The findings show that sodium bicarbonate therapy did not affect day 90 mortality in patients with severe metabolic acidemia (pH ≤7.20) and moderate to severe acute kidney injury.

Less frequent kidney replacement therapy use in the bicarbonate group and lower bloodstream infections illustrated significantly better outcomes.

 Boris Jung et al, Sodium Bicarbonate for Severe Metabolic Acidemia and Acute Kidney Injury, JAMA (2025). DOI: 10.1001/jama.2025.20231

Prit Kusirisin et al, Sodium Bicarbonate in Severe Acidemia and Acute Kidney Injury—Turning the Tide or Chasing a Myth?, JAMA (2025). DOI: 10.1001/jama.2025.20457

Part 2

Could mass arise without the Higgs boson?

The Higgs field gives mass to elementary particles through interaction, not the Higgs boson particle itself. The Higgs boson is a quantum excitation of this pervasive field. The strength of a particle's interaction with the Higgs field determines its mass, while particles like the photon that don't interact with it remain massless. 

The geometry of space, where physical laws unfold, may also hold answers to some of the deepest questions in fundamental physics. The very structure of spacetime might underlie every interaction in nature.

A paper published in Nuclear Physics B explores the idea that all fundamental forces and particle properties could emerge from the geometry of hidden extra dimensions.

According to the study, the universe may contain invisible dimensions folded into intricate seven-dimensional shapes known as G₂-manifolds. Traditionally, these structures have been studied as static. But researchers of this new study consider them as dynamic: evolving under a process called the G₂–Ricci flow, where the internal geometry changes with time.

As in organic systems, such as the twisting of DNA or the handedness of amino acids, these extra-dimensional structures can possess torsion, a kind of intrinsic twist, they explain. When we let them evolve in time, we find that they can settle into stable configurations called solitons. These solitons could provide a purely geometric explanation of phenomena such as spontaneous symmetry breaking.

In the Standard Model of particle physics, the Higgs field gives mass to the W and Z bosons. But the authors suggest that mass could instead arise from geometric torsion in extra dimensions, without introducing an additional Higgs field.

"In our picture," they say, "matter emerges from the resistance of geometry itself, not from an external field."

The theory also links torsion to the curvature of spacetime, offering a possible explanation of the positive cosmological constant that drives cosmic expansion. The authors even speculate about a new particle, the "Torstone," that might be observable in future experiments.

The masses of the W and Z bosons come not from the famous Higgs field, but directly from the geometry of seven-dimensional space, they argue.

Richard Pinčák et al, Introduction of the G2-Ricci flow: Geometric implications for spontaneous symmetry breaking and gauge boson masses, Nuclear Physics B (2025). DOI: 10.1016/j.nuclphysb.2025.116959

AI evaluates texts without bias—until the source is revealed
Large language models evaluate texts consistently and with minimal bias when no source information is provided, showing over 90% agreement across models. However, when the author’s identity or nationality is revealed, significant biases emerge, notably a strong anti-Chinese bias, and trust in human over AI authors. These findings highlight the need for transparency and safeguards in AI-driven evaluations.

How to avoid LLM evaluation bias Make the LLM identity blind:

Remove all identity information regarding author and source of the text, e.g., avoid using phrases like "written by a person from X / by model Y" in the prompt.

Check from different angles: Run the same questions twice, e. g. with and without a source mentioned in the prompt. If results change, you've likely hit a bias.

Or cross-check with a second LLM model: If divergence appears when you add a source that is a red flag.

Force the focus away from the sources: Structured criteria help anchor the model in content rather than identity.

Use this prompt, for example: "Score this using a 4-point rubric (evidence, logic, clarity, counter-arguments), and explain each score briefly." Keep humans in the loop: Treat the model as a drafting help and add a human review to the process—especially if an evaluation affects people.

 Federico Germani et al, Source framing triggers systematic bias in large language models, Science Advances (2025). DOI: 10.1126/sciadv.adz2924

Dinosaur eggshells unlock a new way to tell time in the fossil record

An international team of geologists and paleontologists is pioneering a groundbreaking methodology to reliably determine the age of fossil-bearing rocks—by directly dating fossilized dinosaur eggshells.

Many fossil sites around the world are only coarsely dated. Without precise information on the geologic age of fossils, paleontologists struggle to understand how different species and ecosystems relate across time and space. Usually, researchers rely on dating minerals such as zircon or apatite found associated with fossils, but those minerals aren't always present. Attempts to date the fossils themselves, such as bones or teeth, have often produced uncertain results.

Now researchers  took a different approach. They used advanced uranium–lead (U–Pb) dating and elemental mapping to measure trace amounts of uranium and lead housed inside the calcite of fossilized dinosaur eggshells. These isotopes function like a natural clock, enabling scientists to determine when the eggs were buried.
Fossilized dinosaur eggshells can be directly dated using uranium–lead (U–Pb) isotopes in their calcite, providing geologic ages with about 5% accuracy compared to volcanic-ash dating. This method enables precise dating of fossil sites lacking datable volcanic layers, offering a new tool to reconstruct the timing of dinosaur evolution and ancient ecosystems.

Tests on dinosaur eggs from Utah (U.S.) and the Gobi Desert (Mongolia) showed that the eggshells record ages with an accuracy of about 5% relative to precise volcanic-ash dates. In Mongolia, the team determined the first-ever direct age—around 75 million years old—for a historic locality preserving dinosaur eggs and nests.

 Ryan T. Tucker et al, U-Pb calcite age dating of fossil eggshell as an accurate deep time geochronometer, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-02895-w

How cells choose their direction without external signals

Cell movement is an essential biological process, whether it's cancer cells metastasizing to other parts of the body or immune cells migrating to heal a wound.

An international joint research team has elucidated the principle by which cells decide their direction and move on their own without external signals, offering a crucial clue for identifying the causes of cancer metastasis and immune diseases and establishing new treatment strategies.
Cells determine their movement direction autonomously through an internal program involving Rho family proteins. The Cdc42–FMNL interaction drives straight movement, while Rac1–ROCK enables directional changes. Disrupting Rac1–ROCK binding impairs turning and environmental adaptation. The INSPECT technique allows direct visualization of these protein interactions in living cells.

Heeyoung Lee et al, A Rho GTPase-effector ensemble governs cell migration behavior, Nature Communications (2025). DOI: 10.1038/s41467-025-64635-0

Chronic kidney disease is now the ninth leading cause of death, global analysis finds

Record numbers of men and women globally are now estimated to have reduced kidney function, a new study shows. Figures rose from 378 million people with the disease in 1990 to 788 million in 2023 as the world population grew and aged, making it for the first time a top 10 cause of death worldwide.

 The analysis explored the rise of the illness, in which the kidneys gradually lose their ability to filter waste and excess fluid from the blood. Mild cases may have no symptoms while the most severe stages can require dialysis, kidney replacement therapy, or an organ transplant.

The findings revealed that about 14% of adults in the world have chronic kidney disease. Results further showed that about 1.5 million people died from the condition in 2023, an increase of more than 6% since 1993 when accounting for differences in countries' age demographics over time.

Another major finding was that impaired kidney function, on top of killing people directly, was a key risk factor for heart disease, contributing to about 12% of global cardiovascular mortality. The results showed further that in 2023, the condition was the 12th leading cause of diminished quality of life from disability. The biggest risk factors for kidney disease were found to be high blood sugar, high blood pressure, and high body mass index (a measure of obesity).

Global, regional, and national burden of chronic kidney disease in adults, 1990–2023, and its attributable risk factors: a systematic analysis for the Global Burden of Disease Study 2023, The Lancet (2025). DOI: 10.1016/S0140-6736(25)01853-7

AI bias in hiring decisions is often copied by human reviewers, study reveals

An organization drafts a job listing with artificial intelligence. Droves of applicants conjure résumés and cover letters with chatbots. Another AI system sifts through those applications, passing recommendations to hiring managers. Perhaps AI avatars conduct screening interviews. This is increasingly the state of hiring, as people seek to streamline the stressful, tedious process with AI.

Yet research is finding that hiring bias—against people with disabilities, or certain races and genders—permeates large language models, or LLMs, such as ChatGPT and Gemini. We know less, though, about how biased LLM recommendations influence the people making hiring decisions.
In a new  study, 528 people worked with simulated LLMs to pick candidates for 16 different jobs, from computer systems analyst to nurse practitioner to housekeeper. The researchers simulated different levels of racial biases in LLM recommendations for résumés from equally qualified white, Black, Hispanic and Asian men.

When picking candidates without AI or with neutral AI, participants picked white and non-white applicants at equal rates. But when they worked with a moderately biased AI, if the AI preferred non-white candidates, participants did too. If it preferred white candidates, participants did too. In cases of severe bias, people made only slightly less biased decisions than the recommendations.

