Scientists uncover why carbon-rich meteorites rarely reach Earth

An international team of researchers may have answered one of space science's long-running questions—and it could change our understanding of how life began. Carbon-rich asteroids are abundant in space yet make up less than 5% of meteorites found on Earth.

Published in Nature Astronomy, researchers analyzed close to 8,500 meteoroids and meteorite impacts, using data from 19 fireball observation networks across 39 countries—making it the most comprehensive study of its kind. The paper is titled "Perihelion history and atmospheric survival as primary drivers of Earth's meteorite record."

The team discovered Earth's atmosphere and the sun act like giant filters, destroying fragile, carbon-rich (carbonaceous) meteoroids before they reach the ground.

Scientists have long suspected that weak, carbonaceous material doesn't survive atmospheric entry. What this research shows is many of these meteoroids don't even make it that far: they break apart from being heated repeatedly as they pass close to the sun. The ones that do survive getting cooked in space are more likely to also make it through Earth's atmosphere.

The study also found meteoroids created by tidal disruptions—when asteroids break apart from close encounters with planets—are especially fragile and almost never survive atmospheric entry.

Carbonaceous meteorites are particularly important because they contain water and organic molecules—key ingredients linked to the origin of life on Earth. Carbon-rich meteorites are some of the most chemically primitive materials we can study—they contain water, organic molecules and even amino acids.

However, scientists have so few of them in their meteorite collections that they risk having an incomplete picture of what's actually out there in space and how the building blocks of life arrived on Earth.

Understanding what gets filtered out and why is key to reconstructing our solar system's history and the conditions that made life possible.

 Patrick M. Shober et al, Perihelion history and atmospheric survival as primary drivers of the Earth's meteorite record, Nature Astronomy (2025). DOI: 10.1038/s41550-025-02526-6

Half of the universe's hydrogen gas, long unaccounted for, has been found

Astronomers tallying up all the normal matter—stars, galaxies and gas—in the universe today have come up embarrassingly short of the total matter produced in the Big Bang 13.6 billion years ago. In fact, more than half of normal matter—half of the 15% of the universe's matter that is not dark matter—cannot be accounted for in the glowing stars and gas we see.

New measurements, however, seem to have found this missing matter in the form of very diffuse and invisible ionized hydrogen gas, which forms a halo around galaxies and is more puffed out and extensive than astronomers thought.

The findings not only relieve a conflict between astronomical observations and the best, proven model of the evolution of the universe since the Big Bang, they also suggest that the massive black holes at the centers of galaxies are more active than previously thought, fountaining gas much farther from the galactic center than expected—about five times farther, the team found.

The new  measurements are certainly consistent with finding all of the gas. 

The results of the study, co-authored by 75 scientists from institutions around the world, have been presented at recent scientific meetings, posted as a preprint on arXiv and are undergoing peer review at the journal Physical Review Letters.

While the still mysterious dark matter makes up the bulk—about 84%—of matter in the universe, the remainder is normal matter. Only about 7% of normal matter is in the form of stars, while the rest is in the form of invisible hydrogen gas—most of it ionized—in galaxies and the filaments that connect galaxies in a kind of cosmic network.

The ionized gas and associated electrons strung out in this filament network are referred to as the warm-hot intergalactic medium, which is too cold and too diffuse to be seen with the usual techniques at astronomers' disposal, and therefore has remained elusive until now.

In the new paper, the researchers estimated the distribution of ionized hydrogen around galaxies by stacking images of approximately 7 million galaxies—all within about 8 billion light-years of Earth—and measuring the slight dimming or brightening of the cosmic microwave background caused by a scattering of the radiation by electrons in the ionized gas, the so-called kinematic Sunyaev-Zel'dovich effect.

B. Hadzhiyska et al, Evidence for large baryonic feedback at low and intermediate redshifts from kinematic Sunyaev-Zel'dovich observations with ACT and DESI photometric galaxies, arXiv (2024). DOI: 10.48550/arxiv.2407.07152

An alternative to artificial fertilizers: Small peptides enhance symbiosis between plants and fungi

Industrial farming practices often deplete the soil of important nutrients and minerals, leaving farmers to rely on artificial fertilizers to support plant growth. In fact, fertilizer use has more than quadrupled since the 1960s, but this comes with serious consequences. Fertilizer production consumes massive amounts of energy, and its use pollutes the water, air, and land.

Plant biologists  are now proposing a new solution to help kick this unsustainable fertilizer habit. 

In a new study, the researchers identified a key molecule produced by plant roots, a small peptide called CLE16, that encourages plants and beneficial soil fungi to interact with each other. They say boosting this symbiotic relationship, in which the fungi provide mineral nutrients to the plants through CLE16 supplementation, could be a more natural and sustainable way to encourage crop growth without the use of harmful artificial fertilizers.

The findings are published in the Proceedings of the National Academy of Sciences.

By restoring the natural symbiosis between plant roots and fungi, we could help crops get the nutrients they need without the use of harmful fertilizers.

In this mutually beneficial relationship, soil-borne arbuscular mycorrhizal fungi supply plants with water and phosphorus, which the plants accept in exchange for carbon molecules. These exchanges occur by specialized symbiotic fungal tendrils, called arbuscules, burying themselves into plant root cells.

Around 80% of plants can trade resources with fungi in this way. However, the traits that support this symbiosis have been weakened over centuries of agricultural plant breeding that prioritized creating crops with the biggest yields.

Scientists say new crop varieties could be bred to strengthen these traits again—an opportunity they intend to explore through the Institute's Harnessing Plants Initiative.

 Müller, Lena Maria, A plant CLE peptide and its fungal mimic promote arbuscular mycorrhizal symbiosis via CRN-mediated ROS suppression, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2422215122

Drug pollution in water

The drugs we take, from anxiety medications to antibiotics, don't simply vanish after leaving our bodies. Many are not fully removed by wastewater treatment systems and end up in rivers, lakes, and streams, where they can linger and affect wildlife in unexpected ways.

The new  findings suggest that even tiny traces of drugs in the environment can alter animal behavior in ways that may shape their survival and success in the wild.

A recent global survey of the world's rivers found drugs were contaminating waterways on every continent—even Antarctica. These substances enter aquatic ecosystems not only through our everyday use, as active compounds pass through our bodies and into sewage systems, but also due to improper disposal and industrial effluents.

To date, almost 1,000 different active pharmaceutical substances have been detected in environments worldwide.

