Nontraditional risk factors shed light on unexplained strokes in adults younger than 50

Adults younger than 50 years of age had more than double the risk of having a stroke from migraine or other nontraditional stroke risk factors rather than traditional risks such as high blood pressure, according to research published in Stroke.

Previous research indicates the rate of ischemic (clot-caused) stroke among adults 18–49 years old is increasing and propelled by a corresponding rise in cryptogenic strokes (strokes of unknown cause) in adults without traditional risk factors, including high blood pressure, smoking, obesity, high cholesterol and type 2 diabetes.

Up to half of all ischemic strokes in younger adults are of unknown causes, and they are more common in women. For effective prevention, careful and routine assessment of both traditional and nontraditional risk factors in younger people is critical. 

Researchers analyzed data for more than 1,000 adults aged 18–49 in Europe, with a median age of 41 years. Half of the participants had experienced a cryptogenic ischemic stroke, while half had no history of stroke.

The study examined the associations of 12 traditional risk factors, 10 nontraditional risk factors and five risk factors specific to women (such as gestational diabetes or pregnancy complications). Researchers also closely reviewed participants with a heart defect called patent foramen ovale (PFO), a hole between the heart's upper chambers.

Part 1

A PFO is usually harmless yet is known to increase the odds of stroke. The study aimed to determine which risk factors contribute the most to unexplained strokes.

The analysis found:

Traditional risk factors were more strongly associated with stroke in men and women without a PFO.
In contrast, nontraditional risk factors, such as blood clots in the veins, migraine with aura, chronic kidney disease, chronic liver disease or cancer, were more strongly associated with stroke among study participants with a PFO.
In those without a PFO, each additional traditional risk factor increased stroke risk by 41%, while each nontraditional risk factor increased stroke risk by 70%.
Risk factors related to women also increased stroke risk by 70% independent of traditional and nontraditional risk factors.
Among participants with a PFO, each traditional risk factor increased the risk of stroke by 18%. However, after considering individual demographic factors, such as age, sex and level of education, nontraditional risk factors more than doubled the odds of having an ischemic stroke.
Researchers also analyzed the study population's attributable risk (determining how a disease would be impacted if a certain risk factor were eliminated). To calculate population-attributable risk, researchers analyzed each risk factor and their contribution to the increased risk separately and found:

For strokes that occur without a PFO, traditional risk factors accounted for about 65% of the cases, nontraditional risk factors contributed 27% and risk factors specific to women made up nearly 19% of the cases.
In contrast, for strokes associated with a PFO, traditional risk factors contributed about 34%, nontraditional risk factors accounted for 49% and female-specific risk factors represented about 22%.
Notably, migraine with aura was the leading nontraditional risk factor associated with strokes of unknown origin, with a population-attributable risk of about 46% for strokes among people with a PFO and about 23% for those without a PFO, indicating a higher risk for people with PFO.
The role of non-traditional risk factors, especially migraine headaches, which seems to be one of the leading risk factors in the development of strokes in younger adults, is a new revelation.

Burden of Modifiable Risk Factors in YoungOnset Cryptogenic Ischemic Stroke by High-Risk Patent Foramen Ovale, Stroke (2025). DOI: 10.1161/STROKEAHA.124.049855

Part 2

Red, pink or white, all roses were once yellow says genomic analysis

Red roses, the symbol of love, were likely yellow in the past, indicates a large genomic analysis by researchers.

Roses of all colors, including white, red, pink, and peach, belong to the genus Rosa, which is a member of the Rosaceae family.

Reconstructing the ancestral traits through genomic analysis revealed that all the roads trace back to a common ancestor—a single-petal flower with yellow color and seven leaflets.

The findings are published in Nature Plants.

Accounting for almost 30% of the cut flower market sales, roses are the most widely cultivated ornamental plants and have been successfully domesticated to reflect the aesthetic preferences of each era.

It all began with the rose breeding renaissance in the 1700s, marked by the crossing of ancient wild Chinese roses and old European cultivars—plants selectively bred through human intervention to develop a desirable characteristic.

Currently, we have over 150 to 200 species of roses and more than 35,000 cultivars, displaying a wide range of blooming frequencies, fragrances, and colors. However, global climate change has prompted rose breeders to shift their focus from purely cosmetic traits to breeding rose varieties that are more resistant to stress factors like drought, disease and easier to care for.

Borrowing genetic resources from wild rose varieties, which offer valuable traits such as fragrance and disease resistance, presents a promising strategy for breeding resilient, low-maintenance rose cultivars.

A clear understanding of the origin and evolution of the Rosa genus, both wild and cultivated varieties, can not only advance the breeding efforts but also aid in the conservation of near-threatened rose varieties.

Part 1

Having this in mind, the researchers collected 205 samples of over 80 Rosa species, covering 84% of what is documented in the "Flora of China."

The samples were then analyzed using genomic sequencing, population genetics, and other methods to trace back their ancestral traits. They studied 707 single-copy genes uncovered as a set of conserved genetic markers like single-nucleotide polymorphisms—the most common type of genetic variation found in DNA—which helped them chart the evolutionary and geographical history and connections between the rose species.

Ancestral trait reconstruction showed that the shared ancestor of the studied samples was a yellow flower with a single row of petals and leaves divided into seven leaflets. As roses evolved and were domesticated, they developed new colors, distinct petal markings, and the ability to bloom in clusters.
The study also brought new insight to the widely accepted notion that the Rosa genus originated in Central Asia. The genetic evidence pointed to two major centers of rose diversity in China—one in the dry northwest, where yellow roses with small leaves grow, and another in the warm and humid southwest, where the white, fragrant variety thrives.

 Bixuan Cheng et al, Phenotypic and genomic signatures across wild Rosa species open new horizons for modern rose breeding, Nature Plants (2025). DOI: 10.1038/s41477-025-01955-5

Valéry Malécot, An evolutionary bouquet for roses, Nature Plants (2025). DOI: 10.1038/s41477-025-01971-5

Part 2

Cold welding, also known as cold pressure welding or contact welding, is a solid-state joining process that creates strong bonds between metals without heat. It relies on high pressure to deform the surfaces of the metals, bringing them into intimate contact and forming a strong metallurgical bond.
Here's a more detailed explanation:
How it works:
No Heat:
Unlike traditional welding, cold welding doesn't involve melting or heating the metals.
Pressure:
The process relies on applying high pressure to the joined surfaces, causing plastic deformation and forming a bond.
Solid State:
The metals remain in a solid state throughout the process.
Clean Surfaces:
The surfaces of the metals must be very clean and free of oxides or other contaminants for a strong bond to form.
Advantages:
No Heat Affected Zone (HAZ):
Because no heat is involved, there's no heat affected zone, which can alter the properties of the metal.
Strong Bonds:
Cold welding can create strong bonds that are often as strong as the parent metal.
Dissimilar Metals:
It can be used to join dissimilar metals.
Suitable for Sensitive Materials:
It's ideal for joining metals that are heat-sensitive, such as aluminum and copper, where traditional welding could compromise their properties.
Disadvantages:
Surface Preparation: Requires meticulous surface preparation to remove oxides and contaminants.
Limited to Ductile Metals: Best suited for ductile metals like aluminum, copper, and brass alloys.
High Pressure: Requires high pressure to create the bond, which can be expensive and challenging.
Not for Irregular Surfaces: Less effective on irregular surfaces.
Applications:
Joining Aluminum and Copper:
Widely used for joining these metals, especially in applications where heat is undesirable.
Aerospace and Electronics:
Important in industries where avoiding heat distortion is crucial, such as in aerospace and electronics.
Wire Joining:
Used for joining wires together.
Space Applications:
Can be used in space for joining parts in environments with no heat sources.

Cold welding is a solid-state welding process where metals bond without the need for heat, and it's a significant concern in space due to the vacuum environment. This phenomenon can cause malfunctions and even failures in spacecraft mechanisms, such as deployment issues and stuck mechanisms.
What it is:
Cold welding occurs when clean metal surfaces of the same material are brought into close contact under high pressure, even without heat or external agents.
In space, the vacuum environment removes the air that would normally form an oxide layer on the metal surface, allowing for a stronger bond to form.
This process can be problematic because it can lead to the formation of undesired bonds between moving parts, causing them to become stuck or malfunction.
How it affects space missions:
Deployment Issues:
Cold welding can cause mechanisms designed to deploy antennas, solar panels, or other structures to fail to deploy properly.
Stuck Mechanisms:
It can also lead to mechanisms becoming stuck in a closed or folded position, preventing them from functioning as intended.
Galileo High-Gain Antenna:
A notable example is the 1991 Galileo spacecraft, where the high-gain antenna failed to deploy fully due to cold welding, which caused the umbrella-shaped antenna ribs to bond in their folded configuration.
Wire Harnesses:
Cold welding can also affect wire harnesses, causing individual wires to bond together and increasing harness stiffness, potentially leading to wire breakage or electrical overload.
Mitigation Strategies:
Material Selection:
Using dissimilar metals or metals with low contact adhesion can help prevent cold welding.
Coatings:
Applying coatings that reduce the adhesion of surfaces can also be effective.
Lubrication:
Using appropriate lubricants can reduce friction and prevent the formation of cold welds.
Reduced Contact Area:
Reducing the contact area between moving parts can minimize the potential for cold welding.
Cleanliness:
Maintaining cleanliness and preventing contamination of surfaces can also help prevent cold welding.