Kyra Wilson et al, No Thoughts Just AI: Biased LLM Hiring Recommendations Alter Human Decision Making and Limit Human Autonomy, Proceedings of the AAAI/ACM Conference on AI, Ethics, and Society (2025). DOI: 10.1609/aies.v8i3.36749

Talking with our hands: How culture shapes our gestures

New research  shows that gesture is not merely a matter of individual style or habit, but a reflection of cultural expression tied to racial identity.

The research also suggests that mismatched expectations about gesture may influence the dynamics of interracial communication.

We all clearly communicate in very different ways. Some of us may talk differently than others. Some of us may use our hands more than others. It doesn't mean we can't communicate. When we experience that mismatch in communication, maybe we all need to try a little harder to understand each other across group differences, say the researchers.

Their findings show consistent patterns suggesting that what feels natural when speaking can differ across racial groups, and that those differences can shape how people perceive one another.

Collectively, these studies highlight that gesture is not only a personal characteristic but also a culturally grounded mode of expression, deeply linked to identity and group norms. The research also underscores how mismatched expectations about nonverbal behavior may affect perceptions and interactions across racial groups.

Yes, what I say need not exactly be what you comprehend!

Esha S. Naidu et al, Talk to the hand: Black and White cultural differences in gesture use., Journal of Experimental Psychology: General (2025). DOI: 10.1037/xge0001862

 

Scientists Discover Mysterious Signs of Life in Bizarre Blue Volcanic Goo

Unexpected biosignatures found in a startlingly blue volcanic goo beneath the Pacific Ocean may offer clues to life's origins.
Exhumed from mud volcanoes near the Mariana Trench, at depths of almost 3,000 meters (9,833 feet), the bizarrely colored sediment samples contain fats from mysterious living organisms.

With an extremely high pH of 12 – among the highest recorded in a natural ecosystem – this nutrient-poor ooze would cause severe burns to your skin on contact. Yet researchers have now confirmed that some extremophile microbes live there.

The bottom section of one taken from the Pacman volcano consists mainly of serpentinite with bits of brucite, largely untouched by the seawater above, allowing it to maintain its striking color.

At shallower depths, closer to the mud from the ocean floor, the volcanic sediment pales to a lighter blue-green, and the brucite has been dissolved by salt water.
Within these serpentinite layers, researchers detected fats from bacterial and archaeal cell membranes – the microbes' "first line of defense" against highly alkaline conditions.
The mostly intact state of the fats indicates multiple communities of microbes are currently eking out a living in these extreme conditions, the researchers explain.
Like plants do through photosynthesis, these microbes make their own energy from methane by consuming sulfate, which produces corrosive hydrogen sulfide.

https://www.nature.com/articles/s43247-025-02667-6

Self-reactive T cells may explain why some patients can't reach undetectable HIV levels

Despite the capability of antiretroviral drugs to suppress HIV to undetectable levels, some people living with the human immunodeficiency virus can't reach the goal of viral imperceptibility even with daily doses of the potent medications.

It is a conundrum that has mystified virologists for years, but new research by a team of investigators It is a conundrum that has mystified virologists for years, but new research by a team of investigators.

Based on a study of eight people whose antiretroviral treatment did not drive down HIV to an undetectable level, the  researchers found that constant HIV in the blood is not the result of patients missing medication doses or the virus becoming drug resistant. It persists, they discovered, because of a population of insidious immune components known as "self-reactive CD4⁺ T cells".

These HIV-infected CD4⁺ T cells can release viral RNA that persists in the bloodstream, a phenomenon called nonsuppressible viremia. Simply put, nonsuppressible viremia refers to an ongoing presence of low levels of HIV in the blood.

Antiretroviral therapy halts HIV replication, reducing plasma virus concentrations to below the limit of detection, but it is not curative because of a reservoir of latently infected CD4⁺ T cells," writes lead author of the study, Dr. Fengting Wu, in Science Translational Medicine.

Even with 100% adherence to antiretroviral therapy, a large fraction of people living with HIV have residual viremia. Clinical options for managing nonsuppressible viremia are currently limited.

Even though the viremia may be low, it cannot be controlled by simply upping the dosage of antiretroviral medication. So, despite doctors' best efforts, viral RNA continues to persist in the blood. And more puzzling still, it may take years, even decades, for the viremia to emerge.

All eight patients examined by the researchers had been on long-term antiretroviral treatment for a median of 23 years before developing persistent viremia.

For the patient with the least amount of time on the therapy, it took nine years before nonsuppressible viremia occurred. Another spent 31 problem-free years on the treatment before viremia loomed as an inescapable fact of life. Yet, during the study period, some research participants who had lab-confirmed evidence of nonsuppressible viremia, had no signs of it at all.

Several possibilities could explain the lack of detectable virus production from infected CD4⁺ T cells in some study participants," write the investigators in their paper. "These include a low frequency of infected self-reactive cells, the antigen of interest not being present in the lysate, or the antigen being present at very low concentrations."

Complicating matters further, CD4⁺ T cells make clones of themselves in HIV infection, a process known as clonal expansion. A small fraction of CD4⁺ T cells infected with HIV survive and divide, creating clones of infected cells that form the viral reservoir, the source of the nonsuppressible viremia.

 Fengting Wu et al, Proviruses in CD4⁺ T cells reactive to autologous antigens contribute to nonsuppressible HIV-1 viremia, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.adu4643

How climate change increased the risk of earthquakes in East Africa

Climate change is accelerating continental rifting, the geological process where landmasses slowly pull apart. According to a new study published in the journal Scientific Reports, the East African Rift System (EARS) became more tectonically active after its major lakes shrank due to a drier climate 4,000 to 6,000 years ago. This could have caused more frequent earthquakes and volcanic eruptions.

Researchers studied the Lake Turkana Basin in northern Kenya. This region is ideal for analyzing how climate and tectonics interact because it lies within the magmatically active eastern part of EARS and has witnessed dramatic lake-level shifts.

Scientists examined 27 underwater faults by comparing two time periods in the South Turkana Basin. The first was the wetter Late African Humid Period (9,631–5,333 years ago) and the second was the Post-African Humid Period (5,333 years ago to present), when the climate was much drier. Using geological data and computer models, they calculated how the reduced weight of the lake water affected fault activity.

The researchers discovered that the speed of faulting in the EARS accelerated significantly after the region's major lakes shrank, showing a mean increase of 0.17 mm/year in their slipping rate.

This work provides  the first empirical evidence of increased fault activity in response to climate-induced lake level changes in the East African Rift System over time scales of 10³–10⁴ years and reveal that climate-tectonic interactions are enhanced in magmatically active rift systems.

https://phys.org/news/2025-11-climate-earthquakes-east-africa.html?...

How climate change increased the risk of earthquakes in East Africa

Climate change is accelerating continental rifting, the geological process where landmasses slowly pull apart. According to a new study published in the journal Scientific Reports, the East African Rift System (EARS) became more tectonically active after its major lakes shrank due to a drier climate 4,000 to 6,000 years ago. This could have caused more frequent earthquakes and volcanic eruptions.

Researchers studied the Lake Turkana Basin in northern Kenya. This region is ideal for analyzing how climate and tectonics interact because it lies within the magmatically active eastern part of EARS and has witnessed dramatic lake-level shifts.

Scientists examined 27 underwater faults by comparing two time periods in the South Turkana Basin. The first was the wetter Late African Humid Period (9,631–5,333 years ago) and the second was the Post-African Humid Period (5,333 years ago to present), when the climate was much drier. Using geological data and computer models, they calculated how the reduced weight of the lake water affected fault activity.

The researchers discovered that the speed of faulting in the EARS accelerated significantly after the region's major lakes shrank, showing a mean increase of 0.17 mm/year in their slipping rate.

This work provides  the first empirical evidence of increased fault activity in response to climate-induced lake level changes in the East African Rift System over time scales of 10³–10⁴ years and reveal that climate-tectonic interactions are enhanced in magmatically active rift systems.

 James D. Muirhead et al, Accelerated rifting in response to regional climate change in the East African Rift System, Scientific Reports (2025). DOI: 10.1038/s41598-025-23264-9

Electrostatic defrosting removes ice without heat or chemicals

During winter months, frost can unleash icy havoc on cars, planes, heat pumps, and much more. But thermal defrosting with heaters is very energy intensive, while chemical defrosting is expensive and toxic to the environment.

Now a research team may have found a new and improved method for deicing:

to combat ice by exploiting its own physics instead of using heat or chemicals, creating methods of frost removal that are more cost effective and environmentally friendly.

Their previous work leveraged the small amount of voltage that naturally exists within frost to polarize a nearby water film, creating an electric field that could detach microscopic ice crystals.

Now the team is amping up this concept by applying a high voltage to an opposing electrode to more forcibly dislodge frost from its surface. The result is a new method the team has named "electrostatic defrosting" (EDF). The approach to creating it has been published in Small Methods.

