When rust falls from a tree

Charged droplets can cause surface corrosion

Max Planck Institute for Polymer Research

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Drops can become electrically charged as they slide across surfaces. If they then fall onto a coating—such as on a car—the coating can be corroded by the drop’s electrical discharge and permanently damaged.

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Credit: (c) Katharina Maisenbacher / MPI-P

Many people are familiar with this from everyday life: the paint on a garden fence needs to be repainted after a few years—“the weather has taken its toll.” But even larger structures, from the Eiffel Tower to the Golden Gate Bridge, must be time-consuming repainted to maintain them.

Until now, two main causes were considered the driving forces behind such damage to coatings: first, mechanical stress—that is, a kind of friction between droplets and the surface that gradually wears down the coating or causes it to flake off; and second, chemical factors, particularly when droplets contain acids or salts.

Researchers led by Hans-Jürgen Butt, director at the Max Planck Institute for Polymer Research, have now identified another, previously unknown factor in collaboration with partners from the University of Bonn, South China University of Technology, MIT, and Johannes Gutenberg University Mainz: the electrical charge of droplets. “A few years ago, we investigated the physics behind how water droplets become charged as they slide across surfaces. This is a kind of ‘friction electricity’ in droplets and is physically much more complex than previously assumed,” says Rüdiger Berger, group leader in the “Physics at Interfaces” department. “When such charged droplets strike a coating, they discharge locally and can puncture the layer in specific spots like a small flash of lightning—with consequences for the coating’s durability.”

To demonstrate the damage caused by such electrical breakdowns, the researchers first dropped droplets specifically onto a surface uniformly coated with Teflon—a material commonly found on frying pans. With uncharged droplets, no changes to the coating were visible under the microscope even after 3,000 impacts.

They then had the droplets roll across various everyday surfaces before impact—including a houseplant leaf, PVC, and polystyrene, such as that found in plastic windows. As they slid across these materials, the droplets became charged and subsequently fell onto the Teflon coating. After 3,000 droplets, distinct changes to the surface and the underlying metal were visible under the microscope.

“The charge a droplet acquires as it slides depends heavily on the specific surface—we measured differences of up to a factor of ten,” explains Zhongyuan Ni, the study’s first author. “Regardless of this, we were able to detect changes in the coating in all experiments.”

The researchers hope that their findings, published in the journal Nature, will pave the way for new, more efficient coatings that can protect cultural heritage, cars, or even the garden fence at home for longer and more effectively.

 

 

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Journal

Nature

DOI

10.1038/s41586-026-10941-6 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Spontaneously charged water drops induce corrosion

Article Publication Date

26-Aug-2026

ARACHNOLOGY

Are Joro spiders outcompeting Georgia’s native spiders?

New study suggests there isn’t much overlap between the diets of Joro and native spiders

University of Georgia

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Researchers analyzed the stomach contents of more than 200 Joro spiders from 33 sites across Georgia and South Carolina for the new study.

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Credit: (Photo by Dorothy Kozlowski/UGA)

When Joro spiders first arrived stateside over a decade ago, scientists worried the massive black and yellow spiders would gorge themselves on the same bugs as native spiders (or even the native spiders themselves).

If the invasive arachnids did make massive meals out of Georgia’s insects, the local orb weaver population — already facing dangers from insecticide and pesticide use — could suffer.

But a new study from the University of Georgia may ease some of those concerns.

“In terms of direct competition for food, our study suggests Joro spiders eat different insects and a wider variety as compared to native orb weavers,” said Jason Schmidt, co-author of the study and a professor of entomology in UGA’s College of Agricultural and Environmental Sciences.

Joros prey largely on flies, other bugs native spiders don’t eat

The researchers analyzed the stomach contents of more than 200 Joro spiders from 33 sites across Georgia and South Carolina. They compared DNA fragments found in the digestive tracts of these spiders to more than 140 native orb weavers from across the two states.

