cloud formation

ETH Zurich

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The wind carries dust particles from the Sahara Desert great distances enabling ice cloud formation.

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Credit: Diego Villenueva Ortiz / ETH Zurich

In brief:

• Using 35 years of satellite data, researchers observed a consistent pattern for ice cloud formation stemming from desert dust in the atmosphere.
• The way clouds freeze is vital piece of the puzzle for climate models.
• For the first time, researchers demonstrate that ice formation follows the same pattern at different scales expanding the scope of this type of research.

A new study shows that natural dust particles, swirling in from faraway deserts can trigger freezing of clouds in Earth’s Northern Hemisphere. This subtle mechanism influences how much sunlight clouds reflect and how they produce rain and snow — with major implications for climate projections.

Drawing on 35 years of satellite observations, an international research team led by ETH Zurich found that mineral dust—tiny particles swept up by the wind and carried into the upper atmosphere—can trigger the freezing of cloud droplets. This process is particularly important in northern regions, where clouds often form in a temperature range just below freezing.

“We found that where there’s more dust, clouds are much more likely to freeze at the top,” explains Diego Villanueva, a Post-doctoral researcher for Atmospheric Physics at ETH Zurich and lead author of the study. “This has a direct impact on how much sunlight is reflected back into space and how much precipitation is generated.”

Dust turns clouds to ice

The researchers focused on mixed-phase clouds, which contain both supercooled water and ice, forming between −39 °C and zero °C. These clouds are common in mid- and high-latitudes, especially over the North Atlantic, Siberia, and Canada. They are known to be extremely sensitive to changes in their environment—particularly to the presence of ice-nucleating particles which stem primarily from desert dust aerosols.

By comparing the frequency of ice-topped clouds with dust levels, the researchers observed a remarkably consistent pattern: The more dust and the cooler the clouds, the more frequent the ice clouds. What is more, according to the researchers, this pattern aligned almost perfectly with what laboratory experiments had predicted about how dust triggers droplet freezing.

“This is one of the first studies to show that satellite measurements of cloud composition match what we’ve known from lab work,” says Ulrike Lohmann, senior co-author, and Professor of Atmospheric Physics at ETH Zurich.

A new benchmark for climate models

The way clouds freeze directly affects how much sunlight they bounce back into space and how much water they release as precipitation. These factors are vital for climate models, but until now, many of these models lacked a solid reference point for how cloud freezing really works on a global scale.

The new findings establish a measurable link between airborne dust and cloud-top ice frequency, providing a critical benchmark for improving climate projections. “It helps identify one of the most uncertain pieces of the climate puzzle,” says Villanueva.

A complex picture – with a clear signal

For decades, atmospheric scientists have studied droplet freezing at the microscale. This study shows, for the first time, that cloud ice formation (or glaciation) follows the same behaviour as droplet freezing—but on a much larger scale. This finding expands the scope of atmospheric research in this area - from nanometre-scale structures of dust surfaces that form atmospheric ice crystals to kilometre-scale cloud systems in which ice formation can be observed from space.

Still, the dust–ice link does not play out equally across the globe. In desert regions like the Sahara, cloud formation is sparse, and the strong movement of hotter air may suppress the freezing process. Also in the Southern Hemisphere, marine aerosols may take over dust’s role. The researcher team emphasizes the need for further studies to better understand how other factors such as updraft strength or atmospheric humidity, for example, influence cloud freezing. For now, however, one thing is clear: Tiny dust grains from distant deserts help shape the clouds above our heads—and with them, the future of our climate.

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Journal

Science

DOI

10.1126/science.adt5354 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Dust-driven droplet freezing explains cloud top phase in the northern extratropics

Article Publication Date

31-Jul-2025

 

Climate interventions to save our oceans need stronger governance, experts warn

Climate interventions are accelerating in our oceans – but without responsible governance, they could do more harm than good, according to new research

University of Melbourne

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Climate interventions are accelerating in our oceans – but without responsible governance, they could do more harm than good, according to new research.