As frost crystals grow, the water molecules arrange into a tidy ice lattice. But sometimes a water molecule lands a little off-pattern—maybe it has an extra hydrogen nearby (H3O+) or is missing one entirely (OH–). These tiny errors create what scientists call ionic defects: places in the frost where there is a bit too much positive or negative charge.

The team hypothesized that when applying a positive voltage to an electrode plate held above the frost, the negative ionic defects would become attracted and "migrate" to the top of the frost sheet, while the positive ionic defects would be repelled and migrate toward the base of the frost.

In other words, the frost would become highly polarized and exhibit a strong attractive force to the electrode. If this attractive force is strong enough, frost crystals could fracture off and jump into the electrode.

Even without any applied voltage, the overhanging copper plate removed 15% of the frost. This is because frost can weakly self-polarize even without any applied electric field. However, applying voltage dramatically boosts the extent of polarization. When the team turned on 120 volts of power, 40% of the frost was removed. At 550 volts, 50% was removed. Part 1

Turning up the power further, something curious happened: less frost jumped away, reducing to only 30% removal at 1,100 volts and 20% at 5,500 volts. The results contradicted the theoretical model, which predicted that the performance should continually improve with increasing voltage.

The team found a possible explanation for this plunge in frost removal at higher voltages. When growing frost on an insulating glass substrate, rather than a copper one, the higher voltages performed only slightly worse. This indicated that charge leakage from the polarized frost into the underlying substrate was occurring, especially at high voltages, which could be mitigated by using a more insulating surface.
Upgrading again to an air-trapping superhydrophobic substrate, now the highest voltage removed the most frost, as initially expected. Turning up the voltage now ripped off up to 75% of the frost.
This concept of electric deicing is still in a very early stage.
The research continues, toward the eventual goal of 100% ice removal. Part of this research will include the removal of frost on multiple types of surfaces, expanding the potential applications across both industrial and consumer use.

 Small Methods (2025). DOI: 10.1002/smtd.202501143

Part 2

Brain activity goes to extremes in soccer fans, neuroimaging reveals

Studying brain patterns in soccer fans, researchers found that certain circuit regions of the brain were activated while viewing soccer matches involving their favorite team, triggering positive and negative emotions and behaviors, according to a new study published in Radiology. The researchers say these patterns could apply to other types of fanaticism as well, and that the circuits are forged early in life.

Soccer is a global phenomenon, and its followers exhibit a broad spectrum of behaviors, from spectatorship to intense emotional engagement, providing a useful model for studying social identity and emotional processing in competitive situations.

Rivalries run deep in the history of sports, and fans can be very protective of their "home" team and favorite players. These same fans run the gamut of emotions watching their team succeed or fail over the course of a game or match, cheering when they score or raging at a bad call. Soccer fans are known for their team loyalty and enthusiasm, particularly in Europe and South America.

Soccer fandom provides a high-ecological-validity model of fanaticism with quantifiable life consequences for health and collective behaviour.

For the study, researchers used functional MRI (fMRI)—a technique that measures brain activity by detecting changes in blood flow—to examine 60 healthy male soccer fans (20–45 years) of two historical rivals. Fanaticism was quantified with the Football Supporters Fanaticism Scale, a 13-item scale that measures the fanaticism of football fans, assessing two sub-dimensions: "Inclination to Violence" and "Sense of Belongingness."

Brain imaging data were acquired while participants watched 63 goal sequences from matches involving their favorite team, a rival or a neutral team.

A whole-brain analysis was conducted to compare neural responses when participants viewed their favorite team scoring against an archrival (significant victory) versus when the archrival scored against their team (significant defeat), with control conditions for non-rival goals.

The fMRI results showed that brain activity changed when the fan's team succeeded or failed.

Rivalry rapidly reconfigures the brain's valuation–control balance within seconds. With significant victory, the reward circuitry in the brain is amplified relative to non-rival wins, whereas in significant defeat the dorsal anterior cingulate cortex (dACC)—which plays an important role in cognitive control—shows paradoxical suppression of control signals.

Part 1

Paradoxical suppression refers to the attempt to suppress a thought, feeling or behavior and it results in the opposite outcome.

Higher activation in the reward system regions occurred when participants' teams scored against rivals versus non-rivals, suggesting in-group bonding and social identity reinforcement.
The effect is strongest in highly fanatic participants, predicting momentary self-regulatory failure precisely when identity is threatened and accounting for the puzzling ability of otherwise rational individuals to suddenly "flip" at matches.
Clinically, the pattern implies a state-dependent vulnerability whereby a brief cooling-off or removal from triggers might permit the dACC/salience control system to recover.
The same neural signature—reward up, control down under rivalry—likely generalizes beyond sport to political and sectarian conflicts, say the researchers.
The neural results identify mechanisms which may inform communication, crowd management, and prevention strategies around high-stakes events in the reward amplification and control down-regulation under rivalry, they conclude.

Brain Mechanisms across the Spectrum of Engagement in Football Fans: A Functional Neuroimaging Study, Radiology (2025).

Part 2

Pancreatic cancer forms 'synapses,' scientists discover

Pancreatic cancer cells form pseudosynapses that exploit the nervous system by taking up glutamate via NMDA receptors, triggering calcium influx and sustained signaling that promotes tumor growth and metastasis. Blocking these receptors in mice slowed tumor progression and reduced metastases, suggesting a potential therapeutic target. Similar mechanisms may exist in other tumor types.

Lei Ren et al, Sensory neurons drive pancreatic cancer progression through glutamatergic neuron-cancer pseudo-synapses, Cancer Cell (2025). DOI: 10.1016/j.ccell.2025.09.003

The flexible brain: How circuit excitability and plasticity shift across the day

Our brains do not react in a fixed, mechanical way like electronic circuits. Even if we see the same scene every day on our commute to work, what we feel—and whether it leaves a lasting impression—depends on our internal state at that moment. For example, your commute may be a blur if you're too tired to pay attention to your surroundings.

The 24-hour cycle that humans naturally follow is one of the factors that shapes the brain's internal environment. These internal physiological cycles arise from the interplay between the body's intrinsic circadian clock and the external light-dark cycle that synchronizes it. Yet how such daily fluctuations influence brain chemistry and affect neuronal excitability and plasticity has remained largely unknown.

Now, researchers  have directly observed time-of-day-dependent changes in neural signal responses in the brains of nocturnal rats. Their findings are published in Neuroscience Research.

Using optogenetics, the team activated neurons in the visual cortexes of rats and recorded the resulting electrical activity. This approach allowed precise quantification of neural responsiveness. They found that identical neural stimuli evoked different responses depending on the time of day. Neural activity was reduced at sunrise and enhanced at sunset. Since rats are nocturnal, sunrise represents the period after a night of activity when they are preparing to sleep.

To explore the underlying mechanism explaining why this was occurring, the researchers looked at adenosine, a neuromodulator that accumulates during wakefulness and makes us feel sleepy.

When the researchers blocked the action of adenosine, neural activity at sunrise became disinhibited and enhanced, showing that adenosine helps regulate cortical excitability across the day.

So neural excitability is not constant; it depends on the brain's internal state. 

The results show that even identical neurons can respond differently depending on the time of day, governed by molecules like adenosine that link metabolism, sleep, and neuronal signaling.

Part 1

The team also examined whether the brain's capacity for long-term potentiation (LTP), a cellular basis of learning and memory, changes with time of day. This represents the brain's potential for metaplasticity (the brain's ability to adjust how easily its networks change). Remarkably, repetitive optical stimulation induced LTP-like enhancement at sunrise, but not at sunset.

This was unexpected, as it suggests that although sleep pressure and fatigue peak at sunrise, the brain's metaplastic potential is heightened at this time. These findings indicate that the brain's ability to reorganize itself follows a daily rhythm, with specific periods more favorable for learning and adaptation.

These results imply that our brains have temporal windows that favor adaptability.
Knowing when the brain is most receptive to changing could help optimize training, rehabilitation, and stimulation-based therapies.
In humans, who are mainly active during daylight hours, the capacity for learning and memory formation may peak during the twilight period approaching sunset. In other words, the best time to study or learn something new may be before bedtime.

The study reveals how daily rhythms fine-tune the balance between excitability and plasticity in the cortex. Because adenosine levels and sleep pressure follow circadian patterns, this mechanism may synchronize brain adaptability with behavioral cycles such as rest and activity. The research provides new insight into how the brain coordinates energy use, neural signaling, and learning capacity across the day.

Yuki Donen et al, Diurnal modulation of optogenetically evoked neural signals, Neuroscience Research (2025). DOI: 10.1016/j.neures.2025.104981

Part 2

Age, not sex or location, determines venom yield of India's 'Big Four' snakes, shows study

A new study by researchers from the Indian Institute of Science (IISc) has shown that the amount of venom produced by the big four snakes is overwhelmingly determined by the snake's life stage (age) rather than its sex or geographic location. The finding could have immediate implications for improving antivenom production and clinical treatment across the subcontinent.