Particularly worrying is the fact that the biological targets of many of these drugs, such as receptors in the human brain, are also present in a wide variety of other species. That means animals in the wild can also be affected.

In fact, research over the last several decades has demonstrated that pharmaceutical pollutants can disrupt a wide range of traits in animals, including their physiology, development, and reproduction.

https://www.science.org/doi/10.1126/science.adp7174

Radiation from CT scans could account for 5% of all cancer cases a year, study suggests

CT can save lives, but its potential harms are often overlooked. CTs expose patients to ionizing radiation—a carcinogen—and it's long been known that the technology carries a higher risk of cancer.

Radiation from CT scans may account for 5% of all cancers annually, according to a new study  that cautions against overusing and overdosing CTs.

The danger is greatest for infants, followed by children and adolescents. But adults are also at risk, since they are the most likely to get scans.

Nearly 103,000 cancers are predicted to result from the 93 million CTs that were performed in 2023 alone. This is three to four times more than previous assessments, the researchers say.

The researchers said some CT scans are unlikely to help patients and are overused, such as those for upper respiratory infections or for headaches without concerning signs or symptoms. They said patients could lower their risk by getting fewer of these scans, or by getting lower-dose scans.

There is currently unacceptable variation in the doses used for CT, with some patients receiving excessive doses. 

JAMA Internal Medicine (2025). jamanetwork.com/journals/jamai … ainternmed.2025.0505

Modified antibody fragment blocks fertilization, paving way for nonhormonal contraceptive

Current methods of contraception rely on hormones, which can cause side effects such as mood changes, headaches or increased risk of blood clots. Blocking fertilization on the surface of the egg has been proposed as an alternative, but antibodies were deemed unsuitable due to possible immune responses triggered by their Fc region.

A new study  shows how a small antibody fragment can block fertilization by targeting a key protein on the surface of the egg. This discovery brings a nonhormonal contraceptive one step closer to reality. The study has been published in the Proceedings of the National Academy of Sciences.

In the study, the researchers describe how a modified antibody fragment can block fertilization by targeting the protein ZP2 on the surface of the egg. 

This small antibody fragment can block fertilization by targeting ZP2, a key protein in the outer layer of the egg that is involved in both sperm binding and blocking polyspermy.

The researchers have used X-ray crystallography to map the interaction between the antibody IE-3, which is known to prevent fertilization in mice, and ZP2 at the atomic level. A modified, smaller version of the antibody (scFV) was found to be equally effective, blocking fertilization in 100% of IVF tests with mouse eggs. Because it lacks the immune-triggering Fc region of the full antibody, scFV minimizes potential side effects.

Elisa Dioguardi et al, Structural basis of ZP2-targeted female nonhormonal contraception, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2426057122

Repeated treatment with malaria medication can decrease its effect

In a recently published article in the journal Nature Communications, researchers present results indicating that repeated treatment with piperaquine, an antimalarial drug, can lead to the parasites developing decreased sensitivity to this drug. These findings may impact the use of piperaquine in the future.

Piperaquine is an important antimalarial drug characterized by a long half-life, meaning it remains in the body for several weeks and protects against new infections. This is a key asset of this drug. However, the researchers behind the study have discovered that this advantage can disappear with repeated treatment in areas with high malaria transmission.

The study shows that repeated treatment with dihydroartemisinin-piperaquine can lead to parasites developing drug tolerance by duplicating the plasmepsin 3 (pm3) gene. This allows them to reinfect patients earlier than expected during the expected protective period, reducing piperaquine's effectiveness as a prophylactic medicine.

 Leyre Pernaute-Lau et al, Decreased dihydroartemisinin-piperaquine protection against recurrent malaria associated with Plasmodium falciparum plasmepsin 3 copy number variation in Africa, Nature Communications (2025). DOI: 10.1038/s41467-025-57726-5

Airborne microplastics infiltrate plant leaves, raising environmental concerns

Researchers have found that plant leaves can directly absorb microplastics (MPs) from the atmosphere, leading to a widespread presence of plastic polymers in vegetation. Concentrations of polyethylene terephthalate (PET) and polystyrene (PS) were detected in leaves collected from multiple environments, including urban areas and agricultural sites. The study is published in the journal Nature.

Researchers performed field investigations and laboratory simulation experiments to quantify plastic accumulation in plant leaves. Leaf absorption was confirmed as a significant pathway for plastic accumulation in plants, with evidence of translocation into vascular tissue and retention in specialized structures like trichomes.

MPs have been detected throughout terrestrial environments, including soil, water, and air. Laboratory studies have shown that plant roots can absorb MPs, with submicrometer and nanometer-sized particles of PS and polymethylmethacrylate transported upward from the roots of Triticum aestivum, Lactuca sativa, and Arabidopsis thaliana. Root uptake through the apoplastic pathway has been observed, yet translocation to shoots occurs slowly.

Airborne MPs have been measured at concentrations between 0.4 and 2,502 items per cubic meter in urban settings such as Paris, Shanghai, Southern California, and London. Laboratory experiments demonstrated the foliar absorption of nanoparticles including Ag, CuO, TiO₂, and CeO₂.

Plastic particles have been shown to deposit on plant surfaces, and some studies reported internal accumulation following exposure to high levels of commercial PS models.

At the most polluted sites, concentrations of PET reached tens of thousands of nanograms per gram of dry leaf weight. PS levels followed a similar pattern, with the highest values detected in leaves from the landfill site.

PET and PS were also found in nine leafy vegetables, with open-air crops exhibiting higher levels than greenhouse-grown counterparts. Nano-sized PET and PS were visually confirmed in plant tissue.

Older leaves and outer leaves of vegetables accumulated more plastic than newly grown or inner leaves, suggesting an accumulation over time.

Laboratory exposure of maize to plastic-laden dust resulted in measurable PET absorption in leaf tissue after just one day. PET was not detected in roots or stems under similar root-exposure conditions. Fluorescent and europium-labeled particles enabled visualization of stomatal entry and subsequent migration through the apoplastic pathway.

Part 1

Abscisic acid was applied to maize roots to chemically induce stomatal closure. Plants exposed to dust laden with PET MPs under these conditions showed significantly lower absorption in leaf tissue, confirming that open stomata are crucial for foliar uptake of airborne MPs.

Plastic particles absorbed through leaves accumulated in measurable quantities across multiple species and sites. Airborne PET and PS entered leaves through stomata and moved along internal pathways to vascular tissues and trichomes.

