Stroke triggers a hidden brain change that looks like rejuvenation

 A new study in The Lancet Digital Health suggests the brain can respond to stroke in a surprising way. Researchers at the USC Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI) found that people with severe physical impairments after a stroke may show signs of a "younger" brain structure in areas that were not damaged. This appears to reflect how the brain adapts and reorganizes itself after injury.The research was conducted as part of the Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Stroke Recovery Working Group. Scientists analyzed brain scans from more than 500 stroke survivors collected across 34 research centers in eight countries. By applying deep learning models trained on tens of thousands of MRI scans, the team estimated the "brain age" of different regions in each hemisphere and examined how stroke affects both structure and recovery."We found that larger strokes accelerate aging in the damaged hemisphere but paradoxically make the opposite side of the brain appear younger," said Hosung Kim, PhD, associate professor of research neurology at the Keck School of Medicine of USC and co-senior author of the study. "This pattern suggests the brain may be reorganizing itself, essentially rejuvenating undamaged networks to compensate for lost function."

AI Reveals Brain Rewiring After Stroke

To carry out the analysis, researchers used a type of artificial intelligence called a graph convolutional network. This system estimated the biological age of 18 brain regions based on MRI data. They then compared this predicted age with each person's actual age, a measure known as the brain-predicted age difference (brain-PAD), which serves as an indicator of brain health.When these brain age measurements were compared with motor function scores, a clear pattern emerged. Stroke survivors with severe movement impairments, even after more than 6 months of rehabilitation, showed younger-than-expected brain age in regions opposite the site of injury. This effect was especially strong in the frontoparietal network, which plays an important role in movement planning, attention, and coordination."These findings suggest that when stroke damage leads to greater movement loss, undamaged regions on the opposite side of the brain may adapt to help compensate," Kim explained. "We saw this in the contralesional frontoparietal network, which showed a more 'youthful' pattern and is known to support motor planning, attention, and coordination. Rather than indicating full recovery of movement, this pattern may reflect the brain's attempt to adjust when the damaged motor system can no longer function normally. This gives us a new way to see neuroplasticity that traditional imaging could not capture."

Large-Scale Data Reveals Hidden Patterns

The study relied on ENIGMA, a global collaboration that combines data from more than 50 countries to better understand the brain across different conditions. By standardizing MRI data and clinical information from many research groups, the team created the largest stroke neuroimaging dataset of its kind."By pooling data from hundreds of stroke survivors worldwide and applying cutting-edge AI, we can detect subtle patterns of brain reorganization that would be invisible in smaller studies. These findings of regionally differential brain aging in chronic stroke could eventually guide personalized rehabilitation strategies," said Arthur W. Toga, PhD, director of the Stevens INI and Provost Professor at USC.

Toward Personalized Stroke Recovery

The researchers plan to continue this work by following patients over time, from the early stages after a stroke through long-term recovery. Tracking how brain aging patterns and structural changes evolve could help doctors tailor treatments to each person's unique recovery process, with the goal of improving outcomes and quality of life.Learn more about associations between contralesional neuroplasticity and motor impairment by viewing this video made by the Stevens INI.The study, "Deep learning prediction of MRI-based regional brain age reveals contralesional neuroplasticity associated with severe motor impairment in chronic stroke: A worldwide ENIGMA study," was funded by the National Institutes of Health (NIH) grant R01 NS115845 and supported by international collaborators from institutions including the University of British Columbia, Monash University, Emory University, and the University of Oslo.

Source: ScienceDaily

Scientists solved the mystery of missing ocean plastic—and the answer is alarming

 Scientists have uncovered something surprising in the Atlantic Ocean. The majority of plastic pollution may no longer be visible at all. Instead, it exists as nanoplastics, particles so small they are measured in billionths of a meter.

"This estimate shows that there is more plastic in the form of nanoparticles floating in this part of the ocean than there is in larger micro- or macroplastics floating in the Atlantic or even all the world's oceans!" said Helge Niemann, researcher at NIOZ and professor of geochemistry at Utrecht University. In mid-June, he received a 3.5 million euro grant to further investigate nanoplastics and what ultimately happens to them.