Coral bleaching, rising sea levels, and biodiversity loss are no longer distant threats – they are unfolding now, with profound consequences for marine ecosystems and the communities that depend on them.

In response, scientists, governments, and industries are racing to develop and deploy a suite of interventions to help the ocean respond to climate change.

The new study, published today in Science, reviewed the array of novel interventions that are being used in urgent response to the scale and intensity of the climate crisis and the dramatic changes in our oceans.

These include efforts to make the ocean less acidic to absorb more carbon dioxide, breeding climate-resilient corals that can survive warmer waters, farming seaweed to capture carbon, and restoring mangroves to protect coastlines and naturally store carbon.

Lead author, University of Melbourne Professor Tiffany Morrison said while these interventions offer hope, they also carry significant risks.

“Without robust governance, we risk repeating past mistakes – implementing solutions that are ineffective, inequitable, or even harmful,” Professor Morrison said.

“The pace of innovation is outstripping our ability to regulate, monitor, and evaluate these interventions responsibly.

“Private and nonprofit funding is accelerating the ambition. In 2020 alone, philanthropists had allocated $160 million to oceanic climate action, with another US$250 million announced at COP28 in 2023 for a new global Ocean Resilience and Climate Alliance.”

The researchers say to navigate these challenges, we must embrace the concept of responsible marine transformation – a governance approach that prioritises sustainability, equity, and adaptability.

“This means weighing risks against benefits, resolving ethical liabilities, improving social co-benefits, and aligning adaptation interventions with broader climate mitigation goals,” Professor Morrison said.

“It is vital we conduct rigorous, comparative studies to assess the climate benefits and risks of interventions, including their scalability and long-term viability.”

Co-author, University of Exteter Professor Neil Adger said communities must be engaged.

“This means collaborating with Indigenous peoples and local stakeholders from the outset, ensuring their knowledge, values, and rights shape intervention design and implementation,” Professor Adger said.

“If interventions are proven viable, we must also develop and apply bioethical protocols that address not just animal welfare, but broader ecological and societal implications of upscaled deployment.”

This research was funded by the Australian Research Council (ARC) and the US Society for Nature and People Partnership. Collaborators included James Cook University, the University of Michigan, the University of Exeter, the Gulf of Maine Research Institute, the University of Tasmania, and the Institute of Marine and Atmospheric Studies.

Professor Morrison was recently awarded an Australian Laureate Fellowship from the ARC to improve global marine futures.

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Journal

Science

DOI

10.1126/science.adq0174 

Subject of Research

Not applicable

Article Title

Governing new climate interventions in rapidly changing oceans

Article Publication Date

31-Jul-2025

 

Changes in diet drove physical evolution in early humans

Study: Hominins had a taste for high-carb plants long before they had the teeth to eat them, providing first evidence of behavioral drive in the human fossil record

Dartmouth College

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The researchers report that hominin teeth, especially molars, became smaller and longer over millennia to accommodate a growing diet of tough grass-like plants known as graminoids and their underground storage organs. They found that the turn toward grasses began about 3.8 million years ago with the distant human relative Australopithecus afarensis (left). About 2.3 million years ago, the early human Homo rudolfensis (center) gained regular access to carbohydrate-rich underground plant organs such as tubers, bulbs, and corms. But this dietary shift toward outpaced tooth evolution until about 2 million years ago when species such as Homo ergaster (right) exhibited a spurt of change in tooth size and shape better suited to eating and breaking down cooked plant tissues to derive their nutrients. 

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Credit: L to R: Public domain; Don Hitchcock; Fernando Losada Rodríguez (rotated)

As early humans spread from lush African forests into grasslands, their need for ready sources of energy led them to develop a taste for grassy plants, especially grains and the starchy plant tissue hidden underground.

But a new Dartmouth-led study shows that hominins began feasting on these carbohydrate-rich foods before they had the ideal teeth to do so. The study provides the first evidence from the human fossil record of behavioral drive, wherein behaviors beneficial for survival emerge before the physical adaptations that make it easier, the researchers report in Science.