Concentrations increased with exposure time, environmental levels, and leaf age. Field measurements showed that plastic accumulation in aboveground plant parts exceeds what is typically absorbed through roots.

Widespread detection of plastic polymers and fragments in edible plant parts confirms atmospheric exposure as a significant route of entry into vegetation. As leaves function as a primary source in terrestrial food chains, the presence of accumulated MPs suggests the potential for exposure to multiple layers of the ecosystem.

With plastics around, even vegetarians are not safe!

 Ye Li et al, Leaf absorption contributes to accumulation of microplastics in plants, Nature (2025). DOI: 10.1038/s41586-025-08831-4

Willie Peijnenburg, Airborne microplastics enter plant leaves and end up in our food, Nature (2025). DOI: 10.1038/d41586-025-00909-3

Part 2

Heart valve abnormality is associated with malignant arrhythmias, study reveals

People with a certain heart valve abnormality are at increased risk of severe heart rhythm disorders, even after successful valve surgery. This is according to a new study, "Mitral annular disjunction and mitral valve prolapse: long-term risk of ventricular arrhythmias after surgery" , published in the European Heart Journal.

The condition is more common in women and younger patients with valve disorder and can, in the worst case, lead to sudden cardiac arrest.

Mitral annular disjunction, MAD, is a heart abnormality in which the mitral valve attachment "slides." In recent years, the condition has been linked to an increased risk of severe cardiac arrhythmias. Until now, it has not been known whether the risk of arrhythmias disappears if MAD is surgically corrected.

MAD is often associated with a heart disease called mitral valve prolapse, which affects 2.5% of the population and causes one of the heart's valves to leak. This can lead to blood being pumped backward in the heart, causing heart failure and arrhythmias. The disease can cause symptoms such as shortness of breath and palpitations.

In the current study, researchers  investigated the risk of cardiac arrhythmias in 599 patients with mitral valve prolapse who underwent heart surgery at Karolinska University Hospital between 2010 and 2022. Some 16% of the patients also had the cardiac abnormality MAD.

The researchers have been able to show that people with MAD have a significantly higher risk of suffering from ventricular arrhythmias, a dangerous type of heart rhythm disorder that, in the worst case, can lead to cardiac arrest in a subset of patients.

People with MAD were more likely to be female and were on average eight years younger than those without MAD. They also had more extensive mitral valve disease. Although the surgery was successful in correcting MAD, these patients had more than three times the risk of ventricular arrhythmias during five years of follow-up compared to patients without preoperative MAD.

These results show that it is important to closely monitor patients with this condition, even after a successful operation, say the researchers.

The study has led to new hypotheses that the researchers are now investigating further. One hypothesis is that MAD causes permanent changes in the heart muscle over time. Another is that MAD is a sign of an underlying heart muscle disease.

The researchers are now continuing to study scarring in the heart using MRI (magnetic resonance imaging) and analyze tissue samples from the heart muscle.

Bahira Shahim et al, Mitral annular disjunction and mitral valve prolapse: long-term risk of ventricular arrhythmias after surgery, (2025). DOI: 10.1093/eurheartj/ehaf195

Children exposed to brain-harming chemicals while sleeping: Scientists urge mattress manufacturers to act

Babies and young children may breathe and absorb plasticizers called phthalates, flame retardants, and other harmful chemicals from their mattresses while they sleep, according to a pair of studies published by the University of Toronto in Environmental Science & Technology and Environmental Science & Technology Letters. These chemicals are linked to neurological and reproductive problems, asthma, hormone disruption, and cancer.

Sleep is vital for brain development, particularly for infants and toddlers. However, this research suggests that many mattresses contain chemicals that can harm kids' brains. 

This is a wake-up call for manufacturers and policymakers to ensure our children's beds are safe and support healthy brain development.

In the first study, researchers measured chemical concentrations in 25 bedrooms of children aged 6 months to 4 years. They detected concerning levels of more than two dozen phthalates, flame retardants, and UV-filters in bedroom air, with the highest levels lurking around the beds. In a companion study, researchers tested 16 newly purchased children's mattresses and confirmed that they are likely the major source of these chemicals in children's sleeping environments. When the researchers simulated a child's body temperature and weight on the mattresses, chemical emissions increased substantially, as much as by several times.

The phthalates and organophosphate ester flame retardants measured in this study are hormone disruptors and are linked to neurological harms, including learning disorders, reduced IQ scores, behavioral problems, and impaired memory. Some are also linked to childhood asthma and cancer. Several UV-filters are hormone disruptors.

Children are uniquely vulnerable to exposure, given that they are still developing, have hand-to-mouth behaviors, and have breathing rates ten times higher than adults. They also have more permeable skin and three times the skin surface area relative to their body weight than adults.

Flame retardants are linked to neurological, reproductive, and hormonal harm as well as cancer, and also have no proven fire-safety benefit as used in mattresses.

Flame retardants have a long history of harming our children's cognitive function and ability to learn. It's concerning that these chemicals are still being found in children's mattresses even though we know they have no proven fire-safety benefit, and aren't needed to comply with flammability standards.

The researchers call for manufacturers to be more vigilant about the chemicals in children's mattresses through testing. Further, stronger regulations on the use of flame retardants and phthalate plasticizers in children's mattresses are needed.

Environmental Science & Technology Letters (2025). DOI: 10.1021/acs.estlett.5c00051

Are Sleeping Children Exposed to Plasticizers, Flame Retardants, and UV-Filters from Their Mattresses?, Environmental Science & Technology (2025). DOI: 10.1021/acs.est.5c03560

NASA experiment shows solar wind might make water on the moon

Scientists have hypothesized since the 1960s that the sun is a source of ingredients that form water on the moon. When a stream of charged particles known as the solar wind smashes into the lunar surface, the idea goes, it triggers a chemical reaction that could make water molecules.

Now, in the most realistic lab simulation of this process yet, NASA-led researchers have confirmed this prediction.

The finding, researchers wrote in the Journal of Geophysical Research: Planets, has implications for NASA's Artemis astronaut operations at the moon's South Pole. A critical resource for exploration, much of the water on the moon is thought to be frozen in permanently shadowed regions at the poles.

Solar wind flows constantly from the sun. It's made largely of protons, which are nuclei of hydrogen atoms that have lost their electrons. Traveling at more than 1 million miles per hour, the solar wind bathes the entire solar system. We see evidence of it on Earth when it lights up our sky in auroral light shows.

