Curiosity has its own neural signal: Brain separates valuable information from water rewards in mice
Often, humans and other animals seek information that can help them complete tasks and attain desired rewards. In some cases, however, they seek information driven simply by curiosity and a desire to obtain knowledge for its own sake, even if it does not lead to external rewards. Scientists know this better.
Researchers recently created a new experimental paradigm for studying the neural processes associated with curiosity and the desire for knowledge in mice. This paradigm, outlined in a paper in Nature Neuroscience, allowed them to gain new insights into how the brain represents the value of information regardless of physical rewards.
Previous studies offered some initial clues about how the mammalian brain attributes value to information. However, the process through which it recognizes stimuli that can provide interesting information and represents their value has not yet been elucidated.

This is a higher-order process of cognition, since what is most valuable as information depends on what we already know, and we can't detect and know how good information is by physiological processes in our body, the way we can with food or many other better understood types of reward that motivate our actions.
Researchers offered thirsty mice the choice of poking their noses into two holes.
One hole revealed with a short puff of odor whether they would receive a water reward, and the other revealed nothing but, critically, offered them the exact same chance and amount of water. Prior to making their decision, the mice had to poke in a third hole that presented them with an odor that either directed them to the information- or non-information-providing hole or offered them the choice. In this way, the mice learned that individual odors each predicted a certain amount of information or water reward.
Interestingly, the researchers observed that the mice predominantly preferred poking their noses into the hole that gave them information. This occurred even if the information-providing hole contained less water than the other hole. These findings suggest that mice are often willing to exchange water (i.e., a reward) for information. This, in turn, implies that the mice attribute value to the information itself.
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As the mice were learning this behavioral task, the researchers recorded their brain activity using miniaturized microendoscopes. These are ultrathin, lightweight imaging devices that can measure activity in hundreds of neurons simultaneously. The team observed activation patterns in the orbitofrontal cortex (OFC), a brain region involved in evaluating decisions guided by reward value.
The researchers chose to look at the orbitofrontal cortex because it has been shown to represent the value of options when humans and other animals are making decisions and previous experiments using mice had shown that it represents reward value that is signaled by odors in particular.
To understand how the brain represents the prospect of obtaining information, the researchers compared cases in which, based on the odor they sniffed, the mice expected to receive information with trials in which the reward outcome would remain unknown.

They identified a representation of the predicted value of information in the mouse orbitofrontal cortex.
Approximately 20% of the cells in the OFC showed different neural activity in response to odors that predicted information versus those that predicted no information, and the magnitude of that activity difference scaled with the duration of time the mice had knowledge of the reward outcome. This indicates that they identified a representation of information value that depended on its resolution of uncertainty, which is intrinsic to information and cognition.
The team's findings suggest that the mouse brain processes a desire for knowledge and the drive for physiological rewards differently.

The representation of the predicted value of information was discernible across the neural population in a way that was orthogonal to the representation of the predicted water value, which they observed in response to separate odors in their experiments. Given that they observed this pattern in the OFC, a brain area intimately involved in generating representations of the world to guide decisions, the representation of information value could be a critical signal that allows animals to take actions to gain information and increase their knowledge of the world.
The researchers pursued neural processes underlying curiosity and the drive to seek knowledge, with the goal that their work will also be applicable to humans.
Understanding how we evaluate sources of information and how wanting to gain knowledge drives our behaviour would have important implications for helping people navigate our information-rich modern world, including through learning during childhood development.
Not only could a better understanding of curiosity, the drive to gain information, improve people's success in learning, given the pleasurable, rewarding nature of acquiring knowledge, it could offer us access to more joy and fulfillment—something we all could use.

Jennifer J. Bussell et al, Representations of the intrinsic value of information in mouse orbitofrontal cortex, Nature Neuroscience (2026). DOI: 10.1038/s41593-026-02377-y.

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Cells use a little-known molecule to protect themselves from iron overload

Iron is essential. Our cells need it to produce energy, carry oxygen throughout the body and power countless chemical reactions that sustain life. But this metal has a dark side. When too much of it is left free inside cells, it can trigger destructive reactions that break down DNA, proteins and even cell membranes.
Now researchers have discovered that cells rely on an unexpected protector against this threat: small molecules called polyamines.

The researchers' detailed findings, published in the journal Cell, reveal that polyamines act like storage lockers for iron, safely holding the metal in a nonreactive state until cells need it.
These findings solve a decades-old mystery about why cells maintain such extraordinarily high levels of polyamines and uncover a previously unknown defense mechanism that protects cells from toxic iron overload.

This work could also help scientists develop better cancer treatments by allowing iron overload to trigger cancer cell death. It could also offer new clues about diseases like early-onset Parkinson's disease, in which mutations affect polyamine levels within neurons.

Polyamines buffer labile iron to suppress ferroptosis, Cell (2026). DOI: 10.1016/j.cell.2026.07.040. www.cell.com/cell/fulltext/S0092-8674(26)00872-X

Organs age at different speeds: A blood test might soon tell which ones

Some people seem to age more slowly than others, looking and acting like 45 at 60. Others appear to have gotten ahead of the calendar. But why is that, and what is actually happening inside the body?
AI-based "tissue clocks" can estimate the biological age of human organs from histological images, researchers showed. By analyzing more than 25,000 tissue samples across 40 tissue types, their study reveals that organs age at different rates throughout life and that these changes can even be detected from blood samples. The findings, published in Nature Medicine, provide a new framework for understanding aging and may open new avenues for disease monitoring and early diagnosis.
the researchers turned to the Genotype-Tissue Expression Project (GTEx), which collected tissue samples from 983 individuals across 40 different tissue types, ranging from the brain and heart to the lung, pancreas, skin and intestine. These were transformed into high-resolution digital images of tissue slices, each revealing the microscopic architecture of the organ in question. The scale is staggering: 25,712 images, representing about 480 million individual image tiles, analyzed with state-of-the-art vision models.

They found that the architecture of organs keeps a silent diary of time: Even without explicitly teaching the AI about it, age turned out to be the single strongest factor shaping tissue appearance across all 40 tissue types. Building on this, the research team developed so-called "tissue clocks"—predictive models that estimate a person's biological age from the appearance of their tissue, for each organ independently.

These clocks achieved a mean prediction error of just 4.9 years and outperformed existing DNA-based aging estimates in capturing tissue-specific pathology. Importantly, the predicted biological age was strongly linked to known hallmarks of aging, including telomere shortening, tissue pathology and the number of chronic diseases an individual had.
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Our tissues carry a remarkably detailed record of the aging process.
By combining histology images with artificial intelligence, we can detect patterns of biological aging that are invisible to the human eye and begin to understand how aging unfolds differently across the body.
The analysis revealed that aging does not occur uniformly: Some tissues, such as the lung, kidney, pancreas and adrenal gland, showed signs of accelerated aging between the ages of 20 and 40. Others followed more complex trajectories, with peaks of accelerated aging appearing later in life. The uterus displayed a particularly striking shift around the age of menopause.

The researchers also identified strong links between tissue-specific aging and medical conditions or lifestyle-associated factors. For example, kidney failure was associated with accelerated aging signals in multiple tissues, while diabetes showed pronounced effects in the pancreas.

What stands out is how differently each organ ages, and how that shows up in tissue architecture.
Deep learning lets us read these spatial patterns, capturing aging as architectural remodelling, not just molecular drift. While the tissue clocks captured the normal pace of aging across organs, they also highlighted outliers—individuals whose tissues showed pronounced structural shifts ahead of their chronological age.
However, tissue samples cannot always be collected. By linking blood-based gene expression profiles with the histologically derived tissue age gaps of the same individuals, the researchers built predictors of tissue-specific biological age from blood samples alone.
These blood-based predictors successfully identified aging patterns linked to several diseases, including Alzheimer's disease, Crohn's disease, cystic fibrosis, vasculitis, diabetes and stroke. In Alzheimer's disease, for example, the strongest aging signal was detected specifically in the brain, whereas Crohn's disease showed accelerated aging across the gastrointestinal tract.