The study authors analyzed fossilized hominin teeth for carbon and oxygen isotopes left behind from eating plants known as graminoids, which includes grasses and sedges. They found that ancient humans gravitated toward consuming these plants far earlier than their teeth evolved to chew them efficiently. It was not until 700,000 years later that evolution finally caught up in the form of longer molars like those that let modern humans easily chew tough plant fibers.

The findings suggest that the success of early humans stemmed from their ability to adapt to new environments despite their physical limitations, says Luke Fannin, a postdoctoral researcher at Dartmouth and lead author of the study.

"We can definitively say that hominins were quite flexible when it came to behavior and this was their advantage," Fannin says. "As anthropologists, we talk about behavioral and morphological change as evolving in lockstep. But we found that behavior could be a force of evolution in its own right, with major repercussions for the morphological and dietary trajectory of hominins."

Nathaniel Dominy, the Charles Hansen Professor of Anthropology at Dartmouth and senior author of the study, says isotope analysis overcomes the enduring challenge of identifying the factors that caused the emergence of new behaviors—behavior doesn't fossilize.

"Anthropologists often assume behaviors on the basis of morphological traits, but these traits can take a long time—a half-million years or more––to appear in the fossil record," Dominy says.

"But these chemical signatures are an unmistakable remnant of grass-eating that is independent of morphology," he says. "They show a significant lag between this novel feeding behavior and the need for longer molar teeth to meet the physical challenge of chewing and digesting tough plant tissues."

The team analyzed the teeth of various hominin species, beginning with the distant human relative Australopithecus afarensis, to track how the consumption of different parts of graminoids progressed over millennia. For comparison, they also analyzed the fossilized teeth of two extinct primate species that lived around the same time—giant terrestrial baboon-like monkeys called theropiths and small leaf-eating monkeys called colobines.

All three species veered away from fruits, flowers, and insects toward grasses and sedges between 3.4 million to 4.8 million years ago, the researchers report. This was despite lacking the teeth and digestive systems optimal for eating these tougher plants.

Hominins and the two primates exhibited similar plant diets until 2.3 million years ago when carbon and oxygen isotopes in hominin teeth changed abruptly, the study found. This plummet in both isotope ratios suggests that the human ancestor at the time, Homo rudolfensis, cut back on grasses and consumed more oxygen-depleted water.

The researchers lay out three possible explanations for this spike, including that these hominins drank far more water than other primates and savanna animals, or that they suddenly adopted a hippopotamus-like lifestyle of being submerged in water all day and eating at night.

The explanation most consistent with what's known about early-human behavior, they report, is that later hominins gained regular access to underground plant organs known as tubers, bulbs, and corms. Oxygen-depleted water also is found in these bulging appendages that many graminoids use for storing large amounts of carbohydrates safely away from plant-eating animals.

The transition from grasses to these high-energy plant tissues would make sense for a species growing in population and physical size, Fannin says. These underground caches were plentiful, less risky than hunting, and provided more nutrients for early humans' expanding brains. Having already adopted stone tools, ancient humans could dig up tubers, bulbs, and corms while facing little competition from other animals.

"We propose that this shift to underground foods was a signal moment in our evolution," Fannin says. "It created a glut of carbs that were perennial—our ancestors could access them at any time of year to feed themselves and other people."

Measurements of hominin teeth showed that while they became consistently smaller—shrinking about 5% every 1,000 years—molars grew longer, the researchers report. Hominins' dietary shift toward graminoids outpaced that physical change for most of their history.

But the study found that the ratio flipped about 2 million years ago with Homo habilis and Homo ergaster, whose teeth exhibited a spurt of change in shape and size more suited to eating cooked tissues, such as roasted tubers.

Graminoids are ubiquitous across many ecosystems. Wherever they were, hominins would have been able to maximize the nutrients derived from these plants as their teeth became more efficient at breaking them down, Dominy says.

"One of the burning questions in anthropology is what did hominins do differently that other primates didn't do? This work shows that the ability to exploit grass tissues may be our secret sauce," Dominy says.

