For decades, memory research focused on two brain regions: the hippocampus, home of short-term memory, and the cortex, which was thought to house long-term memories. The latter, scientists imagined, lie gated behind biological on-and-off switches.

Existing models of memory in the brain involved transistor-like memory molecules that act as on/off switches

In other words, in this model, if a short-term memory was tagged for long-term storage, it would remain so indefinitely. But, even as investigations in this vein led to numerous insights, researchers understood that this model was ultimately too simple—for instance, it didn't account for why some long-term memories last weeks while others last a lifetime.

Then, in 2023, the same researchers published a paper that identified a brain pathway that links short- and long-term memories. An important component of which is a region in the center of the brain called the thalamus, which not only helps select which memories should be remembered, but routes them to the cortex for long-term stabilization.

The findings set the stage for tackling some of the most fundamental questions in the field of memory research: What happens to memories beyond short-term storage in the hippocampus—and what molecular mechanisms are behind the sorting process that promotes important memories to the cortex and demotes unimportant ones to be forgotten?

To answer these questions, the team developed a behavioral model using a virtual reality system where mice formed specific memories.

The results suggest that long-term memory is not maintained by a single molecular on/off switch, but by a cascade of gene-regulating programs that unfold over time and across brain regions like a series of molecular timers.

Initial timers turn on quickly and fade just as fast, allowing for rapid forgetting; later timers act more slowly but create more durable memories. This stepwise process allows the brain to promote important experiences for long-term storage, while others fade.

In this study, the researchers used repetition as a proxy for importance, comparing memories of frequently repeated contexts to those encountered less often. The team identified three transcriptional regulators: Camta1 and Tcf4 in the thalamus, and Ash1l in the anterior cingulate cortex, which are not necessary for initially forming memories, but are crucial for maintaining them. Disrupting Camta1 and Tcf4 impaired functional connections between the thalamus and cortex, leading to memory loss.

The model suggests that, after the basic memory is formed in the hippocampus, Camta1 and its targets ensure the initial persistence of the memory. With time, Tc4 and its targets are activated, providing cell adhesion and structural support to further maintain the memory. Finally, Ash1l recruits chromatin remodeling programs that make the memory more persistent.

Unless you promote memories onto these timers, the researchers think you're primed to forget it quickly.

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Interestingly, Ash1l belongs to a family of proteins called histone methyltransferases that retain memory in other biological systems as well. "In the immune system, these molecules help the body remember past infections; during development, those same molecules help cells remember that they've become a neuron or muscle and maintain that identity long-term. The brain may be repurposing these ubiquitous forms of cellular memory to support cognitive memories.

The findings may have implications for memory-related diseases.

By identifying the gene programs that preserve memory, researchers may eventually find ways to route memory through alternate circuits and around damaged parts of the brain in conditions such as Alzheimer's.

If we know the second and third areas that are important for memory consolidation, and we have neurons dying in the first area, perhaps we can bypass the damaged region and let healthy parts of the brain take over.

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Schizophrenia-spectrum disorders are linked to early structural damage in specific brain regions, particularly the temporal, cingulate, and insular lobes, with reduced morphological similarity indicating network disconnection. These changes are more pronounced in severe cases and correlate with altered neurobiology, including increased astrocytes, neurotransmitters, and reduced metabolism.

Natalia García-San-Martín et al, Reduced brain structural similarity is associated with maturation, neurobiological features, and clinical status in schizophrenia, Nature Communications (2025). DOI: 10.1038/s41467-025-63792-6

Mini-fridges on a nanoscale? New cooling technique could make computer chips more powerful

A new ion-based cooling method uses voltage-controlled nanopores in semiconductor membranes to drive selective ion flow, enabling localized heating or cooling at the nanoscale. This approach achieves temperature drops over 2 K and is compatible with current chip fabrication, offering improved thermal management and reduced environmental impact for advanced semiconductor devices.

