Insecticides may contribute to bigger problems with certain weeds

Insecticides may help growers hoping to protect their crops from harmful insects, but they also may contribute to a larger amount of some weeds, according to a study led by researchers.

 The study—published in the journal PeerJ—compared using insecticides preventively at planting versus using an integrated pest management (IPM) approach, which calls for insecticides only when a known insect problem exists.  

The team also investigated the effects of using cover crops—a crop used to cover and protect soil after harvesting the cash crop—when combined with these treatment plans. The researchers found that by the third year, some fields that were treated with insecticides and didn't have a cover crop ended up with slightly more weeds—especially marestail.

However, planting a cover crop prevented this issue, even in fields that were treated with insecticides.

The most likely explanation may be that the preventative insecticides limited the activity of insects that typically eat weeds or weed seeds, allowing the weeds to be more abundant.

 Elizabeth K. Rowen et al, Insecticides may facilitate the escape of weeds from biological control, PeerJ (2025). DOI: 10.7717/peerj.18597

A possible way to generate electricity using Earth's rotational energy

A trio of physicists from  is proposing the possibility of generating electricity using energy from the rotation of the Earth. In their study, published in the journal Physical Review Research, they tested a theory that electricity could be generated from the Earth's rotation using a special device that interacts with the Earth's magnetic field.

Over the past decade, members of the team have been toying with the idea of generating electricity using the Earth's rotation and its magnetic field, and they even published a paper describing the possibility back in 2016. That paper was met with criticism because prior theories have suggested that doing so would be impossible because any voltage created by such a device would be canceled as the electrons rearrange themselves during the generation of an electric field.

The researchers wondered what would happen if this cancelation was prevented and the voltage was instead captured. To find out, they built a special device consisting of a cylinder made of manganese-zinc ferrite, a weak conductor, which served as a magnetic shield. They then oriented the cylinder in a north-south direction set at a 57° angle. That made it perpendicular to both the Earth's rotational motion and the Earth's magnetic field.

Next, they placed electrodes at each end of the cylinder to measure voltage and then turned out the lights to prevent photoelectric effects. They found that 18 microvolts of electricity were generated across the cylinder that they could not attribute to any other source, strongly suggesting that it was due to the energy from the Earth's rotation.

The researchers note that they accounted for the voltage that might have been caused by temperature differences between the ends of the cylinder. They also noted that no such voltage was measured when they changed its angle or used control cylinders. The results will have to be verified by others running the same type of experiment under different scenarios to ensure that there were no other sources of electricity generation that they failed to account for. But the researchers note that if their findings turn out to be correct, there is no reason the amount produced could not be increased to a useful level.

Christopher F. Chyba et al, Experimental demonstration of electric power generation from Earth's rotation through its own magnetic field, Physical Review Research (2025). DOI: 10.1103/PhysRevResearch.7.013285

Eco-friendly detergent made from wood and corn shows promise

From laundry detergent to dishwasher tablets, cleaning products are an indispensable part of life. Yet the chemicals that make these products so effective can be difficult to break down or could even trigger ecosystem-altering algal blooms. Now, researchers reporting in ACS' Langmuir have addressed those challenges with an environmentally compatible detergent made of tiny wood fibers and corn protein that removes stains on clothes and dishes just as well as commercial products.

Increased public concern about household products' impact on the environment has spurred interest in replacing traditional cleaners containing ingredients such as alkylphenol polyethoxylates and phosphates with natural alternatives. Efforts to date have produced mixed results because these cleaners are difficult to make and hard to rinse off, resulting in high manufacturing and retail costs, as well as potential damage to surfaces and fabrics. Therefore, there is a desire for low-cost, easily produced, effective alternatives that are gentle on the environment and the items they are designed to clean. To address this need, some researchers developed an eco-friendly detergent from ingredients found in abundant renewable sources.

The researchers combined cellulose nano fibres from wood with zein protein from corn to create an emulsion. Cellulose can attract and repel water, so it is effective at forming such emulsions and attracting different types of stains. The zein protein, on the other hand, helps stabilize the emulsion and trap oils. They then tested the cleaning capacity of the cellulose/zein detergent on cotton fabrics and dishes stained with ink, chili oil and tomato paste. They compared the performance of their new detergent to laundry powder and commercial dish soap solutions with deionized water.

The cellulose/zein detergent was slightly less effective at cleaning the cotton cloth compared to a laundry powder solution of equal dilution (1% detergent or powder by weight). At a 5% concentration, however, the researchers' product was more effective than the 1% laundry powder solution at cleaning each of the stains from the fabric. Microscopic examination showed that the cellulose/zein detergent left no residue on cotton fabric after washing and rinsing, which suggests it would not damage the cloth.

The researchers also tested their detergent's capacity to remove chili oil stains from plates made of ceramic, stainless steel, glass and plastic. Again, the cellulose/zein detergent cleaned almost as well as the commercial dish soap of equal dilution, and at a 5% concentration, their product was superior. On the stainless-steel plates, for example, a 5% solution of cellulose/zein removed 92% of the stain compared to 87% with a 1% solution of commercial dish soap.

The researchers suggested that these results show that their natural detergent could be an efficient, cost-effective and sustainable alternative to synthetic cleaning agents currently on the market.

 Wenli Liu et al, Physical Cross-Linking of Cellulose Nanofibrils with Zein Particles as an Eco-Friendly Detergent, Langmuir (2025). DOI: 10.1021/acs.langmuir.4c04398

Biologists discover ancient neurohormone that controls appetite

A team of biologists has discovered that a neurohormone controlling appetite in humans has an ancient evolutionary origin, dating back over half a billion years. The findings, published in Proceedings of the National Academy of Sciences , reveal that this satiety-inducing molecule, known as bombesin, is not only present in humans and other vertebrates but also in starfish and their marine relatives.

Bombesin, a small peptide, plays a key role in regulating hunger by signaling when we've had enough to eat. But its story doesn't start with humans or even mammals. New research shows that bombesin-like neurohormones have been controlling appetite in animals since long before the first vertebrates evolved on Earth.

The name, bombesin, comes from the fire-bellied toad (Bombina bombina), from whose skin the peptide was first isolated in 1971. When injected into mammals, bombesin was found to reduce meal size and increase the time between meals.

This led scientists to think that bombesin-like neurohormones, produced in the brain and gut, are part of the body's natural system for controlling food intake. Furthermore, alongside weight-loss-inducing drugs such as Ozempic, compounds that mimic the action of bombesin are in development for the treatment of obesity.

By analyzing the genomes of invertebrate animals, the researchers discovered genes encoding bombesin-like neurohormones in the common starfish (Asterias rubens) and other echinoderms, such as sea urchins and sea cucumbers.

This research not only deepens our understanding of the evolutionary history of neurohormones but also highlights the unexpected connections between humans and the strange, stomach-everting world of starfish.

Elphick, Maurice R., Discovery and functional characterization of a bombesin-type neuropeptide signaling system in an invertebrate, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2420966122. doi.org/10.1073/pnas.2420966122

Triggering parasitic plant 'suicide' to help farmers

Parasitic weeds are ruthless freeloaders, stealing nutrients from crops and devastating harvests. But what if farmers could trick these invaders into self-destructing? Scientists  think they've found a way.

Across sub-Saharan Africa and parts of Asia, places already struggling with food insecurity, entire fields of staples like rice and sorghum can be lost to a group of insidious weeds that drain crops of their nutrients before they can grow. Farmers battle these parasites with few effective tools, but researchers may be able to turn the weeds' own biology against them.

This trick is detailed in the journal Science, and at its heart lies a class of hormones called strigolactones—unassuming chemicals that play dual roles. Internally, they help control growth and the plants' response to stresses like insufficient water. Externally, they do something that is unusual for plant hormones.

Most of the time, plant hormones do not radiate externally—they aren't exuded. But these do. Plants use strigolactones to attract fungi in the soil that have a beneficial relationship with plant roots.

The parasitic weeds have learned to hijack the strigolactone signals, using them as an invitation to invade. Once the weeds sense the presence of strigolactones, they germinate and latch on to a crop's roots, draining them of essential nutrients.

These weeds are waiting for a signal to wake up. We can give them that signal at the wrong time—when there's no food for them—so they sprout and die.

It's like flipping their own switch against them, essentially encouraging them to commit suicide.

This has been seen in lab conditions.

But scientists still have questions about whether the weed suicide strategy will work in real-world fields. They are  testing whether they can fine-tune the chemical signal to be even more effective. If they can, this could be a game-changer for farmers battling these weeds.

Anqi Zhou et al, Evolution of interorganismal strigolactone biosynthesis in seed plants, Science (2025). DOI: 10.1126/science.adp0779

Why Is It Painful To Bite Aluminum Foil?