Histological aging signatures for monitoring tissue-specific aging and disease, Nature Medicine (2026). DOI: 10.1038/s41591-026-04566-5

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What are chalk streams and why are these rare rivers under threat?
Chalk streams are groundwater-fed rivers with clear, cool, mineral-rich water and stable flows; seasonal headwaters called winterbournes support specialised aquatic and terrestrial species. Their biodiversity is threatened by water abstraction, pollution, channel modification, drought and heat. Reducing pollution and restoring natural flows can improve resilience.

What happens when someone's chromosomes, sex hormones and body don't align?
Differences of sex development arise when chromosomes, gonads, hormone production, or hormone responsiveness diverge from typical pathways. Conditions such as congenital adrenal hyperplasia, androgen insensitivity, 5-alpha-reductase deficiency, and sex-chromosome variations can affect anatomy, puberty, fertility, and health. Individualized specialist care, clear information, and psychological support are important.

original article.

Boiling Liquid Does Something in Near-Zero Gravity
Out in deep, dark depths of space, electronics and fuel can still get hot – very hot.

As plans are made for longer missions and more advanced tech systems, one of the key areas scientists want to understand better is what happens to ultra-cold, cryogenic liquids when they boil.

These liquids are used as rocket fuel and to cool electronics, for example, but at the moment, we don't know enough about their boiling behavior in microgravity.

A new study investigating just that, in a series of airborne experiments, has turned up some surprising results. The findings are published in npj Microgravity

We know boiling liquids behave strangely in space; we've seen it happen before.
With less gravity, convection doesn't circulate heat through liquids as readily. And bubbles don't detach from surfaces as easily; they are less buoyant, so they don't float up as they do on Earth.
So it might reasonably be assumed that low gravity would also reduce the cooling capacity of those space bubbles because they can't carry heat away as fast.

But the researchers found the opposite: reduced gravity improved heat removal under certain conditions.

That is, until a heat threshold was exceeded and boiling became unstable.
Researcher s found that bubbles started forming sooner, and heat transfer was improved under near-zero-gravity conditions. The researchers think it's because in microgravity, the bubbles stick closer to the heated surface, which improves heat removal efficiency.
Their hypothesis is that bubbles stop floating away, so they linger on the surface.
When bubbles are on the surface, there is a small liquid gap between the bubble and the heater, and that liquid layer is so thin that it can improve heat transfer.
While that sounds beneficial, the cooling systems reached their limit faster in the simulated space conditions.

The maximum amount of heat that the liquid nitrogen coolant could handle dropped by 65 percent in microgravity compared to the lab tests.

Part 1

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Essentially, the lingering bubbles begin to link together, dry out the surface faster, and cause the cooling mechanism to collapse. Reduced gravity is an advantage for heat transfer, right up until it isn't.

There are limitations to consider here: only nitrogen was tested, and on short parabolic flights.

However, the data gathered will be useful for future modeling as researchers devise equipment for more efficient, safer space travel.

https://www.nature.com/articles/s41526-026-00631-y

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A Common Plastic Increases Risk of Fatty Liver Disease

One of the world's most common plastics – used in food packaging, plastic wraps, storage containers, and takeaway cups – may be partially responsible for your risk of fatty liver disease.

The disease, as we know it today, was first described in 1980.

But physicians have known since the 19th century that fatty infiltration of the liver is somehow related to diet, long before formal studies began.

A new study in mice suggests modern food conveniences might be adding to the problem.
People often aren't aware they have fatty liver disease (the non-alcoholic kind) until it is detected incidentally when they get a scan for some other condition.

When people do experience symptoms, they may present with fatigue, feeling generally unwell, and discomfort under the right side of their ribs.

Excess fat builds up in the liver cells, which can eventually lead to inflammation, then fibrosis (an accumulation of scar tissue), and even cirrhosis (serious damage), if untreated.
You're more at risk for fatty liver disease if you're carrying extra weight, especially around the middle.

Other risk factors include high blood fat levels (LDL cholesterol or triglycerides), type 2 diabetes or prediabetes, and high blood pressure.
All of these risk factors involve food and metabolism, but a new study in mice shows there may be an important aspect of people's diets that has been overlooked: exposure to microplastics, specifically polyethylene.

It's one of the most important plastics for food convenience: it packages takeaways, cling-wraps leftovers, stops your single-use cup from dissolving in your hand.

And, compared to many other polymers, polyethylene has kind of been considered a lesser concern.
Studies suggest that microscopic polyethylene can trigger signs of fatty liver disease, even with a standard diet. Regardless of diet, the addition of microplastics appeared to exacerbate the condition – even among the mice who ate a relatively healthy diet.
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Levels of ALT, an enzyme indicative of poor liver health, and liver triglycerides were higher in both groups of mice in the experiments whose diets were laced with microplastics than in animals fed the same corresponding diet without polyethylene.

The same went for liver cell inflammation and ballooning, and steatosis (fat buildup in the liver).
Genes encoding proteins PPAR-alpha (which regulates liver fat production) and Annexin A2 (which, in the liver, is involved with tissue repair) were both in overdrive in the microplastics-affected livers.

https://www.science.org/doi/10.1126/sciadv.aec8681

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Faecal transplant soothes peanut allergy
Six people with a severe peanut allergy can tolerate the nut after a transplant of gut bacteria from the stool of people without the allergy. Four months after the transplant, five participants could eat 600 milligrams or more of peanut protein — the equivalent of about two and a half peanuts — without triggering a severe immune response. The potential of this type of therapy to have a lasting benefit is really, really exciting, because available treatments for food allergies are limited and short-lived.

https://www.science.org/doi/10.1126/scitranslmed.aee3263

Taking screenshots makes you more likely to forget information

Snapping a photo or taking a screenshot to remember something? According to recent cognitive research, the practice may make you more likely to forget.

Research has consistently shown that if you take photographs or screenshots during an experience, your memory of the information or event is degraded.

Taking photos or screenshots can impair memory for captured information, particularly when images are not later reviewed. Across seven experiments, capture showed no memory benefit and was associated with poorer recall and source memory. Divided attention, cognitive offloading, and attentional disengagement may contribute.

Known as the photo-taking impairment effect, the phenomenon occurs for material that the picture-taker doesn't review afterward. According to other research, using photographs to retrieve and review memories may benefit long-term retention.
However, many of us take more photos and screenshots than we can use—about 20 photos a day, with about 2,000 photos stored on the average smartphone, according to estimates.

Unless you are actively reviewing those images as cues for elaborative memory retrieval, it is unlikely to benefit you.

Another study suggests that our memory isn't impaired when photographs are captured automatically using a wearable clip camera. This indicates that there's something about the act of taking a photo or capturing a screenshot that impairs memory, rather than the knowledge that something is being saved.
One possible mechanism behind digital amnesia is divided attention: The act of capturing an experience takes away cognitive resources that would otherwise be dedicated to encoding the information in memory. While divided attention plays a role, it's unlikely to be the main source of memory impairment. People show a comparable deficit when extra time is provided to view artwork before or after taking a photograph and when the capture task is made less difficult, which should minimize its effects.

Another possibility is cognitive offloading, in which we do not allocate cognitive resources to remember information if it's stored externally. Offloading allows us to redirect those conserved cognitive resources toward aspects of an experience that weren't captured or toward unrelated tasks.

Individuals should only employ the strategy if the information is reliably saved and accessible. However, research has shown that memory remained impaired even when picture-takers knew their images would be immediately deleted. With screenshots in particular, people were less likely to remember whether they captured an image or viewed a piece of art, and had worse memory for the art itself when it was captured.

A third hypothesis is attentional disengagement, in which the act of taking a photograph or screenshot causes us to unconsciously distance ourselves from the experience.
This unconscious detachment may be sparked by a longstanding association between capturing images and the ability to offload information.
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A better option for remembering information: Break out a pen and paper. Writing something down—for example, taking notes during a lecture—forces us to process and organize the information into manageable bullet points and draw connections. Known as "desirable difficulty," the mental effort in this kind of processing may make us more likely to remember the information.