New quantum-based navigation system 50 times more accurate than traditional GPS

A team of researchers has announced the successful demonstration of its newly developed quantum navigation system called "Ironstone Opal."

The group has written a paper describing how their system works and how well it tested against currently available backup GPS systems and has posted it on the arXiv preprint server.

With the advent and subsequent reliance on GPS by private and military vehicles and aircraft for navigation, governments have come to understand how vulnerable such systems can be. Outages can lead to drivers being stranded, pilots scrambling to use outdated systems and difficulties deploying military assets. I myself have faced these difficulties when I was stranded in the middle of roads and also wilderness.

Because of that, scientists around the world have been looking for reasonable backup systems, or even possible alternatives to GPS.

In this new effort, the team at Q-CTRL has developed such a backup system and is claiming that it is 50 times more accurate than any other backup GPS currently available under some scenarios.

The new system, Ironstone Opal, uses quantum sensors that are so sensitive they can be used to precisely self-locate an object using the Earth's magnetic field. The team at Q-CTRL noted that the magnetic field varies depending on location relative to the Earth. To take advantage of that, they built sensors that can precisely read the field and then use AI-based software to give X and Y geographic coordinates in the same fashion as GPS.

The researchers note that their system is passive, which means it does not emit signals that could be "heard" by other devices and cannot be jammed. They also note that their software system can filter out noise generated by vehicles or planes carrying the sensors. They point out that the system is small enough to be installed in any car, truck, or other land vehicle, as well as in drones and other aircraft.

Testing of the system on the ground, the researchers claim, showed it to be 50 times as accurate as any other GPS backup system. In the air, it was found to be 11 times more accurate than other backup systems..

 Murat Muradoglu et al, Quantum-assured magnetic navigation achieves positioning accuracy better than a strategic-grade INS in airborne and ground-based field trials, arXiv (2025). DOI: 10.48550/arxiv.2504.08167

Microplastics still slip through wastewater treatment plants, carrying pollutants and threatening long-term health

Despite advances in wastewater treatment, tiny plastic particles called microplastics are still slipping through, posing potential health and environmental hazards, according to new research.

Because plastic is inexpensive to produce yet lightweight and sturdy, manufacturers have found it ideal for use in nearly every consumer good, from food and beverage packaging to clothing and beauty products. The downside is that when a plastic item reaches the end of its useful life, it never truly disappears. Instead, it breaks down into smaller and smaller pieces called microplastics—particles five millimeters or less, about the width of a pencil eraser—that end up in our soil and water.

 Systematic literature review found  that while most waste water treatment facilities significantly reduce microplastics loads, complete removal remains unattainable with current technologies. The study is  published in Science of the Total Environment.

As a result, many microplastics are being reintroduced into the environment, likely transporting other residual harmful pollutants in wastewater, such the chemicals Bisphenols, PFAS and antibiotics. These microplastics and organic pollutants would exist in trace levels, but we can get exposure through simple actions like drinking water, doing laundry or watering plants, leading to potential long-term serious human health impacts such as cardiovascular disease and cancer.

The researchers  found that the effectiveness of treatments varies depending on the technology communities use and how microplastics are measured to calculate the removal rates.

Jenny Kim Nguyen et al, A review on microplastic fibers and beads in wastewater: The current knowledge on their occurrence, analysis, treatment, and insights on human exposure impact, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.178818

Himalayan snow at 23-year low, threatening 2 billion people: report

Snowfall in Asia's Hindu Kush-Himalayan mountain range has reached a 23-year low, threatening nearly two billion people dependent on snowmelt for water, scientists warned in a report this week.

The Hindu Kush-Himalayan range, which stretches from Afghanistan to Myanmar, holds the largest reserves of ice and snow outside the Arctic and Antarctica and is a vital source of fresh water for about two billion people.

Researchers found "a significant decline in seasonal snow across the Hindu Kush Himalaya region, with snow persistence (the time snow remains on the ground) 23.6% below normal — the lowest in 23 years," the International Center for Integrated Mountain Development (ICIMOD) said.

"This trend, now in its third consecutive year, threatens water security for nearly two billion people," it said in its Snow Update Report.

The study also warned of "potential lower river flows, increased groundwater reliance, and heightened drought risk."

Several countries in the region have already issued drought warnings, with upcoming harvests and access to water at risk for populations already facing longer, hotter, and more frequent heatwaves.

The inter-governmental ICIMOD organization is made up of member countries Afghanistan, Bangladesh, Bhutan, China, India, Myanmar, Nepal and Pakistan.

It urged countries that rely on the 12 major river basins in the region to develop "improved water amangement, stronger drought preparedness, better early warning systems, and greater regional cooperation."

The Mekong and Salween basins -- the two longest rivers in Southeast Asia supplying water to China and Myanmar -- had lost around half of their snow cover, it noted.

Source: News Agencies

Antibiotic pollution in rivers follows 65% increase in human consumption, study shows

Human consumption of antibiotics increased by 65% between 2000 and 2015. These drugs are not completely metabolized while passing through the body, nor completely destroyed or removed by most wastewater treatment facilities.

Published in PNAS Nexus,  researchers calculate that worldwide humans consume around 29,200 tonnes of the 40 most used antibiotics. After metabolism and wastewater treatment, an estimated 8,500 tonnes (29% of consumption) may reach the world's river systems, and 3,300 tonnes (11%) may arrive at the world's oceans or inland sinks (such as lakes or reservoirs).

The authors calculate these figures using a model validated by data on measured concentrations of 21 antibiotics at 877 locations globally. While the total amounts of antibiotic residues translate into only very small concentrations in most rivers, which makes the drugs very difficult to detect, chronic environmental exposure to these substances can still pose a risk.

Antibiotics in rivers and lakes can reduce microbial diversity, increase the presence of antibiotic-resistant genes, and possibly impact the health of fish and algae. The authors calculate that levels of antibiotics are high enough to create a potential risk for aquatic ecosystems and antibiotic resistance during low-flow conditions (i.e., at times of less dilution) on 6 million kilometers of rivers.

Waterways with high concentrations are found across all continents, with the most impacted regions located in Southeast Asia. Amoxicillin is the antibiotic most often predicted to be found at high-risk concentrations and is the most-consumed antibiotic around the world.

The authors note that this version of their model does not include antibiotics given to livestock, which include many of the same drugs, or pharmaceutical manufacturing waste. However, the results show that antibiotic pollution in rivers arising from human consumption alone is a critical issue, which would likely be exacerbated by veterinary or industry sources of related compounds.

According to the authors, monitoring programs and strategies to manage antibiotic contamination of waterways, especially in areas at risk, are warranted.

Heloisa Ehalt Macedo et al, Antibiotics in the global river system arising from human consumption, PNAS Nexus (2025). DOI: 10.1093/pnasnexus/pgaf096

Scientists have found a way to 'tattoo' tardigrades

Tardigrades are clumsy, eight-legged creatures, nicknamed water bears, are about half a millimeter long and can survive practically anything: freezing temperatures, near starvation, high pressure, radiation exposure, outer space and more. Researchers reporting in the journal Nano Letters took advantage of the tardigrade's nearly indestructible nature and gave the critters tiny "tattoos" to test a microfabrication technique to build microscopic, biocompatible devices.

Through this technology,scientists are not just creating micro-tattoos on tardigrades—they are extending this capability to various living organisms, including bacteria.

Microfabrication has revolutionized electronics and photonics, creating micro- and nanoscale devices ranging from microprocessors and solar cells to biosensors that detect food contamination or cancerous cells. But the technology could also advance medicine and biomedical engineering, if researchers can adapt microfabrication techniques to make them compatible with the biological realm.

Researchers employed a process that carves a pattern with an electron beam into a thin layer of ice coating living tissue, called ice lithography, leaving behind a design when the remaining ice sublimates. And what creature is better suited to being frozen, coated in ice, and then exposed to an electron beam than the nearly indestructible tardigrade?