To understand how much venom each snake delivers per bite, the researchers collected and quantified venom from the big four snakes across India's major bioclimatic zones. They collected venom samples from 338 wild-caught snakes during rescue operations coordinated with State Forest Departments and local snake rescuers across 10 states in India between 2021 and 2024. The venom was collected by experienced herpetologists using safe handling methods, encouraging the snake to bite onto a sterile parafilm stretched over a beaker. After extraction, all snakes were safely returned to their natural habitats. The collected crude venom was then freeze-dried (lyophilised) and its dry weight measured using a high-precision microbalance. This systematic, pan-Indian approach to sampling wild populations yielded a vast, diverse dataset.

The findings reveal substantial variation in venom output among the species, a pattern that largely correlates with the snake's overall body size. The two larger species, the Spectacled Cobra and the Russell's Viper, were the high-yield producers, meaning they delivered large quantities of venom with every bite. They averaged 136.10 mg and 106.60 mg of dry venom, respectively. In stark contrast, the smaller Common Krait (Bungarus caeruleus) and the Saw-scaled Viper (Echis carinatus) produced significantly less, with average yields of only 8.95 mg and 2.76 mg.

The most significant factor influencing this yield, however, was the snake's developmental stage. The study found statistically significant differences in venom yield across life stages for the cobra, Russell's viper, and saw-scaled viper. For example, adult Spectacled Cobras had a median venom yield of 125.00 mg, which is nearly three times the 47.60 mg median yield of subadults and almost twenty times the 6.50 mg median yield of juveniles. Similar trends were observed in Russell's Viper, with adults producing the highest median yield (95.69 mg) compared to juveniles (3.00 mg). This pattern strongly suggests that as a snake grows and matures, its capacity to produce and deliver venom increases dramatically.

Interestingly, the researchers found that sex-based differences were statistically insignificant across all four species.

Hiss and tell: What influences venom yields of India’s big four snakes?

https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd....

Did You Know? The "Big Four" are not the only dangerous snakes of India: While the four species are responsible for the most bites, India is home to over 350 snake species, nearly 60 of which are considered clinically relevant to humans.

https://researchmatters.in/news/age-not-sex-or-location-determines-....

Being multilingual es bueno para el cerebro

Want a younger brain? Learn another language

The ability to speak more than one language might slow brain ageing and protect against cognitive decline. In a study of more than 80,000 people, researchers found that people who are multilingual are half as likely to show signs of accelerated biological ageing than are those who just speak one language. The effect was also larger in people that spoke more than one additional language. The researchers hope that their findings will influence policy makers to encourage language learning in education.

I learnt five languages. Can my brain stay forever young?

https://www.nature.com/articles/s43587-025-01000-2.epdf?sharing_tok...

https://www.nature.com/articles/d41586-025-03677-2?utm_source=Live+...

Canada ( and entire Americas region) loses measles elimination status
Canada no longer holds measles elimination status after experiencing a cross-country outbreak that has persisted for more than 12 months. By default, this means that the entire Americas region has also lost its status. Infections took hold in undervaccinated Mennonite communities where the COVID-19 pandemic eroded already-shaky trust in the healthcare system — a shared source of recent measles outbreaks in the United States. The number of new cases is going down, but the loss is “a giant wake-up call that we have gaps in our public health infrastructure”, says physician-scientist Isaac Bogoch.

https://www.cbc.ca/news/health/livestory/canada-measles-elimination...

Computers that run on human brain cells
At a company on the shores of Lake Geneva, clumps of living brain cells are waiting for your call. These blobs, about the size of a grain of sand, are available to research teams studying how brains work or exploring the possibility of making computers with brain-cell processors. These neural cells can receive electrical signals and respond to them — much as computers do. For some scientists, the dream is to build supercomputers that share the astonishing power efficiency of the human brain. What they’re not working on, they emphasize, is ‘brains in jars’: the blobs are not sentient or conscious (yet).

https://www.nature.com/articles/d41586-025-03633-0?utm_source=Live+...

Bees learn to read simple 'Morse code'

Researchers  have shown for the first time that an insect—the bumblebee Bombus terrestris—can decide where to forage for food based on different durations of visual cues. Their paper is published in the journal Biology Letters.

In Morse code, a short duration flash or "dot" denotes a letter "E" and a long duration flash, or "dash," means letter "T." Until now, the ability to discriminate between "dot" and "dash" has been seen only in humans and other vertebrates such as macaques or pigeons.

Now researchers  studied this ability in bees. They built a special maze to train individual bees to find a sugar reward at one of two flashing circles, shown with either a long or short flash duration. For instance, when the short flash, or "dot," was associated with sugar, then the long flash, or "dash," was instead associated with a bitter substance that bees dislike.

In each room in the maze, the position of the dot and dash stimulus was changed, so that bees could not rely on spatial cues to orient their choices. After bees learned to go straight to the flashing circle paired with the sugar, they were tested with flashing lights but no sugar present, to check whether bees' choices were driven by the flashing light, rather than by olfactory or visual cues present in the sugar.

It was clear the bees had learned to tell the light apart based on their duration, as most of them went straight to the 'correct' flashing light duration previously associated with sugar, irrespective of spatial location of the stimulus.

Since bees don't encounter flashing stimuli in their natural environment, it's remarkable that they could succeed at this task. The fact that they could track the duration of visual stimuli might suggest an extension of a time processing capacity that has evolved for different purposes, such as keeping track of movement in space or communication.

Alternatively, this surprising ability to encode and process time duration might be a fundamental component of the nervous system that is intrinsic in the properties of neurons. Only further research will be able to address this issue.

Many complex animal behaviors, such as navigation and communication, depend on time-processing abilities. It will be important to use a broad comparative approach across different species, including insects, to shed light on the evolution of those abilities. Processing durations in insects is evidence of a complex task solution using minimal neural substrate.

This has implications for complex cognitive-like traits in artificial neural networks, which should seek to be as efficient as possible to be scalable, taking inspiration from biological intelligence.

 Duration discrimination in the bumblebee Bombus terrestris, Biology Letters (2025). DOI: 10.1098/rsbl.2025.0440. royalsocietypublishing.org/doi … .1098/rsbl.2025.0440

Scientists discover caves carved by water on Mars that may have once harbored life

If there is, or ever has been, life on Mars, the chances are it would exist in caves protected from the severe dust storms, extreme temperatures, and high radiation present on its surface. One place to focus our attention could be eight possible cave sites (called skylights) recently discovered by researchers.

In a paper published in The Astrophysical Journal Letters, the team presents the first evidence of a new type of cave on the red planet, formed by water dissolving rock. Most Martian caves discovered so far have been lava tubes, but the study authors argue that they have identified the first documented karstic caves on Mars.

"These skylights are interpreted as the first known potential karstic caves on Mars, representing collapse entrances formed through the dissolution of water-soluble lithologies—defining a new cave-forming class distinct from all previously reported volcanic and tectonic skylights," wrote the researchers in their paper.

On Earth, karstic caves are typically formed when water dissolves soluble rock such as limestone or gypsum, creating and enlarging underground cracks and fractures that grow large enough to become caves. The paper proposes a similar process on Mars, where ancient Martian water may have dissolved carbonate- and sulfate-rich rocks on the crust.

The caves are located in the Hebrus Valles, a northwestern region, and are eight pits that were mapped by previous Mars missions. They are deep and predominantly circular depressions, not impact craters, which typically have raised rims and ejected debris around them.

The researchers studied data from the Thermal Emission Spectrometer (TES) that was onboard NASA's Mars Global Surveyor and discovered that the rocks around the pits are rich in carbonates and sulfates. These are the types of rocks that water can easily dissolve. The team also used high-resolution imagery to create 3D structural models of the pits, which showed that their shapes are consistent with collapse caused by water rather than volcanic or tectonic activity.

The search for life on Mars feels like looking for a needle in a haystack. But it could be narrowed down and made easier by having well-defined targets that, more than others, could be possible homes for life.

Therefore, the scientists behind this latest study think the eight possible karstic caves should be high-priority targets for future human or robotic missions to the planet. Even if no life is there, they could serve as landing sites and natural shelters for astronauts when they are not exploring the surface.

 Ravi Sharma et al, Water-driven Accessible Potential Karstic Caves in Hebrus Valles, Mars: Implications for Subsurface Habitability, The Astrophysical Journal Letters (2025). DOI: 10.3847/2041-8213/ae0f1c

Part 2

Gut microbes pass down behavioral traits in mice offspring independent of genes

Gut microbes are essential partners that help digest food, produce vitamins and train the immune system. They can also pass on behavioral traits to their host's offspring, at least in mice. Scientists have discovered that the mouse microbiome can alter the animal's behaviour in just four generations, independent of its genes. The study is published in the journal Nature Communications

Animals and their microbes have coevolved for millions of years. While it was already known that bacteria, viruses and fungi living in the gut can drive inherited changes in some simple creatures, like insects, scientists didn't know till now whether they could be the sole mechanism for passing down a specific trait (like a behavioral tendency) in more complex animals, such as mammals.