However, it's not foolproof; sometimes, writing something down can lead to cognitive offloading—such as forgetting a friend's birthday after we add it to our calendar and set reminders. Like the phone numbers in your contact list, you may no longer be able to remember the specific information.

Screenshotting can potentially supplement your memory if you take only a few intentional shots and review them later—similar to how a calendar reminder can support your memory of an upcoming event. But taking frequent screenshots and letting them accumulate unreviewed has the opposite effect, research shows.
The results of the current study suggest that we are likely harming our memory for information and experiences with the press of a button, and that this impairment may even extend beyond what is captured.

Sophia P. Fabrizio et al, Digital amnesia: The aftermath of a screenshot, Memory & Cognition (2026). DOI: 10.3758/s13421-026-01921-2

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Scientists have designed a functioning virus from scratch using AI. What you need to know
AI-generated genomes for the bacteriophage ΦX174 produced 16 functional phages among 285 synthesized designs, demonstrating that sequence models can generate viable viral genomes based on existing biological patterns. The system remains limited to a simple bacteriophage; clinical phage applications and biosecurity require further validation and oversight.

original article.

Can vitamin C cure a cold? How a Nobel Prize winner convinced us it could
Vitamin C does not prevent colds in the general population or help when started after symptoms begin. Regular supplementation may modestly reduce severe symptom duration and severity, with greater effects in athletes and military personnel. High doses can cause gastrointestinal effects, kidney-stone risk, increased iron absorption, and drug interactions.

original article.

Male Neanderthal pelvises resemble those of modern females, challenging decades-old assumptions
A new study published in Scientific Reports offers an explanation for one of the striking differences between men and women: the evolutionary development of the modern human pelvis.
By comparing Neanderthal pelvises with those of modern humans, the researchers reached a surprising conclusion: The unusual structure of the pelvis may not be that of the Neanderthal, as has been assumed for decades, but rather that of the modern human male.
According to the researchers, the male pelvis evolved into a unique biomechanical shock-absorbing mechanism that stores energy and makes long-distance walking more efficient.
The study is based on a comparison of two nearly complete male Neanderthal pelvises, one from Kebara Cave in Israel and the other from the Sima de los Huesos site in Spain, with dozens of modern human pelvises.

Surprisingly, despite their large size and robust construction, the Neanderthal pelvises were found to resemble those of modern human females in most measurements and proportions rather than those of modern human males.

During every step of bipedal walking, the body's center of mass drops downward. This drop strains the joints and requires energy to raise the body again in preparation for the next step.

According to the new model, the distinctive geometry of the male pelvis enables the thigh muscles to cushion the drop of the body's center of mass, store potential energy during the step and then release that energy immediately afterward—effectively "springing" the body upward into the next step.

In this way, the pelvis functions as a natural shock absorber and energy-return system. It may reduce energy expenditure, improve walking efficiency and thereby provide a significant advantage during long-distance travel on foot. The change in the position of the hip joints also required additional structural adaptations, including the thickening of the pubic bone and deepening of the anterior portion of the pelvis to withstand the new mechanical loads.
Modern human females, by contrast, could not adopt the full suite of these modifications. According to the researchers, the constraints imposed by childbirth require a relatively shallow pelvis and a sufficiently wide birth canal. As a result, the female pelvis remains closer to the ancestral configuration—the same general configuration found in male Neanderthals.
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The findings of the study change the way we understand the evolution of the human pelvis. It is not the Neanderthal pelvis that is the anomaly requiring explanation. Rather, it is the pelvis of the modern human male. The mechanism that evolved within the human male represents the evolutionary innovation.

The researchers note that the study presents a new biomechanical model that may explain a substantial part of the human pelvis's sexual dimorphism, the anatomical differences between females and males.

Yoel Rak et al, Neandertal pelvis reveals specialized walking apparatus in human males, Scientific Reports (2026). DOI: 10.1038/s41598-026-59915-8

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Restoring a missing slice of sunshine to indoor light may help prevent myopia

Myopia, or nearsightedness, develops when the eye grows too long from front to back. This prevents images from focusing directly on the retina in the back of the eye, causing distant objects to appear blurry.

Myopia usually begins in childhood and can progress through adolescence. Beyond the need for glasses or contact lenses, high myopia increases the risk of vision-threatening complications later in life, including retinal detachment, glaucoma and macular degeneration.

Research has already shown that the more time children spend playing with screens indoors instead of outdoors, the more likely they are to develop myopia. In fact, some experts predict that nearly 5 billion people (or 50% of the world's population) will be nearsighted by 2050.
Now, a new study led by vision researchers  suggests that myopia can be prevented with improved indoor lighting.

Details were published online Aug. 18, 2026, in Cell Reports Medicine.

The research focuses on indigo light—a short-wavelength light that is abundant in sunlight but poorly represented in standard white LED lighting. In experiments involving tree shrews—an animal model with a human-like visual system—the team demonstrated that exposure to indigo light completely prevented nearsightedness from developing.
The study used tree shrews because their eyes share anatomical and optical features with human eyes.
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The team used these animals in a series of tests that exposed them to different wavelengths of light while using a biometer to measure eye shape and axial length and an autorefractor to measure refractive changes over time.

Earlier work in mice suggested that violet light near 380 nanometers could suppress myopia and revealed that opsin 5 (OPN5), a light-sensing receptor, was required for this response. But that wavelength did not work in tree shrews because, as in humans, the ocular lens blocks most light below about 400 nanometers.

Human lenses, and now we know tree shrew lenses, don't transmit a lot of light in the ultraviolet spectrum.
The findings support a broader idea that modern indoor life has changed the lighting environment in ways that affect children's eye development. Standard white LEDs typically have a peak around 450 nanometers and emit substantial longer-wavelength light that supports vision. But they provide little of the indigo light that appears to stimulate nonvisual opsins—light-sensitive pathways involved in biological processes beyond image formation.
We evolved outside in the full-spectrum light provided by our sun. When we live inside, we don't get all the wavelengths the eye needs for normal refractive development, and so we get myopia. That's the basic message of this research paper.
One way to prevent myopia would be to encourage children to spend much more time outside, where their eyes can focus across a wider range of near and distant objects while their growing bodies are bathed in full-spectrum sunlight. But reversing the course of our increasingly technical culture appears unlikely.

Another way to prevent myopia would be to improve lighting systems.

Prevention of myopia in a near-primate by supplemental indigo light suggests a hypothesis for the myopia boom, Cell Reports Medicine (2026). DOI: 10.1016/j.xcrm.2026.102999. www.cell.com/cell-reports-medi … 2666-3791(26)00416-7

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A new mathematical tool to uncover 'who eats whom' in nature

Understanding "who eats whom" is the key to keeping our oceans alive—and our dinner plates full. However, this invisible network that makes up the food chain can unravel with the pull of just one thread. Overfish one species, and its predators starve. Cut off a tiny prey species, and the entire food chain collapses—including us.
The intricacies of this web have remained a mystery because traditional ecological research is almost forensic, incredibly slow and strictly limited to the number of species scientists can physically collect during fieldwork. To find a better way, marine scientists had to look outside the ocean entirely and delve into an unexpected specialty: mathematics.
New research published in Methods in Ecology and Evolution on Aug. 6, 2026, blends marine science and engineering mathematics to solve the "impossible" problem of this chaotic web. The resulting algorithm reconstructed invisible ocean networks with 80% accuracy, essentially turning the invisible visible.
The algorithm reconstructed invisible ocean networks with more than 80% accuracy. Even better, its calculations of the percentage of each prey that predators ate had an error rate of less than 5%. Even when fed "noisy" or imperfect field data, the system remained perfectly steady.

Ettore Barbieri et al, The superposition method for the reconstruction of food webs, Methods in Ecology and Evolution (2026). DOI: 10.1111/2041-210x.70376

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Link between whale calls and special relativity

For a more precise and consistent way to detect the presence of whales, oceanographers rarely rely on sight.
Sound from a fin whale can be heard from 100 kilometers (62 miles) away underwater with a single hydrophone. Because those calls travel so far, we can use them to pinpoint where an animal is by comparing when its sound reaches receivers spread across the seafloor.
But there's a catch: If they were trying to track a nearby whale using just standard physics, they'd probably place the animal in the wrong spot—off by hundreds of meters.