The team put tardigrades into a cryptobiotic state (a sort of half-dead, suspended animation) by slowly dehydrating the microscopic animals. Then, the researchers placed an individual tardigrade onto a carbon-composite paper, cooled the sheet below -226°F (-143°C), and covered the water bear with a protective layer of anisole—an organic compound that smells like anise. The frozen anisole protected the tardigrade's surface from the focused electron beam as it drew the pattern.  

When exposed to the beam, the anisole reacted and formed a new biocompatible chemical compound that stuck to the tardigrade's surface at higher temperatures. As the tardigrade warmed to room temperature under vacuum, any unreacted frozen anisole sublimated and left behind the pattern of reacted anisole. Finally, the researchers rehydrated and revived the tardigrade, which then sported a new tattoo.

The precision of this technique allowed the team to create a variety of micropatterns: squares, dots, and lines as small as 72 nanometers wide, and even the university's logo. About 40% of the tardigrades survived the procedure, and the researchers say that could be improved with further fine tuning. Most importantly, the tardigrades didn't seem to mind their new tattoos: Once rehydrated, they showed no changes in behavior. These results indicate that this technique could be suitable for printing micro-electronics or sensors onto living tissue.

It is challenging to pattern living matter, and this advance portends a new generation of biomaterial devices and biophysical sensors that were previously only present in science fiction. This work could enable advancements such as microbial cyborgs and other biomedical applications in the future.

Zhirong Yang et al, Patterning on Living Tardigrades, Nano Letters (2025). DOI: 10.1021/acs.nanolett.5c00378

Scientists discover how memories control metabolism

New multidisciplinary research shows that the brain forms memories of cold experiences and uses them to control our metabolism. This study is the first to show that cold memories form in the brain—and map out how they subsequently drive thermoregulation.

The discovery may have important applications in therapies designed to treat a range of disorders—from obesity to cancer—in which thermoregulation and metabolism (or a lack of control in this area) play a role, as well as opening the door to more fundamental research, which could help us better understand how memories impact our behavior and emotions.

Long-term memories are stored in the brain as ensembles of inter-connected cells, termed engrams. Increasingly, modern neuroscience is beginning to identify engrams that encode for bodily representations, such as experiences of infection; inflammation; food consumption; and pain.

The researchers behind this work hypothesized that the brain may form engrams for temperature representations, and that these would serve to help an organism survive in changing temperatures.

Numerous clinical disorders, ranging from obesity to forms of cancer, may be treated by manipulating thermoregulation through brown adipose tissue. In the future, it will be important to test whether the manipulation of cold memories in humans could provide novel avenues for altering metabolism for therapeutic purposes.

This research opens many new doors for further discovery research, as well as the development of treatments. Understanding how representations of cold experiences affect broader brain functions such as emotion, decision-making, and social behavior will provide insights into the embodied nature of the mind, for example.

The sophisticated aspects of our minds evolved from more basic, visceral, bodily representations.

 Tomás Ryan, Cold memories control whole-body thermoregulatory responses, Nature (2025). DOI: 10.1038/s41586-025-08902-6. www.nature.com/articles/s41586-025-08902-6

**

First skeletal evidence of gladiator bitten by lion in Roman period

A study has uncovered the first physical evidence of human-animal gladiatorial combat in the Roman period.

The research, published in PLOS One, presents compelling skeletal evidence of a human victim attacked by a large carnivorous animal, likely within the context of Roman-era spectacle combat. It was conducted by an international team of archaeologists and osteologists.

While images of gladiators being bitten by lions have appeared in ancient mosaics and pottery, this is the only convincing skeletal evidence using forensic experiments anywhere in the world of bite marks produced by the teeth of a large cat, such as a lion.

The findings center on a single skeleton discovered in a Roman-period cemetery outside York in England, a site believed to contain the remains of gladiators. The individual's bones exhibited distinct lesions that, upon close examination and comparison with modern zoological specimens, were identified as bite marks from a large feline species.

The bite marks on the pelvis of the skeleton represent the first osteological confirmation of human interaction with large carnivores in a combat or entertainment setting in the Roman world.

For years, our understanding of Roman gladiatorial combat and animal spectacles has relied heavily on historical texts and artistic depictions. This discovery provides the first direct, physical evidence that such events took place in this period, reshaping our perception of Roman entertainment culture in the region.

Unique osteological evidence for human-animal gladiatorial combat in Roman Britain, PLOS One (2025). DOI: 10.1371/journal.pone.0319847. journals.plos.org/plosone/arti … journal.pone.0319847

Part 1

Part 2 ( on top of this contain pics)

Lesions on the left iliac spine of 6DT19. Credit: PLOS One (2025). DOI: 10.1371/journal.pone.0319847

Part 2

Stem cells need positional signals to drive regeneration

Scientists  have discovered that Schmidtea polychroa, a flatworm capable of regenerating lost tissue, develops this ability progressively during early life stages. Whole-body regeneration emerges during specific embryonic and juvenile stages, with head regeneration limited until the organism gains the capacity to reset its body's main axis. Stem-like cells are necessary for tissue growth yet insufficient on their own to trigger full regeneration.

Regeneration encompasses biological processes that replace tissues during normal maintenance or after injury. Some aquatic invertebrates such as hydrozoans, planarians, and acoels can regenerate entire bodies from mere tissue fragments. Certain fish, amphibians, and reptiles can regrow lost appendages.

Regenerative abilities change throughout an organism's life. In many species, embryos and juveniles regenerate more readily than adults. Aging has been associated with reduced regeneration in structures such as the mouse heart and digit tip, Xenopus limbs and tail, and Drosophila imaginal disks.

Even highly regenerative animals like tunicates and sponges show reduced ability as they age. These changes have been linked to stem cell exhaustion, loss of cellular plasticity, epigenetic alterations, and metabolic shifts. Gains in regenerative ability during adulthood have also been observed in sponges, crinoids, ctenophores, annelids, tunicates, and some vertebrates such as Xenopus tadpoles and certain lizards.

Planarian flatworms retain whole-body regenerative capacity into adulthood. Their regenerative ability depends on adult pluripotent stem cells, called neoblasts, which are distributed throughout the body. Neoblasts respond to injury through position-specific signaling from surrounding tissues and generate new tissues during maintenance, asexual reproduction, and regeneration.

Research Results reveal that whole-body regeneration is not an inherent, default property of possessing stem cells but instead depends on developmental cues that enable axis reset. The ability to regenerate a head only emerged after embryos gained competence to reset anterior-posterior polarity. Fragments containing functional progenitor cells still failed to regenerate unless specific polarity signals were activated.

Axis reset emerges as a critical gatekeeper in whole-body regeneration, with direct manipulation of signaling pathways enabling regeneration in fragments previously unable to recover. Findings point to regeneration as a conditional capability, one that may be switched on or off depending on developmental state and molecular context.

Broader strategies to induce regeneration in less regenerative animals may require restoring not just stem cell presence, but also the injury-induced cues that trigger polarity establishment and tissue identity. Results may challenge assumptions that regenerative loss is irreversible and suggest new targets for restoring tissue-forming potential.

Mammals, including humans, have limited regenerative capacity and are restricted to replacing select tissues and cell types.

Part 1

Repair in mammals often proceeds through scarring, a process that rapidly seals wounds without restoring original tissue architecture. This may reflect an evolutionary trade-off in larger or more complex organisms, where fast tissue sealing through fibrosis can ensure immediate survival, even at the cost of long-term function or structural integrity.

Greater understanding of the requirements for regeneration in worms and other regenerating species brings science closer to the goal of one day reverse-engineering regenerative responses in therapeutic settings.

Clare L.T. Booth et al, Developmental onset of planarian whole-body regeneration depends on axis reset, Current Biology (2025). DOI: 10.1016/j.cub.2025.03.065

Part 2

The world's biggest companies have caused $28 trillion in climate damage

The world's biggest corporations have caused $28 trillion in climate damage, a new study estimates as part of an effort to make it easier for people and governments to hold companies financially accountable.

A research team came up with the estimated pollution caused by 111 companies, with more than half of the total dollar figure coming from 10 fossil fuel providers: Saudi Aramco, Gazprom, Chevron, ExxonMobil, BP, Shell, National Iranian Oil Co., Pemex, Coal India and the British Coal Corporation.

The researchers figured that every 1% of greenhouse gas put into the atmosphere since 1990 has caused $502 billion in damage from heat alone, which doesn't include the costs incurred by other extreme weather such as hurricanes, droughts and floods. People talk about making polluters pay, and sometimes even take them to court or pass laws meant to rein them in. The study is an attempt to determine the causal linkages that underlie many of these theories of accountability.