Half ice, half fire': Physicists discover new phase of matter in a magnetic material

Scientists  have discovered a new phase of matter while studying a model system of a magnetic material.

The phase is a never-before-seen pattern of electron spins—the tiny "up" and "down" magnetic moments carried by every electron. It consists of a combination of highly ordered "cold" spins and highly disordered "hot" spins, and it has thus been dubbed "half ice, half fire." The researchers discovered the new phase while studying a one-dimensional model of a type of magnetic material called a ferrimagnet.

"Half ice, half fire" is notable not only because it has never been observed before, but also because it is able to drive extremely sharp switching between phases in the material at a reasonable, finite temperature. This phenomenon could one day result in applications in the energy and information technology industries.

The researchers describe their work in the Dec. 31, 2024, edition of the journal Physical Review Letters.

 Weiguo Yin et al, Phase Switch Driven by the Hidden Half-Ice, Half-Fire State in a Ferrimagnet, Physical Review Letters (2024). DOI: 10.1103/PhysRevLett.133.266701. On arXiv: arxiv.org/html/2401.00948v2

This Electronics-free Robot Can Walk Right Off the 3D-Printer

Scientists uncover how enzymes evolved to function at low temperatures

Life has evolved over billions of years, adapting to the changing environment. Similarly, enzymes—proteins that speed up biochemical reactions (catalysis) in cells—have adapted to the habitats of their host organisms. Each enzyme has an optimal temperature range where its functionality is at its peak.

For humans, this is around normal body temperature (37 °C). Deviating from this range causes enzyme activity to slow down and eventually stop. However, some organisms, like bacteria, thrive in extreme environments, such as hot springs or freezing polar waters. These extremophiles have enzymes adapted to function in harsh conditions.

For instance, enzymes from thermophiles, organisms that thrive in high-temperature environments, are heat resistant and show good catalytic activity at high temperatures; declining significantly at lower temperatures. In contrast, enzymes from mesophiles and psychrophiles, organisms that inhabit moderate and cold environments, lack thermostability and show high catalytic activity at lower temperatures.

Since ancestral enzymes no longer exist, scientists use a technique called ancestral sequence reconstruction (ASR) to study their evolution.

ASR combines molecular phylogenetics with genetic and protein engineering to infer and reconstruct the genetic or protein sequences of extinct organisms using phylogenetically related sequences from living species.

3-Isopropylmalate dehydrogenase (IPMDH), an enzyme involved in leucine biosynthesis (the metabolic pathway that synthesizes leucine, one of the 20 proteinogenic amino acids), is an excellent candidate for studying thermostability and cold adaptation due to its extensive evolutionary history.
Researchers traced its evolution from the enzyme of the most ancient thermophilic common ancestor to the mesophilic bacterium Escherichia coli using ASR.
They reconstructed 11 intermediate ancestral enzymes along the evolutionary trajectory connecting the last common bacterial ancestor and E. coli IPMDH (EcIPMDH).
After that, they analyzed changes in enzyme activity at each evolutionary stage, especially improvements in catalytic activity at low temperatures.
They observed a notable increase in catalytic activity at 25 °C, which did not follow a gradual, linear pattern. Instead, a dramatic improvement occurred between the fifth (Anc05) and sixth (Anc06) intermediate ancestors.
To find the underlying molecular mechanisms, the researchers compared the amino acid sequences of the ancestral enzymes and used site-directed mutagenesis, a technique that allows precise alterations to DNA and protein sequences.

They identified three key amino acid substitutions that significantly enhanced catalytic activity at 25 °C. Surprisingly, these mutations occurred far from the active site, challenging the previous belief that temperature adaptation is primarily driven by active-site modifications.

Molecular dynamics simulations revealed a key structural shift between Anc05 and Anc06. While Anc05 remained in an open conformation, Anc06 could adopt a partially closed conformation, reducing activation energy and enhancing enzymatic efficiency at low temperatures.

This transition occurred 2.5–2.1 billion years ago, coinciding with the Great Oxidation Event, which led to a sharp decline in atmospheric methane and global cooling. The researchers suggest that this climate shift may have driven the adaptation of enzymes to lower temperatures.
By identifying key mutations that enhance enzyme efficiency, ASR provides valuable insights into how life evolved in response to Earth's changing environment. Applying this approach to various enzymes is expected to reveal how organisms and their enzymes have evolved in response to Earth's environmental changes over the past four billion years.
Beyond fundamental research, these findings could aid in bioengineering enzymes for applications in biotechnology, pharmaceuticals, and environmental science.

Shuang Cui et al, Insights into the low‐temperature adaptation of an enzyme as studied through ancestral sequence reconstruction, Protein Science (2025). DOI: 10.1002/pro.70071

Part 2

**

 New research suggests plants, fungi and even viruses use venom

A new study reveals plants, fungi, bacteria, protists, and even some viruses deploy venom-like mechanisms, similar to that of venomous snakes, scorpions and spiders.

The study is published in the journal Toxins.

The definition of venom is a biological toxin introduced into the internal milieu of another organism through a delivery mechanism such as a sting or bite that inflicts a wound.

 The new findings show that reliance on venom for solving problems like predation, defense, and competition is far more widespread than previously recognized.

Until now, our understanding of venom, venom delivery systems, and venomous organisms has been based entirely on animals, which represents only a tiny fraction of the organisms from which we could search for meaningful tools and cures.

According to the study, plants inject toxins into animals through spines, thorns, and stinging hairs, and some also co-exist with stinging ants by providing living spaces and food in exchange for protection. Even bacteria and viruses have evolved mechanisms, like secretion systems or contractile injection systems, to introduce toxins into their targets through host cells and wounds.

We've only scratched the surface in understanding the evolutionary pathways of venom divergence, which include gene duplication, co-option of existing genes, and natural selection.

William K. Hayes et al, It's a Small World After All: The Remarkable but Overlooked Diversity of Venomous Organisms, with Candidates Among Plants, Fungi, Protists, Bacteria, and Viruses, Toxins (2025). DOI: 10.3390/toxins17030099

Brains might eat myelin during marathons

Brain scans of marathon runners suggest that myelin — a fatty substance that insulates the electrical signals transmitted by nerve cells — might also be a source of energy for the brain. After a race, runners’ levels of myelin are lower in areas involved in motor control and sensory and emotional processing than before they set off. The loss doesn’t seem to affect cognitive function, and levels bounced back after a couple of months. The experience might even be beneficial because it “exercises the brain’s metabolic machinery”.

https://www.nature.com/articles/s42255-025-01244-7?utm_source=Live+...

https://www.nature.com/articles/d41586-025-00864-z?utm_source=Live+...

Tadpoles try to flee dangerous virus in their pond by growing much faster than normal, research shows

The world's amphibians are in trouble. Because of their sensitivity to climate change, habitat loss, and pollution, they may be the canary in the coal mine for the nascent anthropogenic mass extinction. Approximately 200 amphibian species have become extinct since the 1970s, and the International Union for the Conservation of Nature estimates that 34% of the 7,296 known remaining species are likewise at risk.

Another reason why amphibians are vulnerable is their susceptibility to disease. An emerging, potentially deadly disease of frogs and salamanders is ranavirus, a genus of at least seven species within the family Iridoviridae. Ranavirus can rapidly jump from host to host among fish, amphibians, and reptiles: a flexibility that can have catastrophic consequences if new host species haven't yet evolved any immunity.

But as a new study in Frontiers in Amphibian and Reptile Science has now shown, amphibians aren't entirely defenseless against ranavirus.

In response to ranavirus, wood frog tadpoles change their growth, development, and resource allocation. This may help tadpoles tolerate the energetic demands of infection or escape risky environments to avoid infection entirely.

Ranavirus has been implicated in 40% to 60% of amphibian die-offs in some parts of the world. Infected larvae stop feeding and become lethargic, while swimming abnormally and bleeding internally. An outbreak often leads to the death of all larvae in a pond, and there is evidence that outbreaks are becoming more frequent due to climate change.

The authors of the paper studied the growth and development of the wood frog Rana sylvatica in a forest. 

They compared three pond types: 35 which remained free from ranavirus over an entire season; seven which contained some infected tadpoles but saw little or no mortality; and five with an outbreak that killed off the entire cohort.

From mid-April to mid-July, the researchers regularly visited ponds to estimate the number of live and dead individuals. They collected up to 20 tadpoles from each and humanely euthanized them. In the laboratory, they determined the presence or absence of ranavirus in the liver of 1,583 of these with quantitative real-time PCR.

They also measured the total length of 4,299 tadpoles and determined their developmental stage—the so-called Gosner stage, which ranges from zero for embryos to 42 for tadpoles on the brink of metamorphosis.

Part 1

Because of the life-history plasticity common to many amphibians, growth and development can vary independently: for example, tadpoles may grow slowly and thus be smaller than average, yet relatively large for their Gosner stage due to lagging development.