Ocean Expedition Reveals Tiny Plastic Particles

To gather data, Utrecht master's student Sophie ten Hietbrink spent four weeks aboard the research vessel RV Pelagia. The ship traveled from the Azores to the European continental shelf, where she collected water samples at 12 different locations.

Each sample was carefully filtered to remove anything larger than one micrometer. What remained contained the smallest particles. "By drying and heating the remaining material, we were able to measure the characteristic molecules of different types of plastics in the Utrecht laboratory, using mass spectrometry," Ten Hietbrink explains.

First Real Estimate of Ocean Nanoplastics

Previous studies had confirmed that nanoplastics existed in ocean water, but no one had been able to calculate how much was actually there. This research marks the first time scientists have produced a meaningful estimate.

Niemann notes that this breakthrough was made possible by combining ocean research with expertise from atmospheric science, including contributions from Utrecht University scientist Dusân Materic.

27 Million Tons of Invisible Plastic

When the team scaled their measurements across the North Atlantic, the results were striking. They estimate that about 27 million tons of nanoplastics are floating in this region alone.

"A shocking amount," Ten Hietbrink says. The finding may finally explain a long-standing mystery. Scientists have struggled to account for all the plastic ever produced. Much of it appeared to be missing. This study suggests that a large share has broken down into tiny particles that are now suspended throughout the ocean.

How Nanoplastics Enter the Ocean

These microscopic plastics come from multiple sources. Larger plastic debris can fragment over time due to sunlight. Rivers also carry plastic particles from land into the sea.

Another pathway comes from the atmosphere. Nanoplastics can travel through the air and fall into the ocean with rain or settle directly onto the water's surface through a process known as dry deposition.

Potential Risks to Ecosystems and Human Health

The widespread presence of nanoplastics raises serious concerns. Niemann points out that these particles are small enough to enter living organisms.

"It is already known that nanoplastics can penetrate deep into our bodies. They are even found in brain tissue," he says. Because they are now known to be present throughout the ocean, they likely move through entire food webs, from microorganisms to fish and ultimately to humans. The full impact on ecosystems and health is still unclear and requires further study.

What Scientists Still Don't Know

There are still important gaps in knowledge. Researchers did not detect certain common plastics, such as polyethylene or polypropylene, in the smallest particle range.

"It may well be that those were masked by other molecules in the study," Niemann says. The team also wants to determine whether similar levels of nanoplastics exist in other oceans. Early indications suggest this could be the case, but more research is needed.

Prevention May Be the Only Solution

While this discovery fills a critical gap in understanding ocean pollution, it also presents a difficult reality. These particles are too small and too widespread to remove.

"The nanoplastics that are there can never be cleaned up," Niemann emphasizes. The findings highlight the urgency of preventing further plastic pollution before it breaks down into an even more persistent and invisible problem.

Source: ScienceDaily

This quantum computing breakthrough may not be what it seemed

 A team of researchers led by Sergey Frolov, a physics professor at the University of Pittsburgh, along with collaborators from Minnesota and Grenoble, carried out a series of replication studies focused on topological effects in nanoscale superconducting and semiconducting devices. This area of research is considered crucial because it could enable topological quantum computing, a proposed approach to storing and processing quantum information in a way that naturally resists errorsAcross multiple experiments, the researchers consistently identified other ways to interpret the same data. Earlier studies had presented these results as major steps forward in quantum computing and were published in leading scientific journals. However, the follow-up replication studies struggled to gain acceptance from those same journals. Editors often rejected them on the grounds that replication work lacks novelty or that the field had already moved on after a few years. In reality, replication studies require significant time, resources, and careful experimentation, and meaningful scientific questions do not become outdated so quickly.

Combining Evidence and Calling for Reform

To strengthen their case, the researchers brought together several replication efforts into a single, comprehensive paper focused on topological quantum computing. Their goal was twofold: to show that even striking experimental signals that appear to confirm major breakthroughs can sometimes be explained in other ways, especially when more complete datasets are analyzed, and to suggest improvements to how research is conducted and reviewed. These proposed changes include greater data sharing and more open discussion of alternative interpretations to improve the reliability of experimental findings.