Makusu Tsutsui et al, Gate-Tunable Ionothermoelectric Cooling in a Solid-State Nanopore, ACS Nano (2025). DOI: 10.1021/acsnano.5c13339

Persistent environmental toxins already accumulate in animal tissues during the fetal stage, research finds

Flashy feathers may put some male pheasant species' lives at risk

The male Lady Amherst's pheasant knows how to put on a show when it comes to attracting mates. As well as elaborate courtship displays, they will unfurl their golden feathers to form a cape around their neck, which can prove irresistible to some females of the species. 

However, according to new research published in the journal Biology Letters, this spectacular ornamentation comes at a potentially life-threatening cost. It can severely restrict their field of vision, making them more vulnerable to predators.

As with most animals, vision is critical for birds, helping them forage for food, spot lurking predators, and keep an eye on rivals. For years, scientists understood that a bird's vision was largely shaped by its ecology (where it lives, what it eats, and how it forages) rather than its gender. But this research is the first to show that male and female birds see the world differently.

The study authors used a technique called ophthalmoscopic reflex to map the bird's visual field. This involves shining a light into a bird's eye and mapping where the reflection disappears, which marks the edge of its field of vision.

The team studied four captive Lady Amherst's pheasants and three golden pheasants (males of this species also have a colorful cape of feathers).

They found that males have a 30 to 40-degree smaller vertical range of binocular vision, which means they can't see as well above and in front of their heads. The researchers also discovered that males have a blind spot that is much larger than females, measuring over 114 square centimeters compared to about 21 square centimeters. The blind spot behind their head was also wider than that of females by about 10 degrees.

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To confirm feathers were the cause, the scientists also studied two related pheasant species that lack elaborate head plumage. In these birds, male and female fields of vision were identical. 

According to the researchers, the enlarged blind area of the Lady Amherst's and golden pheasant males leaves them more vulnerable to predation than females. This visual cost is the latest example of the handicap principle, an evolutionary idea that suggests that if a male can survive despite carrying a feature that puts it at a disadvantage, it must have superior genes.

"The reduced visual field in males compared to females in these pheasants, as a result of feather ornamentation, could be viewed as a relative handicap," wrote the researchers in their paper.

Alexandra E. R. Lamond et al, The visual impediment of cranial ornamentation in male Chrysolophuspheasants, Biology Letters (2025). DOI: 10.1098/rsbl.2025.0405

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Why watching someone get hurt on screen makes you wince: How the brain triggers echoes of touch sensation

Many people say that seeing bodily injury on film makes them flinch, as if they "feel" it themselves. It is as if the sting leaps straight off the screen and into your skin. 

But explaining why and how this happens has puzzled scientists for a long time. Now, scientists have uncovered a major clue as to why. Parts of the brain originally thought to only process vision are also organized according to a "map" of the body, allowing what we see to trigger echoes of touch sensations. 

The study, published recently (Wednesday, 26 November), in the journal Nature, shows that watching movies can activate touch-processing regions of your own brain in a highly organized way. In short, your brain doesn't just watch, it simulates what it sees. 

When you watch someone being tickled or getting hurt, areas of the brain that process touch light up in patterns that match the body part involved. Your brain maps what you see onto your own body, 'simulating' a touch sensation even though nothing physical happened to you.

This cross-talk works in the other direction too. For example, when you navigate to the bathroom in the dark, touch sensations help your visual system create an internal map of where things are, even with minimal visual input. This 'filling in' reflects our different senses cooperating to generate a coherent picture of the world.