Christopher W. Callahan et al, Carbon majors and the scientific case for climate liability, Nature (2025). DOI: 10.1038/s41586-025-08751-3

Tiny plastic particles found in artery-clogging plaque in the neck

People with plaque in the blood vessels of their neck have a higher amount of tiny plastic particles in those vessels compared to people with healthy arteries. This increase was significantly higher in people who had experienced a stroke, mini-stroke or temporary loss of vision due to clogged blood vessels, according to preliminary research presented at the American Heart Association's Vascular Discovery 2025 Scientific Ses..., April 22–25 .

Micronanoplastics are tiny pieces of plastic created in industrial processes or from larger plastic objects as they degrade in the ocean or the soil. Micronanoplastics are not uniform in size and are a mixture of micro and nano plastic sizes.

While microplastics are sometimes visible at less than 5 millimeters in size, nanoplastics are microscopic, less than 1,000 nanometers across. This makes them more easily dispersed and able to penetrate cells and tissues in living organisms. Researchers suggest that terminology should gradually transition to nanoplastics because that is more precisely what is being studied.

These types of plastics are commonly found in the environment, especially in ocean garbage patches. Over many years, these plastics break down, mix into the soil and water, and can build up in the food chain.

Many people think that micro and nanoplastics mainly come from using plastic utensils, cutting boards, packaging, water bottles and other plastic items. However, the main source is the food and water we eat and drink.

In 2024, researchers in Italy reported finding micronanoplastics in plaque from some people without symptoms who underwent surgery to remove carotid artery plaque.

Symptoms caused by carotid plaque buildup may include stroke, mini-stroke or temporary blindness. Followed for almost three years after surgery, people with micronanoplastics in their carotid plaque were significantly more likely to die or to have a non-fatal heart attack or stroke.

Part 1

The current study, which included fewer than 50 participants, was built on previous research conducted in Italy. Researchers compared the levels of micronanoplastics found in the carotid arteries of three groups: people with healthy arteries; those with plaque but no symptoms; and those experiencing symptoms due to plaque buildup.

Researchers also compared plaques with low and high plastic levels to assess the effects of micronanoplastics on markers of inflammation, the gene activity of immune cells called macrophages and stem cells that help stabilize plaque.

The analysis found that the concentration of micronanoplastics in carotid arteries was:

16 times higher (895 micrograms/gram vs. 57 micrograms/gram) in plaque among people without symptoms compared to the levels found in artery walls of deceased tissue donors of similar age with no plaque; and
51 times higher (2,888 micrograms/gram vs. 57 micrograms/gram) in plaque from people who had experienced stroke, mini-stroke or temporary loss of vision due to blockage of blood flow to the retina, in comparison to samples from age-matched, deceased tissue donors.
Comparing high-plastic and low-plastic plaque levels, the analysis found:

no link between the amount of micronanoplastics and signs of sudden inflammation; and
differences in gene activity in plaque-stabilizing cells and less activity in anti-inflammatory genes of plaque macrophage immune cells.
"These findings indicate that the biological effects of micronanoplastics on fatty deposits are more complex and nuanced than simply causing sudden inflammation.

https://professional.heart.org/en/meetings/vascular-discovery-from-...

Part 2

Blocking a master regulator of immunity eradicates liver tumors in mice

A protein identified nearly 40 years ago for its ability to stimulate the production of red blood cells plays a  critical role in dampening the immune system's response to cancer.

Blocking the activity of the protein turns formerly "cold," or immune-resistant, liver tumors in mice into "hot" tumors teeming with cancer-fighting immune cells. When combined with an immunotherapy that further activates these immune cells against the cancer, the treatment led to complete regression of existing liver tumors in most mice. Treated animals lived for the duration of the experiment. In contrast, control animals survived only a few weeks.

This is a fundamental breakthrough in our understanding of how the immune system is turned off and on in cancer.

Although the work was completed in mice, there are strong indications that the protein, erythropoietin or EPO, plays a similar role in many types of human cancers.

 David Kung-Chun Chiu et al, Tumor-derived erythropoietin acts as an immunosuppressive switch in cancer immunity, Science (2025). DOI: 10.1126/science.adr3026. www.science.org/doi/10.1126/science.adr3026

UN warns vaccine-preventable diseases on the rise globally

Outbreaks of vaccine-preventable diseases such as measles, meningitis, and yellow fever are on the rise globally amid misinformation and cuts to international aid, the United Nations and the Gavi vaccine alliance warned this week.

Vaccines have saved more than 150 million lives over the past five decades. Funding cuts to global health have put these hard-won gains in jeopardy.

The increasing outbreaks around the world are "putting lives at risk and exposing countries to increased costs in treating diseases."

Measles, for example, is making an "especially dangerous comeback," with cases rising every year since 2021 and reaching an estimated 10.3 million in 2023, which is a 20% increase since 2022.

The organizations believe that the trend is likely to have continued into 2024 and 2025.

In the past 12 months, 138 countries have reported measles cases, with 61 experiencing large or disruptive outbreaks—the highest number observed in any 12-month period since 2019, according to the statement.

The joint statement was signed by the World Health Organization, the United Nations children's fund UNICEF, and Gavi, and was released Wednesday at the start of World Immunization Week, which runs April 24-30.

Cases of meningitis and yellow fever have also increased significantly in Africa in 2024, it said.

The spikes are taking place amid rising misinformation, population growth and humanitarian crisis.

https://www.who.int/news/item/24-04-2025-increases-in-vaccine-preve...

Super stem cells become better versions of themselves by changing their diet

In a new study, researchers  have successfully created stem cells that are better at developing into other cell types, like a younger, fitter version of themselves—by changing their diet. These stem cells are better than normal stem cells at creating specialized cells like liver, skin or nerve cells, which is a core trait of stem cells.

Researchers showed that by changing their diet, the stem cells can rejuvenate and turn into 'super stem cells.' It forces them to metabolize their energy in a different way than they normally would, and that process essentially reprograms the stem cells.

The net result is that they behave like they are from an earlier stage of development, which enhances their ability to develop, or differentiate, into other types of cells.

Specifically, the researchers changed what type of sugar the stem cells have available in the medium they grow in. The cells use the sugar to generate energy.

"What is really striking is that they're not just better at differentiating, but they stay fit and keep healthy much better over time compared to stem cells in standard culture conditions. And it is done with a relatively simple method.

Altering metabolism programs cell identity via NAD+-dependent deacetylation, The EMBO Journal (2025). DOI: 10.1038/s44318-025-00417-0

A Single-Celled Microbe Can Transform Into a Multicellular Creature

A single-celled microbe that revels in Earth's most hostile salt lakes has the remarkable ability to transform its mote of a body into multicellular tissue when the pressure's on.

Haloferax volcanii is a member of the often-overlooked archaea domain, which looks quite similar to bacteria and yet have more in common with our own domain, eukaryota. Multicellularity is common in eukaryotes and rare among bacteria, and as far as we know, H. volcanii is only the second archaeon found to take this multicellular leap.

H. volcanii has some impressive shape shifting techniques up its tiny sleeves to help it thrive in such extreme environments as the Dead Sea and the Great Salt Lake.

Why our waistlines expand in middle age

Peoples' waistlines often expand in middle age, but the problem isn't strictly cosmetic. Belly fat accelerates aging and slows down metabolism, increasing their risk for developing diabetes, heart problems and other chronic diseases. Exactly how age transforms a six pack into a softer stomach, however, is murky.

Now preclinical research has uncovered the cellular culprit behind age-related abdominal fat, providing new insights into why our midsections widen with middle age.

The researchers discovered that aging triggers the arrival of a new type of adult stem cell and enhances the body's massive production of new fat cells, especially around the belly.

The scientists conducted a series of mouse experiments later validated on human cells.

They focused on white adipose tissue (WAT), the fatty tissue responsible for age-related weight gain.

While it's well-known that fat cells grow larger with age, the scientists suspected that WAT also expanded by producing new fat cells, meaning it may have an unlimited potential to grow.

To test their hypothesis, the researchers focused on adipocyte progenitor cells (APCs), a group of stem cells in WAT that evolve into fat cells.

They first transplanted APCs from young and older mice into a second group of young mice. The APCs from the older animals rapidly generated a colossal amount of fat cells.

When the team transplanted APCs from young mice into the older mice, however, the stem cells did not manufacture many new fat cells. The results confirmed that older APCs are equipped to independently make new fat cells, regardless of their host's age.

Using single-cell RNA sequencing, the scientists next compared APC gene activity in young and older mice. While barely active in young mice, APCs woke up with a vengeance in middle-aged mice and began pumping out new fat cells.

While most adult stem cells' capacity to grow wanes with age, the opposite holds true with APCs—aging unlocks these cells' power to evolve and spread. This is the first evidence that our bellies expand with age due to the APCs' high output of new fat cells.