Most of the solar particles don't reach the surface of Earth because our planet has a magnetic shield and an atmosphere to deflect them. But the moon has no such protection. As computer models and lab experiments have shown, when protons smash into the moon's surface, which is made of a dusty and rocky material called regolith, they collide with electrons and recombine to form hydrogen atoms.

Then, the hydrogen atoms can migrate through the lunar surface and bond with the abundant oxygen atoms already present in minerals like silica to form hydroxyl (OH) molecules, a component of water, and water (H₂O) molecules themselves.

Scientists have found evidence of both hydroxyl and water molecules in the moon's upper surface, just a few millimeters deep. These molecules leave behind a kind of chemical fingerprint—a noticeable dip in a wavy line on a graph that shows how light interacts with the regolith. With the current tools available, though, it is difficult to tell the difference between hydroxyl and water, so scientists use the term "water" to refer to either one or a mix of both molecules.

Many researchers think the solar wind is the main reason the molecules are there, though other sources like micrometeorite impacts could also help by creating heat and triggering chemical reactions.

Spacecraft measurements had already hinted that the solar wind is the primary driver of water, or its components, at the lunar surface. One key clue, confirmed by Yeo's team's experiment: the moon's water-related spectral signal changes over the course of the day.

In some regions, it's stronger in the cooler morning and fades as the surface heats up, likely because water and hydrogen molecules move around or escape to space. As the surface cools again at night, the signal peaks again. This daily cycle points to an active source—most likely the solar wind—replenishing tiny amounts of water on the moon each day.

Li Hsia Yeo et al, Hydroxylation and Hydrogen Diffusion in Lunar Samples: Spectral Measurements During Proton Irradiation, Journal of Geophysical Research: Planets (2025). DOI: 10.1029/2024JE008334

**

Researchers resurrect extinct gene in plants with major implications for drug development

Researchers resurrected an extinct plant gene, turning back the evolutionary clock to pave a path forward for the development and discovery of new drugs.

Specifically, the team repaired a defunct gene in the coyote tobacco plant.

In a new paper, they detail their discovery of a previously unknown kind of cyclic peptide, or mini-protein, called nanamin that is easy to bioengineer, making it "a platform with huge potential for drug discovery" . The paper is published in the journal Proceedings of the National Academy of Sciences.

It will provide chemical biologists with other tools to develop new peptide-based cancer treatments, for discovering new antibiotics and also for agricultural applications for defense against pathogens and insects.

Made up of short strings of amino acids, cyclic peptides are very small and almost tailor-made for use in drug development.

Cyclic peptides are much smaller, so it's like a small molecule drug but has the chemical features of a protein. You can also engineer it. We can easily generate a library that produces millions of these peptides that can be used for drug screening.

The researchers  previously discovered that cyclic peptides exist in plants, which brought him to coyote tobacco. As they delved into the genetic code of this plant, they discovered a pseudogene that was no longer functional.

This particular gene had previously encoded the cyclic peptide nanamin in coyote tobacco, but over time, due to adaptive mutations, it had faded away into the evolutionary past. But that didn't stop the researchers.

They found that this gene still existed in related plant species and, using a new method called molecular gene resurrection, cloned the gene and corrected the mutation.

To their surprise, they were able to recover the ancestral function of this gene.

Beyond resurrecting an extinct gene, this research proves the viability of cyclic peptides, and nanamin specifically, as the foundation for a number of novel uses.

Nanamin's size and chemical mutability makes it an asset for discovering new drugs and agriculture.

Elliot M. Suh et al, The emergence and loss of cyclic peptides in Nicotiana illuminate dynamics and mechanisms of plant metabolic evolution, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2425055122

Key to the high aggressiveness of pancreatic cancer identified

Pancreatic cancer is one of the most aggressive cancers and has one of the lowest survival rates—only 10% after five years. One of the factors contributing to its aggressiveness is its tumor microenvironment, known as the stroma, which makes up the majority of the tumor mass and consists of a network of proteins and different non-tumor cells. Among these, fibroblasts play a key role, helping tumor cells to grow and increasing their resistance to drugs.

Now, a study  by researchers has identified a new key factor contributing to this feature of pancreatic cancer: a previously unknown function of Galectin-1 protein inside the nuclei of fibroblasts.

This discovery, published in the journal PNAS, offers new insights into the role of these cells in the progression of pancreatic cancer.

The stroma is considered a key component in the aggressive nature of pancreatic cancer, as it interacts with tumor cells, protects them, and hinders the action of drugs. Moreover, stromal cells, particularly fibroblasts, produce substances that support tumor growth and dissemination. 

Until now, fibroblasts were known to secrete Galectin-1, a protein with pro-tumoral properties. This study, however, shows that the molecule is also located inside fibroblasts—specifically in their nuclei—where it plays a key role in gene expression regulation.

The presence of this molecule activates fibroblasts, making them support tumor cell development. The researchers also discovered that Galectin-1 can regulate gene expression in these cells at a highly specific level without altering the DNA sequence, through epigenetic control. One of the genes it regulates is KRAS, which plays a critical role in pancreatic tumors.

This gene is also present in tumor cells in 90% of patients, though in this case it is mutated. It is considered one of the main drivers of uncontrolled growth and tumor aggressiveness.

 The newly discovered functions now pave the way for developing new strategies to tackle this type of tumor.

Judith Vinaixa et al, Nuclear Galectin-1 promotes KRAS -dependent activation of pancreatic cancer stellate cells, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2424051122

Researchers uncover molecular connection between body fat and anxiety

Researchers  have revealed a novel link between body fat (adipose tissue) and anxiety, shedding light on the intricate relationship between metabolism and mental health.

The findings, published in Nature Metabolism on April 15, 2025, are particularly relevant given the rising rates of anxiety and obesity, highlighting the importance of understanding the underlying biological processes.

Understanding the link between adipose tissue and anxiety opens up new avenues for research and potential treatments.

The research team discovered that psychological stress, which triggers the fight or flight response, initiates a process called lipolysis in fat cells. This process leads to the release of fats, which in turn stimulates the release of a hormone called GDF15 from immune cells found in fat tissue. GDF15 then communicates with the brain, resulting in anxiety.

Researchers came to their conclusion through a series of meticulously designed experiments involving mice. Behavioral tests assessed anxiety-like behavior, and molecular analyses identified the activated pathways. A clear connection between metabolic changes in adipose tissue and anxiety was established, offering new insights into the interplay between metabolism and mental health.