Nicholas Hedger, Vicarious body maps bridge vision and touch in the human brain, Nature (2025). DOI: 10.1038/s41586-025-09796-0. www.nature.com/articles/s41586-025-09796-0

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To show how it is possible that our sense of touch is activated purely by visual information, the researchers developed novel methods to analyze brain activity in 174 people while they watched films such as "The Social Network" and "Inception."Surprisingly, brain regions traditionally considered to process purely visual information showed patterns that reflected sensations on the viewer's own body, not just what appeared on screen. These visual regions contained "maps" of the body similar to those usually found in touch-processing areas of the brain. In other words, the "machinery" the brain uses to process touch is "baked in" to our visual system.The study found two ways these body maps line up with visual information. In dorsal (higher up) regions of the visual system, body maps match where things appear in our field of view: Parts of the brain tuned to feet sensations were also tuned to lower parts of the visual scene, while parts tuned to face sensations were also tuned to upper parts of the visual scene. In ventral (lower down) regions, the body maps match what body part someone is looking at, regardless of where it appears in the visual scene. Put simply, our visual system is intimately connected to our sense of touch, mapping what we observe onto the coordinates of our body.The researchers are particularly excited by the clinical applications of this research. Dr. Hedger said, "This discovery could transform how we understand conditions like autism."Many theories suggest that internally simulating what we see helps us understand other people's experiences, and these processes may work differently in autistic people. Traditional sensory tests are exhausting, especially for children or people with clinical conditions. We can now measure these brain mechanisms while someone simply watches a film, opening up new possibilities for research and diagnosis."

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Virus battles drug-resistant infections

Jumbo bacteriophages, viruses that infect bacteria, possess unique shielded compartments protecting their genetic material and can evade bacterial immune defenses. Advances in imaging have revealed these features, suggesting that engineered jumbo phages could offer effective therapies against drug-resistant bacterial infections, addressing a growing global health threat.

Thomas G. Laughlin et al, Architecture and self-assembly of the jumbo bacteriophage nuclear shell, Nature (2022). DOI: 10.1038/s41586-022-05013-4

Scientists recruit bed bugs as crime scene sleuths

Tropical bed bugs can retain human DNA for up to 45 days after feeding, enabling recovery of phenotypic traits such as gender, eye, hair, and skin color using STR and SNP markers. Their limited mobility and tendency to remain hidden make them valuable forensic tools at crime scenes, though their usefulness is restricted to recent events within a 45-day window.

Reprogrammed Human Stomach Organoids Secrete Insulin

Transplanting human gastric organoids engineered to release insulin in diabetic mice reduced hyperglycemia, offering a therapeutic avenue for type 1 diabetes.

An estimated 9.5 million people all over the world live with type 1 diabetes, wherein the beta cells in their pancreas cannot produce enough insulin to keep blood glucose in check. In the long run, elevated glucose can damage organs such as the kidneys, heart, and eyes. Over the past few decades, scientists have been studying how to generate functional insulin-secreting cells which could be transplanted into patients.

Now, researchers engineered human stomach organoids to secrete insulin. Transplanting these into diabetic mice reduced hyperglycemia. Their findings, published today in Stem Cell Reports, could help develop technologies to engineer a person’s own insulin-secreting cells for diabetes treatment.

Lu J, et al. Modeling in vivo induction of gastric insulin-secreting cells using.... Stem Cell Rep. 2025. 

Switching immune cells to 'night mode' could limit damage after a heart attack

Treating mice with a drug that inhabits the neutrophil clock reduced the amount of myocardial tissue damage after a heart attack and helped to preserve heart function over the following days and weeks.

The drug, known as ATI2341, targets a receptor protein on the surface of neutrophils and switches the cells into a less active mode usually only seen at night.

In their active, daytime mode, neutrophils accumulate around the edge of the initial wound caused by a heart attack, where they are poised to damage neighboring healthy cardiac tissue and extend the size of the injury. In night mode, however, neutrophils accumulate in the center of the initial wound, well away from the surrounding, healthy tissue.

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ATI2341 also protected mice from several other types of neutrophil-induced tissue damage but, crucially, did not impair the animals' ability to fend off bacterial and fungal infections.