While Joros do eat some of the same insects as orb weavers, the species’ diets differed significantly, the study found. In fact, the Joros preyed on 26 unique species that the native spiders didn’t touch, including a variety of bugs such as leafhoppers and aphids.

Native spider species had the same diet regardless of whether Joros were present in the area, the study found. This finding suggests that Joros aren’t necessarily making it more difficult for orb weavers to find their favorite snacks.

In terms of direct competition for food, our study suggests Joro spiders eat different insects and a wider variety as compared to native orb weavers.

Jason Schmidt, College of Agricultural & Environmental Sciences

With their large, sticky webs and giant size, some people worry that the new spider species would prey on the monarch butterfly, adding yet another danger to the many already facing the imperiled species.

But the current study found Joros aren’t eating a lot of butterflies, monarch or otherwise.

“They’re feeding on things that we would consider pests,” Schmidt said. “A lot of little flies. For the size of the spider, it looks kind of like popcorn.”

Joros take up more space than other spider species

They are, however, taking up a bunch of physical space.

“Joro spiders make these crazy-looking yellow webs that are often tangled with other webs,” Schmidt said. “That style of building is quite different from other spiders.”

But you can often find other native spiders in webs right next to them, Schmidt said. And without detailed records of how many spider species inhabited an area prior to the Joros’ arrival, it’s hard to determine their impact.

“I don’t think they’re necessarily competing for space,” Schmidt said, “though others may have different opinions on that.”

What to do about Joros when they’re here for the long haul

One thing researchers do agree on? Joros are likely here to stay.

So it may be better to make peace with the Joros’ presence than try to eradicate every web you come across.

The South — and the entire Eastern seaboard for that matter — has a similar climate to the Joro’s native Japan. And it’s approximately the same latitude, making it an ideal home for the invasive creepy-crawlies.

Joros are also cold-hardy, surviving early freezes that kill off other arachnids.

And they’re surprisingly adaptable, often building webs alongside busy roads, in between powerlines and even on top of gas pumps.

In trying to kill the spiders … you’ll increase the likelihood of having a bunch of really difficult pests show up.

Jason Schmidt

Baby Joros can use their silk to carry themselves long distances on the wind, a behavior called ballooning. That’s part of the reason why Joros are spreading so rapidly across the state of Georgia and beyond. When hatchlings emerge each spring, they ride the winds sometimes to new places. Their offspring continue the cycle the following year.

The good news is they largely don’t pose a threat to people or their pets. And as far as giant and somewhat scary-looking spiders go, Joros have rather timid personalities. In fact, they’re more likely to flee than fight, or in their case bite.

“They’re pretty docile,” Schmidt said. “I’ve had them right on my face and in my hair, climbing around on me. I haven’t been bitten.”

As for whether the Joro spider will ultimately pose an ecological threat to native species, the jury is still out. But Schmidt encourages people to avoid using broad insecticides to rid their yard of Joros.

“There aren’t any insecticides specifically labeled for spider, so people will go out and just spray all over and kill a bunch of other insects that you actually want in your yard,” Schmidt said.

Further, blanketing your yard in insecticide can backfire.

“In trying to kill the spiders, other beneficial insects feeding on pests in our yards will be impacted, and you’ll increase the likelihood of having a bunch of really difficult pests show up because you killed off some of the good guys out there.”

That said, if you simply cannot stand having Joros near your house, it may be better to take them out one by one, removing individual webs and spiders.

Published by PLOS One, the study was co-authored by Valdosta State University’s Erin Grabarczyk.

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Journal

PLOS One

DOI

10.1371/journal.pone.0351929 

Article Title

DNA metabarcoding to estimate diet overlap between the introduced Joro spider (Trichonephila clavata) and three native orb-weaving spiders

 

Paving the way to critical minerals

Texas A&M researchers are working to develop a faster, cost-effective way to identify critical minerals — essential components for everyday technologies

Texas A&M University

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The prototype will undergo initial testing at the National Oilwell Varco (NOV) STC facility.