In a paper recently published in the journal Physical Review E, researchers offer a potential explanation for why this occurs: The humble whale call is, improbably, tangled up with the same speed limits Einstein deduced from the universe. Their findings could improve whale tracking for conservationists.
When a whale calls, the sound doesn't take a single path to each receiver. Some of the sound travels directly to a receiver, while some of it ricochets off the ocean surface first, arriving fashionably late.
That delay can put the two signals out of phase, causing them to interfere with one another and shifting when sound appears to arrive at a receiver.
The researchers stumbled onto this while refining a computer program meant to calculate the correct speed of sound for his whale-tracking equations. The results were surprising.

The first time, they got a number that was around 1,000 meters per second, well below the roughly 1,500 meters per second that sound normally travels in seawater. And then, further on, they got values that were sometimes 3,000 meters per second.

After examining the software for a few hours, they discovered that the behaviour wasn't a coding error, but a physical effect caused when a receiver picked up both the direct signal and its reflected echo when a whale was near the ocean's surface.
Physicists call this "temporal interference," the same phenomenon that causes TV broadcasts at your home antenna to fade out because two paths arrive out of phase or out of sync. The interference can also shift the peak of the energy earlier and break the speed limit.

What appears to speed up is not the signal carrying information but the position of the signal's strongest peak. That crucial distinction is the reason their finding aligns with Einstein's theory.

For more than a century, physicists have known that waves can sometimes appear to travel faster than light when their shape changes. But the information encoded in those waves still cannot travel faster than light—the central principle of Einstein's theory of special relativity.

John L. Spiesberger et al, Supersonic and superluminal energy and speed of information via temporal interference in a dispersionless environment, Physical Review E (2026). DOI: 10.1103/1mth-rs2j. On arXiv: arxiv.org/abs/2510.20060

Why do we get sleepy? How neurons control sleep drive

Why does staying awake inevitably make us sleepy? Researchers have identified neuronal populations in the brains of mice that become activated during prolonged wakefulness and are crucial for sleep drive. Their findings provide new insights into how the brain generates the need for sleep.
After a long day or a sleepless night, the urge to sleep becomes almost impossible to resist. This increasing sleep pressure, also known as sleep drive, ensures that prolonged wakefulness is followed by deeper and longer recovery sleep. As sleep is essential for survival, scientists have long been investigating how the brain keeps track of time spent awake and translates it into the need for sleep.
They now have identified specific neurons that are crucial for this balanced relationship between sleep and wakefulness. This is an important missing piece of the puzzle in understanding why we become sleepy.
To identify the brain regions involved, the researchers compared brain activation patterns in mice during normal sleep-wake cycles, sleep deprivation and recovery sleep. This highlighted specific brain areas that reflected time spent awake. Within one of these regions, they further identified two distinct neuronal populations that influence sleep drive: GABAergic and serotonergic neurons in the brainstem. The activation of both neuronal populations increased the longer the animals stayed awake and declined again after sleep onset.

The researchers next asked whether these neuronal populations merely reflect wakefulness or actively generate a compensatory response to sleep. When both populations were artificially activated, mice slept longer and more deeply, displaying a form of recovery sleep that normally follows prolonged wakefulness. In contrast, inhibiting these neurons strongly reduced sleep and allowed animals to maintain alert wakefulness.
These neurons do not simply signal that an animal has been awake. The experiments show that they are crucial to promote sleep, and that they may be key components of the neural circuitry that generates sleep drive. The findings therefore provide one of the clearest demonstrations to date that specific wake-active neurons increase the drive to sleep rather than merely responding to wakefulness.
Further experiments showed that long-term inhibition of the two neuronal populations substantially reduced the need for sleep, with mice sleeping approximately 70% less than usual. Unexpectedly, most of these animals did not exhibit some of the severe behavioural impairments that typically accompany sleep deprivation. In other words, these neurons appear to determine not only how much the animals sleep but also how strongly their need for sleep builds over time.
Understanding how the brain generates sleep drive would provide entirely new opportunities for sleep research.

William Joo et al, Wake-activated neuronal populations that regulate sleep drive., Nature (2026). DOI: 10.1038/s41586-026-10928-3

Is the laundry still damp, or just cold? Why your skin can't tell the difference

Humans lack dedicated wetness receptors; perceived wetness arises from integrated cold, friction, pressure, and contextual sensory signals. Cold dry laundry can mimic dampness because both activate cold receptors. Rubbing, squeezing, visual inspection, or warming fabric can improve discrimination.

original article.

A new transmissible cancer in bullhead catfish
Genomic analysis showed melanoma tumours in brown bullhead catfish are clonally related to each other rather than to their hosts, indicating a transmissible cancer, brown bullhead transmissible melanoma. Historical reports suggest similar lesions may be longstanding and widespread, but their relationship to this disease is unconfirmed.

transmissible cancer.

original article.

Why does salmonella cause serious illness in some people but not others?
Salmonella usually remains in the gut, but some strains can survive within immune cells and spread to the bloodstream, potentially causing sepsis. Severe invasive disease depends on bacterial type and strain, infectious dose, age, immune status and underlying conditions. Hospitalization data may overrepresent severe cases and cannot alone establish unusual strain virulence.

original article.

A smarter antibody could skip the fetus
Researchers have engineered a possible way around the risk some antibody drugs pose in pregnancy. These drugs, used against cancer, autoimmune disease and migraines, are hard to use safely in pregnancy because they are actively carried to the fetus via a receptor called FcRn. But the process has a quirk: mouse models and human tissue showed that the receptor binds to both IgG antibodies — which are used in the majority of approved antibody therapies — and albumin, but only shuttles the antibody across the placenta. By fusing therapeutic antibodies to albumin, the team made drugs that reached the fetus far less and reduced adverse events in mice.

https://www.science.org/doi/10.1126/sciimmunol.aee5151?utm_source=L...

https://www.genengnews.com/topics/drug-discovery/albumin-fused-anti...

Dark energy and quantum gravity may be deeply intertwined

For close to a century, physicists have pursued a way to unite gravity with quantum mechanics. Known as quantum gravity, this goal has remained frustratingly out of reach so far. Similarly elusive is the force of dark energy, which is believed to be driving the universe's accelerating expansion.
But through new research published in Physical Review D, physicists have proposed a new explanation suggesting that these two phenomena might not be separate at all. Instead, dark energy could be a natural side effect of quantum gravity, acting on the geometry of space itself.
Gravity and quantum mechanics shape the universe on vastly different scales: While quantum mechanics concerns the realm of subatomic particles, gravity shapes structures as large as galactic clusters and cosmic filaments.

Individually, both of these theories have been tested to extraordinary precision through decades of painstaking experiments. However, the extreme conditions where both should apply at once, such as inside a black hole, have remained far beyond what any experiment can reach.
In his study, physicists took a different approach: suggesting that we can't pin down both the size and expansion rate of the universe at the same time with perfect accuracy. This limitation is built into the fundamental uncertainty that governs the quantum world: When applied to the universe as a whole, it subtly changes the equations that describe how cosmic expansion should behave over time. This built-in uncertainty could then produce exactly the kind of accelerating expansion that cosmologists currently attribute to dark energy.

Depending on the exact mathematical details, this macroscopic imprint of quantum gravity could also replace the singularity at the instant of the Big Bang, which cosmologists have long struggled to explain. Rather than relying on a point of infinite density, their proposal suggests that the Big Bang followed a gentler rebound from a previously contracting universe.
If this idea is correct, it could provide a far cleaner explanation for the origins of dark energy. In contrast to many existing theories, this would mean that the phenomenon doesn't need to be explained by some hidden particle or exotic field waiting to be discovered: Instead, it is a property of space itself, hiding in plain sight in our observations of the universe.