 Logan K. Townsend et al, GDF15 links adipose tissue lipolysis with anxiety, Nature Metabolism (2025). DOI: 10.1038/s42255-025-01264-3

New pollen-replacing food for honey bees brings hope for their survival

Changes in land use, urban expansion, and extreme weather all negatively impact nutrition for honey bees and other pollinators. Many crops depend on these pollinators for survival. Honey bees are generalists and do not get all their nutrition from a single source. They need variety in their diet to survive but find it increasingly difficult to find the continuous supply of pollen they need to sustain the colony.

Changes in land use, urban expansion, and extreme weather all negatively impact nutrition for honey bees and other pollinators.

Now Scientists have unveiled a new food source designed to sustain honey bee colonies indefinitely without natural pollen.

Published in the journal Proceedings of the Royal Society B, the research details successful trials where nutritionally stressed colonies, deployed for commercial crop pollination  thrived on the new food source.

This innovation, which resembles the man-made diets fed to livestock and pets all their lives, contains all the nutrients honey bees need. It's expected to become a potent strategy for combating the escalating rates of colony collapse and safeguarding global food supplies reliant on bee pollination.
The newly developed food source resembles human "Power Bars." These are placed directly into honey bee colonies, where young bees process and distribute the essential nutrients to larvae and adult bees.

This breakthrough addresses one of the growing challenges faced by honey bees: lack of adequate nutrition in their environment.

The reported scientific work shows in commercial field conditions that providing nutritionally stressed colonies with the pollen-replacing feed results in a major measurable step change in colony health compared to current best practices. This new product has the potential to change the way honey bees are managed.

A critical discovery within the research is the role of isofucosterol, a molecule found naturally in pollen that acts as a vital nutrient for honey bees.

Colonies fed with isofucosterol-enriched food survived an entire season without pollen access, while those without it experienced severe declines, including reduced larval production, adult paralysis, and colony collapse. The new feed also contains a comprehensive blend of the other nutrients honey bees require.

A nutritionally complete pollen-replacing diet protects honey bee colonies during stressful commercial pollination - Requirement for isofucosterol, Proceedings of the Royal Society B: Biological Sciences (2025). DOI: 10.1098/rspb.2024.3078. royalsocietypublishing.org/doi … .1098/rspb.2024.3078

Scientists find evidence that challenges theories of the origin of water on Earth

A team of researchers have uncovered crucial evidence for the origin of water on Earth. Using a rare type of meteorite, known as an enstatite chondrite, which has a composition analogous to that of the early Earth (4.55 billion years ago), they have found a source of hydrogen which would have been critical for the formation of water molecules.

Crucially, they demonstrated that the hydrogen present in this material was intrinsic, and not from contamination. This suggests that the material which our planet was built from was far richer in hydrogen than previously thought.

The findings, which support the theory that the formation of habitable conditions on Earth did not rely on asteroids hitting Earth, have been published in the journal Icarus..

Without hydrogen, a fundamental elemental building-block of water, it would have been impossible for our planet to develop the conditions to support life.

The origin of hydrogen, and, by extension, water, on Earth has been highly debated, with many believing that the necessary hydrogen was delivered by asteroids from outer space during Earth's first approximately 100 million years. But these new findings contradict this, suggesting instead that Earth had the hydrogen it needed to create water from when it first formed.

The research team analyzed the elemental composition of a meteorite known as LAR 12252, originally collected from Antarctica. They used an elemental analysis technique called X-Ray Absorption Near Edge Structure (XANES) spectroscopy at the Diamond Light Source synchrotron at Harwell, Oxfordshire.

 A previous study led by a French team(1,2) had originally identified traces of hydrogen within the meteorite inside organic materials and non-crystalline parts of the chondrules (millimeter-sized spherical objects within the meteorite). However, the remainder was unaccounted for—meaning it was unclear whether the hydrogen was native or due to terrestrial contamination.

The new work by the team suspected that significant amounts of the hydrogen may be attached to the meteorite's abundant sulfur. Using the synchrotron, they shone a powerful beam of X-rays onto the meteorite's structure to search for sulfur-bearing compounds.

When initially scanning the sample, the team focused their efforts on the non-crystalline parts of the chondrules, where hydrogen had been found before.

Part 1

But when serendipitously analyzing the material just outside of one of these chondrules, composed of a matrix of extremely fine (sub-micrometer) material, the team discovered that the matrix itself was incredibly rich in hydrogen sulfide. In fact, their analysis found that the amount of hydrogen in the matrix was five times higher than that of the non-crystalline sections.

Since the proto-Earth was made of material similar to enstatite chondrites, this suggests that by the time the forming planet had become large enough to be struck by asteroids, it would have amassed enough reserves of hydrogen to explain Earth's present-day water abundance.

Because the likelihood of this hydrogen sulfide originating from terrestrial contamination is very low, this research provides vital evidence to support the theory that water on Earth is native—that it is a natural outcome of what our planet is made of.

Thomas J. Barrett et al,The source of hydrogen in earth's building blocks, Icarus (2025). DOI: 10.1016/j.icarus.2025.116588

In contrast, in other parts of the meteorite that had cracks and signs of obvious terrestrial contamination (such as rust), very little or no hydrogen was present. This makes it highly unlikely that the hydrogen sulfide compounds detected by the team originated from an earthly source.

Footnotes:

1. L. Piani el al., "Earth's water may have been inherited from material similar to enstatite chondrite meteorites," Science (2020). science.sciencemag.org/cgi/doi … 1126/science.aba1948

2. "The origins of water," Science (2020). science.sciencemag.org/cgi/doi … 1126/science.abc1338

Part 2

Forensic Science: Glowing gunshot residue: New method illuminates crime scene clues

Crime scene investigation may soon become significantly more accurate and efficient thanks to a new method for detecting gunshot residues. Researchers  developed the technique that converts lead particles found in gunshot residue into light-emitting semiconductors. This method is faster, more sensitive, and easier to use than current alternatives.

Forensic experts at the Amsterdam police force are already testing it in actual crime scene investigations. The researchers published their findings in Forensic Science International on March 9.

The innovative light-emitting lead analysis method offers exciting opportunities for crime scene investigations. When a weapon is fired, it leaves gunshot residue containing lead traces on the surrounding environment, including clothing and skin.