The research team designed an experiment in which they strictly controlled the host animal's genes. First, they took gut microbiota from wild-derived mice and gave it to genetically identical germ-free mice in the lab.
Then they set up a selection line, repeatedly choosing the two mice that traveled the least and transferring their microbes into a fresh batch of genetically identical, germ-free mice for the next generation. The scientists focused on locomotor activity (movement) because previous tests had confirmed that it was a behavior strongly influenced by the microbiome. The researchers also ran a control line where two donor mice were chosen at random.

This serial transfer of gut microbes carried on for four generations. By using germ-free mice, the researchers could be sure that any behavioral changes they observed were due to the selection and transfer of the microbial community.
Part 1

Selecting for low activity successfully caused slower movement across the four generations. The researchers analyzed the composition of the microbial community and found that this reduction in activity was linked to higher levels of the bacterium Lactobacillus, which produces the substance indolelactic acid (ILA). They also showed the link was causal. When they independently gave Lactobacillus or ILA to other mice, it was enough to suppress their locomotion.

This work highlights the role of microbiome-mediated trait inheritance in shaping host ecology and evolution," wrote the researchers in a paper.

The novelty in our study lies in experimentally demonstrating that selection on a host trait can lead to changes in that same trait over time purely through microbiome transmission, without any genetic evolution in the host.

 Taichi A. Suzuki et al, Selection and transmission of the gut microbiome alone can shift mammalian behavior, Nature Communications (2025). DOI: 10.1038/s41467-025-65368-w

Part 2

Scientists tie lupus to a virus nearly all of us carry

One of humanity's most ubiquitous infectious pathogens bears the blame for the chronic autoimmune condition called systemic lupus erythematosus (lupus), Stanford Medicine investigators and their colleagues have found.

The Epstein-Barr virus (EBV), which usually resides silently inside the bodies of 19 out of 20 people, is directly responsible for commandeering what starts out as a minuscule number of immune cells to go rogue and persuade far more of their fellow immune cells to launch a widespread assault on the body's tissues, the scientists have shown.

The work is published in the journal Science Translational Medicine.

About five million people worldwide have lupus, in which the immune system attacks the contents of cell nuclei. This results in damage to organs and tissues throughout the body—skin, joints, kidneys, heart, nerves and elsewhere—with symptoms varying widely among individuals. For unknown reasons, nine out of 10 lupus patients are women.

With appropriate diagnosis and medication, most lupus patients can live reasonably normal lives, but for about 5% of them the disorder can be life-threatening. 

Existing treatments slow down disease progression but don't 'cure' it.

By the time we've reached adulthood, the vast majority of us have been infected by EBV. Transmitted in saliva, EBV infection typically occurs in childhood, from sharing a spoon with or drinking from the same glass as a sibling or a friend, or maybe during our teen years, from exchanging a kiss. EBV can cause mononucleosis, "the kissing disease," which begins with a fever that subsides but lapses into a profound fatigue that can persist for months.

Practically the only way to not get EBV is to live in a bubble. If you've lived a normal life the odds are nearly 20 to 1 you've got it.

part 1

Once you've been infected by EBV, you can't get rid of it, even if you remain or become symptom-free. EBV belongs to a large family of viruses, including those responsible for chickenpox and herpes, that can deposit their genetic material into the nuclei of infected cells. There the virus slumbers in a latent form, hiding from the immune system's surveillance agents. This may last as long as the cell it's hiding in stays alive; or under certain conditions, the virus may reactivate and force the infected cell's replicative machinery to produce myriad copies of themselves that break out to infect other cells and other people.
Among the cell types in which EBV takes up permanent residence are B cells, immune cells that do a couple of important things after they ingest bits of microbial pathogens. For one, they can produce antibodies: customized proteins that find and bind immune-system-arousing proteins or other molecules (immunologists call them "antigens") on microbial pathogens that have infected an individual, or are trying to.

In addition, B cells are what immunologists call "professional antigen-presenting cells": They can process antigens and display them on their surfaces in a way that encourages other immune cells to raise the intensity of their hunt for the pathogen in question. That's a substantial force multiplier for kick-starting an immune response.

Our bodies harbor hundreds of billions of B cells, which over the course of numerous rounds of cell division develop an enormous diversity of antibodies. In the aggregate, these antibodies can bind an estimated 10 billion to 100 billion different antigenic shapes. This is why we're able to mount a successful immune response to so many different pathogens.

Oddly, about 20% of the B cells in our bodies are autoreactive. They target antigens belonging to our own tissues—not by design, but due to the random way B-cell diversity comes about: through sloppy replication, apparently engineered by evolution to ensure diversification. Fortunately, these B cells are typically in a dopey state of inertia, and they pretty much leave our tissues alone.
Part 2

But at times, somnolent autoreactive B cells become activated, take aim at our own tissues and instigate one of the disorders collectively called autoimmunity. Some awakened autoreactive B cells crank out antibodies that bind to proteins and DNA inside the nuclei of our cells. Such activated "antinuclear antibodies"—the hallmark of lupus—trigger damage to tissues randomly distributed throughout the body, because virtually all our body's cells have nuclei.

The vast majority of EBV-infected people (most of us, that is) have no idea they're still sheltering a virus and never get lupus. But essentially everyone with lupus is EBV-infected, studies have shown. An EBV-lupus connection has long been suspected but never nailed down until now.
Although latent EBV is ubiquitous in the sense that almost everybody carries it, it resides in only a tiny fraction of any given person's B cells. As a result, until the new study, it was virtually impossible for existing methods to identify infected B cells and distinguish them from uninfected ones.
But researchers now developed an extremely high-precision sequencing system that enabled them to do this. They found that fewer than 1 in 10,000 of a typical EBV-infected but otherwise healthy individual's B cells are hosting a dormant EBV viral genome.

Employing their new EBV-infected-B-cell-identifying technology along with bioinformatics and cell-culture experimentation, the researchers found out how such small numbers of infected cells can cause a powerful immune attack on one's own tissues. In lupus patients, the fraction of EBV-infected B cells rises to about 1 in 400—a 25-fold difference.
It's known that the latent EBV, despite its near-total inactivity, nonetheless occasionally nudges the B cell in which it's been snoozing to produce a single viral protein, EBNA2. The researchers showed that this protein acts as a molecular switch—in geneticists' language, a transcription factor—activating a battery of genes in the B cell's genome that had previously been at rest. At least two of the human genes switched on by EBNA2 are recipes for proteins that are, themselves, transcription factors that turn on a variety of other pro-inflammatory human genes.

The net effect of all these genetic fireworks is that the B cell becomes highly inflammatory: It dons its "professional antigen-presenting cell" uniform and starts stimulating other immune cells (called helper T cells) that happen to share a predilection for targeting cell-nuclear components. These helper T cells enlist multitudes of other antinuclear B cells as well as antinuclear killer T cells, vicious attack dogs of the immune system.

When that militia bulks up, it doesn't matter whether any of the newly recruited antinuclear B cells are EBV-infected or not. (The vast majority of them aren't.) If there are enough of them, the result is a bout of lupus.
Part 3

Scientists suspect that this cascade of EBV-generated self-targeting B-cell activation might extend beyond lupus to other autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and Crohn's disease, where hints of EBV-initiated EBNA2 activity have been observed.
The million-dollar question: If about 95% of us are walking around with latent EBV in our B cells, why do some of us—but not all of us—get autoimmunity? The researchers speculate that perhaps only certain EBV strains spur the transformation of infected B cells into antigen-presenting "driver" cells that broadly activate huge numbers of antinuclear B cells.
Many companies are working on an EBV vaccine, and clinical trials of such a vaccine are underway. But that vaccine would have to be given soon after birth, they noted, as such vaccines are unable to rid an already-infected person of the virus.

Shady Younis et al, Epstein-Barr virus reprograms autoreactive B cells as antigen presenting cells in systemic lupus erythematosus, Science Translational Medicine (2025). DOI: 10.1126/scitranslmed.ady0210

Part 4

Bacteria spin rainbow-colored, sustainable textiles

In the future, clothes might come from vats of living microbes. Reporting in the journal Trends in Biotechnology, researchers demonstrate that bacteria can both create fabric and dye it in every color of the rainbow—all in one pot. The approach offers a sustainable alternative to the chemical-heavy practices used in today's textile industry.

The industry relies on petroleum-based synthetic fibers and chemicals for dyeing, which include carcinogens, heavy metals, and endocrine disruptors.

These processes generate lots of greenhouse gases, degrade water quality, and contaminate the soil, so researchers wanted to find a better solution.

Known as bacterial cellulose, fibrous networks produced by microbes during fermentation have emerged as a potential alternative to petroleum-based fibers such as polyester and nylon.