Savvas M. Koushiappas, Cosmological uncertainty relation and late-universe acceleration, Physical Review D (2026). DOI: 10.1103/zgnd-h2xv. On arXiv: arxiv.org/abs/2604.27771

Simple mouth rinse may help detect stomach and colorectal cancer signals
It's widely understood that the microbiome—especially microbes found in the mouth and the gut—can have a profound effect on health. In a study published in the journal Cell Host & Microbe on Aug. 20, researchers report that by analyzing the makeup of oral microbes, they may be able to detect signals associated with gastric (stomach) and colorectal cancer. These findings could lead to the development of new, less invasive screening tests for gastrointestinal cancers.
Many species of microbes associated with the mouth are also present in the gut and may flourish there. These observations made the researchers

wonder whether oral microbes reach and persist in the gastrointestinal tract differently in people with cancer.
To conduct the study, the researchers recruited 507 volunteers to donate both oral and fecal samples, using a highly standardized collection process. The cohort included 129 healthy individuals; 215 people with metabolic disorders such as metabolic syndrome, hypertension, hyperlipidemia and type 2 diabetes; 77 people with gastric cancer; and 86 people with colorectal cancer. For the volunteers with cancer, samples were collected before the start of any treatment.

The team used gene sequencing to create what they called a mouth-to-feces (MF) index, which measures the extent to which identical microbial sequence variants are found in oral and fecal samples from the same person. They then evaluated how well the MF index could distinguish cancer patients from healthy individuals. The analysis revealed distinct signatures in people with gastric or colorectal cancer.

The findings were more nuanced than a simple cancer-versus-healthy comparison. The MF index was significantly elevated in patients with gastric or colorectal cancer but not in people with metabolic disorders. After accounting for alcohol consumption, regular exercise and BMI, the association remained robust for both gastric and colorectal cancers.
The team also compared the signatures found in the cancer patients with results from fecal occult blood tests, a standard colorectal cancer screening tool that analyzes stool samples. They found higher sensitivity with the oral samples, which were collected by a simple mouth rinse.

"It was notable that cancer-related information could be recovered from oral samples alone," say the researchers. Although only a small fraction of oral bacterial variants were also detected in the gut, models built using only these oral features could distinguish patients with cancer from healthy individuals across several independent cohorts.
In the longer term, combining microbial patterns with genetics, lifestyle and clinical outcomes may help explain why oral microbes persist more readily in some people than in others and may improve individualized risk prediction.

Mouth-to-gut microbial transmission signatures enable robust, non-invasive diagnosis of gastrointestinal cancers, Cell Host & Microbe (2026). DOI: 10.1016/j.chom.2026.07.007. www.cell.com/cell-host-microbe … 1931-3128(26)00308-2

Why immune responses to vaccines vary from person to person

Vaccines protect most people from serious illness, but the strength of that protection can vary considerably from one person to another. A new study helps us understand why.
Before a vaccine ever enters the body, the immune system may already hold clues to how strongly it will respond. In blood samples from more than 4,000 people, researchers measured antibodies against 185 antigens—targets recognized by the immune system, including those from common viruses and bacteria as well as targets associated with autoimmune diseases.

They then used artificial intelligence to analyze patterns in samples collected before and after COVID-19 vaccination, identifying antibody signatures that helped distinguish strong vaccine responders from weak ones.

The research opens a possible path toward more personalized vaccination strategies.
What this study found is that certain biomarkers, when analyzed with AI, can predict who is likely to respond well to a vaccine, even before they receive it. This suggests that some people may be more immune-ready than others.
Usually, scientists evaluate vaccine response after the shot by measuring whether the immune system produces antibodies against the target. Here, the researchers asked a different question: Could patterns already present in the blood predict the response before vaccination?

Age, sex, genetics, prior illnesses and underlying health conditions have all been linked to how strongly people respond to vaccines. People with immune-compromising conditions are often at higher risk of weaker responses. But even within these groups, outcomes can differ sharply.

The new approach is one of the first to use a broad, pre-vaccine antibody "fingerprint" to assess immune readiness. Unlike some prediction methods that rely on genetic analyses, this strategy uses antibody patterns in blood, which may be easier to adapt for clinical use.
Part 1

To test whether that antibody fingerprint could reveal vaccine readiness, the researchers analyzed antibody responses to 185 antigens. These included SARS-CoV-2, the virus that causes COVID-19, other common viruses and bacteria, and targets associated with autoimmune diseases.

The study included 8,687 samples from 4,089 participants, spanning healthy volunteers and people with conditions or treatments linked to immune suppression, such as HIV, multiple myeloma, solid organ malignancy, autoimmune disease, inflammatory bowel disease and solid organ transplantation.

The researchers found that several immunosuppressed groups were more likely to have blunted responses to COVID-19 vaccination. But those categories were imperfect predictors. Some immunosuppressed participants mounted strong responses, while about 5% to 6% of healthy participants had weak responses.
The study found that higher levels of certain preexisting antibodies, including antibodies to common microbes such as Staphylococcus aureus, RSV and human respirovirus 3, were associated with stronger COVID-19 vaccine responses.

The researchers describe these as "sentinel" antibodies because they may indicate a person's baseline immune readiness. They are not necessarily fighting the vaccine target directly. Instead, they may reflect how responsive the antibody-producing arm of the immune system is likely to be.

The researchers then asked whether the full antibody fingerprint, not just a few individual markers, could help identify people likely to have weak vaccine responses. Their deep-learning model analyzed patterns across the antibody panel, combining many measurements into a broader immune profile.

The study highlights a key strength of AI in health research: its ability to find subtle, predictive patterns in millions of biological data points that might otherwise remain hidden. The approach suggests that vaccine readiness may be better understood by looking at the immune system as a whole, rather than focusing only on a single disease or a single antibody.

The work also highlights the value of newer technologies that can measure large numbers of antibody responses at once. Instead of asking whether someone has antibodies to one pathogen, the method can scan a wider immune landscape, capturing patterns formed by many previous encounters with viruses, bacteria and other immune targets.
Sentinel antibody profiling could help guide vaccine testing, vaccine development and clinical care for people at risk of weak immune responses.

The approach might eventually help doctors identify patients who need additional vaccine doses, closer follow-up or alternative protective measures. It could also help researchers better understand why some people respond well to vaccination while others do not.

Pre-vaccine sentinel antibodies predict blunted vaccine responses, Cell Press Blue (2026). DOI: 10.1016/j.cpblue.2026.100088. www.cell.com/cell-press-blue/f … 3051-3839(26)00086-1

Part 2

Too much RNA can starve cells of energy, study finds

Why do you feel very weak after viral infections?

A new study by researchers has uncovered a previously unknown consequence of viral infection: Too much RNA inside a cell can disrupt its ability to produce energy.
Published in the journal Proceedings of the National Academy of Sciences, the study found that when excess RNA builds up inside cells during poxvirus infection, it can impair mitochondria—the structures responsible for generating most of a cell's energy—reducing the cell's ability to function normally.

The discovery could have broad implications for understanding viral infections, age-related diseases and RNA-based therapeutics, including mRNA vaccines, because excess RNA can accumulate in each of these conditions.
Scientists have long known that RNA degradation helps control protein production and remove defective RNA. This new study reveals another important role: It helps cells maintain the energy they need to function properly.
The findings suggest that RNA degradation serves a broader purpose than scientists once realized. In addition to controlling protein production, supporting RNA quality control and helping cells regulate immune responses, it also helps protect the cell's ability to generate energy.

RNA exists in many forms. Messenger RNA (mRNA) carries the genetic instructions cells use to make proteins, which help cells perform their normal functions. Another form, double-stranded RNA (dsRNA), is commonly produced during viral infections and alerts the immune system that something is wrong.

During viral infection, viruses can produce large amounts of RNA. If cells cannot break down the excess RNA quickly enough, the buildup can damage mitochondria and reduce the cell's ability to generate energy.

While scientists already knew that excess dsRNA can trigger immune responses and that cells need to control dsRNA levels, the effects of mRNA came as a surprise.

mRNA is a normal component of our cells, but it seems like with many good things, if we get too much, that can become a problem for the cell. When too much RNA builds up, including mRNA, it can damage the mitochondria and interfere with the cell's ability to produce energy.
Viruses rely entirely on host cells for energy and protein production, but producing too much viral RNA can overwhelm the very cells viruses depend on to survive.
poxviruses—the family of viruses that includes smallpox and mpox—appear to use RNA cleanup systems to degrade RNAs and keep infected cells functioning long enough for the virus to continue replicating.