Obtaining an indication of gunshot residue at the crime scene is a major advantage, helping us answer key questions about shooting incidents. For instance, determining whether the damage found could have been caused by a bullet and determining the relative position of a person who might have been involved in a shooting incident. We test for lead traces on possible bullet holes and a suspect's or a victim's clothing or hands.

Currently, police send all samples to the lab for analysis. However, the methods used there are often time-consuming, labor-intensive, and require expensive equipment.

The new analysis method builds on recent advances in perovskite research. Perovskites are a promising material used in applications ranging from solar cells to LEDs. A few years ago, researchers  developed an easy-to-use lead detection method based on perovskite technology.

In this method, a reagent converts lead-containing surfaces into a perovskite semiconductor. Shining with a UV lamp will make the newly formed semiconductor emit a bright green glow visible to the naked eye—making even small traces of lead easily detectable.

In 2021, Noorduin and Lukas Helmbrecht (formerly Ph.D. student in the group) established a start-up company to develop this lead testing method into a practical lead detection kit: Lumetallix. Over the past years, many people worldwide have been investigating their surroundings using the Lumetallix test kit. They report positive tests in all sorts of objects, for example: dinner plates, beer glasses, but also in paint dust at construction sites.

Now researchers developed an altered version of the Lumetallix reagent for the forensic application: one that reacts especially well with lead atoms in gunshot residue and produces a long-lasting green glow.

To validate the effectiveness of this method, the researchers conducted a series of controlled experiments. The results revealed well-defined luminescent patterns that were clearly visible to the naked eye, even at extended distances.

Part 1

The researchers made two other remarkable discoveries:

First, unlike other methods, the new light-emitting technique remains effective even after extensive washing of the shooter's hands. This is important for forensic investigations, as suspects often try to tamper with or remove evidence of their involvement.

Second, bystanders standing approximately 2 meters away from the shooter also tested positive for lead traces on their hands. "These findings provide valuable pieces of the puzzle when reconstructing a shooting incident. But, a positive test also needs to be carefully interpreted. It does not automatically mean that you fired a gun.

The researchers think this new method will be especially beneficial to first responders, such as police officers, who can use it to rapidly screen potential suspects and witnesses to secure crucial evidence.

Kendra Adelberg et al, Perovskite-based photoluminescent detection of lead particles in gunshot residue, Forensic Science International (2025). DOI: 10.1016/j.forsciint.2025.112415

Part 2

Bonobos refuse to participate when faced with unequal rewards

To better understand the evolutionary origins of fairness, researchers  investigated inequity aversion in bonobos, one of humans' closest relatives.

 The researchers conducted two rounds of experiments using established inequity paradigms: one in which the bonobos exchanged tokens for rewards, and another in which they tested whether their reactions might have been caused by disappointment in the experimenter. The study is published in the Proceedings of the Royal Society B: Biological Sciences.

The results showed that bonobos refused to participate more often when they received a lesser reward than their partner. Unlike chimpanzees, their responses could not be explained by disappointment alone, supporting the idea that bonobos genuinely recognize and respond to unfair treatment.

Unlike chimpanzees, their reactions were not simply due to disappointment with the experimenter, but reflected a genuine aversion to unequal treatment.

Interestingly, bonobos were more tolerant of inequity when interacting with closely affiliated partners, similar to patterns seen in humans. This suggests that social bonds may influence reactions to fairness, reinforcing the idea that inequity aversion has evolved as a stabilizing force for cooperation.

Kia Radovanović et al, Bonobos respond aversively to unequal reward distributions, Proceedings of the Royal Society B: Biological Sciences (2025). DOI: 10.1098/rspb.2024.2873

People, not alligators, are at fault in most alligator bite cases

Risky human behavior, not aggression by alligators, is the leading cause of alligator bites, according to a study by scientists.

Published in the journal Human–Wildlife Interactions, the research is the first to develop a ranking system that categorizes human actions immediately before an alligator encounter. Researchers found that in 96% of recorded incidents, some form of human inattention or risk-taking preceded the attack. The findings show that alligator bites are not random; they're preventable.

The insights come at a time of year when alligator activity is ramping up. Mating season, which runs from April through June in some places, brings more frequent movement and territorial behavior among alligators, making human awareness and safe practices even more essential.

To reach their conclusions, the team analyzed nearly three centuries of records from 1734 to 2021 on human–alligator interactions using the CrocBITE database, now called CrocAttack.org. The team then augmented that information with internet searches, literature review and communications with wildlife agencies. Each case was classified by the level of human behavior risk: no risk, low, moderate or high.

Most bites occurred following moderate-risk behaviors, such as swimming or wading in areas known to be inhabited by alligators. The highest proportion of fatal bites occurred after high-risk behaviors, such as deliberately entering alligator-inhabited waters. In contrast, low and no-risk behaviors, like walking near water or simply being present on land, rarely resulted in attacks.

The takeaway lesson from this study is that many bites can be prevented if humans are aware of their surroundings and minimize risky behaviors such as walking small pets near bodies of water or swimming where alligators are known to be present, say the researchers. 

The most surprising finding was how high the percentage was for humans engaging in risky behavior. This indicates that humans—rather than alligators—are at fault in the vast majority of cases where bites occur.

The results emphasize that alligators aren't seeking conflict, but they will respond when humans provide what scientists call an "attractive stimulus," such as by splashing, swimming or entering alligator habitats.

Although some bites happened without clear warning, in many cases, people unknowingly triggered the alligator's natural response to defend itself or to hunt.

Researchers stress that humans are entering the environment of a large, wild predator much like hikers entering bear country or swimmers in shark-inhabited waters and should assume some level of responsibility and attentiveness.

Mark S Teshera et al, Human-Alligator Incidents in the United States: Risky Human Behaviors Cause Most "Attacks", Human–Wildlife Interactions (2023). DOI: 10.26077/wvfj-s221. digitalcommons.usu.edu/cgi/vie … cle=1885&context=hwi

Curiosity rover finds large carbon deposits on Mars

And scientists are trying to answer some of the questions on earlier Martian life and that of the Earth at present with these findings

Research from NASA's Curiosity rover has found evidence of a carbon cycle on ancient Mars, bringing scientists closer to an answer on whether the red planet was ever capable of supporting life.

The team is working to understand climate transitions and habitability on ancient Mars as Curiosity explores Gale Crater.

The paper, published in the journal Science, reveals that data from three of Curiosity's drill sites had siderite, an iron carbonate material, within sulfate-rich layers of Mount Sharp in Gale Crater.