Part 1

Aging also transformed the APCs into a new type of stem cell called committed preadipocytes, age-specific (CP-As). Arising in middle age, CP-A cells actively churn out new fat cells, explaining why older mice gain more weight.

A signaling pathway called leukemia inhibitory factor receptor (LIFR) proved critical for promoting these CP-A cells to multiply and evolve into fat cells.

The scientists discovered that the body's fat-making process is driven by LIFR. While young mice don't require this signal to make fat, older mice do.

Guan Wang et al, Distinct adipose progenitor cells emerging with age drive active adipogenesis, Science (2025). DOI: 10.1126/science.adj0430

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Industrial waste is turning to rock in just decades, research reveals

An aluminum tab from a drinks can found encased in a new form of rock on the Cumbrian coastline has helped provide scientists with a shocking new insight into the impact of human activity on Earth's natural processes and materials.

Researchers have found that slag, an industrial waste product produced by the steel industry, is turning into solid rock in as little as 35 years.

The finding challenges centuries of understanding of the planet's geological processes, where research has shown that rock forms naturally over millions of years.

The researchers have documented for the first time a new "rapid anthropoclastic rock cycle," which mimics natural rock cycles but involves human material over accelerated timescales. They think the cycle is likely to be underway at similar industrial sites around the globe.

The team warn that the rapid and unplanned-for development of rock around industrial waste sites could have negative impacts on ecosystems and biodiversity, as well as coastal management and land planning.

In a paper published in the journal Geology, the researchers explain how detailed analysis of a 2-kilometer stretch of slag deposit at Derwent Howe in West Cumbria led to their discovery of a new Earth system cycle.

Derwent Howe was home to iron and steel-making foundries during the 19th and 20th centuries, and its coast accumulated 27 million cubic meters of furnace slag over the course of its industrial history.

Study explores the motivations behind helping others

Why are some people more helpful than others? In a new JNeurosci paper, researchers used rats to explore why some individuals may be more receptive to the distress of others and how this information leads to helpful behaviour.

During a task the researchers previously developed, they observed the behaviors and brain activity of helpful rats compared to less helpful rats. In this task that probes helping behavior, rats are given the option to release a distressed peer trapped in a restrainer.

Rats that were more likely to come to the aid of others had increased activity in brain regions associated with empathy and motivation compared to less helpful rats.

The researchers also observed that helper rats had increased oxytocin receptor expression in a brain region that drives motivation compared to the less helpful rats. According to the authors, this could mean that caring for others, more than relating to others' distresses, contributes to helpfulness.

When oxytocin signaling was inhibited, rats were less friendly with others, suggesting oxytocin may support helping by making rats feel attachment to others.

 Neural and Behavioral Correlates of Individual Variability in Rat Helping Behavior: A Role for Social Affiliation and Oxytocin Receptors, JNeurosci (2025). DOI: 10.1523/JNEUROSCI.0845-24.2025

Mice develop fibromyalgia-like pain after receiving gut microbiota from human patients

Research has discovered that transplanting gut microbiota from women with fibromyalgia into mice induces pain, immune activation, metabolomic changes, and reduced skin innervation.

The exact cause of fibromyalgia is unknown. Fibromyalgia affects 2% to 4% of the population, primarily women, and is characterized by chronic widespread pain, fatigue, sleep disruptions, and cognitive difficulties. Most patients suffer from significant symptoms that negatively impact quality of life.

Dysregulated activity of the central nervous system, altered neurotransmitters, neuroinflammation, and reduced intraepidermal nerve fiber density have been observed in fibromyalgia patients. Functional gastrointestinal disorders and depression are also common.

Previous studies have revealed that gut microbiota composition differs between women with fibromyalgia and healthy controls, yet the connection between this altered microbiota and any functional role it might play remains a mystery.

In the study, "The gut microbiota promotes pain in fibromyalgia," published in Neuron, researchers conducted a fecal microbiota transplantation study to determine whether altered gut microbiota from fibromyalgia patients could cause pain and related symptoms.

Researchers performed fecal microbiota transplantation (FMT) into germ-free female mice using samples collected from women with fibromyalgia and age-matched healthy controls. An open-label clinical trial enrolled 14 women with severe fibromyalgia who received five oral FMT doses from healthy female donors.

To assess pain and systemic changes in mice, the study employed behavioral assays, single-cell RNA sequencing, metabolomic profiling, dorsal root ganglia calcium imaging, and spinal microglia analysis. Clinical participants received oral FMT capsules biweekly for five doses following antibiotic and bowel cleansing preparation.

Mice that received microbiota from fibromyalgia patients developed mechanical, heat, and cold hypersensitivity, spontaneous pain, and muscle pain within four weeks. Persistent pain and depression-like behaviors were observed in mice four months post-transplantation.

Changes coincided with altered gut microbiota composition, immune activation marked by classical monocytes and spinal microglia, shifts in amino acid and bile acid metabolism, and reduced intraepidermal nerve fiber density. Replacing fibromyalgia-associated microbiota with that from healthy donors reversed pain hypersensitivity. Oral bile acid supplementation also reduced pain responses in mice.

Part 1

In the human clinical study, 14 women with severe, treatment-resistant fibromyalgia received FMT from healthy donors. Post-treatment, 12 participants reported a clinically significant reduction in pain.

Improvements, while not complete reversals, were observed in overall symptom burden, sleep quality, anxiety, and depression scores. Quantitative sensory testing showed reductions in cold pain hypersensitivity. Stool analysis confirmed successful bacterial engraftment from healthy donors.

Based on the results, alterations in gut microbiota may play a causal role in the development of pain and other symptoms associated with fibromyalgia. Because the human trial was open-label, lacked a control arm, and enrolled only women, the findings are preliminary and need confirmation in randomized controlled trials.
Modulating the gut microbiota through fecal transplantation presents a potential therapeutic strategy for individuals suffering from this chronic pain syndrome. Establishing the functional significance of gut microbiota in fibromyalgia would open new opportunities for evaluating microbial-based interventions.

Weihua Cai et al, The gut microbiota promotes pain in fibromyalgia, Neuron (2025). DOI: 10.1016/j.neuron.2025.03.032

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Flares from magnetized stars can forge planets' worth of gold

Astronomers have discovered a previously unknown birthplace of some of the universe's rarest elements: a giant flare unleashed by a supermagnetized star. The astronomers calculated that such flares could be responsible for forging up to 10% of our galaxy's gold, platinum and other heavy elements.

The discovery also resolves a decades-long mystery concerning a bright flash of light and particles spotted by a space telescope in December 2004. The light came from a magnetar—a type of star wrapped in magnetic fields trillions of times as strong as Earth's—that had unleashed a giant flare.

The powerful blast of radiation only lasted a few seconds, but it released more energy than the sun does in 1 million years. While the flare's origin was quickly identified, a second, smaller signal from the star, peaking 10 minutes later, confounded scientists at the time. For 20 years, that signal went unexplained.

Now, a new insight by astronomers at the Flatiron Institute's Center for Computational Astrophysics (CCA) in New York City has revealed that the unexplained smaller signal marked the rare birth of heavy elements such as gold and platinum. In addition to confirming another source of these elements, the astronomers estimated that the 2004 flare alone produced the equivalent of a third of Earth's mass in heavy metals. They report their discovery in a paper published on April 29 in The Astrophysical Journal Letters.

This is really just the second time we've ever directly seen proof of where these elements form, the first being neutron star mergers, say the researchers. 

Part1

Most of the elements we know and love today weren't always around. Hydrogen, helium and a dash of lithium were formed in the Big Bang, but almost everything else has been manufactured by stars in their lives, or during their violent deaths. While scientists thoroughly understand where and how the lighter elements are made, the production locations of many of the heaviest neutron-rich elements—those heavier than iron—remain incomplete.

These elements, which include uranium and strontium, are produced in a set of nuclear reactions known as the rapid neutron-capture process, or r-process. This process requires an excess of free neutrons—something that can be found only in extreme environments. Astronomers thus expected that the extreme environments created by supernovae or neutron star mergers were the most promising potential r-process sites.

It wasn't until 2017 that astronomers were able to confirm an r-process site when they observed the collision of two neutron stars. These stars are the collapsed remnants of former stellar giants and are made of a soup of neutrons so dense that a single tablespoon would weigh more than 1 billion tons. The 2017 observations showed that the cataclysmic collision of two of these stars creates the neutron-rich environment needed for the formation of r-process elements.
However, astronomers realized that these rare collisions alone can't account for all the r-process-produced elements we see today. Some suspected that magnetars, which are highly magnetized neutron stars, could also be a source.