Researchers set out to create fibers with vivid natural pigment by growing cellulose-spinning bacteria alongside color-producing microbes. The microbial colors stemmed from two molecular families: violaceins—which range from green to purple—and carotenoids, which span from red to yellow.

But the first experiments failed. The team learned that the cellulose-spinning bacteria Komagataeibacter xylinus and the color-producing bacteria Escherichia coli interfered with each other's growth.

Tweaking their recipe, the researchers found a way to make peace between the microbes. For the cool-toned violaceins, they developed a delayed co-culture approach by adding in the color-producing bacteria after the cellulose bacteria had already begun growing, allowing each to do its job without thwarting the other.

For the warm-toned carotenoids, the team devised a sequential culture method, where the cellulose is first harvested and purified, then soaked in the pigment-producing cultures. Together, the two strategies yielded a vibrant palette of bacterial cellulose sheets in purple, navy, blue, green, yellow, orange, and red.

To see if the colors could survive the rigors of daily life, the team tested the materials by washing, bleaching, and heating them, as well as soaking them in acid and alkali. Most held their hues, and the violacein-based textile even outperformed synthetic dye in washing tests.

Researchers are  proposing an environmentally friendly direction toward sustainable textile dyeing while producing cellulose at the same time.

Accepting it is in your hands!

Scaling up production and competing with low-cost petroleum products are among the remaining hurdles. Real progress will also require a shift in the consumer mindset toward prioritizing sustainability over price.

But the bacteria-based fabrics are at least five years from store shelves.  

One-pot production of colored bacterial cellulose, Trends in Biotechnology (2025). DOI: 10.1016/j.tibtech.2025.09.019

Could altering mosquitoes' internal clocks stop them from biting?

People who live in the tropical areas where Aedes aegypti mosquitoes reside have probably known for centuries, or even millennia—thanks to their itchy bites—that the mosquitoes hunt most often at dawn and dusk.

A new study offers scientific proof of that hunting behavior, and new insight into the biological mechanism behind it. It also offers a potential path to reducing bites and helping stop the spread of deadly, mosquito-borne disease.

The research focuses on Aedes aegypti, a type of mosquito that lives primarily in tropical areas, and that can carry diseases like dengue, chikungunya, and Zika. Although this mosquito species cannot survive harsh winters, in recent years they have made their habitats in new areas as climate change enables them to thrive in more temperate climates.

There are many reasons people could, in theory, get more bites from these mosquitoes at dawn and dusk. It could be that they're just outside more, or that humans are more attractive to them at these times. This study focused on understanding if this biting pattern is also influenced by mosquitoes' own daily rhythm.

The research team began by video recording mosquitoes, and watching how they responded to carbon dioxide, a signal mosquitoes use to locate humans. The team used machine learning to quantify the mosquitoes' movements.
They found that the mosquitoes had a more persistent response to the same amount of carbon dioxide at dawn and dusk, exactly the times of day that many people (both mosquito researchers and not) have reported getting more bites.

This is consistent with the idea that they're actually better predators at that time of day.
Part 1

Suspecting that what was changing was not the mosquitoes' ability to sense us at these times of day, but the persistence, or aggressiveness, of their response, the research team used CRISPR-Cas9, a gene editing tool, to mutate a gene that controls mosquitoes' internal clocks..
They found that mutating the gene changed their behavioral timing, making the mosquitoes less persistently responsive to carbon dioxide in the morning. Normally, biting rates are high in the mornings, but when they disrupted the clock gene, the mutant mosquitoes were less successful at feeding during that time.
This is the first time we've found that there's an internal rhythm in the mosquito's behavior that could be driving these bites at dawn and dusk. Their internal clocks make them more persistent and predatory in their response to humans at these times of day.
Scientists could, in theory, find ways to lock mosquitoes in a state that prevents them from effectively seeking out humans. This could mean fewer uncomfortable bites and less disease.
But the mosquitoes in our place bite us all the time, not only during dawn and dusk.
When we try to protect ourselves at dawn and dusk, they evolve to bite us all through the day!
Hmmm! Researchers are you listening?

Linhan Dong et al, Time-of-day modulation in mosquito response persistence to carbon dioxide is controlled by Pigment-Dispersing Factor, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2520826122

Part 2

Can't sleep? Your microbiome may play a role

Sleep is an absolute necessity but most of us aren't getting enough of it.

Sleep is required to consolidate memories, regenerate tissue and build up energy for emotional regulation and alertness during the day. Sleep deprivation disrupts these processes, increases stress and predisposes people to heart, psychiatric and neurological problems.

Factors like stress, jet lag, work, diet and screen time all interfere with our ability to get the 7–9 hours of solid slumber needed to recover from the physiological pummels of the day.

But there's more to this story than travel and cellphones. How much sleep we get, and its quality, may have ties to the microbial variety your body harbours!

We may have some control over how our sleep plays out, but many pieces of the puzzle—particularly those at the cellular level—are out of our hands. Some of them, in fact, are in our guts.
Studies in animal models and humans suggest there is a bidirectional relationship between the composition of the gut microbiota and sleep quality and duration. In mice, altering the gut microbial community, such as through antibiotic treatment, can lead to poorer, more fragmented sleep.

Indeed, a more diverse microbiome is generally correlated with increased sleep efficiency and total sleep time. Better sleep is also associated with a higher abundance of bacteria with health-promoting metabolic functions, like production of short-chain fatty acids (SCFAs), whereas conditions like insomnia are linked with lower abundances of these microbes. Whether insomnia causes these alterations, or vice versa, is still unclear—likely, they feed into one another.

Like many of the chemicals and processes powering our bodies, the composition of the microbiome naturally fluctuates throughout the day. These changes are linked to host circadian processes, and alterations in sleep (e.g., jet lag) can disrupt microbiota rhythms, resulting in important health implications.

"[What] we find in stress-related disorders, [and] in many mental health disorders in general, is that they're often associated with disordered sleep and dysregulation of sleep and circadian rhythms.
Researchers recently showed in animal models that daily fluctuations in stress pathways closely linked to sleep (e.g., cortisol levels) are modulated by the microbiome. 

They found  that there are circuits in the brain that are sensitive to microbial signals. Now, they  are seeking to identify the mechanisms that underlie those sensitivities.

https://asm.org/articles/2025/november/cant-sleep-your-microbiome-m...

Part 2

The internal clock of immune cells: Is the immune system younger in the morning?

As the immune system ages, it reacts more slowly to pathogens, vaccines become less effective, and the risk of cancer increases. At the same time, the immune system follows a 24-hour rhythm, as the number and activity of many immune cells fluctuate throughout the day.

Researchers  have now investigated whether this daily rhythm influences the aging of the immune system and whether the immune system behaves "younger" or "older" at certain times of the day.

For the new study published in Frontiers in Aging, researchers took blood samples from participants in the morning, at noon, and in the evening. Using the so-called "IMMune Age indeX (IMMAX)," they determined each individual's immune age and analyzed how it changed throughout the day.

The IMMAX is a biomarker determined by the ratio of certain immune cells in the blood. As part of biological age, it correlates with actual chronological age.

Individual immune cells that are relevant for calculating the IMMAX fluctuate throughout the day. For example, in the morning, researchers observed an increased frequency of natural killer cells (NK cells)—key protective cells that defend the body against infections and cancer. In contrast, other immune cell types showed the opposite pattern.

The circadian rhythm regulates immune system activity. Hormones, body temperature, nerve signals, and messenger molecules tell immune cells when to move or become active. This leads to daily fluctuations in the number of immune cells in the blood. However, these fluctuations do not appear to influence immune age over the course of the day, as the researchers discovered. Despite measurable daily differences, the IMMAX remained largely stable, as individual immune cell types apparently balance each other out.

The IMMAX is a biomarker for immune age that is largely independent of the time of day. Nevertheless, slight differences were observed depending on a person's chronotype—that is, whether they are more active early in the day ("larks") or late in the day ("owls"). For early risers ("larks"), the IMMAX value decreased slightly from morning to noon. This suggests that the time of blood sampling in relation to waking up is important.
"When we wake up in the morning and become active, this apparently influences the movement of our immune cells and thus has a slight effect on the IMMAX value.

In large cohort studies, the timing of sampling is less critical, as fluctuations are balanced out.

Sina Trebing et al, Influence of circadian rhythm on the determination of the IMMune age indeX (IMMAX), Frontiers in Aging (2025). DOI: 10.3389/fragi.2025.1716985

The study findings can help develop early-stage cancer prevention strategies.

Researchers have discovered why a specific mutation leads to tumorous growth in human lungs. The same mutation, however, fails to develop a tumor in human breasts, reducing the chances of a cancer.

They focused on the human epithelial tissues, the thin sheets of cells that line our vital organs. That’s because eighty percent of all human cancers begin in epithelial tissues. 

epithelial cells act as the body’s first barrier and are constantly exposed to stress, damage, and mutations. In fact, both the lung and the breast epithelial tissues display ‘epithelial defense against cancer’ — the epithelium’s natural act against tumorous cells. That’s why the group tested a specific cancerous mutation that occurs in both breast and lung epithelial tissues.