The results showed that tadpoles in 'die-off' ponds at first grew significantly faster, which led to a larger body size over the first month of life. Tadpoles also matured faster in die-off ponds, being on average 0.38 stages ahead in their development.

But once mass mortality started, the rate of growth and development in these pools crashed, so that they were overtaken in body size and stage by those in uninfected or uninfected ponds, and ended up small for their stage at their death from the disease.

Similarly, in infected ponds that ultimately saw no die-off, tadpoles grew significantly faster and developed precociously over the first month of life, so that they were larger in body size as well as on average 1.7 Gosner stages ahead of tadpoles in uninfected ponds.
The authors conclude that tadpoles respond to the presence of ranavirus by speeding up their growth rate and progressing through successive developmental stages faster early in life.

Accelerating growth and resource allocation early on may allow tadpoles to improve their physical condition, and thus the strength of their immunity, in anticipation of infection. They might also metamorphose and move onto land earlier, potentially reducing their exposure to ranavirus.
These responses are likely to give tadpoles a survival advantage.

Logan Scott Billet, et al. Sublethal effects of a mass mortality agent: pathogen-mediated plasticity of growth and development in a widespread North American amphibian, Frontiers in Amphibian and Reptile Science (2025). DOI: 10.3389/famrs.2025.1529060

How some trees benefit from being struck by lightning

Getting zapped with millions of volts of electricity may not sound like a healthy activity, but for some trees, it is. A new study, published in New Phytologist, reports that some tropical tree species are not only able to tolerate lightning strikes, but benefit from them. The trees may have even evolved to act as lightning rods.

What is clear is that lightning plays an underappreciated role in tree competition. And with lightning on the rise in many regions due to climate change , its influence may increase, potentially favoring lightning-tolerant species like Dipteryx oleifera. Understanding lightning and its role in shaping forests may be important for predicting changes in biodiversity and carbon storage, and for informing tropical reforestation efforts.

 How some tropical trees benefit from being struck by lightning: evidence for Dipteryx oleifera and other large-statured trees, New Phytologist (2025). DOI: 10.1111/nph.70062

High mortality risk found from increase in hot-dry events

As global warming intensifies and populations continue to grow, the likelihood of extreme high-temperature events is increasing. Hot–dry compound events, in particular, pose a direct threat to human health. High temperatures can have prolonged and delayed effects on people's health; and under conditions of low relative humidity, the mortality associated with extreme heat rises significantly.

Previous climate risk analyses have largely focused on the abnormal state of a single variable, but concurrent extreme events, i.e., compound extreme events, tend to have more severe impacts on the environment and human systems than individual extremes. Therefore, the study of compound extreme events related to both is urgently needed.

A recent study reveals a decadal-scale increase in hot–dry events with a high risk of mortality over the past 20 years.  The findings have recently been published in Atmospheric and Oceanic Science Letters.

Yuting Ma et al, The increase in hot–dry events with a high risk of mortality in China associated with the phase transition of the Atlantic Multidecadal Oscillation, Atmospheric and Oceanic Science Letters (2025). DOI: 10.1016/j.aosl.2025.100609

Researchers discover new class of antibiotics

The last time a new class of antibiotics reached the market was nearly three decades ago—but that could soon change, thanks to a discovery by researchers .

A team led by researcher Gerry Wright has identified a strong candidate to challenge even some of the most drug-resistant bacteria on the planet: a new molecule called lariocidin. The findings were published in the journal Nature on March 26, 2025.

The discovery of the all-new class of antibiotics responds to a critical need for new antimicrobial medicines, as bacteria and other microorganisms evolve new ways to withstand existing drugs. This phenomenon is called antimicrobial resistance—or AMR—and it's one of the top global public health threats, according to the World Health Organization.

Our old drugs are becoming less and less effective as bacteria become more and more resistant to them. About 4.5 million people die every year due to antibiotic-resistant infections, and it's only getting worse.

A research team found that the new molecule, a lasso peptide, holds great promise as an early drug lead because it attacks bacteria in a way that's different from other antibiotics. Lariocidin binds directly to a bacterium's protein synthesis machinery in a completely new way, inhibiting its ability to grow and survive.

This is a new molecule with a new mode of action. Lariocidin is produced by a type of bacteria called Paenibacillus, which the researchers retrieved from a soil sample . 

The research team allowed the soil bacteria to grow in the lab for approximately one year—a method that helped reveal even the slow-growing species that could have otherwise been missed. One of these bacteria, Paenibacillus, was producing a new substance that had strong activity against other bacteria, including those typically resistant to antibiotics.

When the researchers figured out how this new molecule kills other bacteria, it was a breakthrough moment.

In addition to its unique mode of action and its activity against otherwise drug-resistant bacteria, the researchers are optimistic about lariocidin because it ticks a lot of the right boxes: it's not toxic to human cells, it's not susceptible to existing mechanisms of antibiotic resistance, and it also works well in an animal model of infection.

The research team is now laser-focused on finding ways to modify the molecule and produce it in quantities large enough to allow for clinical development. 

The researchers are now working on ripping this molecule apart and putting it back together again to make it a better drug candidate.

Gerard Wright, A broad-spectrum lasso peptide antibiotic targeting the bacterial ribosome, Nature (2025). DOI: 10.1038/s41586-025-08723-7. www.nature.com/articles/s41586-025-08723-7

Rapid liver regeneration: New mechanism is triggered by glutamate just minutes after damage occurs

The liver is a vital organ, crucial to digestion, metabolism and the elimination of toxins. It has a unique ability, regeneration, which allows it to replace liver cells damaged by the very toxins that these cells eliminate. However, the liver stops regenerating in cases of diseases that involve chronic liver damage, such as cirrhosis. Such diseases are becoming increasingly prevalent, associated with bad dietary habits and alcohol.

Learning to activate liver regeneration is therefore a priority today, to benefit mainly patients with severe liver damage and also those who have had part of their liver cut out to remove a tumor.

Research at the National Cancer Research Center (CNIO), published in Nature, has discovered in animal models a previously unknown mechanism of liver regeneration. It is a process that is triggered very quickly, just a few minutes after acute liver damage occurs, with the amino acid glutamate playing a key role.

The authors write that, in light of their results, nutritional glutamate supplementation can effectively promote liver regeneration and benefit patients with severe and chronic liver damage, such as those recovering after hepatectomy, to stimulate liver growth, or even those awaiting a transplant.

Part 1

Liver regeneration was known to occur through the proliferation of liver cells, known as hepatocytes. However, the molecular mechanisms involved were not fully understood. This current discovery is very novel, as it describes communication between two different organs, the liver and bone marrow, involving the immune system.

The results show that liver and bone marrow are interconnected by glutamate. After acute liver damage, liver cells, called hepatocytes, produce glutamate and send it into the bloodstream; through the blood, glutamate reaches the bone marrow, inside the bones, where it activates monocytes, a type of immune system cell.

Monocytes then travel to the liver and along the way become macrophages—also immune cells. The presence of glutamate reprograms the metabolism of macrophages, and these consequently begin to secrete a growth factor that leads to an increase in hepatocyte production.

In other words, a rapid chain of events allows glutamate to trigger liver regeneration in just minutes, through changes in the macrophage metabolism. It is a new, complex and ingenious perspective on how the liver stimulates its own regeneration.
In the liver, there are different types of hepatocytes, organized in different areas; the hepatocytes in each area perform specific metabolic functions.

The study reveals that hepatocytes producing a protein known as glutamine synthetase, which regulates glutamate levels, play a key role in regeneration.
Dietary glutamate supplementation may simply be recommended in the future after liver extirpation, and also to reduce liver damage caused by cirrhosis, which is common in patients with a poor diet or unhealthy lifestyle or other serious liver diseases, say the researchers.

María del Mar Rigual et al, Macrophages harness hepatocyte glutamate to boost liver regeneration, Nature (2025). DOI: 10.1038/s41586-025-08778-6. www.nature.com/articles/s41586-025-08778-6

Part 2

DNA microscope creates 3D images of organisms from the inside out

Standard genetic sequencing approaches can tell you a lot about the genetic makeup and activity in a sample, like a piece of tissue or drop of blood. But they don't tell you where specific genetic sequences were located inside that sample, or their relationship to other genes and molecules.

Researchers  are now developing a new technology that overcomes these challenges. By tagging each DNA or RNA molecule and allowing neighboring tags to interact, the technique constructs a molecular network that encodes their relative positions, creating a spatial map of genetic material.

This technique, called volumetric DNA microscopy, creates a 3D image of an entire organism from the inside out, giving scientists an unprecedented view of genetic sequences and where they are located, down to individual cells. 

The researchers have spent more than 12 years developing DNA microscopy.