Aroca-Crevillén et al. A circadian checkpoint relocates neutrophils to minimize injury, Journal of Experimental Medicine (2025). DOI: 10.1084/jem.20250240

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'Self-activation' is part of the success strategy of parasitic weeds 

Certain parasitic weeds can autonomously activate their feeding organs (haustoria) before encountering a host by producing and releasing specific substances from their seeds. This early self-activation enables rapid and effective host attachment, contributing to their persistence and difficulty of control in agriculture. The process is influenced by compounds from both host and non-host seeds, and targeting these early signaling pathways may offer new weed management strategies.

Guillaume Brun et al, Seed metabolites headstart haustoriogenesis and potentiate aggressiveness of parasitic weeds, Science Advances (2025). DOI: 10.1126/sciadv.aea1449

Fat tissue around the heart may contribute to greater heart injury after a heart attack 

Greater epicardial adipose tissue (EAT) volume, measured by cardiovascular imaging, is independently associated with larger myocardial infarct size and greater area at risk after myocardial infarction, though not with reduced left ventricular ejection fraction. Non-invasive EAT quantification may enhance cardiovascular risk assessment beyond traditional factors.

Epicardial adipose tissue (EAT) is the layer of fat between the myocardium and the lining of the heart, directly surrounding the coronary arteries. Under certain pathological conditions, EAT releases inflammatory mediators leading to myocardial infiltration and constrictive effects. Over time, adverse remodeling of the myocardium can occur.

Researchers have now shown that patients with increased EAT volume exhibited greater acute myocardial injury following MI.

https://www.escardio.org/The-ESC/Press-Office/Press-releases/fat-ti...

Abdominal obesity and muscle loss increase the risk of death by 83% after age 50, study finds

Tattoos might put the immune system at risk

 Studies in mice suggest that the pigment used in tattoos accumulates in the lymph nodes and might affect immune responses. Researchers found that ink remained in the lymph nodes for months and had varying effects: it weakened the animals’ response to a COVID vaccine but increased the reaction to an influenza vaccine.

https://www.pnas.org/doi/10.1073/pnas.2510392122

Space debris poses growing threat, but new study suggests cleanup is feasible

So in his latest study, titled "Space Logistics Analysis and Incentive Design for Commercialization of Orbital Debris Remediation" and published in the Journal of Spacecraft and Rockets, researchers investigated ways to create commercial opportunities for space operators and debris remediators to clean up dangerous junk.

The study analyzed three possible scenarios of debris cleanup—controlled reentry back to Earth, uncontrolled reentry back to Earth, and recycling in space. All three methods would require a space debris remediation satellite - a vehicle designed to capture and remove space junk from orbit. 

In the uncontrolled re-entry scenario, the remediation service vehicle would grab the debris from the orbit path it flies in and bring it down to about 350 kilometers away from Earth. The piece of debris would continue orbiting around our planet until it entered the atmosphere and either burned or landed someplace.

It will either burn or drop somewhere on Earth, but we don't know where because it depends on the atmospheric drag it receives. This uncontrolled reentry method is the cheapest as the remediation vehicle doesn't have to fly long distances.

In the controlled reentry scenario, the remediation service vehicle would bring the debris much closer to Earth, down to about 50 kilometers.  Controlled reentry is more expensive because the servicer needs to bring the debris down closer to Earth and then fly up again to get the next piece of debris. That consumes more energy and more fuel than an uncontrolled reentry .

In the recycling scenario, the debris would be transported from its original orbit to a recycling center up in space. The transportation would require fuel, adding to the cost, but a lot of energy would also be saved by reusing aluminum, the metal commonly used in spacecraft, up in orbit rather than having to bring it up from Earth.

It takes about $1,500 per kilogram to launch anything from Earth to space.  . So if you don't have to launch from Earth, it's a benefit.

Space operators stand a lot to gain from debris removal. Their satellites can operate more safely and efficiently, so they save money on fuel and operations, since they don't have to make extra maneuvers to avoid collisions.