Researchers have long recognized that breast and lung epithelial tissues exhibit distinct differences. Breast epithelium is relatively stable and compact — the cells are tightly packed with stronger junctions. On the other hand, lung epithelium expands and relaxes with each breath, which is why its cells are more flexible, elongated, and loosely connected.

The group, through a combination of live imaging and computer models, has determined how these differences directly lead to the lung epithelium being more prone to growing tumors compared to the breast.

Once a cancerous mutation sets in the breast tissue, single mutant cells are pushed out, and groups of cells get stuck together. In lung tissue, the same mutant cells spread easily and make finger-like shapes.

The team found that the “tug-of-war” forces between normal and mutant cells decide whether cancerous cells are removed, trapped, or allowed to grow. Thus, cell mechanics help explain tissue-specific cancer risk. The surprise was how directly those mechanics determine whether mutant cells are restrained or allowed to spread.

A belt forms around the tumor in the breast epithelia, raises tension, jams the mutant cluster, and often forces out single mutants. Thus, this belt restrains the tumor.

In the lung epithelia, the cells are more elongated, motile, and weakly connected. So, no such belt forms, allowing the mutant cells to survive, grow longer, and spread into the tissue.

The group’s work demonstrates a pathway to resisting the growth of mutations into tumors, and eventually, into cancers. 

https://elifesciences.org/reviewed-preprints/106893v1

How much protein you really need

Most official guidelines recommend a bare minimum of close to one gram of protein per kilogram of body weight per day. But many scientists object to suggestions flying around social media that people need m.... Here’s what experts advise:

• Protein needs can vary from person to person and can change throughout a lifetime. “For older adults, 1.2 grams per kilogram is just giving them a little extra protection,” says nutrition and exercise researcher Nicholas Burd.
• Meeting your protein needs with plants rather than meat is better for your heart and the planet, but it might require a greater variety of foods (and maybe supplements).
• If you’re getting enough calories and eating a varied diet, you’re probably getting enough protein.
• For most people, unless you have kidney disease, too much protein won’t hurt you.

https://www.nature.com/articles/d41586-025-03632-1?utm_source=Live+...

Our solar system is moving faster than expected

How fast and in which direction is our solar system moving through the universe? This seemingly simple question is one of the key tests of our cosmological understanding. A research team of astrophysicists has now found new answers, ones that challenge the established standard model of cosmology.

The study's findings have just been published in the journal Physical Review Letters.

Their analysis shows that the solar system is moving more than three times faster than current models predict. This result clearly contradicts expectations based on standard cosmology and forces us to reconsider our previous assumptions. 

To determine the motion of the solar system, the team analyzed the distribution of so-called radio galaxies, distant galaxies that emit particularly strong radio waves, a form of electromagnetic radiation with very long wavelengths similar to those used for radio signals. Because radio waves can penetrate dust and gas that obscure visible light, radio telescopes can observe galaxies invisible to optical instruments.

As the solar system moves through the universe, this motion produces a subtle "headwind": slightly more radio galaxies appear in the direction of travel. The difference is tiny and can only be detected with extremely sensitive measurements.

Using data from the LOFAR (Low Frequency Array) telescope, a Europe-wide radio telescope network, combined with data from two additional radio observatories, the researchers were able to make an especially precise count of such radio galaxies for the first time. They applied a new statistical method that accounts for the fact that many radio galaxies consist of multiple components. This improved analysis yielded larger but also more realistic measurement uncertainties.

Despite this, the combination of data from all three radio telescopes revealed a deviation exceeding five sigma, a statistically very strong signal considered in science as evidence for a significant result.

The measurement shows an anisotropy ("dipole") in the distribution of radio galaxies that is 3.7 times stronger than what the standard model of the universe predicts. This model describes the origin and evolution of the cosmos since the Big Bang and assumes a largely uniform distribution of matter.

If our solar system is indeed moving this fast, we need to question fundamental assumptions about the large-scale structure of the universe, say the cosmologists. 

Alternatively, the distribution of radio galaxies itself may be less uniform than we have thought. In either case, the current models are being put to the test.

The new results confirm earlier observations in which researchers studied quasars, the extremely bright centers of distant galaxies where supermassive black holes consume matter and emit enormous amounts of energy. The same unusual effect appeared in these infrared data, suggesting that it is not a measurement error but a genuine feature of the universe.

Lukas Böhme et al, Overdispersed Radio Source Counts and Excess Radio Dipole Detection, Physical Review Letters (2025). DOI: 10.1103/6z32-3zf4

Chinese team finds a fern that makes rare earth elements

Scientists have discovered a fern from South China that naturally forms tiny crystals containing rare earth elements (REEs). This breakthrough opens the door to a promising new way of "green mining" of these minerals called phytomining.

REEs are a group of 17 elements, all metals with similar properties that are essential for everything from wind turbines and electric car batteries to smartphones and medical scanners.

Extracting them is expensive and normally involves large-scale conventional mining operations that rely on harsh chemicals and cause significant pollution and land damage. That's why researchers are exploring cleaner, sustainable plant-based alternatives to collect REEs.

According to a paper published in the journal Environmental Science & Technology, the researchers studied the Blechnum orientale fern, which had been collected from REE-rich areas in South China. It was already known to be a hyperaccumulator, which is a plant that can grow in soil and water with high concentrations of metals and absorb them through its roots. But what they didn't know was the chemical form the REEs take when inside the plant. This knowledge is vital for designing the most efficient extraction process.

Using high-powered imaging technology and chemical analysis, the team discovered that the fern was forming nanoscale crystals of the REE-rich mineral monazite within its tissues, particularly in the cell walls and spaces between cells. Monazite is one of the main sources of rare earth elements in geological ore deposits worldwide.

The study authors also observed the crystal form, noting that it grows in a highly complex self-organizing pattern of tiny branches, likening it to a microscopic "chemical garden." This is the first time scientists have seen a living plant create a rare earth element crystal.

While we might not be going out to garden for REEs in the immediate future, the research is further proof that phytomining is feasible. The discovery, even with just one fern, strengthens the case that plants could one day provide a valuable, cheaper, and less destructive method for extracting much-needed rare earth elements.

 Liuqing He et al, Discovery and Implications of a Nanoscale Rare Earth Mineral in a Hyperaccumulator Plant, Environmental Science & Technology (2025). DOI: 10.1021/acs.est.5c09617

Magnetic nanoparticles that successfully navigate complex blood vessels may be ready for clinical trials
Magnetic microrobots with iron oxide and tantalum nanoparticles can be precisely guided through complex blood vessels using modular electromagnetic navigation, delivering drugs directly to target sites such as thrombi. These microrobots achieve over 95% delivery accuracy in realistic vessel models and animal tests, supporting readiness for clinical trials and potential applications beyond vascular occlusions.

Every year, 12 million people worldwide suffer a stroke; many die or are permanently impaired. Currently, drugs are administered to dissolve the thrombus that blocks the blood vessel. These drugs spread throughout the entire body, meaning a high dose must be administered to ensure that the necessary amount reaches the thrombus. This can cause serious side effects, such as internal bleeding.

Since medicines are often only needed in specific areas of the body, medical research has long been searching for a way to use microrobots to deliver pharmaceuticals to where they need to be: in the case of a stroke, directly to the stroke-related thrombus.

Now, a team of researchers at ETH Zurich has made major breakthroughs on several levels. They have published their findings in Science.

The microrobot the researchers use comprises a proprietary spherical capsule made of a soluble gel shell that they can control with magnets and guide through the body to its destination. Iron oxide nanoparticles in the capsule provide the magnetic properties.

Because the vessels in the human brain are so small, there is a limit to how big the capsule can be. The technical challenge is to ensure that a capsule this small also has sufficient magnetic properties.

The microrobot also needs a contrast agent to enable doctors to track via X-ray how it is moving through the vessels. The researchers focused on tantalum nanoparticles, which are commonly used in medicine but are more challenging to control due to their greater density and weight.

Combining magnetic functionality, imaging visibility and precise control in a single microrobot required perfect synergy between materials science and robotics engineering, which has taken the researchers many years to successfully achieve.

They developed precision iron oxide nanoparticles that enable this delicate balancing act.

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The microrobots also contain the active ingredient they need to deliver. The researchers successfully loaded the microrobots with common drugs for a variety of applications—in this case, a thrombus-dissolving agent, an antibiotic or tumor medication.

These drugs were released by a high-frequency magnetic field that heats the magnetic nanoparticles, dissolving the gel shell and the microrobot.

The researchers used a two-step strategy to bring the microrobot close to its target: first, they injected the microrobot into the blood or cerebrospinal fluid via a catheter. They went on to use an electromagnetic navigation system to guide the magnetic microrobot to the target location.