In a paper published in Nature Biotechnology the researchers used the technology to create a complete DNA image of a zebrafish embryo, a common model organism for studying development and neurobiology.

Part 1

Unlike traditional microscopes that use light or lenses, DNA microscopy creates images by calculating interactions among molecules, providing a new way to visualize genetic material in 3D.

First, short DNA sequence tags called unique molecular identifiers (UMIs) are added to cells. They attach to DNA and RNA molecules and begin making copies of themselves. This starts a chemical reaction that creates new sequences, called unique event identifiers (UEIs), that are unique to each pairing.
It's these pairings that help create the spatial map of where each genetic molecule is located. UMI pairs that are close together interact more frequently and generate more UEIs than those that are farther apart.

Once the DNA and RNA are sequenced, a computational model reconstructs their original locations by analyzing the physical links between UMI-tags, creating a spatial map of gene expression.
DNA microscopy doesn't rely on prior knowledge of the genome or shape of a specimen, so it could be useful for understanding genetic expression in unique, unknown contexts. Tumors generate countless new genetic mutations, for example, so the tool would be able to map out the tumor microenvironment and where it interacts with the immune system.

 Spatial-transcriptomic imaging of an intact organism using volumetric DNA microscopy, Nature Biotechnology (2025). DOI: 10.1038/s41587-025-02613-z

Part 2

An Easy Way to Remove Microplastics From Your Drinking Water

Human retinal stem-like cells with potential to repair vision loss discovered

Researchers  have identified a population of human neural retinal stem-like cells able to regenerate retinal tissue and support visual recovery.

Vision loss caused by retinal degeneration affects millions worldwide. Conditions such as retinitis pigmentosa and age-related macular degeneration involve the irreversible loss of light-sensitive neural cells in the retina. While current treatments may slow progression, they do not replace damaged tissue.

For decades, scientists have explored whether stem cells could be used to regenerate the retina, but the existence of true retinal stem cells in humans has remained uncertain. In fish and amphibians, the outer edge of the retina houses stem cells that regenerate tissue continuously. Whether a comparable system exists in the human eye has been debated for more than two decades.

In the study, "Identification and characterization of human retinal stem cells capable of retinal regeneration," published in Science Translational Medicine, researchers used single-cell and spatial transcriptomic methods to investigate the presence and identity of retinal stem-like cells in humans.

Researchers examined human fetal retinal tissue from four donors at 21 weeks of gestation, using spatial transcriptomics and single-nucleus sequencing to identify and localize cell types in the retina.

Researchers analyzed gene expression and chromatin accessibility to detect populations with stem cell–like properties. Additional samples from donors between 16 and 22 weeks of gestation were used to confirm the location of these cells in the peripheral retina.

A distinct population of neural retinal stem-like cells was identified in the peripheral retina of human fetal tissue. Located in the ciliary marginal zone, these cells showed molecular features consistent with self-renewal and the ability to differentiate into all major retinal cell types. Similar cells appeared in the same anatomical region of retinal organoids, with overlapping gene expression profiles.

Part 1

Following injury in organoids, stem-like cells migrated into the damaged area and produced new retinal cells. Gene activity during the repair process matched patterns observed during natural fetal development.
In a mouse model of inherited retinal degeneration, transplanted cells remained viable for up to 24 weeks. Donor cells integrated into the host retina, developed into mature retinal types, and formed connections with neighboring cells. Treated animals exhibited improved retinal structure and stronger visual responses compared to controls.
Human retinal stem-like cells demonstrated the capacity to regenerate tissue and restore visual function across both fetal tissue and retinal organoid models. In both injury models and transplant experiments, the cells demonstrated the ability to restore retinal structure and contribute to visual function.
Post-transplantation, the cells remained viable for at least 24 weeks, differentiated into photoreceptors, ganglion cells, and bipolar cells, and formed functional synapses with host tissue. Treated mice demonstrated improved retinal morphology and performance in visual function assays across multiple time points. No intraocular tumors were observed following transplantation.

Compared to previously studied retinal progenitor cells, this population showed broader differentiation capacity and longer-term viability. Transplanted cells contributed to retinal structure and restored visual function in mice, without adverse effects.

Results suggest that retinal organoids may serve as a source of human stem-like cells for future research and therapeutic development. Further studies will be needed to assess safety, immune compatibility, and effectiveness in models that more closely resemble human disease.

Hui Liu et al, Identification and characterization of human retinal stem cells capable of retinal regeneration, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adp6864

Part 2

After 7,000 years without light and oxygen in Baltic Sea mud, researchers bring prehistoric algae back to life

A research team was able to revive dormant stages of algae that sank to the bottom of the Baltic Sea almost 7,000 years ago. Despite thousands of years of inactivity in the sediment without light and oxygen, the investigated diatom species regained full viability.

The study, published in The ISME Journal, was carried out as part of a collaborative research project PHYTOARK, which aims at a better understanding of the Baltic Sea's future by means of paleoecological investigations of the Baltic Sea's past.

Many organisms, from bacteria to mammals, can go into a kind of "sleep mode," known as dormancy, in order to survive periods of unfavorable environmental conditions.

They switch to a state of reduced metabolic activity and often form special dormancy stages with robust protective structures and internally stored energy reserves. This also applies to phytoplankton, microscopically small plants that live in the water and photosynthesize. Their dormant stages sink to the bottom of water bodies, where they are covered by sediment over time and preserved under anoxic conditions.

Such deposits are like a time capsule containing valuable information about past ecosystems and the inhabiting biological communities, their population development and genetic changes.

In this new study,  researchers analyzed specifically for viable phytoplankton dormant cells from the past. 

This approach bears the rather unusual name of 'resurrection ecology': Dormant stages that can be clearly assigned to specific periods of Baltic Sea history due to the clear stratification of the Baltic Sea sediment are to be brought back to life under favorable conditions, then they are genetically and physiologically characterized and compared with present-day phytoplankton population.

By analyzing other sediment components, so-called proxies, it will also be possible to draw conclusions about past salinity, oxygen and temperature conditions.

By combining all this information, they aim to better understand how and why Baltic Sea phytoplankton has adapted genetically and functionally to environmental changes.

Part 1

The researchers examined sediment cores taken from 240 meters water depth in the Eastern Gotland Deep during an expedition with the research vessel Elisabeth Mann Borgese in 2021.

In favorable nutrient and light conditions, viable algae could be awakened from dormancy from nine sediment samples and individual strains were isolated. The samples were taken from different sediment layers that represent a time span of around 7,000 years and thus the main climate phases of the Baltic Sea.
The diatom species Skeletonema marinoi was the only phytoplankton species that was revived from all samples. It is very common in the Baltic Sea and typically occurs during the spring bloom. The oldest sample with viable cells of this species was dated to an age of 6,871 ± 140 years.

"It is remarkable that the resurrected algae have not only survived 'just so,' but apparently have not lost any of their 'fitness,' i. e. their biological performance ability. They grow, divide and photosynthesize like their modern descendants.
The measurement of photosynthetic performance also showed that even the oldest algae isolates can still actively produce oxygen—with average values of 184 micromoles of oxygen per milligram of chlorophyll per hour. These are also values that are comparable to those of current representatives of this species.
The researchers also analyzed the genetic profiles of the resurrected algae using microsatellite analysis—a method in which certain short DNA segments are compared. The result: The samples from sediment layers of different ages formed distinctive genetic groups.

Firstly, this ruled out the possibility that cross contamination could have occurred during the cultivation of the strains from sediment layers of different ages. Secondly, this proves that successive populations of S. marinoi in the Baltic Sea have changed genetically over the millennia.
Part 2

The phenomenon that organisms survive in dormancy over very long periods of time and can therefore potentially recolonize habitats under suitable conditions is also known from other studies—for example for plant seeds or small crustaceans, some of which remain viable for several centuries, even millennia.

However, the successful resurrection of a dormant stage after such a long time, as in the case of S. marinoi, has rarely been documented. At around 7000 years old, the tiny cells of this diatom are among the oldest organisms to have been successfully revived from an intact dormant stage. From aquatic sediments, no older such cases are known to date.

Sarah Bolius et al, Resurrection of a diatom after 7000 years from anoxic Baltic Sea sediment, The ISME Journal (2025). DOI: 10.1093/ismejo/wrae252

Part 3

Women can hear better than men: Researchers find amplitude more influenced by sex than age

Scientists have found that sex is the leading factor explaining differences in hearing sensitivity, with women having significantly more sensitive hearing than men.

Hearing problems are on the rise worldwide, and while hearing sensitivity is well known to decrease with age, little research has been done on the other biological and environmental factors that influence them, such as sex, ear side, language, ethnicity, and local environment.