"Even now, our global economy turns on a few species of grass––rice, wheat, corn, and barley," he says. "Our ancestors did something completely unexpected that changed the game for the history of species on Earth."

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Journal

Science

DOI

10.1126/science.ado2359 

Method of Research

Experimental study

Subject of Research

People

Article Title

Behavior drives morphological change during human evolution

Article Publication Date

31-Jul-2025

WITHOUT DOGE

US Medicare could save $3.6 billion without risk to older adults, study suggests

Fewer low-value tests, scans and procedures could also save older adults $800 million in out-of-pocket costs

Michigan Medicine - University of Michigan

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The federal government’s Medicare program and older adults together spend $4.4 billion a year on care that has low clinical value for patients and can even raise their risk of harm, a new study finds.

The study focuses on 47 tests, scans and procedures that research has shown don’t benefit most patients. Reducing their use in patients who clearly won’t benefit could preserve Medicare funding for more important care, the researchers conclude.

In fact, focusing on just five of the services could prevent $2.6 billion in spending by Medicare and the older adults enrolled in it. All five have received a grade of “D” from the U.S. Preventive Services Task Force because research has shown they are ineffective or have risks that outweigh their benefit.

The D grade means the Secretary of Health and Human Services can authorize the Medicare system to withhold payment under the Affordable Care Act.

The five services are: screening for all older adults for chronic obstructive pulmonary disease; screening for bacteria in the urine of patients without symptoms; testing men older than 70 for prostate-specific antigen if they have no personal or family history of prostate issues; and screening older adults with no symptoms for blockage in the carotid arteries in their neck, or for heart rhythm issues using an electrocardiogram.

The study also includes 42 services identified as low-value for some or all patients by other entities, including major medical professional societies, based on research studies. Seventeen of them, and three of the grade D services, together accounted for 94% of the low-value care identified in the study.

Health economist David D. Kim, Ph.D. of the University of Chicago and primary care physician A. Mark Fendrick, M.D. of the University of Michigan Medical School’s Center for Value-Based Insurance Design did the study in light of federal efforts to reduce waste and curb the growth in costs for Medicare. They published their findings in JAMA Health Forum.

“Patients who can benefit from these services should absolutely receive them, but we show that tremendous savings could be achieved by avoiding them in patients who won’t benefit or could be harmed,” said Kim. “It’s also important to note that our findings don’t include spending on care that follows a low-value test, scan or procedure, which in the case of universal PSA screening has been estimated to be $6 for every $1 spend on screening.”

Fendrick notes that the study is based on clinical evidence, which draws distinctions between patients who could or could not stand to benefit from one of the 47 services.

The researchers achieved this by looking closely at anonymous data from services that traditional Medicare paid for in a random sample of people between 2018 and 2020. They then extrapolated their findings to the entire Medicare population. 

“This research is very policy relevant as it takes a clinically driven, patient-focused approach to quantifying unnecessary medical spending,” said Fendrick. “This is much more nuanced than ‘blunt’ policies that reduce government spending on health care but could harm patients.”

He notes that the section of the ACA that authorizes Medicare to remove coverage for low-value preventive services that have received a D grade from USPSTF is an example of value-based insurance design in the ACA; links to this provision and others are available from the U-M VBID center website.

The entire list of services analyzed in the study, and their rank in both total spending and in the 20 most-used services, is available here.

The study was funded by a research grant to Kim from Arnold Ventures, a philanthropic fund which played no role in the study. Kim is an alumnus of the U-M School of Public Health biostatistics program.

Reference: Projected Savings from Reducing Low-Value Services in Medicare, JAMA Health Forum, doi:10.1001/jamahealthforum.2025.3050

 

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Journal

JAMA Health Forum

DOI

10.1001/jamahealthforum.2025.3050 

Method of Research

Data/statistical analysis

Subject of Research

People

Article Title

Projected Savings from Reducing Low-Value Services in Medicare

Article Publication Date

1-Aug-2025