Asaad Abdul-Hamid et al, Space Logistics Analysis and Incentive Design for Commercialization of Orbital Debris Remediation, Journal of Spacecraft and Rockets (2025). DOI: 10.2514/1.a36465

https://phys.org/news/2025-12-space-debris-poses-threat-cleanup.htm...

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Most normal matter in the universe isn't found in planets, stars or galaxies

Only about 9% of the universe’s normal (baryonic) matter is found in stars and cold gas within galaxies, while 76% resides in the intergalactic medium and 15% in galaxy halos. This distribution matches Big Bang predictions, confirming that most normal matter exists as diffuse gas between galaxies, not in visible structures. Dark matter and dark energy remain the dominant, poorly understood components.

Classical Indian dance inspires new ways to teach robots how to use their hands  

Analysis of Bharatanatyam dance gestures revealed a more versatile set of hand movement synergies than those found in natural grasps. These mudra-derived synergies enabled robots to replicate a wider range of hand motions, such as American Sign Language letters, more effectively. The findings support developing task-specific movement libraries for robotics and physical therapy applications.

Parthan Olikkal et al, Reconstructing hand gestures with synergies extracted from dance movements, Scientific Reports (2025). DOI: 10.1038/s41598-025-25563-7

For the first time, researchers observe how influenza viruses infect living cells 

 A novel microscopy technique enabled real-time, high-resolution observation of influenza virus entry into living cells. Findings show that cells actively participate in viral uptake by recruiting clathrin proteins and forming membrane pockets, rather than being passive targets. This method offers valuable insights for antiviral drug development and can be applied to study other viruses.

Aiko Yoshida et al, Enhanced visualization of influenza A virus entry into living cells using virus-view atomic force microscopy, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2500660122

Single enzyme failure found to drive neuron loss in dementia 

 Loss of function in the enzyme glutathione peroxidase 4 (GPX4) disrupts neuronal protection against ferroptosis, leading to neuron death and early-onset dementia. A specific GPX4 mutation impairs its ability to neutralize lipid peroxides at the cell membrane, triggering neurodegeneration. Inhibiting ferroptosis can slow this process in experimental models.

Svenja M. Lorenz et al, A fin-loop-like structure in GPX4 underlies neuroprotection from ferroptosis, Cell (2025). DOI: 10.1016/j.cell.2025.11.014

https://medicalxpress.com/news/2025-12-enzyme-failure-neuron-loss-d...

How volcanic eruptions set off a chain of events that brought the Black Death to Europe
Volcanic eruptions around 1345 triggered consecutive years of cooling, leading to crop failures and famine in southern Europe. To prevent starvation, Italian city states imported grain from the Black Sea, inadvertently introducing Yersinia pestis via infected fleas on ships. This sequence of climate, agricultural, and trade events enabled the Black Death's rapid spread across Europe.

'Brainquake' phenomenon links psychotic states to chaotic information flow

Deadly Asian floods are no fluke.

They're a climate warning, scientists say Southeast Asia is experiencing increasingly severe and unpredictable floods and storms, consistent with climate change projections. The region is warming nearly twice as fast as the global average, intensifying extreme weather events. Governments are struggling to prepare for and respond to these disasters, which are exacerbated by deforestation and unregulated development. Economic losses are substantial, while climate finance remains insufficient.
Climate patterns last year helped set the stage for 2025's extreme weather.Atmospheric levels of heat-trapping carbon dioxide jumped by the most on record in 2024. That "turbocharged" the climate, the United Nation's World Meteorological Organization says, resulting in more extreme weather.Asia is bearing the brunt of such changes, warming nearly twice as fast as the global average. Scientists agree that the intensity and frequency of extreme weather events are increasingWarmer ocean temperatures provide more energy for storms, making them stronger and wetter, while rising sea levels amplify storm surges While the total number of storms may not dramatically increase, their severity and unpredictability will What we're seeing in the region is dramatic and it's unfortunately a stark reminder of the consequences of the climate crisis, scientists conclude.
Source: News Agenices

Electric vehicle high-nickel batteries: Fundamental cause of performance degradation identified

Succinonitrile (CN₄), an electrolyte additive previously used to enhance stability in lithium-ion batteries, has been identified as a primary cause of rapid degradation in high-nickel batteries. CN₄ binds strongly to nickel ions, disrupting the cathode’s protective layer, causing structural damage, and accelerating performance loss.