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Credit: National Oilwell Varco

What do wind turbines, EV batteries, military equipment and your smartphone have in common? Probably more than you think. 

To be manufactured, these products require critical minerals that are found beneath our feet. 

But gaining access to these minerals, which are crucial and in high demand worldwide, is not a simple process. Currently, the United States relies heavily on importing these materials, which can be delayed for various reasons. As a result, finding domestic sources of critical minerals is a priority. 

But finding new sources of critical minerals can take years of drilling, sample collection and laboratory testing before geologists know whether a site contains sufficient deposits to merit development. Researchers at Texas A&M University are working to change that. 

A team led by Dr. Roman Shor, associate professor in the Harold Vance Department of Petroleum Engineering, received $3.5 million from the U.S. Department of Energy Advanced Research Projects Agency (ARPA-E) through its Reliable Ore Characterization with Keystone Sensing (ROCKS) program to develop an advanced drilling system that can identify valuable minerals in real time. 

Their project, Rapid Analysis of Precious and Targeted Ores with Rotary Drilling (RAPTOR), brings together researchers from Texas A&M, The University of Texas at Austin and industry partners. 

The research team will develop a mobile and efficient drilling system, based on coiled tubing drilling, that combines faster drilling technology, real-time rock analysis and artificial intelligence. Their goal is to dramatically reduce the time needed to evaluate potential deposits of rare earth elements and other critical minerals. 

“Critical minerals are essential components in everyday technologies,” said Shor. “But searching for these minerals can take years and cost large amounts of money for sometimes little payoff.” 

Critical minerals are necessary in large quantities for batteries, motors, inverters and semiconductors, but are generally present at low concentrations in rock formations.  Finding deposits with higher concentrations is essential.

Companies looking for critical minerals often drill hundreds of shallow exploratory boreholes, collect thousands of feet of rock core and send samples off for analysis. The process takes years at a time when critical minerals are in extremely high demand for the products consumers rely on for safety, communication and energy. Shor’s project could replace much of that lengthy process with immediate data collected at the drill site. 

Instead of waiting for results to come back from a lab, the research team is developing a system that continuously collects samples to analyze as they reach the surface. Using advanced sensing technologies and machine learning, the system will identify the minerals and elements present in the samples in real time, allowing drilling teams to make immediate decisions about where to continue drilling. 

The project also incorporates rotary percussive drilling technology, which combines traditional rotary drilling with a hammering action to drill through rock more efficiently. Previous studies have shown this approach can significantly increase drilling speed compared to conventional methods.

“There are many challenges we face in accessing critical minerals in the United States,” said Shor. “Our drilling system design, coupled with advanced controls and real-time digital twinning, would help solve many of them while lowering exploration costs, improving drilling efficiency and enabling faster identification of critical minerals.” 

Shor, the principal investigator, along with co-PIs Dr. Wencheng Jin and Dr. Siddharth Misra, will work in collaboration with Drs. Eric van Oort, Pradeep Ashok and Maggie Chen from UT, Chuck Wright from National Oilwell Varco (NOV) and David Tonner from Diversified Wellbore Logging.

ARPA-E’s ROCKS program aims to accelerate U.S. mineral independence by developing cutting-edge drilling, sensing and analytical technologies that enable rapid, high-resolution and cost-effective assessments of critical mineral deposits. 

By Kendra Bolin, Harold Vance Department of Petroleum Engineering, Texas A&M University

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Rules of the school

Computational models and virtual reality help researchers discover the social interaction rules of fish moving as a collective school

University of California - San Diego

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Researchers examined the dynamics of fish schools and the underlying rules of their social interactions.

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Credit: UC San Diego

For centuries, scientists have been fascinated by the remarkable coordinated movements of flocking birds, swarming insects and schooling fish.

Researchers have studied these natural phenomena in order to understand the rules of interactions between individuals that can produce complex group-level behavior. A collaboration of physicists and neurobiologists at the University of California San Diego has been studying schools of micro glassfish (Danionella cerebrum) to understand how the interactive mental processes of individual fish produce group-level decisions.