Researchers  calculated in 2024 that giant flares could eject material from a magnetar's crust into space, where r-process elements could form.

It's pretty incredible to think that some of the heavy elements all around us, like the precious metals in our phones and computers, are produced in these crazy extreme environments

The group's calculations show that these giant flares create unstable, heavy radioactive nuclei, which decay into stable elements such as gold. As the radioactive elements decay, they emit a glow of light, in addition to minting new elements. The group also calculated in 2024 that the glow from the radioactive decays would be visible as a burst of gamma rays, a form of highly energized light. When they discussed their findings with observational gamma-ray astronomers, the group learned that, in fact, one such signal had been seen decades earlier that had never been explained. Since there's little overlap between the study of magnetar activity and heavy-element synthesis science, no one had previously proposed element production as a cause of the signal.

In the new paper, the astronomers used the observations of the 2004 event to estimate that the flare produced 2 million billion billion kilograms of heavy elements (roughly equivalent to Mars' mass). From this, they estimate that one to 10% of all r-process elements in our galaxy today were created in these giant flares. The remainder could be from neutron star mergers, but with only one magnetar giant flare and one merger ever documented, it's hard to know exact percentages—or if that's even the whole story.

Anirudh Patel et al, Direct Evidence for r-process Nucleosynthesis in Delayed MeV Emission from the SGR 1806–20 Magnetar Giant Flare, The Astrophysical Journal Letters (2025). DOI: 10.3847/2041-8213/adc9b0

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Heart disease deaths worldwide linked to chemical widely used in plastics

Daily exposure to certain chemicals used to make plastic household items could be linked to more than 365,000 global deaths from heart disease in 2018 alone, a new analysis of population surveys shows.

While the chemicals, called phthalates, are in widespread use globally, Africa, South Asia, and the Middle East populations bore a much larger share of the death toll than others—about half the total.

For decades, experts have connected health problems to exposure to certain phthalates found in cosmetics, detergents, solvents, plastic pipes, bug repellents, and other products. When these chemicals break down into microscopic particles and are ingested, studies have linked them to an increased risk of conditions ranging from obesity and diabetes to fertility issues and cancer.

 The current study focused on a kind of phthalate called di-2-ethylhexyl phthalate (DEHP), which is used to make food containers, medical equipment, and other plastic softer and more flexible. Exposure has been shown in other studies to prompt an overactive immune response (inflammation) in the heart's arteries, which, over time, is associated with an increased risk of heart attack or stroke.

In their new analysis, the authors estimated that DEHP exposure contributed to 368,764 deaths, or more than 10% of all global mortality from heart disease in 2018 among men and women aged 55 through 64. A report on the findings is published in the journal eBioMedicine.

"By highlighting the connection between phthalates and a leading cause of death across the world, our findings add to the vast body of evidence that these chemicals present a tremendous danger to human health," said study  authors.

According to the authors, the resulting economic burden from the deaths identified in their study was estimated to be around $510 billion and may have reached as high as $3.74 trillion.

In a past study from 2021, the research team tied phthalates to more than 50,000 premature deaths each year, mostly from heart disease.

 Phthalate exposure from plastics and cardiovascular disease: global estimates of attributable mortality and years life lost, eBioMedicine (2025). DOI: 10.1016/j.ebiom.2025.105730

Scientists develop silk microneedles to deliver nutrients and chemicals to plants

When farmers apply pesticides to their crops, 30 to 50% of the chemicals end up in the air or soil instead of on the plants. Now, a team of researchers has developed a much more precise way to deliver substances to plants: tiny needles made of silk.

In a study published in Nature Nanotechnology, the researchers developed a way to produce large amounts of these hollow silk microneedles. They used them to inject agrochemicals and nutrients into plants, and to monitor their health.

In demonstrations, the team used the technique to give plants iron to treat a disease known as chlorosis, and to add vitamin B12 to tomato plants to make them more nutritious. The researchers also showed the microneedles could be used to monitor the quality of fluids flowing into plants and to detect when the surrounding soil contained heavy metals.

Overall, the researchers think the microneedles could serve as a new kind of plant interface for real-time health monitoring and biofortification.

Yunteng Cao et al, Nanofabrication of silk microneedles for high-throughput micronutrient delivery and continuous sap monitoring in plants, Nature Nanotechnology (2025). DOI: 10.1038/s41565-025-01923-2

Blood droplets on inclined surfaces reveal new cracking patterns

Drying droplets have fascinated scientists for decades. From water to coffee to paint, these everyday fluids leave behind intricate patterns as they evaporate. But blood is far more complex—a colloidal suspension packed with red blood cells, plasma proteins, salts, and countless biomolecules.

As blood dries, it leaves behind a complex microstructural pattern—cracks, rings, and folds—each shaped by the interplay of its cellular components, proteins, and evaporation dynamics. These features form a kind of physical fingerprint, quietly recording the complex interplay of physics that unfolded during the desiccation of the droplet.

Researchers explored how blood droplets dry by varying both their size—from tiny 1-microliter drops to larger 10-microliter ones—and the angle of the surface, from completely horizontal to a steep 70° incline. Using an optical microscope, a high-speed camera, and a surface profiler, they tracked how the droplets dried, shrank and cracked.

 On flat surfaces, blood droplets dried predictably, forming familiar coffee-ring-like deposits surrounded by networks of radial and azimuthal cracks. But as the researchers increased the tilt, gravity pulled the red blood cells downhill, while surface tension tried to hold them up. This resulted in asymmetric deposits and stretched patterns—a kind of biological landslide frozen in time.

Cracking patterns were different on the advancing (downhill) and receding (uphill) sides. On the advancing side, where the dried blood mass accumulated more, the cracks were thicker and more widely spaced. On the receding side, where the deposit thinned out, the cracks were finer. Larger droplets (10 microliter) exaggerated the asymmetry even more, with gravity playing a bigger role as the droplets grew heavier—leaving behind a long, thin "tail" of blood that dried and showed scattered dried red blood cells.

Part 1

To explain what they observed, the researchers developed a first-order theoretical model showing how mechanical stresses build up unevenly on either side of the droplet—a difference that helps explain the asymmetric cracking patterns they saw.

These findings have real-world implications. In forensic science, for example, investigators use bloodstain pattern analysis—or BPA—to reconstruct events at crime scenes. Their results suggest that both the tilt of the surface and the size of the droplet can significantly alter the resulting patterns. Ignoring these factors could lead to misinterpretations, potentially affecting how such evidence is read and understood.

Bibek Kumar et al, Asymmetric Deposits and Crack Formation during Desiccation of a Blood Droplet on an Inclined Surface, Langmuir (2025). DOI: 10.1021/acs.langmuir.4c03767

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SUVs pose greater risk of death or serious injury to pedestrians and cyclists, study shows

The likelihood of a pedestrian or cyclist being fatally injured is 44% higher if they are hit by a sports utility vehicle (SUV) or light truck vehicle (LTV) compared with smaller passenger cars, new research shows. For children there is an even larger effect, with a child hit by an SUV or LTV being 82% more likely to be killed than a child hit by a passenger car.

Researchers gathered real-world collision data from over 680,000 collisions from the last 35 years.

They compared the severity of injuries suffered by pedestrians or cyclists struck by SUVs or LTVs with the injuries of pedestrians or cyclists struck by passenger cars. LTVs are a category of vehicle that covers SUVs, small vans and pick-up trucks – the researchers found similar increases in risk when they looked at SUVs only.

The research is published in Injury Prevention.

SUVs and LTVs are typically taller, wider and heavier than traditional passenger cars, such as sedans or hatchbacks.

Multiple cities worldwide have recently introduced, or are currently considering, policies that discourage the use of these large vehicles.

In the study, the authors found that in the case of a crash, pedestrians or cyclists struck by an SUV or LTV suffered more severe injuries than those hit by a passenger car. The odds of fatal injury increased by 44% for people of all ages struck by an SUV, compared with those hit by a passenger car. Among children, the odds of fatal injury increased by 82%, and among children under the age of 10 it increased by 130%.

Part 1

When looking at the likelihood of having a fatal or a serious injury, as compared to a slight injury, the likelihood increased by around a quarter (odds 24% higher in adults and 28% higher in children) for those hit by an SUV or LTV. These effects were all similar for both pedestrians and cyclists.

Previous research indicates that a key mechanism for this increased risk is likely to be the taller and blunter profile of the front end of SUVs and LTVs. A taller front end means that a pedestrian or cyclist is struck higher up on their body (e.g. the pelvis not the knees for an adult, or the head not the pelvis for a child).