A Lengthy Path to Publication

Gaining acceptance for these conclusions took time. The broader scientific community needed extensive discussion and debate before considering the possibility that earlier interpretations might be incomplete. The paper underwent a record two years of peer and editorial review after being submitted in September 2023. It was ultimately published in the journal Science on January 8, 2026.A group of scientists, including Sergey Frolov, professor of physics at the University of Pittsburgh, and coauthors from Minnesota and Grenoble have undertaken several replication studies centered around topological effects in nanoscale superconducting or semiconducting devices. This field is important because it can bring about topological quantum computing, a hypothetical way of storing and manipulating quantum information while protecting it against errors.In all cases they found alternative explanations of similar data. While the original papers claimed advances for quantum computing and made their way into top scientific journals, the individual follow-ups could not make it past the editors at those same journals. Reasons given for its rejection included that being a replication it was not novel; that after a couple of years the field has moved on. But replications take time and effort and the experiments are resource-intensive and cannot happen overnight. And important science does not become irrelevant on the scale of years.The scientists then united several replication attempts in the same field of topological quantum computing into a single paper. The aim was twofold: demonstrate that even very dramatic signatures that may appear consistent with major breakthroughs can have other explanations-especially when fuller datasets are considered, and outline changes to the research and peer review process that have the potential to increase the reliability of experimental results: sharing more data and openly discussing alternative explanations.It took significant time and argumentation for the rest of the community to accept this possibility: the paper spent a record two years under peer and editorial review. It was submitted in September 2023. It was published in the journal Science on January 8, 2026.

Source: ScienceDaily

This hidden state of water could explain why life exists

 Researchers at Stockholm University have used advanced x-ray lasers to uncover a long-suspected feature of water: a critical point that appears when water is deeply supercooled. This occurs at about -63 °C and 1000 atmosphere. Even under everyday conditions, this hidden point influences how water behaves, helping explain many of its unusual properties. The results were published in the journal Science.

Water is everywhere and essential for life, yet it does not act like most other liquids. Properties such as density, heat capacity, viscosity, and compressibility respond to temperature and pressure in ways that are opposite to what scientists see in typical substances.

In most materials, cooling causes them to contract and become denser. Based on this pattern, water should reach its highest density when it freezes. Instead, ice floats, and liquid water is actually most dense at 4 degrees C. That is why colder water remains below warmer water in lakes and oceans.

When water is cooled below 4 degrees, it begins expanding again. If pure water is cooled below 0 degrees (where crystallization happens slowly), this expansion continues and even accelerates as the temperature drops further. Other properties, including compressibility and heat capacity, also behave in increasingly unusual ways as the temperature decreases.

Capturing Water's Hidden State With X-Ray Lasers

To investigate these strange behaviors, scientists used extremely fast x-ray pulses generated by powerful lasers in South Korea. These pulses allowed them to observe water in a supercooled state just before it turned into ice.

"What was special was that we were able to X-ray unimaginably fast before the ice froze and could observe how the liquid-liquid transition vanishes and a new critical state emerges," says Anders Nilsson, Professor of Chemical Physics at the Department of Physics at Stockholm University. "For decades there has been speculations and different theories to explain these remarkable properties and one theory has been the existence of a critical point. Now we have found that such a point exists."

Two Liquid Forms of Water and a Critical Transition

Under low temperatures and high pressure, water can exist as two distinct liquid phases with different molecular bonding structures. As conditions change, these two forms merge into a single phase at the critical point.

Near this point, the system becomes highly unstable, and water rapidly shifts between the two liquid states or mixtures of them. These fluctuations extend across a wide range of temperatures and pressures, even reaching normal environmental conditions. Scientists believe these constant shifts are what give water its unusual characteristics.

Beyond the critical point, water enters a supercritical state, and under everyday conditions, it already exists in this regime.

A "Black Hole-Like" Effect in Water Dynamics

The researchers also found that molecular motion slows dramatically as water approaches the critical point.

"It looks almost that you cannot escape the critical point if you entered it, almost like a Black Hole," says Robin Tyburski, researcher in Chemical Physics at Stockholm University.

A Breakthrough Decades in the Making

"It's amazing how amorphous ices, such an extensively studied state of water, happened to become our entrance to the critical region. It's a great inspiration for my further studies and a reminder of the possibilities of making discoveries in much-studied topics such as water," says Aigerim Karina, Postdoc in Chemical Physics at Stockholm University.