Seung Hee Han et al, Unveiling Bidentate Nitrile-Driven Structural Degradation in High-Nickel Cathodes, ACS Energy Letters (2025). DOI: 10.1021/acsenergylett.5c02845

Ant brood signal deadly infection in altruistic self-sacrifice

Terminally ill ant pupae emit specific non-volatile odor signals that prompt worker ants to remove and disinfect them, preventing pathogen spread within the colony. This targeted signaling occurs only when infections are uncontrollable, ensuring colony health while minimizing unnecessary sacrifice, and parallels immune responses in multicellular organisms.

Sylvia Cremer, Altruistic disease signalling in ant colonies, Nature Communications (2025). DOI: 10.1038/s41467-025-66175-z. www.nature.com/articles/s41467-025-66175-z

Cancer cells keep their chromosomes intact to continue dividing relentlessly

Cancer cells maintain their ability to divide by using telomerase to repair chromosome ends (telomeres). An internal actin protein network in the nucleus helps telomerase access damaged telomeres, supporting cell survival even after chemotherapy-induced DNA damage. Targeting telomerase or this actin network could enhance chemotherapy effectiveness and reduce side effects.

Ashley Harman et al, Nuclear actin and DNA replication stress regulate telomere maintenance by telomerase, Nature Communications (2025). DOI: 10.1038/s41467-025-66506-0

Scientists call for greater focus on conserving whole ecosystems instead of charismatic species

Conservation programs are often too focused on a single charismatic species.

With many species worldwide experiencing population declines, there is an urgent need for conservation initiatives to support their recovery. However, this urgency, combined with insufficient scientific knowledge about endangered species, means that conservationists have often relied on oversimplified measures of success. For example, historical conservation efforts often focused on the abundance of a single charismatic species as a proxy for overall ecosystem health.

Researchers highlight three examples from China where oversimplified conservation priorities led to negative outcomes. The Chinese giant salamander (Andrias davidianus) is known as a "cryptic species," because it has multiple, genetically distinct populations that look identical to the naked eye.

Unaware of this, conservationists began a large-scale captive breeding and reintroduction program, which led to genetic mixing that threatened native populations. In the case of the crested Ibis (Nipponia nippon) and Père David's deer (Elaphurus davidianus), intensive captive breeding and release programs with limited suitable habitat have resulted in overcrowding, inbreeding and increased mortality.

Although well-intentioned, these initiatives have caused unforeseen issues for the ecosystem, and have often failed to improve the conservation status of the target species.

To avoid repeating these mistakes, the researchers advocate for a more nuanced approach to conservation, focused on creating balanced ecosystems, restoring habitats and minimizing human intervention. Although there has recently been more emphasis placed on protecting whole ecosystems, charismatic species conservation is still prevalent in the world.

Conservation programs that aim to preserve and restore ecosystem functions are a more effective use of limited resources, and are less likely to have unintended consequences, the researchers say. 

Shi H-T, et al. Are we over-conserving charismatic species? PLOS Biology (2025). DOI: 10.1371/journal.pbio.3003494

Ming Siang Lem et al, Ultrasonic pulse repetition rates triggering escape responses of a moth pest, Pest Management Science (2025). DOI: 10.1002/ps.70204

Cancer-promoting DNA circles hitchhike on chromosomes to spread to daughter cells

Extrachromosomal DNA circles (ecDNA) in cancer cells persist by attaching to chromosomes during cell division using specific retention elements, mimicking natural gene regulation mechanisms. Disrupting this attachment, such as by adding methyl groups to retention elements, leads to ecDNA loss and reduced cancer cell survival, highlighting a potential therapeutic target for cancer treatment.