A taller and blunter front end also means that the pedestrian or cyclist is more likely to be thrown forward onto the road, at which point the striking vehicle may hit them a second time or roll over their body.
If all SUVs were replaced with passenger cars, the number of pedestrians and cyclists killed in car crashes would decrease, say the researchers.

 Do sports utility vehicles (SUVs) and light truck vehicles (LTVs) cause more severe injuries to pedestrians and cyclists than passenger cars in the case of a crash? A systematic review and meta-analysis, Injury Prevention (2025). DOI: 10.1136/ip-2024-045613

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Skin wounds in humans found to heal nearly three times slower than those in other primates

A team of evolutionary scientists, dermatologists and wildlife specialists has found that human skin wounds take nearly three times as long to heal as they do in other primates. In their study, published in the journal Proceedings of the Royal Society B: Biological Sciences, the group conducted experiments involving skin healing speed in humans and several other primates.

Prior research  suggest that other animals recover from skin wounds faster than humans. In this new effort, the research team sought to measure such differences.

The experiments involved comparing skin wounds in humans—courtesy of volunteers at a hospital undergoing skin tumor removal—and several primates. Wound healing pace in chimpanzees was measured by studying chimps housed at a sanctuary who endured skin wounds periodically due to fighting between males.

In looking at the data, the researchers found that all the test subjects healed at nearly the same rate—0.62 millimeters of new skin growth a day—except for humans, who healed at an average of 0.25 millimeters per day. The researchers also tested mice and rats and found their healing rates were similar to those of non-human primates.

The research team suggests the reason for the difference lies in humans having lost their fur. They note that hair follicle stem cells can grow skin cells when needed. Humans have replaced most of their hair follicles with sweat glands, which also have stem cells that can grow into skin cells, but do so far less efficiently.

As humans lost their fur, the researchers note, they replaced them with sweat glands to prevent overheating. The trade-off was obviously worth it, or humans would be covered in fur today. They also note that the expanding brain may have helped along the way, providing humans with the ability to treat skin wounds in ways other animals cannot.

Akiko Matsumoto-Oda et al, Inter-species differences in wound-healing rate: a comparative study involving primates and rodents, Proceedings of the Royal Society B: Biological Sciences (2025). DOI: 10.1098/rspb.2025.0233

Size and chemical makeup determine which ancient animals fossilize

Why do some ancient animals become fossils while others disappear without a trace? A new study  published in Nature Communications, reveals that part of the answer lies in the body itself. The research shows that an animal's size and chemical makeup can play an important role in determining whether it's preserved for millions of years—or lost to time.

Fossils are more than just bones; some of the most remarkable finds include traces of soft tissues like muscles, guts, and even brains. These rare fossils offer vivid glimpses into the past, but scientists have long puzzled over why such preservation happens only for certain animals and organs but not others.

To dig into this mystery, a team of scientists turned to the lab. They conducted state-of-the-art decay experiments, allowing a range of animals including shrimps, snails, starfish, and planarians (worms) to decompose under precisely controlled conditions.

As the bodies broke down, the researchers used micro-sensors to monitor the surrounding chemical environment, particularly the balance between oxygen-rich (oxidizing) and oxygen-poor (reducing) conditions.

The results were striking. The researchers discovered that larger animals and those with a higher protein content tend to create reducing (oxygen-poor) conditions more rapidly. These conditions are crucial for fossilization because they slow down decay and trigger chemical reactions such as mineralization or tissue replacement by more durable minerals.

This means that, in nature, two animals buried side by side could have vastly different fates as fossils, simply because of differences in size or body chemistry. One might vanish entirely, while the other could be immortalized in stone.

According to this study, animals such as large arthropods are more likely to be preserved than small planarians or other aquatic worms. This could explain why fossil communities dating from the Cambrian and Ordovician periods (around 500 million years ago) are dominated by arthropods.

These findings not only help explain the patchy nature of the fossil record but also offer valuable insight into the chemical processes that shape what ancient life we can reconstruct today. Pinpointing the factors that drive soft-tissue fossilization brings us closer to understanding how exceptional fossils form—and why we only see fragments of the past.

 Nora Corthésy et al, Taxon-specific redox conditions control fossilisation pathways, Nature Communications (2025). DOI: 10.1038/s41467-025-59372-3

Re-writing textbooks: New insights into cell division

Scientists  have changed our understanding of how cells in living organisms divide, which could revise what students are taught at school. In a study published this week in Science, the researchers challenge conventional wisdom taught in schools for over 100 years.

Students are currently taught that during cell division, a parent cell will become spherical before splitting into two daughter cells of equal size and shape. However, the study reveals that cell rounding is not a universal feature of cell division and is not how it often works in the body.

Dividing cells, the researchers show, often don't round up into sphere-like shapes. This lack of rounding breaks the symmetry of division to generate two daughter cells that differ from each other in both size and function, known as asymmetric division.

Asymmetric divisions are an important way that the different types of cells in the body are generated, to make different tissues and organs. Until now, asymmetric cell division has predominantly only been associated with highly specialized cells, known as stem cells.

The scientists found that it is the shape of a parent cell before it even divides that can determine if they will round or not in division and determines how symmetric—or not—its daughter cells will be. Cells that are shorter and wider in shape tend to round up and divide into two cells which are similar to each other. However, cells that are longer and thinner don't round up and divide asymmetrically, so that one daughter is different from the other.

Part 1

The findings could have far-reaching implications on our understanding of the role of cell division in disease. For example, in the context of cancer cells, this type of "non-round," asymmetric division could generate different cell behaviors known to promote cancer progression through metastasis.

Harnessing this information could also impact regenerative medicine, enabling us to better manufacture the cell types needed to regenerate damaged tissues and organs. Scientists may one day be able to influence the function of daughter cells by simply manipulating their parental cell shape.

Holly E. Lovegrove et al, Interphase cell morphology defines the mode, symmetry, and outcome of mitosis, Science (2025). DOI: 10.1126/science.adu9628. www.science.org/doi/10.1126/science.adu9628

Part 2

Genetic analysis of all-women extreme divers finds changes linked to blood pressure and cold tolerance

A new analysis of a group of all-women extreme divers off the coast of Korea has uncovered genetic differences that could help them survive the intense physiological stresses of free-diving—and could ultimately lead to better treatments for blood pressure disorders.

The researchers worked with the Haenyeo: women who have spent their whole lives diving in the waters off Jeju Island, 50 miles south of mainland South Korea. They free-dive up to 60 feet below the surface to harvest seaweed, abalone, and other food items from the seafloor, spending hours a day in the water all year round.

For hundreds of years, Haenyeo diving was a staple of Jeju's economy and culture, although the practice is now waning.

They're absolutely extraordinary women, say the researchers. Every day, they head out and get in the water, and that's where they work all day. Surprisingly women over 80 dive off a boat before it even stopped moving.

To figure out if the Haenyeo's diving abilities are aided by differences in genetics, the researchers measured physiological variables related to diving ability, such as blood pressure and heart rate. They then sequenced participants' DNA—and found two changes related to diving physiology that could give the Haenyeo advantages underwater.

Haenyeo divers are more than four times more likely than mainland Koreans to have a genetic change associated with lower blood pressure while diving. The researchers think this difference could keep divers and their unborn children safe when diving during pregnancy.

Part 1

Breath-hold diving not only limits the body's oxygen supply but also raises divers' blood pressure during a dive, the researchers say. Holding one's breath in other contexts, such as sleep apnea, is associated with pregnancy-related blood pressure disorders, although it's unknown whether diving causes the same effect.

The researchers speculate that if the genetic change helps lower blood pressure, it could be especially vital for the Haenyeo. These women dive throughout pregnancy and must avoid blood pressure conditions such as preeclampsia, which can be fatal.

This is not something that every human or every woman is able to do. It's kind of like they have a superpower, courtesy, their genes and practice.

A second genetic difference is related to pain tolerance—specifically, cold-based pain. Air temperatures off Jeju Island drop to around freezing in the winter, but the Haenyeo don't stop diving. 

The genetic differences that could boost diving ability are found throughout the population of Jeju Island. But much of what makes the Haenyeo women special comes from a lifetime of practice.

Researchers have long known that when anyone dives—trained or untrained, Haenyeo or not—their heart rate reflexively drops to conserve oxygen for longer. For an average untrained person from Jeju Island, heartbeat slows down by about 20 beats per minute over the course of a simulated dive. For Haenyeo with a lifetime of diving experience, heart rate drops by up to twice that.

The researchers hope that their discovery of a genetic difference linked to blood pressure will ultimately advance care for health conditions, like stroke, that are related to high blood pressure.