"It was a dream come true to be able to measure water under such low temperature condition without freezing," says Iason Andronis, PhD student in Chemical Physics at Stockholm University. "Many have dreamt about finding this critical point but the means have not been available before the development of the x-ray lasers."

"I find it very exciting that water is the only supercritical liquid at ambient conditions where life exists and we also know there is no life without water. Is this a pure coincidence or is there some essential knowledge for us to gain in the future?" says Fivos Perakis, an associate professor in Chemical Physics at Stockholm University.

Source: ScienceDaily

Lost in space: Microgravity makes sperm lose their sense of direction

 Starting a family beyond Earth could be more challenging than expected. New research from Adelaide University shows that sperm struggle to navigate in low gravity, suggesting that gravity plays a key role in helping them reach an egg.

Scientists from the Robinson Research Institute, the School of Biomedicine, and the Freemasons Centre for Male Health and Wellbeing studied how space-like conditions affect sperm navigation, fertilization, and early embryo development.To simulate microgravity, researchers used a 3D clinostat machine developed by Dr. Giles Kirby at Firefly Biotech. This device continuously rotates cells to mimic the disorienting effects of zero gravity. Sperm from three different mammals, including humans, were tested by sending them through a maze designed to resemble the female reproductive tract.

"This is the first time we have been able to show that gravity is an important factor in sperm's ability to navigate through a channel like the reproductive tract," said senior author Dr. Nicole McPherson from Adelaide University's Robinson Research Institute.

"We observed a significant reduction in the number of sperm that were able to successfully find their way through the chamber maze in microgravity conditions compared to normal gravity.

"This was experienced right across all models, despite no changes to the way sperm physically move. This indicates that their loss of direction was not due to a change in motility but other elements."

Progesterone May Help Guide Sperm

The researchers also found that adding the sex hormone progesterone improved how well human sperm navigated under simulated microgravity conditions.

"We believe this is because progesterone is also released from the egg and can help guide sperm to the site of fertilization, but this warrants further exploration as a potential solution," said Dr. McPherson.

Fertilisation and Embryo Development Affected

The team examined how exposure to microgravity during fertilisation influences early embryo development in animal models.

After four hours in simulated zero gravity, the number of successfully fertilized mouse eggs dropped by 30 per cent compared to normal Earth conditions.

"We observed reduced fertilization rates during four-to-six hours of exposure to microgravity. Prolonged exposure appeared to be even more detrimental, resulting in development delays and, in some cases, reduced cells that go on to form the fetus in the earliest stages of embryo formation," said Dr. McPherson."These insights show how complex reproductive success in space is and the critical need for more research across all early stages of development."

Why Gravity Matters for Reproduction

Earlier research has explored how sperm move in space, but none had tested their ability to navigate through a reproductive channel under controlled conditions like this.

The findings were published in Communications Biology.

This study was conducted in collaboration with Adelaide University's Andy Thomas Centre for Space Resources, which focuses on the challenges of long-term space exploration and living beyond Earth.

"As we progress toward becoming a spacefaring or multi-planetary species, understanding how microgravity affects the earliest stages of reproduction is critical," said Associate Professor John Culton, Director of the Andy Thomas Centre for Space Resources.

Future Research on Reproduction in Space

The next phase of the research will explore how different gravity environments, including those on the Moon, Mars, and in artificial gravity systems, affect sperm navigation and early embryo development.

A key question is whether these effects change gradually as gravity decreases or if there is a threshold where changes occur suddenly, creating an "all or nothing" response.

Answering this will be essential for planning human reproduction in future Moon and Mars settlements and for designing artificial gravity systems that support healthy development.

"In our most recent study, many healthy embryos were still able to form even when fertilized under these conditions. This gives us hope that reproducing in space may one day be possible," said Dr. McPherson.

Source: ScienceDaily

One of Earth’s most explosive supervolcanoes is recharging

 Scientists have discovered that the magma reservoir tied to the largest volcanic eruption of the Holocene is filling again. The finding, led by Kobe University researchers studying Japan's Kikai caldera, offers new insight into how massive caldera systems such as Yellowstone and Toba evolve over time and may help improve future eruption forecasting.