The discovery of large carbon deposits in Gale Crater represents both a surprising and important breakthrough in our understanding of the geologic and atmospheric evolution of Mars. 

The abundance of highly soluble salts in these rocks and similar deposits mapped over much of Mars has been used as evidence of the 'great drying' of Mars during its dramatic shift from a warm and wet early Mars to its current, cold and dry state.

Sedimentary carbonate has long been predicted to have formed under the CO₂-rich ancient Martian atmosphere. 

NASA's Curiosity rover landed on Mars on Aug. 5, 2012, and has traveled more than 34 kilometers on the Martian surface.

Part 1

The discovery of carbonate suggests that the atmosphere contained enough carbon dioxide to support liquid water existing on the planet's surface. As the atmosphere thinned, the carbon dioxide transformed into rock form.
NASA says future missions and analysis of other sulfate-rich areas on Mars could confirm the findings and help to better understand the planet's early history and how it transformed as its atmosphere was lost.
Scientists are trying to determine whether Mars was ever capable of supporting life—and the latest paper brings them closer to an answer. It tells us that the planet was habitable and that the models for habitability are correct.
The broader implications are the planet was habitable up until this time, but then, as the CO2 that had been warming the planet started to precipitate as siderite, it likely impacted Mars' ability to stay warm.

"The question looking forward is how much of this CO2 from the atmosphere was actually sequestered? Was that potentially a reason we began to lose habitability?"
The latest research fits with his ongoing work on Earth—trying to turn anthropogenic CO2 into carbonates as a climate change solution.

Learning about the mechanisms of making these minerals on Mars helps us to better understand how we can do it here.
Studying the collapse of Mars' warm and wet early days also tells us that habitability is a very fragile thing. It's clear that small changes in atmospheric CO2 can lead to huge changes in the ability of the planet to harbour life.
The most remarkable thing about Earth is that it's habitable and it has been for at least four billion years. Something happened to Mars that didn't happen to Earth.
What is it and how can we avoid such a situation, if we ever can, here on Earth?

We must catch these answers that are blowing in the thin Martian atmosphere and embedded in the dust on the planet's surface.

Benjamin M. Tutolo, Carbonates identified by the Curiosity rover indicate a carbon cycle operated on ancient Mars, Science (2025). DOI: 10.1126/science.ado9966. www.science.org/doi/10.1126/science.ado9966

Part 2

Astronomers detect strongest sign yet of possible life on a planet beyond our own

Astronomers have detected the most promising signs yet of a possible biosignature outside the solar system, although they remain cautious.

Using data from the James Webb Space Telescope (JWST), the astronomers have detected the chemical fingerprints of dimethyl sulfide (DMS) and/or dimethyl disulfide (DMDS), in the atmosphere of the exoplanet K2-18b, which orbits its star in the habitable zone.

On Earth, DMS and DMDS are only produced by life, primarily microbial life such as marine phytoplankton. While an unknown chemical process may be the source of these molecules in K2-18b's atmosphere, the results are the strongest evidence yet that life may exist on a planet outside our solar system.

The observations have reached the 'three-sigma' level of statistical significance—meaning there is a 0.3% probability that they occurred by chance. To reach the accepted classification for scientific discovery, the observations would have to cross the five-sigma threshold, meaning there would be below a 0.00006% probability they occurred by chance.

The researchers say between 16 and 24 hours of follow-up observation time with JWST may help them reach the all-important five-sigma significance. Their results are reported in The Astrophysical Journal Letters.

Earlier observations of K2-18b—which is 8.6 times as massive and 2.6 times as large as Earth, and lies 124 light years away in the constellation of Leo—identified methane and carbon dioxide in its atmosphere. This was the first time that carbon-based molecules were discovered in the atmosphere of an exoplanet in the habitable zone.

Those results were consistent with predictions for a 'Hycean' planet: a habitable ocean-covered world underneath a hydrogen-rich atmosphere.

However, another, weaker signal hinted at the possibility of something else happening on K2-18b. Scientists didn't know for sure whether the signal they saw last time was due to DMS, but just the hint of it was exciting enough for them to have another look with JWST using a different instrument.

To determine the chemical composition of the atmospheres of faraway planets, astronomers analyze the light from its parent star as the planet transits, or passes in front of the star as seen from Earth. As K2-18b transits, JWST can detect a drop in stellar brightness, and a tiny fraction of starlight passes through the planet's atmosphere before reaching Earth.

Part 1

The absorption of some of the starlight in the planet's atmosphere leaves imprints in the stellar spectrum that astronomers can piece together to determine the constituent gases of the exoplanet's atmosphere.

The earlier, tentative, inference of DMS was made using JWST's NIRISS (Near-Infrared Imager and Slitless Spectrograph) and NIRSpec (Near-Infrared Spectrograph) instruments, which together cover the near-infrared (0.8-5 micron) range of wavelengths. The new, independent observation used JWST's MIRI (Mid-Infrared Instrument) in the mid-infrared (6-12 micron) range.
This is an independent line of evidence, using a different instrument than the scientists did before and a different wavelength range of light, where there is no overlap with the previous observations. "The signal came through strong and clear."
It 's an incredible realization seeing the results emerge and remain consistent throughout the extensive independent analyses and robustness tests.
DMS and DMDS are molecules from the same chemical family, and both are predicted to be biosignatures. Both molecules have overlapping spectral features in the observed wavelength range, although further observations will help differentiate between the two molecules.
However, the concentrations of DMS and DMDS in K2-18b's atmosphere are very different than on Earth, where they are generally below one part per billion by volume. On K2-18b, they are estimated to be thousands of times stronger—over ten parts per million.
Earlier theoretical work had predicted that high levels of sulfur-based gases like DMS and DMDS are possible on Hycean worlds (covered in oceans). Given everything we know about this planet, a Hycean world with an ocean that is teeming with life is the scenario that best fits the data we have, say the scientists.
While the results are exciting, it's vital to obtain more data before claiming that life has been found on another world. While scientists are cautiously optimistic, there could be previously unknown chemical processes at work on K2-18b that may account for the observations.
Scientists have to conduct further theoretical and experimental work to determine whether DMS and DMDS can be produced non-biologically at the level currently inferred.
The inference of these biosignature molecules poses profound questions concerning the processes that might be producing them.
It's important that we're deeply skeptical of our own results, because it's only by testing and testing again that we will be able to reach the point where we're confident in them,"  the scientists add. "That's how science has to work."