So researchers conducted hearing tests for 450 individuals across 13 global populations—Equador, England, Gabon, South Africa, and Uzbekistan. These populations were selected to capture a wide range of ecological and cultural contexts, including underrepresented rural and non-European groups.

They investigated the sensitivity of the cochlea in the ear, looking at how it transmitted brain signals in response to different amplitudes and frequencies of sound by measuring so-called Transient-Evoked Otoacoustic Emissions (TEOAE).

It's already well known that people generally have better hearing in their right ear, compared with their left, and that hearing usually declines with age. However, the researchers were surprised by their results on the effects of sex and the environment.

Their findings, published in the journal Scientific Reports, show that hearing amplitude is more influenced by sex than age, with women showing an average of two decibels more sensitive hearing than men across all the populations studied.

The second most significant influence was the environment, which not only affected the response to volume but also the range of frequencies of sound perceived. People living in forest areas had the highest hearing sensitivity and those living at high altitudes had the lowest.

Part 1

They found that population, environment, and language all significantly contribute to the variation in hearing across human groups, but it wasn't clear whether this was due to the whole body being affected by the environment or due to long-term adaptations to varying soundscapes, noise levels, or exposure to pollution.

The researchers suggest that people living in forests could have higher sensitivity because they've adapted to soundscapes with lots of non-human sounds, where vigilance is essential for survival. Or it could be due to being exposed to lower levels of pollution.

People living at higher altitudes may have reduced sensitivity due to a number of reasons, including the impact of lower atmospheric pressure on measurements, potential sound reduction in high altitude environments, or physiological adaptations to lower oxygen levels.

The team also found a difference between urban and rural populations, with those living in cities having a shift towards higher frequencies, possibly due to filtering out low-frequency traffic noise.

Patricia Balaresque et al, Sex and environment shape cochlear sensitivity in human populations worldwide, Scientific Reports (2025). DOI: 10.1038/s41598-025-92763-6

Part 2

Measles outbreak leads to dangerous vitamin A toxicity

As a measles outbreak spreads across the U.S., doctors are now seeing a new and unexpected danger: children getting sick from taking too much vitamin A.

At Covenant Children's Hospital in Lubbock, Texas, several unvaccinated children showed signs of liver problems after taking large amounts of vitamin A, according to Dr. Lara Johnson, the hospital's chief medical officer.

U.S. Department of Health and Human Services Secretary Robert F. Kennedy Jr. has promoted vitamin A during the outbreak, even suggesting it might help prevent measles. But doctors say this isn't true.

If people have the mistaken impression that you have an either-or choice of MMR vaccine or vitamin A, you're going to get a lot of kids unnecessarily infected with measles. That's a problem, especially during an epidemic.

And second, you have this unregulated medicine in terms of doses being given and potential toxicities, say the doctors.

The measles, mumps and rubella (MMR) vaccine is the only proven way to prevent measles. It is 97% effective after two doses. 

Vitamin A can be helpful as a supplement for people with measles when given the right dose by a doctor. But taking too much, especially without medical supervision, can be dangerous.

Vitamin A is fat-soluble and can build up in the body. This can lead to dry skin, blurry vision, bone problems and liver damage. In pregnant women, it can even cause birth defects.

If kids are well nourished,  they don't need extra vitamin A.

Recovery for patients with acute toxicity can be rapid when the vitamin is discontinued. Sadly, some of the more serious problems with vitamin A toxicity are not always reversible.

The Council for Responsible Nutrition (CRN), a group representing supplement makers, also warned parents not to give their children high doses of vitamin A.

"While vitamin A plays an important role in supporting overall immune function, research hasn't established its effectiveness in preventing measles infection. CRN is concerned about reports of high-dose vitamin A being used inappropriately, especially in children," it said in a statement.

Doctors say some parents may be following questionable advice from social media or health influencers.

Source: News agencies

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Adverse outcomes increased with long-term inhaled corticosteroids in COPD

For patients with chronic obstructive pulmonary disorder (COPD), long-term inhaled corticosteroid (ICS) treatment is associated with increased rates of adverse composite and specific individual outcomes, according to a study published in the March/April issue of the Annals of Family Medicine.

examined electronic health record data for individuals older than 45 years with COPD to assess long-term ICS risks. The prevalent cohort had a COPD diagnosis any time during the observation period (318,385 individuals), and the inception cohort had a COPD diagnosis after entry into the database (209,062 individuals).

A composite outcome of any new diagnosis of type 2 diabetes, cataracts, pneumonia, osteoporosis, or nontraumatic fracture and recurrent event outcomes of repeated pneumonia or nontraumatic fracture were compared for long- versus short-term ICS exposure (>24 months versus <4 months).

The researchers found that the composite dichotomous outcome was significantly greater for long- versus short-term ICS use for both the prevalent and inception cohorts (hazard ratios, 2.65 and 2.60, respectively). The absolute risk difference of the composite outcome was 20.26% for the inception cohort, with a number needed to harm of five.

For recurrent pneumonia and recurrent fracture, the hazard ratios were significantly increased in the prevalent and inception cohorts (hazard ratios, 2.88 and 2.85 for pneumonia, respectively; 1.77 and 1.57 for fracture, respectively).

"The clinical use of and indications for ICS therapy in COPD should be carefully considered for each individual before initiation of long-term ICS therapy," the authors write.

Wilson D. Pace et al, Adverse Outcomes Associated With Inhaled Corticosteroid Use in Individuals With Chronic Obstructive Pulmonary Disease, The Annals of Family Medicine (2025). DOI: 10.1370/afm.240030

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Short-term reactivation of brain between encoding of memories enhances recall, study finds

Past neuroscience and psychology studies have shown that after the human brain encodes specific events or information, it can periodically reactivate them to facilitate their retention, via a process known as memory consolidation. The reactivation of memories has been specifically studied in the context of sleep or rest, with findings suggesting that during periods of inactivity, the brain reactivates specific memories, allowing people to remember them in the long term.

Researchers  recently conducted a study exploring the possibility that the brain engages in a similar reactivation process during wakefulness to store important information for shorter periods of time. Their findings, published in Nature Neuroscience, suggest that the spontaneous reactivation of specific stimuli in the brain during the brief intervals between their encoding predicts the accuracy with which people remember them at the end of a memory task.

David J. Halpern et al, Study-phase reinstatement predicts subsequent recall, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-01884-8.

New study validates lower limits of human heat tolerance

A new study has confirmed that the limits for human thermoregulation—our ability to maintain a stable body temperature in extreme heat—are lower than previously thought.

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

The study found that many regions may soon experience heat and humidity levels that exceed the safe limits for human survival

Utilizing a widely used technique known as thermal-step protocols, researchers  exposed 12 volunteers to various heat and humidity conditions to identify the point at which thermoregulation becomes impossible. What made this study different was that participants returned to the laboratory for a daylong exposure to conditions just above their estimated limit for thermoregulation. Participants were subjected to extreme conditions, 42°C with 57% humidity, representing a humidex of approximately 62°C.

The results were clear. The participants' core temperature streamed upwards unabated, and many participants were unable to finish the 9-hour exposure. This data provides the first direct validation of thermal step protocols, which have been used to estimate upper limits for thermoregulation for nearly 50 years.

The implications of this research extend beyond academia. As cities prepare for hotter summers, understanding these limits can help guide health policies and public safety measures.

Robert D. Meade et al, Validating new limits for human thermoregulation, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2421281122

How perceptions are influenced by expectations: Songbird study draws parallels with human speech processing

Past neuroscience and psychology studies have shown that people's expectations of the world can influence their perceptions, either by directing their attention to expected stimuli or by reducing their sensitivity (i.e., perceptual acuity) to variations within the categories of stimuli we expect to be exposed to.

Researchers carried out a study involving songbirds aimed at better understanding how expectation-fueled biases in perception shape brain activity and behaviour.  

Their findings, published in Nature Neuroscience, suggest that the perceptions of songbirds, like those of humans, are influenced by expectations, with peripheral sensory systems utilizing expectations to enhance sensory perception and retain high-fidelity representations of the world.

Human speakers are known to have different voices, while also pronouncing many words differently. Past studies suggest that the human brain possesses robust underlying mechanisms designed to address these differences, by grouping speech sounds into stable perceptual categories, a process referred to as "categorical perception". 

One of these mechanisms is that we use context to cue and bias our perception.

The researchers examined the vocal behaviour and perceptions of songbirds. This is because songbirds are known to share many similarities with humans in terms of their vocal behaviour, thus studying them can help to better understand human speech and speech-related perceptions.

The team's initial experiments utilizing synthesized birdsongs showed that, similarly to humans who are listening to others speak, the perceptions of songbirds while listening to birdsongs are biased by their expectations.