Their new paper, published in Physical Review Letters, dives into these questions and provides a new understanding of how individual fish use their perception of their neighbors’ movements to copy those actions, leading to schooling behavior in groups. The research was led by Palka Puri, a recent graduate of UC San Diego’s Physics PhD program, with Associate Professor Johnatan Aljadeff and Assistant Professor Matthew Lovett-Barron, both faculty in UC San Diego’s School of Biological Sciences.

Puri’s work provides a detailed, turn-by-turn account of the schooling behavior of micro glassfish across a range of developmental stages. Based on the computational model developed and investigated in the paper, scientists can now interpret the actions of individual fish and predict the dynamics of schools forming and breaking. The findings also open a door to understand how collective movement — a complex social behavior — emerges from sensory and motor processing in the brain of each fish.

The computational model described in this new paper overcomes prior limitations in the study of animal collectives. While physicists have long investigated collective behavior with models of active matter, it has been challenging to connect these models to the macroscopic movement patterns of animal groups in nature. By examining the movements of fish across group sizes, UC San Diego researchers discovered that individual fish “copy” the movement direction of a randomly-chosen nearby neighbor. This model can explain how schooling emerges during development, as the authors have previously shown. This pair-wise interaction leads to highly dynamic behavior in groups, which is fundamentally different from predictions of a classical model, in which fish align with the average direction of their neighbors.

The authors then went further, testing whether their models can predict the behavior of real glassfish by studying their interactions with “virtual fish” swimming in a virtual reality environment. When the authors programmed virtual fish to change directions, the real glassfish behaved according to the predictions of the pair-wise copying model.

The authors also identified specific moments when fish implement the interactions defined by the model. The end of one fish’s turn opens a “window of opportunity” for its neighbors to align with them. The researchers discovered that mature glassfish generate copying turns with fast reaction times, allowing for insight into the constant give-and-take of social interactions.

These breakthroughs will enable further investigations into the mechanisms of group movement, where Aljadeff and Lovett-Barron seek to understand the neurobiology of social copying in schools.

“Identification of these precisely timed social interactions, together with improved technologies for brain-wide neural imaging, will advance our understanding of how processing in the brains of individuals supports collective behavior,” said Aljadeff, a faculty member in the Department of Neurobiology.

“The findings in this paper open exciting new opportunities for understanding how the brains of these fish pay attention to each other and copy each other’s actions,” said Lovett-Barron, also with the Department of Neurobiology. “Each fish is sensing and responding to their social partner’s actions at discrete moments in time, and performing a specific mental computation. Since we can record across the brains of these transparent Danionella fish, we can start to uncover how their tiny brains achieve this. We hope to ultimately understand how complex collective behaviors like schooling emerge from the brains of many interacting animals.”

Sidebar: The Howard Hughes Medical Institute has recently announced a new research effort into the neural mechanisms underlying complex behavior of the glassfish Danionella (recently featured in NPR and Science Magazine), described as a once-obscure fish now taking center stage as a model research organism. Future research on the physics and neuroscience of collective movements will greatly benefit from the combination of tractable mathematical models and empirical studies of glassfish collective behavior.

 

In previously accepted “classical” research, scientists predicted that fish align to the average direction of fish in their neighborhood (orange, left). Puri et al. report that glassfish instead copy one single neighbor at a time (blue, right). 

 

Precise moments for pairwise copying in schools: Fish movement is segmented into alternating bursts (acceleration, turning) and glides (deceleration, linear motion). The coordination between bursts and glides of neighboring fish provides information on the timing and “intent” of each turn.

Credit

UC San Diego

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Journal

Physical Review Letters

DOI

10.1103/rlkf-vwlc 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Collective Motion in Danionella Emerges from Discrete Copying Interactions

Article Publication Date

26-Aug-2026

 

Thousands of new mothers suffering undiagnosed PTSD after childbirth

Peer reviewed – analysis - humans

University of East Anglia

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Tens of thousands of new mums across Britain may be suffering undiagnosed PTSD following childbirth, according to a University of East Anglia report.