If the cell is not healthy, the virus would not replicate well. The virus needs to keep RNA levels balanced inside the cell.
The team also found that mitochondrial impairment occurred before major immune responses were activated and did not depend on the immune system's usual response to infection, further supporting the idea that RNA itself contributes to the damage.
Researchers think the negatively charged RNA may accumulate around mitochondria and disrupt the electrical balance needed for energy production, although how it happens is unknown.
Part 1

The findings may also have implications beyond viral infections.

Researchers have observed RNA accumulation in a variety of conditions—including some cancers, neurodegenerative diseases and age-related disorders—suggesting that mitochondrial damage may be one way excess RNA contributes to those conditions.

Perturbation of RNA homeostasis impairs mitochondrial respiration during poxvirus infection through excess RNA accumulation, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.26051941

Part 2

Gray and white matter jointly shape cognitive aging, new evidence shows

Researchers have found that two distinct types of brain tissue work together to support cognition in older adults and that the health of the brain's short-range wiring may help soften the cognitive effects of gray matter loss.
The study, published in Alzheimer's & Dementia: The Journal of the Alzheimer's Association, analyzed brain scans and cognitive assessments from 459 community-dwelling adults 60 and older across India.

It is among the first studies to examine the brain's superficial white matter in a community-based population from a low- and middle-income country.

Superficial white matter is a thin layer of nerve fibers immediately beneath the brain's outer gray matter. These short, curved fibers act like local roads, carrying signals between nearby areas of the cerebral cortex. Gray matter, by comparison, contains many of the brain cells that process information.

Gray matter and superficial white matter are physically close and may play different roles: gray matter processes information, while superficial white matter helps nearby brain regions communicate.
These new findings suggest that cognitive health depends not only on how much gray matter is preserved, but also on the condition of the wiring that connects it.
The researchers used an advanced form of diffusion MRI, which measures how water moves through brain tissue, to assess microscopic features of superficial white matter. They focused on measures that reflect neurite density, the small projections that allow nerve cells to send and receive signals, and the amount of freely moving water around them. Lower neurite density or more free water can indicate tissue disruption associated with processes such as loss of myelin, inflammation or swelling.
Participants also completed tests of language, memory, executive function and visuospatial ability. The team found that healthier superficial white matter was most consistently associated with stronger language skills. The clearest links appeared in frontotemporal areas involved in recognizing words, speaking fluently and holding language information in mind.

Gray matter atrophy measures remained the strongest overall predictors of cognition. However, the relationship between gray matter and cognitive performance depended in part on superficial white matter: When this local wiring showed poorer integrity, gray matter loss was more strongly tied to worse language performance and cognitive impairment. When superficial white matter was healthier, those associations were weaker.

The findings point to superficial white matter as a possible source of resilience.
Two people with a similar degree of gray matter loss may not experience the same cognitive effects if the local connections surrounding that gray matter differ in health. Following participants over time will be essential to test whether preserving these connections can help maintain cognition.

Yingxu Liu et al, Superficial white matter and gray matter jointly support cognition among older adults in India, Alzheimer's & Dementia (2026). DOI: 10.1002/alz.71697

Dehydration can cause more than thirst: Expert explains how it can affect the heart
Dehydration reduces circulating blood volume, increasing cardiac workload and triggering faster heart rate and blood-vessel constriction. Severe dehydration can impair organ blood flow, causing dizziness, palpitations, chest discomfort, fainting, or heatstroke. Older adults, children, people with heart disease, and those using fluid-altering medications are at increased risk.
Think of the heart as a pump. For it to work properly, enough blood needs to return to it with every heartbeat.
When you become dehydrated, the amount of fluid circulating in your bloodstream decreases. That means less blood returns to the heart, so it has to work harder to keep blood moving throughout your body."

Your body has several built-in ways to respond to dehydration. Blood vessels narrow to help maintain blood pressure, and your heart beats faster to keep blood moving. If dehydration becomes more severe, those usual responses can begin to fail. As a result, organs such as the brain, kidneys, liver and digestive system may not receive enough blood to function properly.
As dehydration worsens, symptoms can include:

Racing heartbeat or palpitations
Fatigue
Lightheadedness
Dizziness
Vision changes
Shortness of breath
Chest discomfort
If dehydration becomes severe, it can lead to heatstroke or fainting. These are medical emergencies and should be evaluated by a health care professional immediately.
Anyone can become dehydrated, but some people are at greater risk, including:

Older adults
Children
Athletes
Outdoor workers
People with heart disease
People taking certain medications, such as diuretics or GLP-1 receptor agonists
"People with heart failure or other forms of heart disease should be especially careful.
Part 1

Staying hydrated and preventing complications
There isn't a one-size-fits-all recommendation for how much water you need. For most healthy people, thirst is a reliable guide. If you feel thirsty, drink something. If you know you'll be spending time outdoors in the heat or exercising for an extended period, increase your fluid intake beforehand.

Dehydration isn't always easy to recognize, so it helps to look for other signs. Dry mouth, dry skin, dark urine, foamy urine or a burning sensation when you urinate may all indicate you need more fluids. One of the simplest ways to monitor your hydration is to pay attention to the color of your urine. Pale or clear urine generally suggests you're well hydrated, while darker urine may be a sign that you need more fluids.

Water is an excellent first choice for staying hydrated, but if you're truly dehydrated, water alone may not always be enough. Your blood contains electrolytes such as sodium, potassium and magnesium. Drinking water along with consuming something salty may help replace both fluids and electrolytes. People participating in prolonged exercise or endurance activities also may benefit from electrolyte-containing sports drinks.
Alcohol is a major contributor to dehydration because it changes how the brain and kidneys regulate fluids and can increase fluid loss. Highly caffeinated drinks also can contribute to dehydration. If you're trying to rehydrate, choose water or electrolyte-containing drinks instead of sugary drinks or soda.

The best way to prevent dehydration is to stay ahead of it. Make drinking fluids a regular part of your day. Drinking smaller amounts throughout the day is often more effective than consuming a large amount all at once.
If you'll be gardening, exercising or working outdoors in hot, humid weather, plan ahead, stay aware of how you're feeling and adjust your activities if needed."

Most importantly, know your personal risk. If you're older, have heart disease or take medications that affect your body's fluid balance, you may need to pay especially close attention to staying hydrated. Planning ahead, listening to your body and recognizing the signs of dehydration can help protect your heart and your overall health.

Part 2

Cabin crew at greater risk of radiation‑based cancer than nuclear technologists, new study suggests
Analysis of 12.7 million death records linked pilots and cabin crew with the highest proportions of deaths from selected radiation-associated cancers (6.7% and 6.9%). Repeated cosmic-radiation exposure at flight altitude may contribute, but individual flight histories and doses were unavailable, so causation cannot be established.

original article.

How the brain distinguishes the consequences of our own choices from events beyond our control

A new study has identified the brain mechanisms that help us work out whether the consequences we experience are caused by our own actions or by circumstances beyond our control.
The study, published in Neuron, found that both confidence in our own decisions and estimates of external circumstances provide important clues. When people were confident in a decision but received an unexpected negative outcome, they were more likely to attribute it to external circumstances. On the other hand, when they were less certain about their decision, they were more likely to consider their own performance as the cause.
At the same time, they used these experiences to continually update their estimate of how much control they generally had over the external circumstances.
Participants made these conclusions partly because they tracked how certain they were about their own performance throughout the assessment, even before they obtained any feedback.
Using ultra-high-field brain imaging and targeted noninvasive brain stimulation, the researchers identified two prefrontal-subcortical brain circuits involved in this process. The findings provide new insight into how our sense of control is formed and how it subsequently shapes learning from success and failure.
Using an ultra-high-resolution functional MRI scanner in 22 participants, the researchers traced this process to a circuit connecting the dorsomedial prefrontal cortex (dmPFC) with the dorsal raphe nucleus, a small structure deep in the brain. Activity in the dmPFC tracked participants' confidence, their estimate of how much control they had, and whether they attributed an outcome to their own performance or to randomness.