Genetic and Training Adaptations in the Haenyeo Divers of Jeju, Korea, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.115577. www.cell.com/cell-reports/full … 2211-1247(25)00348-1

Part 2

Scientists develop antivenom that neutralizes the neurotoxins of 19 of the world's deadliest snakes

By using antibodies from a human donor with a self-induced hyper-immunity to snake venom, scientists have developed the most broadly effective antivenom to date, which is protective against the likes of the black mamba, king cobra, and tiger snakes in mouse trials. Described in the journal Cell, the antivenom combines protective antibodies and a small molecule inhibitor and opens a path toward a universal antiserum.

How we make antivenom has not changed much over the past century. Typically, it involves immunizing horses or sheep with venom from a single snake species and collecting the antibodies produced. While effective, this process could result in adverse reactions to the non-human antibodies, and treatments tend to be species and region-specific.

While exploring ways to improve this process, scientists stumbled upon someone hyper-immune to the effects of snake neurotoxins. The donor, for a period of nearly 18 years, had undertaken hundreds of bites and self-immunizations with escalating doses from 16 species of very lethal snakes that would normally kill a horse.

After the donor, Tim Friede, agreed to participate in the study, researchers found that by exposing himself to the venom of various snakes over several years, he had generated antibodies that were effective against several snake neurotoxins at once.

What 's exciting about the donor 's his once-in-a-lifetime unique immune history. Not only did he potentially create these broadly neutralizing antibodies, in this case, it could give rise to a broad-spectrum or universal antivenom.

To build the antivenom, the team first created a testing panel with 19 of the World Health Organization's category 1 and 2 deadliest snakes across the elapid family, a group which contains roughly half of all venomous species, including coral snakes, mambas, cobras, taipans, and kraits.

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Next, researchers isolated target antibodies from the donor's blood that reacted with neurotoxins found within the snake species tested. One by one, the antibodies were tested in mice envenomated from each species included in the panel. In this way, scientists could systematically build a cocktail comprising a minimum but sufficient number of components to render all the venoms ineffective.

The team formulated a mixture comprising three major components: two antibodies isolated from the donor and a small molecule. The first donor antibody, called LNX-D09, protected mice from a lethal dose of whole venom from six of the snake species present in the panel.

To strengthen the antiserum further, the team added the small molecule varespladib, a known toxin inhibitor, which granted protection against an additional three species. Finally, they added a second antibody isolated from the donor, called SNX-B03, which extended protection across the full panel.

Moreover, their results suggest that the three-part cocktail could be effective against many other, if not most, elapid snakes not tested in this study.

Snake-venom protection by a cocktail of varespladib and broadly neutralizing human antibodies, Cell (2025). DOI: 10.1016/j.cell.2025.03.050. www.cell.com/cell/fulltext/S0092-8674(25)00402-7

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In extreme conditions, heat does not flow between materials—it bounces off

A new study published in Nature Communications shows, for the first time, how heat moves—or rather, doesn't—between materials in a high-energy-density plasma state.

The work is expected to provide a better understanding of inertial confinement fusion experiments, which aim to reliably achieve fusion ignition on Earth using lasers. How heat flows between a hot plasma and a material's surface is also important in other technologies, including semiconductor etching and vehicles that fly at hypersonic speeds.

High-energy-density plasmas are produced only at extreme pressures and temperatures. The study shows that interfacial thermal resistance, a phenomenon known to impede heat transfer in less extreme conditions, also prevents heat flow between different materials in a dense, super-hot plasma state.

Researchers focused on how heat moves between metal and plastic heated to extreme temperatures and pressures. 

In their experiment, the tungsten wire was heated to about 180,000 degrees Fahrenheit while its plastic coating remained relatively cool at "only" 20,000 degrees Fahrenheit. Using a series of laser shots with progressively delayed timing, the researchers were able to see if the heat was moving between the tungsten and plastic.

When they looked at the data, they were totally shocked because the heat was not flowing between these materials. It was getting stuck at the interface between the materials. 

The reason was interfacial thermal resistance. The electrons in the hotter material arrive at the interface between the materials carrying thermal energy but then scatter off and move back into the hotter material.

Cameron H. Allen et al, Measurement of interfacial thermal resistance in high-energy-density matter, Nature Communications (2025). DOI: 10.1038/s41467-025-56051-1

https://vimeo.com/1065285809

Home washing machines fail to remove important pathogens from textiles

Health care workers who wash their uniforms at home may be unknowingly contributing to the spread of antibiotic-resistant infections in hospitals, according to a new study published in PLOS One.

Hospital-acquired infections are a major public health concern, in part because they frequently involve antibiotic-resistant bacteria. Many nurses and health care workers clean their uniforms at home in standard washing machines, but some studies have found that bacteria can be transmitted through clothing, raising the question of whether these machines can sufficiently prevent the spread of dangerous microbes.

In the new study, researchers evaluated whether six models of home washing machine successfully decontaminated health care worker uniforms, by washing contaminated fabric swatches in hot water, using a rapid or normal cycle. Half of the machines did not disinfect the clothing during a rapid cycle, while one-third failed to clean sufficiently during the standard cycle.

The team also sampled biofilms from inside 12 washing machines. DNA sequencing revealed the presence of potentially pathogenic bacteria and antibiotic resistance genes. Investigations also showed that bacteria can develop resistance to domestic detergent, which also increases their resistance to certain antibiotics.

This research shows that domestic washing machines often fail to disinfect textiles, allowing antibiotic-resistant bacteria to survive. If we're serious about the transmission of infectious disease via textiles and tackling antimicrobial resistance, we must rethink how we launder what we wear.  

Caroline Cayrou et al, Domestic laundering of healthcare textiles: Disinfection efficacy and risks of antibiotic resistance transmission, PLOS One (2025). DOI: 10.1371/journal.pone.0321467. journals.plos.org/plosone/arti … journal.pone.0321467

Special relativity made visible

When an object moves extremely fast—close to the speed of light—certain basic assumptions that we take for granted no longer apply. This is the central consequence of Albert Einstein's special theory of relativity. The object then has a different length than when it is at rest, and time passes differently for the object than it does in the laboratory. All this has been repeatedly confirmed in experiments.

However, one interesting consequence of relativity has not yet been observed—the so-called Terrell-Penrose effect. In 1959, physicists James Terrell and Roger Penrose (Nobel laureate in 2020) independently concluded that fast-moving objects should appear rotated. 

Now, a collaboration study has succeeded for the first time in reproducing the effect using laser pulses and precision cameras—at an effective speed of light of 2 meters per second. The research is published in the journal Communications Physics.

Suppose a rocket whizzes past us at 90% of the speed of light. For us, it no longer has the same length as before it took off, but is 2.3 times shorter. This is the relativistic length contraction, also known as the Lorentz contraction.

However, this contraction cannot be photographed. If you want to take a picture of the rocket as it flew past, you will have to take into account that the light from different points take different lengths of time to reach the camera. 

The light coming from different parts of the object and arriving at the lens or our eye at the same time is not emitted at the same time—and this results in complicated optical effects.

Let's imagine that the super-fast object is a cube. Then the side facing away from us is further away than the side facing towards us. If two photons reach our eye at the same time, one from the front corner of the cube and one from the back corner, the photon from the back corner has traveled further. So it must have been emitted at an earlier time. And at that time, the cube was not at the same position as when the light was emitted from the front corner. This makes it look to us as if the cube has been rotated.

This is a combination of relativistic length contraction and the different travel times of light from different points. Together, this leads to an apparent rotation, as predicted by Terrell and Penrose.

Of course, this is irrelevant in everyday life, even when photographing an extremely fast car. Even the fastest Formula One car will only move a tiny fraction of the distance in the time difference between the light emitted by the side of the car facing away from us and the side facing towards us. But with a rocket traveling close to the speed of light, this effect would be clearly visible.

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Technically, it is currently impossible to accelerate rockets to a speed at which this effect could be seen in a photograph. However, physicists found another solution inspired by art: they used extremely short laser pulses and a high-speed camera to recreate the effect in the laboratory.
They moved a cube and a sphere around the lab and used the high-speed camera to record the laser flashes reflected from different points on these objects at different times.
It is easy to combine images of different parts of a landscape into one large image. What has been done here for the first time is to include the time factor: the object is photographed at many different times. Then the areas illuminated by the laser flash at the moment when the light would have been emitted from that point if the speed of light was only 2 m/s are combined into one still image. This makes the Terrell-Penrose effect visible.
They combined the still images into short video clips of the ultra-fast objects. The result was exactly what they expected.
The demonstration of the Terrell-Penrose effect is not only a scientific success—it is also the result of an extraordinary symbiosis between art and science.

Dominik Hornof et al, A snapshot of relativistic motion: visualizing the Terrell-Penrose effect, Communications Physics (2025). DOI: 10.1038/s42005-025-02003-6

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