Some volcanic eruptions are so extreme that they release enough magma to bury all of Central Park under 12 kilometers of material. After such an event, the landscape collapses into a broad, relatively shallow crater known as a caldera. Famous examples include Yellowstone in the United States, Toba in Indonesia, and the largely submerged Kikai caldera in Japan. Kikai last erupted 7,300 years ago in the most powerful eruption of the current geological epoch, the Holocene. While scientists know these systems can erupt again, the buildup to such events remains poorly understood. "We must understand how such large quantities of magma can accumulate to understand how giant caldera eruptions occur," says Kobe University geophysicist SEAMA Nobukazu.Underwater Seismic Imaging Reveals Magma System

Kikai's underwater setting provides a unique research advantage. Seama explains, "The underwater location allows us to implement systematic, large-scale surveys." Working with the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the team used airgun arrays to generate controlled seismic pulses and ocean bottom seismometers to track how those waves move through the Earth's crust. This approach allowed them to build a detailed picture of the structures beneath the caldera.

The results, published in Communications Earth & Environment, confirm a large magma-rich zone directly beneath the site of the ancient eruption. The researchers were able to map the reservoir's size and shape and determine its connection to past activity. Seama says, "Due to its extent and location it is clear that this is in fact the same magma reservoir as in the previous eruption."

Fresh Magma Injection Drives Recharging Process

The magma currently present does not appear to be leftover from the earlier eruption. Scientists had already observed a lava dome forming at the center of the caldera over the past 3,900 years. Chemical analysis shows that this newer material differs from what was released during the previous eruption. "This means that the magma that is now present in the magma reservoir under the lava dome is likely newly injected magma," summarizes Seama. These findings support a broader model explaining how magma reservoirs beneath caldera volcanoes refill over time.

Implications for Yellowstone and Future Eruptions

The proposed magma re-injection model aligns with observations of large, shallow magma systems beneath other major calderas such as Yellowstone and Toba. Seama suggests this work could help scientists better understand how magma supply cycles develop after massive eruptions. He concludes, saying: "We want to refine the methods that have proved to be so useful in this study to more deeply understand the re-injection processes. Our ultimate goal is to become better able to monitor the crucial indicators of future giant eruptions."

Source: ScienceDaily

Scientists shocked to find lab gloves may be skewing microplastics data

 A University of Michigan study suggests that the nitrile and latex gloves scientists commonly use could be causing microplastics levels to appear higher than they actually are.

Researchers found that these gloves can unintentionally transfer particles onto lab tools used to analyze air, water, and other environmental samples. The contamination comes from stearates, which are not plastics but can closely resemble them during testing. Because of this, scientists may be detecting particles that are not true microplastics. To reduce this issue, U-M researchers Madeline Clough and Anne McNeil recommend using cleanroom gloves, which release far fewer particles.Stearates are salt-based, soap-like substances added to disposable gloves to help them separate easily from molds during manufacturing. However, their chemical similarity to certain plastics makes them difficult to distinguish in lab analyses, increasing the risk of false positives when studying microplastic pollution.

The researchers emphasize that this does not mean microplastics are not a real problem.

"We may be overestimating microplastics, but there should be none," said McNeil, senior author of the study and U-M professor of chemistry, macromolecular science and engineering, and the Program in the Environment. "There's still a lot out there, and that's the problem."

Clough added, "As microplastic researchers looking for microplastics in the environment, we're searching for the needle in the haystack, but there really shouldn't be a needle to begin with."

The research, led by Clough, a recent doctoral graduate, was published in RSC Analytical Methods and supported by the U-M College of Literature, Science, and the Arts' Meet the Moment Research Initiative.

Unexpected Source Behind Inflated Results

The discovery began during a collaborative project examining airborne microplastics in Michigan. The effort involved researchers from multiple U-M departments, including Chemistry, Statistics, and Climate and Space Sciences Engineering. Clough and McNeil worked with collaborators such as chemistry professor Andy Ault and graduate students Rebecca Parham and Abbygail Ayala to collect air samples.

To capture particles, the team used air samplers equipped with metal surfaces that collect material from the atmosphere. These samples were then analyzed using light-based spectroscopy to identify the types of particles present.

While preparing the sampling surfaces, Clough followed standard practice and wore nitrile gloves. However, when she reviewed the results, the number of detected microplastics was thousands of times higher than expected.

Source: ScienceDaily