A second circuit, connecting another region of the prefrontal cortex with dopamine-associated regions of the midbrain, was linked to how these judgments influenced the brain's response to feedback.
The findings could ultimately help researchers better understand why people's perceptions of control can sometimes become distorted. Altered perceptions of control and causal attribution have been associated with conditions including depression, anxiety and schizophrenia, although the researchers stress that the present study investigated healthy adults and was not designed to test clinical interventions.

Two prefrontal-subcortical circuits estimate controllability and reflect its impact on learning, Neuron (2026). DOI: 10.1016/j.neuron.2026.07.029. www.cell.com/neuron/fulltext/S0896-6273(26)00584-2

Why memories get fuzzier with age

New Research shows how our memories change with age and why specific details associated with past events can fade over time. The new study reveals that as people age, they not only remember fewer details from their past—but also struggle more when switching between different types of memories.
The work is published in the journal Psychology and Aging. It points to a shift in how we remember things as we age—where vivid, moment-specific recollections gradually give way to broader, more generalized knowledge.

Rather than portraying memory decline as a simple loss, the study offers a nuanced picture of aging cognition and sheds light on how memory evolves over a lifetime. The team hopes its findings could help guide new approaches to support healthy cognitive aging.

As we get older, our memories tend to become less detailed and more general, focusing on the overall story rather than specific moments.
This shift is linked to changes in how the brain recalls information, meaning older people often remember the big picture but with fewer vivid details.
Researchers found that across all age groups, memory performance declined when participants had to switch between memory types.

However, older adults were particularly affected in one area—they were less accurate at recalling more mundane repetitive memories like commuting to work under switching conditions.

Interestingly, their ability to recall specific memories like a birthday party was less affected by the task-switching challenge.

This suggests that certain types of memory retrieval may be more vulnerable to the effects of aging when multitasking or adapting to changing demands.
The most striking findings came from analyzing the content of the memories themselves.

When recalling specific events, older adults' narratives contained fewer details such as sights, sounds and emotions tied to a moment.

However, they remembered more semantic details—general knowledge or interpretations of the event. A similar pattern was observed when participants in the study were asked to recall categoric memories.
The findings highlight that changes in memory are not simply about forgetting, but about how memories are accessed and expressed.

When older adults recall events, the richness of those memories may be reduced.

This shift may reflect changes in underlying brain systems involved in memory, particularly those responsible for retrieving detailed contextual information and managing complex cognitive tasks.
This has practical implications for everyday life. Tasks that require people to quickly adapt their thinking or switch between different kinds of recall—such as storytelling, decision-making or problem-solving—may become more challenging with age.
At the same time, the increased reliance on semantic knowledge may have benefits. Generalized memories can support wisdom, pattern recognition and efficient communication, even if the finer details are lost.

Greta Melega et al, Age-related differences in autobiographical memory recall: Impact of retrieval mode switching., Psychology and Aging (2026). DOI: 10.1037/pag0001009

Some city trees have an ozone downside
Some of the species of trees planted in urban areas — species that are often chosen for their quick growth and climate resilience — have an unfortunate downside: they emit high levels of volatile organic compounds (VOCs) that contribute to ozone pollution. VOCs react with nitrogen oxides (NOx) to create ozone, which can cause breathing difficulties. A study in Beijing found that vegetation accounted for about 10% of the total VOC emissions during a period in 2021. Reducing NOx emissions, which mostly come from vehicles and industry, would help keep ozone in check.

https://www.science.org/doi/10.1126/sciadv.aee5583

These trees are making air quality in cities worse

The people who research their own disease
Molecular biologist Francesca Granata studies a rare condition called porphyria that can cause burning or itching skin — a path she chose after her own diagnosis in 2008. She and other researchers who study their own rare diseases told Nature that their personal experience with an illness enables them to empathize with other patients, driving them to find better therapies for themselves and others. There is potential bias in studying their own disease, but contributing to an increased understanding of their condition can be deeply fulfilling, they say.

https://www.nature.com/articles/d41586-026-02455-y?utm_source=Live+...

When you eat may matter as much as what you eat for longevity and heart health

What we eat plays a vital role in maintaining a healthy lifestyle. A well-balanced meal rich in essential micronutrients not only fuels the body but may also help protect against metabolic and cardiovascular diseases. There is another question worth asking: Does when we eat matter just as much as what we eat?
We have a decent understanding of the circadian rhythm—the body's internal clock, synced to the 24-hour cycle, that regulates not just sleep but essential biological functions, from hormone release to cellular repair. Scientists are now digging deeper into its links with food in a field of research called chrononutrition—the study of how meal timing interacts with our body's circadian rhythms to influence health, metabolism and weight regulation.
researchers have found that skipping breakfast or eating late could disrupt our internal body clocks and harm metabolic health.

A recent study explored this question in greater depth by examining whether meal timing and the length of our daily eating window are associated with mortality risk and life expectancy among U.S. adults.

Data tracking more than 30,000 adults age 40 and older revealed that when we eat our first and last meals may be linked to our risk of death and overall life expectancy. Starting the day with a later first meal was associated with a progressively higher risk of death from any cause and cardiovascular disease. People whose first meal was after noon had a 29% higher risk of death from any cause compared with those who ate their first meal between 7 and 8 a.m.

For the last meal, the lowest risk was observed around 7–8 p.m., and the highest risk was observed among those who ate past midnight.
Using a first meal between 7 and 8 a.m. as the ideal baseline, the researchers found that having that first meal between 8 and 10 a.m. was linked to a 10% higher risk of death from any cause. Waiting until 10 a.m. to noon, that risk climbed to 19%, while stroke-related deaths nearly doubled, rising 59%. Skipping breakfast altogether and waiting until after noon, overall death risk rose to 29%, with heart disease deaths jumping to 43%.

When it came to dinner, eating too early or too late came with a cost. Eating before 7 p.m. was tied to a 13% higher risk of death, while eating too late, past midnight, proved far more dangerous, driving overall mortality up by 27% and heart disease deaths up by 51%. The sweet spot was between 7 and 8 p.m.
The researchers say that while the results point to potential links among meal timing, mortality and life expectancy, this was an observational study, so it cannot prove that meal timing causes earlier death.

Wen Hu et al, Meal timing and eating window with all-cause and cardiovascular mortality and life expectancy: population-based cohort study, European Journal of Clinical Nutrition (2026). DOI: 10.1038/s41430-026-01796-1

Getting pregnant while already pregnant is an extremely rare phenomenon known as superfetation. It happens when a second egg is released, fertilized, and implants in the uterus weeks after an initial pregnancy has already begun, resulting in two fetuses with different gestational ages.
How It Normally Blocked
Your body has strong natural barriers to prevent this:
No Ovulation: Pregnancy hormones like progesterone stop your ovaries from releasing more eggs.
Cervical Plug: Thick mucus blocks sperm from entering the uterus.
Uterine Lining Changes: The lining changes so a new embryo cannot implant.
Why It Is So Rare
For superfetation to happen, all natural body blocks must fail at the same time.
Only a tiny number of natural cases are documented worldwide.
Most reported cases involve fertility treatments or assisted reproductive technology.
However, some people of science that different fetal sizes on early scans are usually just fraternal twins or normal growth variations rather than true superfetation.

Hidden Pulses Within Your Brain May Hold Your Thoughts Together
When you recognize a familiar face, your brain must connect that face with a name, a place, and perhaps a memory.

Those pieces of information are not necessarily handled in the same part of the brain. Yet they come together so smoothly that you experience them as a single thought.

Scientists may now have found one way the brain pulls off this trick.

A new study suggests that distant parts of the brain briefly fall into the same rhythm when we hold and retrieve information. During these fleeting moments, their cells become more likely to send signals together, potentially allowing separate pieces of a thought to be joined.