Venkat Sankar et al, Genetic elements promote retention of extrachromosomal DNA in cancer cells, Nature (2025). DOI: 10.1038/s41586-025-09764-8

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Images that require less neural energy to process are generally rated as more aesthetically pleasing, indicating that visual preference may be influenced by the brain's tendency to conserve energy. This suggests that aesthetic appreciation is linked to a balance between adequate visual stimulation and minimizing metabolic expenditure.

Beauty may be 'easy on the eyes' because it saves brain power

Humans may find images that take less energy to process aesthetically pleasing, suggesting that our attraction to beauty is at least partially an energy conservation strategy. 

Looking at something can feel effortless, but in energetic terms, it isn't cheap. The brain uses 20% of the body's energy, and the visual system accounts for about 44% of that expenditure. Looking at very simple stimuli, like a blank white room, is energy-efficient but boring. Looking at very busy or unusual images can feel tiring and unpleasant. 

Publishing in PNAS Nexus, researchers presented 4,914 images of objects and scenes to an in-silico model of the visual system to estimate the number of neurons needed to look at them. The authors compared these estimates to enjoyment ratings from 1,118 participants recruited using Amazon Mechanical Turk.

Next, they used blood oxygen level-dependent signal brain imaging to measure the energy costs of looking at images for 4 participants. In both experiments, study participants found images that took less energy to process more attractive. The authors asked for a quick response, meant to capture initial impressions, not the more complex pleasures that may arise from contemplating an image in a broader context by engaging with its meaning.

According to the authors, visual aesthetic appreciation may be a manifestation of an energy-conserving heuristic that creates a sweet spot between sufficient stimulation of the visual system and excessive metabolic cost.

Yikai Tang et al, Less is more: Aesthetic liking is inversely related to metabolic expense by the visual system, PNAS Nexus (2025). DOI: 10.1093/pnasnexus/pgaf347

"Caching," is the scientific term for storing food in hidden places for later use. This behaviour is widespread across the animal kingdom, from squirrels, to crows, and wolves.

Caching behavior generally falls into one of two categories.

One is known as larder hoarding—think of a squirrel stashing nuts in just one or two places to draw from as they get through a long winter. 

 The other is known as scatter hoarding. It is where animals make smaller caches of surplus food in many different locations, reducing the chance of losing everything to a competitor or going hungry in lean seasons. It's mostly seen in wild canids such as foxes and wolves.  

This behavior in modern dogs is an instinctual remnant. It reflects the competitive feeding patterns of their ancestors who lived by hunting, for whom securing food was unpredictable, but crucial for survival. 

 Dogs appear to rely on a combination of scent and observational spatial memory to remember where they have cached special items, such as food, treats and toys.

https://theconversation.com/your-dog-is-not-a-doomsday-prepper-here...

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Exposure to fatty food odors during pregnancy and breastfeeding, even without maternal weight gain or high-fat intake, can alter offspring brain circuits related to reward and metabolism, increasing their risk of obesity and insulin resistance. Ingested flavoring agents with fatty odors were sufficient to trigger these effects in mice, highlighting potential implications for human metabolic health.

https://medicalxpress.com/news/2025-12-fatty-food-pregnancy-obesity...

Why your faucet drips: Water jet breakup traced to angstrom-scale thermal capillary waves

The breakup of a water jet into droplets is primarily triggered by intrinsic thermal capillary waves—angstrom-scale surface fluctuations—rather than external disturbances or nozzle imperfections. These minute thermal oscillations are amplified by Rayleigh-Plateau instability, determining the breakup length across a wide range of jet sizes.