Overall, this study confirmed the hypothesis that the song perceptions of songbirds closely resemble the speech perceptions of humans. Specifically, it gathered strong evidence suggesting that the vocal perceptions of songbirds are also biased and influenced by expectations.

The second important finding of this study emerged from the team's second experiment probing the neural basis of context-dependent categorical perception in songbirds. While their first experiment showed that the birds' expectations influenced how they classified songs, the second was aimed at determining whether the birds' sensory systems reflected this shift in perception.

The findings showed that  the sensory brain appears to use expectation in a more clever way, by rededicating neural responses to focusing on relevant, expected signals, improving perceptual acuity.

"It then leaves the bias to downstream processing like motor and decision-making regions of the brain. In this way, the brain can retain high-fidelity, unbiased, representations of the world, while still incorporating bias to make optimal decisions.

Tim Sainburg et al, Expectation-driven sensory adaptations support enhanced acuity during categorical perception, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-01899-1.

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How Microorganisms looks under the microscope

Implant-derived metals found in cerebrospinal fluid

New research has found that metal particles from artificial joint implants can enter the central nervous system and accumulate in cerebrospinal fluid, raising concerns about potential neurological effects.

Joint replacement surgery has transformed orthopedic care, improving mobility and quality of life for millions of people. Modern implants, made from combinations of metals, are designed for durability and biocompatibility.

Over time, wear and corrosion of these materials can release microscopic particles into surrounding tissue. These byproducts have been linked to problems near the implant  site, including inflammation, tissue damage, and loosening of the joint.

Emerging concerns point to the possibility of metal particles entering the bloodstream and affecting organs far from the implant. Case reports have described serious effects on the heart, thyroid, and nervous system in patients with elevated levels of certain metals, particularly cobalt and chromium. Neurological changes have been reported in some patients following joint replacement.

Previous research has largely focused on these  metals and has relied on blood and serum measurements, leaving open the question of whether such particles reach the central nervous system.

In the study, "Metal Concentrations in Blood and Cerebrospinal Fluid of Patients With Arthroplasty Implants," published in JAMA Network Open, researchers conducted a single-site cross-sectional study to determine whether metals from joint implants can be found in cerebrospinal fluid and bloodstream.

A cohort was assessed of 204 adult participants, 102 with an existing large joint implant (median age 71.7) and 102 in a control group that had never received joint replacement surgery (median age 67.2).

Samples were collected during elective surgery under spinal anesthesia or during lumbar puncture for routine diagnostic or therapeutic reasons. Inductively coupled plasma mass spectrometry measured concentrations of ten metals in blood, serum, and cerebrospinal fluid, including cobalt, chromium, titanium, niobium, zirconium, and others known to be used in implant materials.

Cobalt levels in cerebrospinal fluid were significantly higher in patients with joint implants than in matched controls. Median cobalt concentrations were 0.03 μg/L in the implant group and 0.02 μg/L in the control group. Strong correlations were observed between cobalt levels in cerebrospinal fluid and those in serum and whole blood, suggesting systemic exposure may be reaching the central nervous system.

Part 1

Patients with implants also exhibited higher levels of chromium, titanium, niobium, and zirconium in blood and serum. In cerebrospinal fluid, titanium, niobium, and zirconium levels were significantly elevated, but only when serum levels of these metals were also increased. This is an important finding as it supports the accuracy of less invasive blood sampling as an indicator of possible cerebrospinal fluid inundation.

Patients with implant components containing cobalt-chromium-molybdenum alloys had the highest cerebrospinal fluid concentrations of both cobalt and chromium. Cobalt levels in cerebrospinal fluid were significantly elevated even among patients with implants in place for less than ten years. Pain in the joint containing the implant was also associated with higher cobalt levels in cerebrospinal fluid.

No increase in cerebrospinal fluid metal levels was observed in patients with implants lacking cobalt-chromium-molybdenum components. Patients with cemented implants showed elevated levels of zirconium in blood and serum, though not in cerebrospinal fluid. Aluminum did not appear elevated in the implant group despite being present in certain implant alloys.
Blood-brain barrier integrity, assessed by serum S-100B levels, appeared unaffected and uncompromised in the implant group. Among those with elevated cerebrospinal fluid cobalt or zirconium, serum S-100B levels were lower than in matched controls.

Findings indicate that metal particles released from joint implants can accumulate in the central nervous system, especially those containing cobalt-chromium-molybdenum.
Results suggest that arthroplasty-related metal exposure is not confined to local tissues but extends systemically and may involve the brain. While blood-brain barrier dysfunction was not evident, the presence of these metals in cerebrospinal fluid raises questions about long-term neurological safety.

Anastasia Rakow et al, Metal Concentrations in Blood and Cerebrospinal Fluid of Patients With Arthroplasty Implants, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.2281

Part 2

Scientists merge two 'impossible' materials into new artificial structure

An international team of researchers has merged two lab-synthesized materials into a synthetic quantum structure once thought impossible to exist and produced an exotic structure expected to provide insights that could lead to new materials at the core of quantum computing.

The work, described in a cover story in the journal Nano Letters, explains how four years of continuous experimentation led to a novel method to design and build a unique, tiny sandwich composed of distinct atomic layers.

One slice of the microscopic structure is made of dysprosium titanate, an inorganic compound used in nuclear reactors to trap radioactive materials and contain elusive magnetic monopole particles, while the other is composed of pyrochlore iridate, a new magnetic semimetal mainly used in today's experimental research due to its distinctive electronic, topological and magnetic properties.

Individually, both materials are often considered "impossible" materials due to their unique properties that challenge conventional understanding of quantum physics.

The construction of the exotic sandwich structure sets the stage for scientific explorations in what is referred to as the interface, the area where the materials meet, in the atomic scale.

This work provides a new way to design entirely new artificial two-dimensional quantum materials, with the potential to push quantum technologies and provide deeper insight into their fundamental properties in ways that were previously impossible.

Mikhail Kareev et al, Epitaxial Stabilization of a Pyrochlore Interface between Weyl Semimetal and Spin Ice, Nano Letters (2025). DOI: 10.1021/acs.nanolett.4c03969

Air pollution and traffic noise increase the risk of stroke through combination effect

New research shows that air pollution and traffic noise together may pose a greater risk for stroke than either factor alone. The researchers found that even at low levels—below the EU's air quality standards and around WHO noise recommendation levels—the risk of stroke increased significantly.

The study, published in Environment International, analyzed data from 136,897 adults in Sweden, Denmark, and Finland. The results show that a 5 µg/m³ increase in air pollution (PM_2.5) raises the risk of stroke by 9%, while an 11 dB increase in traffic noise increases the risk by 6%.

When both factors are combined, the risk may be even higher. For example, in quieter areas (40 dB), an increase in PM_2.5 was linked to a 6% rise in stroke risk, but in noisier areas (80 dB), the same increase in PM_2.5 raised the risk by 11%, though this result was not statistically significant.

The fact that we see clear associations even at relatively low levels indicates that current exposure limits may not be sufficient to protect public health. Stronger regulations are needed to reduce exposure and lower the risk of stroke and other diseases, say the researchers.

 Huyen Nguyen Thi Khanh et al, Exploring the interaction between ambient air pollution and road traffic noise on stroke incidence in ten Nordic cohorts, Environment International (2025). DOI: 10.1016/j.envint.2025.109403

Developing an Ecotoxicological Classification for Frequently Used Drugs in Primary Care

A classification of drugs based on their environmental impact

Scientists at the University of Lausanne (UNIL) and University center Unisanté classified 35 commonly used drugs based on their impact on the aquatic biodiversity.

The aim of this research is to provide medical staff with a tool for considering the environmental risks associated with certain common drugs when prescribing them. The proposed list is subject to change when new data becomes available, their rarity being a limiting factor for classification.

Every day all around the world, thousands of drugs are consumed, whether to relieve pain, regulate blood pressure or treat infections. But what happens after ingesting these products? Evacuated via urine, many substances end up in wastewater. They are only partially eliminated by these systems, and end up in lakes, rivers and streams, posing a risk to aquatic ecosystems. This risk is now recognized, but it is difficult for doctors to know how to integrate it into their practice.

At the University of Lausanne (UNIL), scientists from the Faculty of Biology and Medicine (FBM) and the Faculty of Geosciences and Environment (FGSE) have carried out a classification of widely-used drugs according to their ecotoxicity, i.e. their danger to the aquatic ecosystem. Published in the International Journal of Environmental Research and Public Health, the study reveals that drugs commonly prescribed in general medicine—to combat inflammation or infection, for example—have significant consequences for the health of fish, algae and bacteria essential to aquatic biodiversity.

The researchers classified 35 drugs commonly consumed into categories ranging from low to high toxicity for aquatic ecosystems. To do this, they cross-referenced three pieces of information: the 50 most widely sold drugs  (by weight), those for which ecotoxicity thresholds exist, and the concentration of those found in the rivers  (in the form of active ingredients).