Researchers were especially interested in extremely brief bursts of electrical activity called ripples. A ripple is a very brief burst of rhythmic oscillations in neuron excitability – roughly 90 cycles per second, lasting only about a tenth of a second.
Part 1

A 4-star system caught eclipsing itself in a way never seen before
Astronomers have found a four-star system doing something that has never been confirmed before. The system, TIC 433545934, has two close pairs of stars orbiting each other. While each pair eclipses its own two stars, as usual, only one pair eclipses the other. A paper outlining the properties of this unique system was submitted to the arXiv preprint server on Aug. 13. It has been accepted for publication in the journal Astronomy & Astrophysics.

Tamás Borkovits et al, TIC 433545934: The first 2+2 type doubly eclipsing binary with extra, mutual eclipses, arXiv (2026). DOI: 10.48550/arxiv.2608.13034

How space rocks become meteorites

What happens to a space rock as it falls through Earth's atmosphere and becomes a meteorite? By studying 75 meteorite falls captured on video and in photographs, researchers identified seven distinct phases in the journey from space rock to meteorite. Their findings show that melting and fragmentation, rather than simply evaporation and "burning up," control how a rock loses mass, slows down and ultimately reaches the ground.
Phase 1 starts high in the atmosphere, when the air is dense enough to create a shock wave in front of the falling rock. Collisions with air molecules heat the rock and the gas around it until they glow. This is what we see as a meteor or "shooting star."

As the rock falls into thicker air, Phase 2 begins and the meteor gets brighter. Some meteors show that the rock is spinning rapidly by changing brightness in a regular pattern. The fastest-spinning rocks in the study made a full turn every 0.5 to 5 seconds.

In Phase 3, the meteor gets much brighter and turns into a fireball. The researchers found that melting now causes most of the rock's mass loss. The fast-moving air pulls melted material off the surface, leaving droplets behind that keep evaporating.
At around 60 kilometers (around 40 miles) above Earth, the fireball reaches Phase 4 by settling into a melting equilibrium. Its brightness stays the same or grows at a steady pace. The rock ultimately can lose up to 40% of its mass just from melting.
Deeper in the atmosphere, higher pressure makes the rock break apart, starting Phase 5. The fireball may flare up several times as pieces break off.

The researchers discovered that rocks start to break apart when the air pressure in front of the rock is only about one-fifth of the strength measured in meteorites found on Earth. They think that heat and cracks from earlier collisions in space can explain why the rocks break earlier than expected.

Only at this time does the remaining rock quickly become smaller and slow down significantly, more rapidly if the rock breaks aggressively.
If the back of the main rock stays whole, it creates a low-pressure area behind it that pulls smaller pieces along.
When the back of the rock finally breaks apart in Phase 6, the fireball gives off a last bright flare and sends pieces flying out faster. Since the rock has already slowed down, these late flares are usually red instead of the bright green seen earlier.

That final disruption sends fragments flying at higher relative speeds.
In Phase 7, melting and fragmentation keep happening until the last pieces slow down enough to stop glowing. Melting ends, leaving a thin fusion crust on their surfaces. Winds can then blow the darkened fragments off course as they finish falling to the ground as meteorites.
The 75 investigated meteorite falls included several different meteorite types. The study identified the altitudes at which these different materials went through the seven phases.

By studying the atmospheric slowdown of small, solid space rocks of different types, researchers also gained insight into what happens to more dangerous airbursting asteroids the size of cars to city blocks.

Asteroids up to tens of meters in size are also solid rocks because they tend to spin faster than do the larger rubble-pile asteroids.

Peter Jenniskens et al, Bolide Light Curve Systematics from 75 Recovered Meteorites, Meteoritics & Planetary Science (2026). DOI: 10.1111/maps.70203

How chromosomes find their partners

For a long time, so-called satellite DNA was considered largely worthless. Now, researchers have shown in fruit flies that these repetitive sections of genetic material act as a kind of barcode, enabling the correct chromosomes to recognize one another.
The body cells of humans and animals contain a double set of chromosomes. One-half of the genetic material comes from the mother; the other stems from the father.

During the formation of sperm or egg cells, this double set of chromosomes must be halved to form a single set. This takes place during what is known as meiosis. In this process, a cell with a double set of chromosomes gives rise to daughter cells with a single set of chromosomes. This halving is necessary because, during fertilization, two germ cells—and thus their genetic material—fuse together.

Afterwards, there is once again a double set of chromosomes. If this did not happen, the number of chromosomes would double from one generation to the next as the germ cells fuse.

To ensure that chromosomes can be distributed evenly during meiosis, the maternal and paternal versions of the same chromosome must locate one another within a cell and temporarily pair up. This is no easy task amid the vast jumble of the cell nucleus. Mismatches must be avoided at all costs during the pairing phase to prevent chromosomes from being distributed incorrectly.
But how do the matching chromosome pairs actually find each other?
Researchers have now investigated—using the example of egg cell formation in female fruit flies (Drosophila)—how this "matchmaking" process takes place in the cell nucleus and have made a surprising discovery.
For a long time, scientists have known that large swaths of animal genomes consist of repetitive DNA sequences. Known as satellite DNA, experts regarded these repeats as useless "junk DNA" because they do not contain blueprints for proteins. Nor were other researchers able to attribute any role to satellite DNA during meiosis. Indeed, when they removed these satellite DNA repeats from just one chromosome, chromosome pairing still proceeded without error.

In Nature Communications, researchers demonstrate that unique satellite DNA patterns on each pair of chromosomes, comparable to a barcode on a product in a supermarket, help matching chromosomes find each other.
Part 1

The researchers argue that it is not enough to simply remove satellite DNA from just one chromosome. With only one "barcode" disrupted, all the other chromosome pairs with intact satellite DNA "barcodes" can find each other. Ultimately, only the pair of chromosomes from which the researchers removed the barcode remains. They find each other like the last two face-down cards in a game of Memory.

Therefore, the ETH researchers removed the satellite DNA barcode from two different chromosomes, leaving the two pairs without any guidance.

And indeed, without their barcode, partner selection went awry and failed, meaning that the chromosomes frequently docked with the wrong partners. "This showed us that satellite DNA functions as a recognition aid and ensures that the chromosomes that belong together can reliably find one another.
Simply recognizing each other, however, is not enough. The researchers went on to discover that chromosome pairing also requires a molecular "glue" to properly "marry" the two partners together. A protein called D1 plays this role. It recognizes the matching barcodes on the chromosomes that belong together, binds them and holds the two together.

However, if the recognition pattern on one of the two chromosomes is altered—for example, if part of the barcode is deleted or changes occur due to natural mutations—the D1 protein can bond two chromosomes together that do not belong together. The pairing then goes wrong.
The new findings also explain how new species arise. Satellite DNA changes a great deal more rapidly than the rest of the genome. As long as individuals of a species produce offspring with one another, the satellite DNA barcodes remain similar across the population. because of the constant mixing of genetic material. Individuals with recognition patterns that differ too greatly suffer from meiosis defects and are unable to reproduce.

However, if a population of an animal species becomes geographically isolated—for example, because of the formation of a mountain range over millions of years—the satellite DNA in both groups evolves independently. When the two groups meet again after a long period, the recognition patterns of the chromosomes no longer match. The result: The animals can no longer reproduce, and one species has become two.

Studies on crosses between Drosophila melanogaster and its relative Drosophila simulans are consistent with this idea. The two species diverged two to three million years ago. The barcodes of their chromosomes now differ so greatly that massive chromosome-pairing defects occur during meiosis in hybrids.

Lena Skrutl et al, Meiotic pairing through barcode-like satellite DNA repeats, Nature Communications (2026). DOI: 10.1038/s41467-026-74398-x

Part 2

Antarctic bacteria share 'life‑support' genes to survive extreme conditions

Antarctic soil microbes extensively exchange genes via horizontal transfer; evidence occurred in ~98% of 676 analyzed species. Frequently transferred genes support aerotrophy, enabling energy generation from atmospheric hydrogen and carbon monoxide. Selection retains beneficial genes, supporting survival in cold, dry, nutrient-poor soils.

original article.