The catheter's design is based on a commercially available model with an internal guidewire connected to a flexible polymer gripper. When pushed beyond the external guide, the polymer gripper opens and releases the microrobot.
To precisely steer the microrobots, the researchers developed a modular electromagnetic navigation system suitable for use in the operating theater.

 Fabian C. Landers et al, Clinically ready magnetic microrobots for targeted therapies, Science (2025). DOI: 10.1126/science.adx1708. www.science.org/doi/10.1126/science.adx1708

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The rust that could reveal alien life

Iron rusts. On Earth, this common chemical reaction often signals the presence of something far more interesting than just corroding metal—for example, living microorganisms that make their living by manipulating iron atoms. Now researchers argue these microbial rust makers could provide some of the most promising biosignatures for detecting life on Mars and the icy moons of the outer solar system.

Researchers now have compiled a comprehensive review of how iron metabolizing bacteria leave distinctive fingerprints in rocks and minerals, and why these signatures matter for astrobiology. The research, published in Earth-Science Reviews, bridges decades of terrestrial microbiology with the practical challenges of searching for life beyond Earth.

Iron ranks among the most abundant elements in the solar system, and Earth's microorganisms have evolved remarkably diverse ways to exploit it. Some bacteria oxidize ferrous iron to generate energy, essentially breathing iron the way humans breathe oxygen. Others reduce ferric iron, using it as the final electron acceptor in their metabolism. These processes don't happen in isolation. Iron metabolizing microbes link their element of choice to the carbon and nitrogen cycles, coupling iron transformations to carbon dioxide fixation, organic matter degradation, and even photosynthesis.

The byproducts of these microbial reactions create what researchers call biogenic iron oxyhydroxide minerals. These aren't subtle traces. Organisms that thrive in neutral pH environments and oxidize iron produce distinctive structures such as twisted stalks, tubular sheaths, and filamentous networks of iron minerals mixed with organic compounds. The minerals precipitate as the bacteria work, forming rusty deposits that can persist in the geological record for billions of years.

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This durability makes iron biosignatures particularly attractive for planetary exploration. Unlike fragile organic molecules that degrade under radiation and harsh chemistry, mineralized iron structures can survive. Researchers have identified these biosignatures in environments ranging from hydrothermal vents on the ocean floor to terrestrial soils, from acidic mine drainage to neutral freshwater springs. Wherever liquid water contacts iron-bearing rocks, iron-metabolizing bacteria typically establish themselves.

Mars presents an obvious target. The planet's distinctive red color comes from oxidized iron in surface dust and rocks. Ancient Mars hosted liquid water, and spacecraft have documented iron-rich minerals throughout the geological record. If microbial life ever evolved on Mars, iron metabolism would have provided an accessible energy source. The minerals these hypothetical organisms produced could still exist, locked in ancient sediments awaiting discovery by rovers equipped with the right instruments.

The icy moons Europa and Enceladus offer different but equally compelling possibilities. Both harbor subsurface oceans beneath frozen shells. Europa's ocean likely contacts a rocky seafloor, where water and rock interactions would release dissolved iron. Enceladus actively vents ocean material through ice geysers at its south pole. Mission concepts propose sampling these plumes or landing near the vents, analyzing ejected particles for iron minerals that might betray biological origins.

The review emphasizes that recognizing biogenic iron minerals requires understanding how they form, what textures they create, and how they differ from abiotic iron precipitates. Mission planners must equip spacecraft with instruments capable of detecting not just iron minerals generally, but the specific morphological and chemical signatures that distinguish biology from geology.

The stakes are high. Finding iron biosignatures on another world wouldn't just confirm life exists elsewhere, it would reveal that the same fundamental chemistry supporting Earth's deep biosphere operates throughout the solar system.

Laura I. Tenelanda-Osorio et al, Terrestrial iron biosignatures and their potential in solar system exploration for astrobiology, Earth-Science Reviews (2025). DOI: 10.1016/j.earscirev.2025.105318

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How chromosomes separate accurately: Molecular 'scissors' caught in action

Cell division is a process of remarkable precision: during each cycle, the genetic material must be evenly distributed between the two daughter cells. To achieve this, duplicated chromosomes, known as sister chromatids, are temporarily linked by cohesin—a ring-shaped protein complex that holds them together until separation.

Researchers have uncovered the mechanism by which separase—the molecular ''scissors'' responsible for this cleavage—recognizes and cuts cohesin.

Their findings, published in Science Advances, shed new light on chromosome segregation errors that can lead to certain forms of cancer.

Before a cell divides, its chromosomes are duplicated. These identical copies, called sister chromatids, are held together by cohesin—a ring-like structure composed of several proteins that prevents premature separation.

When the cell is ready to divide, separase, a specialized enzyme, cleaves one of the cohesin subunits, the protein SCC1, allowing the chromatids to separate and the genetic material to be evenly distributed between the two daughter cells. Any malfunction in this process can compromise genome stability, potentially resulting in severe diseases, including cancer.

Using cryo-electron microscopy (cryo-EM)—a cutting-edge technique that enables biological samples to be visualized in their native state at near-atomic resolution—the team captured the interaction between separase and SCC1 and identified the precise cleavage sites on the protein.

Biochemical and structural analyses also revealed multiple "docking sites" on the surface of separase, ensuring high-affinity binding of SCC1 to separase prior to cleavage. These contact points include five phosphate-binding sites that recognize phosphorylated residues on SCC1.

These affinity experiments showed that these phosphate–separase interactions stabilize the complex and accelerate SCC1 cleavage, ensuring fast and precise separation of chromosomes.

The work provides an extensive functional and structural framework to understand how separase is regulated and how it recognizes its substrates.

Jun Yu et al, Substrate recognition by human separase, Science Advances (2025). DOI: 10.1126/sciadv.ady9807

Testosterone in body odor linked to perceptions of social status 

As humans, we are constantly navigating social status, using subconscious strategies to assert either our dominance or prestige.

We often use voice or  body language to communicate this. Imagine a politician with a slow, booming voice, expanding their chest and extending their arms, quickly asserting authority over their audience.

We also use our sense of smell, according to new research from the University of Victoria (UVic), published in Evolution and Human Behaviour.

This study examines the role of body odor in people's perceptions of others' social status. 

Researchers examined whether scent cues associated with levels of circulating testosterone impact people's social status judgments. They found that both male and female participants in their study perceived men with higher levels of testosterone to be more dominant than men with lower testosterone levels.

Chemical signaling is the most widespread form of communication on Earth. Many animals will use scent to express and understand social status within their group. Mice, for example, scent-mark their territory to assert their dominance.

Previous research shows that humans use two different strategies to assert and maintain social status: dominance and prestige. Dominance is coercive, using tactics to force compliance. Prestige, on the other hand, involves showing valuable skills and traits that lead others to show deference voluntarily.

Research also reveals that scent plays an important role in human communication—of fear, sickness, safety, attraction, and personality traits such as dominance and neuroticism.

This is the first study to directly examine whether humans use scent cues related to circulating testosterone levels in the formation of social status judgments.

No significant relationship was found in the study between testosterone levels and perceived prestige. Perceptions of dominance, on the other hand, were associated with higher testosterone levels.

This study contributes to a growing body of work seeking to understand how social communication occurs through scent. 

However, the findings should be interpreted with caution. The study involved a relatively small and uniform sample, and replication with larger and more diverse groups will be important to confirm whether these patterns hold.

Marlise K. Hofer et al, The role of testosterone in odor-based perceptions of social status, Evolution and Human Behavior (2025). DOI: 10.1016/j.evolhumbehav.2025.106752

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Hitler's DNA reveals possible genetic disorder tied to sexual and social behaviour

Adolf Hitler most likely suffered from the genetic condition Kallmann Syndrome that can manifest itself in undescended testicles and a micropenis, researchers  said this week, following DNA testing of the Nazi dictator's blood.

The new research also quashes the suggestion that Hitler had Jewish ancestry.

Popular World War II songs often mocked Hitler's anatomy but lacked any scientific basis.

The findings by an international team of scientists and historians now appear to confirm longstanding suspicions around his sexual development.

No one has ever really been able to explain why Hitler was so uncomfortable around women throughout his life, or why he probably never entered into intimate relations with women.

But now we know that he had Kallmann Syndrome, this could be the answer we've been looking for, say the researchers.

The research findings are featured in a new documentary, "Hitler's DNA: Blueprint of a Dictator." 

The testing found a "high likelihood" that Hitler had Kallmann Syndrome and "very high" scores—in the top one percent—for a predisposition to autism, schizophrenia and biopolar disorder. 

The research team stressed that such conditions, however, could not explain or excuse Hitler's warmongering or racist policies.

The testing was made possible after researchers obtained a sample of Hitler's blood from a piece of material taken from the sofa on which he shot himself.

The DNA results additionally rule out the possibility that Hitler had a Jewish grandfather via his grandmother.

Source: AFP

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