Among the most problematic drugs are common painkillers and anti-inflammatories such as diclofenac, which is toxic to fish liver and can lead to fish death. There are also antibiotics such as ciprofloxacin, which can eliminate bacteria useful to the ecosystem's balance, and encourage the emergence of antibiotic-resistant bacteria. Mefenamic acid and paracetamol, on the other hand, are in the category with the lowest environmental risks.

This classification is far from complete, because of the lack of data. It does, however, give some initial indications for practitioners, say the eco-toxicologists.

 Developing an Ecotoxicological Classification for Frequently Used Drugs in Primary Care, International Journal of Environmental Research and Public Health (2025). doi.org/10.3390/ijerph22020290

Frustration can lead to failure for search and rescue dogs

Search and rescue dogs are heroes in fur coats, using their incredible sense of smell to find lost hikers, disaster victims, and missing people. But a new study suggests that these life-saving dogs may face an unexpected obstacle: frustration.

Researchers found that frustration significantly impacts search and rescue dogs' ability to perform search tasks effectively. In a study published in Frontiers in Veterinary Science, they reported that when the dogs experience frustration—such as blocked access to a reward or an unfulfilled expectation—they are slower to complete their searches and are more prone to errors.

Search and rescue dogs are trained to work in high-pressure environments, from collapsed buildings to dense forests. While they are known for their endurance and focus, certain factors can affect their work.

To test what factors affect their work, researchers  enlisted a dozen dogs and their handlers to participate in three activities. The dogs wore special collars to track heart rate and heart rate variability—key indicators of exertion and stress. Researchers also recorded the dogs' search accuracy and speed in locating a target odor and surveyed the dogs' handlers on their behaviors.

In the first activity, the dogs rested under normal, quiet conditions for 10 minutes.

In the second "frustration activity," handlers teased the dogs with an unattainable toy, withheld their attention, and then led the dog to complete a search.

In the third exercise, the handlers led the dogs through a moderate workout before completing the search.
The results showed:
After experiencing frustration, search dogs took significantly longer to indicate they found their search targets.
The dogs made more errors after the frustration activity.
Frustration increased the dogs' heart rate and decreased their heart rate variability, indicating a higher level of stress and reduced ability to recover.
Physical exertion caused increased heart rate but did not change heart rate variability, indicating no significant stress response to exercise.

The researchers say the information is valuable for search and rescue (SAR) handlers, many of whom rely on longstanding training methods that use frustration as a tool to build dogs' perseverance. We often think of frustration as a motivator, but these  findings show that it can backfire, slowing dogs down and increasing errors. And that's a serious concern.

It's our responsibility to make their work as stress-free and enjoyable as possible, they conclude.

Sally Dickinson et al, Frustration and its impact on search and rescue canines, Frontiers in Veterinary Science (2025). DOI: 10.3389/fvets.2025.1546412

Border fences are bad for wildlife

International border barriers everywhere are harming wildlife by bisecting their habitats, disrupting their hunting and collecting patterns and preventing them from commingling. In some cases, the borders are causing so much harm that they could cause certain species to go extinct.

That's according to a new study published in the journal Biological Conservation.

The literature review, which analyzed 42 studies on wildlife and borders by scientists across the globe, was part of a special issue on addressing land degradation.

With border barriers, the habitat that animals once moved freely across is divided, fragmenting populations, reducing availability to water, lowering gene flow and even killing animals that try to cross.

Animals don't recognize political boundaries—they are tied to the resources that they need to survive. It's hard seeing animals come up against a new barrier—a huge wall or fence—that stops their ability to get a drink of water or find seasonal foods, especially in desert environments.

The problem has become worse due to a dramatic increase in border barriers in the 21st century. According to a report from the Migration Policy Institute there were just two dozen border walls across the world in 2000; two decades later, that number has tripled. 

The researchers found   three main ways in which physical borders were harming wildlife.

Part 1

The first is habitat fragmentation. Borders can cut animals off from their natural ranges, and that is especially dangerous for animals with a very small travel radius, such as reptiles and some birds. Imagine a lizard who only travels up to a quarter mile from home. Then, imagine a fence going up in the middle of that lizard's already tiny range, restricting its stomping grounds—and potential food supply—even more. And don't forget that border infrastructure like bright lights, non-native landscaping, roads and increased staff will further hamper that lizard's ability to hunt, forage and even reproduce.
The second involves less genetic variation. International borders can disrupt animals' ability to interact and breed with each other. That means that over time, they become less genetically diverse, leading to a decrease in immunity to certain diseases. With time, they may even become inbred and unable to reproduce.
And, finally, there are fewer safety nets. Some endangered species are legally protected in one country but illegally poached in another. Without international cooperation on wildlife conservation, lax hunting laws and enforcement will continue to hurt animals who exist on both sides of a border fence.
There are a few benefits too:
Even in places where animals are threatened by poaching on one side of a border fence, they're shielded from it on the other—guaranteeing they won't go completely extinct. Borders can also shield animals from disease.
Part 2

"So, the question is how do you keep the positives of border fences and toss the negatives?"
Here are four ways the researchers think physical borders can maintain national security while also minimizing harm to wildlife.

Cut down on lights and noise. Many international border areas were dark, quiet and uninhabited before fences and walls were installed. That means the animals who live there haven't grown accustomed to navigating light-flooded, noise-polluted environments full of human activity. Dimming lights and restricting the hours in which noisy construction can take place would go a long way toward supporting wildlife in those areas.

Let animals pass. What if border walls carved out passageways for small animals? What if border security workers opened temporary gaps in the fence a few times every migratory season? Taking these occasional measures would help lessen the disruption some species have experienced with the construction of border walls.
Use different materials. A coiled, sharp material called concertina wire tops many border fences to discourage people from climbing over. One study found that for some species, concertina wire was responsible for one to two deaths per mile per year along about 600 miles of the U.S.-Mexico border, a perilously high mortality rate. Constructing fences with a different type of wire could save thousands of animals' lives every year.

Increase binational cooperation. To ensure a better future for some of the world's most beloved species, government leaders and scientists on both sides of every border barrier should work together to arrive at common security and preservation goals.

Cole Sennett et al, International border fences and walls negatively affect wildlife: A review, Biological Conservation (2024). DOI: 10.1016/j.biocon.2024.110957

Part 3

Omega-6 fatty acid promotes the growth of an aggressive type of breast cancer, study finds

Linoleic acid, an omega-6 fatty acid found in seed oils such as soybean and safflower oil, and animal products including pork and eggs, specifically enhances the growth of the hard-to-treat "triple negative" breast cancer subtype, according to a preclinical study  by  Medicine investigators. The discovery could lead to new dietary and pharmaceutical strategies against breast and other cancers.

In the study, published March 14 in Science, the researchers found that linoleic acid can activate a major growth pathway in tumor cells by binding to a protein called FABP5. Comparing breast cancer subtypes, the team observed that this growth pathway activation occurs in triple-negative tumor cells, where FABP5 is particularly abundant, but not in other hormone-sensitive subtypes. In a mouse model of triple-negative breast cancer, a diet high in linoleic acid enhanced tumor growth.

This discovery helps clarify the relationship between dietary fats and cancer, and sheds light on how to define which patients might benefit the most from specific nutritional recommendations in a personalized manner.

Omega-6 linoleic acid is a diet-derived nutrient that is considered essential in mammals for supporting multiple bodily processes. However, the abundance of this fat in "Western-style" diets has increased significantly since the 1950s, coinciding with the increased usage of seed oils in fried and ultra-processed foods.

This has led to concerns that excessive omega-6 intake might be one of the explanations for rising rates of certain diseases, including breast cancers. But decades of studies have yielded mixed and inconclusive results, and have never uncovered any biological mechanism tying omega-6s to cancers.

In the new study, the researchers sought to resolve this confusion by initially looking at breast cancer, which has been linked to modifiable factors such as obesity. They looked at the ability of omega-6 fatty acids—particularly linoleic acid, the dominant one in the Western diet—to drive an important, nutrient-sensing growth pathway called the mTORC1 pathway.

A key initial finding was that linoleic acid does indeed activate mTORC1 in cell and animal models of breast cancers, but only in triple-negative subtypes. (The term "triple negative" refers to the absence of three receptors, including estrogen receptors, that are often expressed by breast tumor cells and can be targeted with specific treatments.)

The scientists discovered that this subtype-specific effect occurs because the polyunsaturated fatty acid forms a complex with FABP5, which is produced at high levels in triple-negative breast tumors but not in other subtypes, leading to the assembly and activation of mTORC1, a major regulator of cell metabolism and cancer cell growth.