Stefan Kooij et al, What Determines the Breakup Length of a Jet?, Physical Review Letters (2025). DOI: 10.1103/jf6w-l5sy

How airplanes discharge static electricity

Urban raccoons exhibit shorter snouts compared to rural populations, a trait associated with early domestication syndrome. This morphological change is likely driven by the advantages of tameness and reduced aggression in accessing human food waste. The findings suggest that proximity to humans can induce domestication-related traits in wild species.

Artem Apostolov et al, Tracking domestication signals across populations of North American raccoons (Procyon lotor) via citizen science-driven image repositories, Frontiers in Zoology (2025). DOI: 10.1186/s12983-025-00583-1

Which gut microbes matter most? Large study ranks bacteria by health and diet links

The gut microbiome has been a rising star in the world of health science over the last several years, garnering interest from both researchers and the general public. This is mostly due to its connection to general health and diseases, like type 2 diabetes and heart disease, as well as the fact that it is a modifiable element of human health. However, the science surrounding the fascinating world of gut microbes is still developing and there is much to learn.

A new study, published in Nature, has added significantly to our understanding of the human microbiome. The study team analyzed the gut microbiome, diet and health markers from over 34,500 people in the US and UK, and linked hundreds of specific gut microbe species to key indicators of health and diet. The data come from the Zoe PREDICT program in the UK and US, which is run by the microbiome testing company Zoe.

The researchers used machine learning to link certain gut microbe species in 34,694 study participants to diet and common health risk factors such as BMI, triglycerides, blood glucose and HbA1c, as well as clinical markers that are intermediary measures of cardiometabolic health. Out of 661 non-rare microbial species, the researchers focused in on the 50 that were most favorably associated with good health and the 50 that were the most unfavorably associated with good health.

This process resulted in the development of the "ZOE Microbiome Health Ranking 2025" and "Diet Ranking 2025," used to score microbes as either favorable or unfavorable for health on a scale of 0 to 1. Those closer to zero are considered positively correlated to the health markers and those closer to one are negatively correlated. This was done for all 661 microbes studied.

The ranking system identified hundreds of gut microbe species—described as species-level genome bins (SGBs) in the paper—significantly associated with health markers and diet quality. They found that favorable microbes were more common in people with lower BMI and fewer diseases, while unfavorable microbes were more common in those with obesity and disease. A part of the study focusing on BMI, used data from 5,348 healthy individuals, and divided them into three BMI categories; healthy weight, overweight and obese.

"Meta-analysis based on linear regression on single cohorts showed that individuals with healthy weight carried, on average, 5.2 more of the 50 favorably ZOE MB health-ranked SGBs than people with obesity," the study team writes.

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The team also assessed whether the ZOE MB health-ranked SGBs were more abundant in participants with a defined disease. Indeed, they found that people in the control group had higher favorably ranked gut microbes than people with disease, and that those with diseases had more unfavorably ranked gut microbes than those without disease.

Dietary interventions were also found to increase favorable microbes and reduce unfavorable ones. The team analyzed data from two studies, referred to as ZOE METHOD and BIOME, in which participants either followed a personalized dietary intervention program (PDP) designed to improve the microbiome or took a prebiotic supplement. The microbiomes of these participants changed significantly by the end of the studies.

"The dietary intervention groups of both clinical trials that aimed at improving diet using different approaches (prebiotic blend for BIOME and PDP for METHOD) showed the highest number of significantly changing SGBs. Focusing on the most significant gut microbial SGBs with the largest change in relative abundance after dietary interventions, they found increasing Bifidobacterium animalis—a bacterium present in dairy-based foods and in the microbiome of people consuming larger amounts of them, an unknown Lachnospiraceae bacterium and R. hominis both previously associated with a vegan diet, and another unknown Lachnospiraceae bacterium linked to a vegetarian diet," the authors explain.

In addition to linking known bacterial species to measures of health and diet, the team also discovered many key health-associated microbes that were previously uncharacterized species.

Francesco Asnicar et al, Gut micro-organisms associated with health, nutrition and dietary interventions, Nature (2025). DOI: 10.1038/s41586-025-09854-7

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