The analysis suggests that emotional and psychological trauma following childbirth may go unrecognised or misdiagnosed during postnatal GP consultations, due to multiple contributing factors.

The warning comes after two damning reports into maternity and neonatal services in England from Baroness Amos and Donna Ockenden, and against a growing concern about maternal mental health.

Post-traumatic stress disorder (PTSD) can develop after a difficult pregnancy or birth and causes symptoms including flashbacks, nightmares, anxiety and persistent negative thoughts.

Now, the UEA team are urging the NHS to equip GPs with better ways to identify new mothers with PTSD to prevent more women falling through the gaps.

'Tip of the iceberg'

According to recent figures, suicide remained the leading cause of death among women between six weeks and one year after pregnancy in the UK during 2021–2023.

The researchers describe these deaths as the "tip of the iceberg", arguing that many more women are living with serious mental health difficulties but are unable to access the support they need.

Lead researcher and GP Dr Megan Foreman, from UEA’s Norwich Medical School, said: “Research shows that around one in 20 postnatal women develop PTSD, which is equivalent to tens of thousands of mothers across the UK.

“It usually happens after a traumatic pregnancy or delivery, but it can also happen after a medically uncomplicated birth.

The hidden consequences

“The consequences of untreated birth trauma for women and families can be far-reaching.

“Some women become so anxious that they repeatedly seek reassurance from healthcare professionals for themselves or their baby. Others avoid healthcare services altogether, including during future pregnancies.

“They may also request elective Caesarean sections in later pregnancies to regain a sense of control. Or others may reject recommended medical care or opt for home births, even in high-risk pregnancies, to avoid interventions associated with their previous experience.”

GPs 'diagnosing in the dark'

“The biggest issue is that GPs are effectively ‘diagnosing in the dark’ because they are not equipped with the information or tools to make proper assessments.”

Although birth trauma is mentioned in national guidance from NICE and NHS England, the new report shows that GPs are not given practical advice on how to measure severity, assess risk or decide who requires specialist treatment.

It also suggests that many healthcare professionals, including GPs, feel they lack the confidence and skills needed to support women affected by birth trauma.

“GPs are also facing growing pressures, staff shortages and limited appointment times, despite being the main gateway to specialist mental health services for new mothers,” said Dr Foreman.

“Some women are also being misdiagnosed with postnatal depression, potentially delaying access to the recommended psychological therapies that are most likely to help.”

The analysis points out that antidepressants are generally less effective for PTSD than specialist psychological interventions and are not recommended by NICE as a first-line treatment for the disorder.

A call to strengthen recognition

The researchers are now calling for urgent work to develop clear guidance in collaboration with women, including a validated assessment tool that could be used by GPs during the routine six-to-eight-week postnatal appointment to help to identify PTSD symptoms.

However, they warn that the process must be handled sensitively.

Dr Foreman said: “Many new mothers attend appointments with their newborns, often combining their own health check with baby examinations or vaccinations. Some may not yet feel able to discuss a traumatic birth experience.

“Asking the wrong questions at the wrong time could leave women feeling unsupported or retraumatised.”

Instead, the authors say any future guidance should be accompanied by better GP training, improved awareness and clear referral pathways into specialist services.

“GPs are uniquely placed to spot warning signs,” said Dr Foreman. “But without better evidence and practical tools, many mothers with childbirth-related PTSD risk being left to cope alone, without the support they need.”

This research was led by UEA in collaboration with City St George’s University of London and the University of Birmingham.

‘Diagnosing in the dark: The childbirth-related post-traumatic stress disorder GP evidence gap’ is published in the British Journal of General Practice.

ENDS

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Journal

British Journal of General Practice

Method of Research

Content analysis

Subject of Research

People

Article Title

‘Diagnosing in the dark: The childbirth-related post-traumatic stress disorder GP evidence gap

Article Publication Date

28-Aug-2026