Part 1

Feeding mice that model triple-negative breast cancer a high-linoleic-acid diet increased FABP5 levels, mTORC1 activation and tumor growth. The researchers also found increased levels of FABP5 and linoleic acid in the tumors and blood samples from newly diagnosed triple-negative patients.

The findings show that linoleic acid can have a role in breast cancer, though in a more targeted and defined context than previously appreciated. The study also is thought to be the first to establish a specific mechanism through which this common dietary ingredient influences disease.

Nikos Koundouros et al, Direct sensing of dietary ω-6 linoleic acid through FABP5-mTORC1 signaling, Science (2025). DOI: 10.1126/science.adm9805

Part 2

Scientists create 'fungi tiles' with elephant skin texture to cool buildings

A team of scientists  has developed "fungi tiles" that could one day help to bring the heat down in buildings without consuming energy.

These wall tiles are made from a new biomaterial combining fungi's root network—called mycelium—and organic waste. Earlier research has shown that mycelium-bound composites are more energy efficient than conventional building insulation materials such as expanded vermiculite and lightweight expanded clay aggregate.

Building on this proven insulating property, the  team worked with local ecology and biomimicry design firm bioSEA to add a bumpy, wrinkly texture to the tile, mimicking an elephant's ability to regulate heat from its skin. Elephants do not have sweat glands and rely on these wrinkles and crevices on their skin to regulate heat.

In laboratory experiments, the scientists found that the cooling rate of their elephant skin–inspired mycelium tile was 25% better than a fully flat mycelium tile, and the heating rate was 2% lower. They also found that the elephant skin-inspired tile's cooling effect improved a further 70% in simulated rain conditions, making it suitable for tropical climates.

Mycelium-bound composites are created by growing fungi on organic matter such as sawdust or agricultural waste. As the fungus grows, it binds the organic matter into a solid, porous composite.

For this study, the  scientists used the mycelium of oyster mushroom (Pleurotus ostreatus)—a commonly found fungus—and bamboo shavings collected from a furniture shop.

These two components were mixed with oats and water and packed into a hexagonal mold with an elephant skin–inspired texture designed by bioSEA using computational modeling and algorithms to select the optimal design.

The mycelium tiles were left to grow in the dark for two weeks, then removed from the hexagonal mold and left to grow in the same conditions for another two weeks.

Finally, the tiles were dried in an oven at 48°C for three days. This final step removes any remaining moisture, prohibiting further mycelial growth.

The scientists found that the elephant skin-inspired tile absorbed heat more slowly. When its bumpy textured surface faced the heat source, its temperature increased by 5.01°C per minute, compared to 5.85°C per minute when its flat surface was exposed to heat. As a control, the scientists also heated a flat mycelium tile and found it gained 5.11°C per minute.

The elephant-skin-inspired tile cooled fastest when heated from the flat side, losing 4.26°C per minute. When heated from the textured side, its flat side lost 3.12°C per minute. The fully flat control tile lost 3.56°C per minute.

Based on these findings, the scientists recommended installing the tiles with the flat side adhered to the building façade and the textured surface exposed to external heat for optimal thermal performance.

 Eugene Soh et al, Biodegradable mycelium tiles with elephant skin inspired texture for thermal regulation of buildings, Energy and Buildings (2024). DOI: 10.1016/j.enbuild.2024.115187

Microplastics detected in cat placentas and fetuses during early pregnancy

In a small study of eight cats at early stages of pregnancy, researchers detected 19 different kinds of microplastic particles in fetuses from two cats and in the placentas of three cats.

Humans and other animals worldwide are increasingly exposed to microplastics, which are small particles of plastic contaminants. Studies suggest that microplastics can have a variety of adverse health effects. For instance, research in rodents suggests that fetuses exposed to microplastics during pregnancy may experience impaired development. Microplastics have also been found in human amniotic fluid, further raising concerns about fetal exposure.

To deepen our understanding of this topic, researchers investigated whether microplastics could be found in cat placentas and fetuses during early stages of pregnancy. They evaluated eight pregnant stray cats that had been brought to a veterinary hospital as part of a population-control program in northern Italy.

Using a standard chemical analysis technique known as Raman spectroscopy, the researchers detected microplastics in fetal tissue from two of the cats and in placental tissue from three of the cats. They found a total of 19 different types of microplastics in the tissue samples.

These findings show that even during early stages of pregnancy, microplastics may accumulate in cat placentas. They also suggest that microplastics may be able to cross the placental barrier and accumulate in cat fetuses. However, further research will be needed to determine whether microplastics in cat placentas and fetuses might impact fetal health and development.

In light of their findings and the findings of earlier studies, the researchers call for limits on the general use of plastics and for the development of alternative materials. They also call for policymakers and industrial stakeholders to enact strategies for mitigating plastic pollution that poses risks to humans and animals.

 Detection of microplastics in the feline placenta and fetus, PLOS One (2025). DOI: 10.1371/journal.pone.0320694

Flowerpot snake's DNA repair ability provides insights into human genetic conditions like Down syndrome

The flowerpot snake, one of the world's smallest snakes, has some unusual distinctions. Also known as the Brahminy blind snake, it's the only known snake species with three sets of chromosomes instead of two—and it can reproduce without a mate.

By analyzing the flowerpot snake's unique genome, scientists are uncovering how the tiny reptile repairs its DNA and prevents harmful mutations. The findings, published in the journal Science Advances, provide valuable insights into genetic repair mechanisms that could deepen our understanding of human gene evolution.

This DNA repair and replication activity supports a fascinating mechanism called premeiotic endoreplication, a process through which the snake duplicates its chromosomes before dividing them, sidestepping the need for the typical pairing of chromosomes seen in sexual reproduction. This mechanism allows the snake to produce offspring that are exact genetic clones of itself.

The flowerpot snake's genetic and reproductive quirks may also provide insights into human trisomy conditions, such as Down syndrome.

For example, we know that having multiple sets of chromosomes is rare for animals, yet flowerpot snakes survive just fine with three instead of the normal two humans have.

Using advanced genomic technology, the research team discovered that the flowerpot snake, native to Africa and Asia, has 40 chromosomes, organized into three subgenomes. These subgenomes formed through complex genetic events, including chromosome fusion in ancestral species. The researchers hypothesize that this genetic structure enables the snake to reproduce without needing sperm from a male partner.

One major question the scientists explored was whether this reproductive strategy comes with evolutionary drawbacks. Asexual species typically struggle because they lack genetic shuffling, which helps eliminate harmful mutations over time. However, the flowerpot snake appears to have developed a way to counteract this risk. The researchers think its slow but steady evolutionary pace helps limit the accumulation of harmful mutations.

They also examined how genetic variations across different flowerpot snake populations suggest chromosome exchanges between the subgenomes. These exchanges appear to balance genetic diversity and stability—maintaining enough variation for adaptation while preventing incompatibilities that could disrupt reproduction.

The study also revealed something unexpected—many of the flowerpot snake's immune-related and sexually selected genes, such as those involved in sperm development, have lost their functions.

Yunyun Lv et al, Genomic Insights into Evolution of Parthenogenesis and Triploidy in the Flowerpot Snake, Science Advances (2025). DOI: 10.1126/sciadv.adt6477. www.science.org/doi/10.1126/sciadv.adt6477

 How heavy drinking damages cognition

For the first time, researchers demonstrate in an animal how heavy alcohol use leads to long-term behavioral issues by damaging brain circuits critical for decision-making.

Rats exposed to high amounts of alcohol exhibited poor decision-making during a complex task, even after a months-long withdrawal period. Key areas of their brains had undergone dramatic functional changes compared to healthy rats.

The findings, published in Science Advances, provide a new explanation of alcohol's long-term effects on cognition.

We now have a new model for the unfortunate cognitive changes that humans with alcohol-use disorder show, say the researchers.

We know that humans who are addicted to alcohol can show deficits in learning and decision-making that may contribute to their poor decisions related to alcohol use. We needed an animal model to better understand how chronic alcohol abuse affects the brain. Knowing what is happening in the brain of an animal when they are having these decision-making difficulties will tell us what is happening in humans.

In their experiments, the researchers found that the rats exposed to drinking did very badly when compared to controls.

The team linked the behavioral difficulties to dramatic functional transformations in the dorsomedial striatum, a part of the brain critical for decision-making. The alcohol had damaged neural circuits, causing alcohol-exposed rats to process information less effectively.

One surprise was how long alcohol dependence impairs cognition and neural function, even after withdrawal.

This may give us insight into why relapse rates for people addicted to alcohol are so high. Alcohol-induced neural deficits may contribute to decisions to drink even after going to rehab. We can clearly demonstrate these deficits can be long-lasting.

Chronic Ethanol Exposure Produces Sex-Dependent Impairments in Value Computations in the Striatum, Science Advances (2025). DOI: 10.1126/sciadv.adt0200