Nikku Madhusudhan et al, New Constraints on DMS and DMDS in the Atmosphere of K2-18 b from JWST MIRI, The Astrophysical Journal Letters (2025). DOI: 10.3847/2041-8213/adc1c8

Part 2

Extreme microbial adaptations arise in one of  most polluted waterways

The industrially ravaged Gowanus Canal, long regarded as a symbol of urban environmental neglect, is being reimagined through the lens of scientific inquiry as a complex reservoir of microbial life shaped by intense selective pressures.

Research  has discovered microbes in Brooklyn's Gowanus Canal that carry genes for breaking down industrial pollutants and neutralizing heavy metals. Genetic screening also uncovered resistance to multiple antibiotic classes and thousands of biosynthetic gene clusters with implications for developing new antibiotics, industrial enzymes, and bioactive compounds.

Built in the mid 1800s, the 2.9 km long industrial canal has experienced over 150 years of unregulated environmental abuse. As a hub of heavy industry, various mills, petroleum and chemical plants have lined the canal banks.

Unknown volumes of arsenic, heavy metals, polychlorinated biphenyls, coal tar, petroleum products, volatile organic compounds, chlorinated solvents and untreated sewage overflow have discharged into the small waterway.

Designated a Superfund site in 2010, the Gowanus Canal is one of the most contaminated waterways in the United States. When the EPA began evaluating the site for restoration, they discovered approximately two hundred previously unknown and unpermitted pipes that discharge directly into the canal.

So toxic are the sediments and extreme the environment that mere skin contact with the water poses a health hazard for humans. To microbiologists, such extreme environments are highly intriguing opportunities to see how life finds a way to adapt and even thrive. Microbial life has previously been discovered in similarly extreme contexts.

Discoveries in NASA clean rooms revealed microbes that lived off of paint and cleaning solutions. An enzyme that revolutionized early genomic research came from a bacterium found in the hot springs of Yellowstone National Park. Microorganisms discovered in contaminated environments have previously been used to degrade petroleum hydrocarbons and other pollutants.

While the Gowanus Canal is unquestionably an environmental disaster, it can also serve as a long-running experiment in microbial evolution.

In the study, "Metagenomic interrogation of urban Superfund site reveals antimicrobial resistance reservoir and bioremediation potential," published in the Journal of Applied Microbiology, researchers performed a metagenomic analysis of microbial communities in the Gowanus Canal.

Part 1

With a comprehensive dataset and in-depth profiling of Gowanus microbial communities, researchers were able to identify previously undocumented microbial lineages and assess their potential for environmental remediation.

Metagenomic analysis of sediment samples from the Gowanus Canal revealed a diverse microbial community comprising 455 distinct microbial species, including bacteria, archaea, and viruses.

Across both surface and core samples, researchers identified 64 metabolic pathways involved in the degradation of organic contaminants, alongside 1,171 genes associated with the detoxification of heavy metals such as iron, copper, and nickel. Researchers identified 2,319 biosynthetic gene clusters, many of which may be linked to the production of novel secondary metabolites with potential therapeutic or industrial value.
A comprehensive screening of antimicrobial resistance genes demonstrated the presence of 28 resistance genes across eight different antibiotic classes, including agents commonly used in clinical settings such as rifampin and aminoglycosides.

Coexistence of pollutant-degrading genes and antimicrobial resistance likely arises from ecological adaptations driven by prolonged exposure to urban and industrial waste. Microorganisms within the canal deploy multiple degradation pathways to metabolize pollutants like toluene and phenolic compounds, while simultaneously exhibiting traits that confer resilience to heavy metal stress.
Findings suggest that extreme urban ecosystems like the Gowanus Canal may act as reservoirs of both beneficial and hazardous genetic elements. Some of the antimicrobial resistance genes appear to originate from human gut-associated microbes, likely introduced through untreated sewage overflow, raising urgent new concerns around public health risks.

While not an experiment any scientist would have chosen to run, if future research findings lead to novel industrial or clinical insights, it could transform the Gowanus Canal from a symbol of urban neglect into that of a living laboratory. One where the pressures of prolonged contamination have forged a microbial community that has created the keys to future ecological restoration and molecular innovation.

Sergios-Orestis Kolokotronis et al, Metagenomic interrogation of urban Superfund site reveals antimicrobial resistance reservoir and bioremediation potential, Journal of Applied Microbiology (2025). DOI: 10.1093/jambio/lxaf076

Part 2

Scientists hack cell entry to supercharge cancer drugs

A new discovery could pave the way for more effective cancer treatment by helping certain drugs work better inside the body. Scientists have found a way to improve the uptake of a promising class of cancer-fighting drugs called PROTACs, which have struggled to enter cells due to their large size.

The new method works by taking advantage of a protein called CD36 that helps pull substances into cells. By designing drugs to use this CD36 pathway, researchers delivered 7.7 to 22.3 times more of the drug inside cancer cells, making the treatment up to 23 times more potent than before, according to the study published April 17 in Cell.

Data from mouse studies shows this enhanced uptake led to stronger tumor suppression without making the drugs harder to dissolve or less stable.

The strategy called chemical endocytic medicinal chemistry (CEMC) takes advantage of a natural process where cells "swallow" molecules called endocytosis. It could change the future of drug design—especially for drugs that were once considered too big to work.

CD36-mediated endocytosis of proteolysis-targeting chimeras, Cell (2025). DOI: 10.1016/j.cell.2025.03.036. www.cell.com/cell/fulltext/S0092-8674(25)00386-1

How cleft lip and cleft palate can arise

Cleft lip and cleft palate are among the most common birth defects.

These defects, which appear when the tissues that form the lip or the roof of the mouth do not join completely, are thought to be caused by a mix of genetic and environmental factors.

In a new study,  biologists have discovered how a genetic variant often found in people with these facial malformations leads to the development of cleft lip and cleft palate.

Their findings suggest that the variant diminishes cells' supply of transfer RNA, a molecule that is critical for assembling proteins. When this happens, embryonic face cells are unable to fuse to form the lip and roof of the mouth.

A non-syndromic orofacial cleft risk locus links tRNA splicing defects to neural crest cell pathologies, The American Journal of Human Genetics (2025). DOI: 10.1016/j.ajhg.2025.03.017. www.cell.com/ajhg/fulltext/S0002-9297(25)00138-7

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

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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.

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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.

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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