Comment

Comment by Dr. Krishna Kumari Challa on October 1, 2025 at 10:16am

Scientists read mice's 'thoughts' from their faces

It's easy to read emotions on people's faces—each one has its clear, unmistakable signature. But what about thoughts? A study published in Nature Neuroscience shows that mice's problem-solving strategies can be deciphered from subtle facial movements.

According to the authors, this is a proof of concept that the contents of the mind can be read out from video recordings, potentially offering powerful new research and diagnostic tools.

Scientists found that they can get as much information about what the mouse was 'thinking' as they could from recording the activity of dozens of neurons.

Having such easy access to the hidden contents of the mind could provide an important boost to brain research. However, it also highlights a need to start thinking about regulations to protect our mental privacy.

 Facial expressions in mice reveal latent cognitive variables and their neural correlates, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02071-5.

Comment by Dr. Krishna Kumari Challa on September 30, 2025 at 6:50am

Mamba snake bites worsen after antivenom

Mamba (Dendroaspis species) snake bites are a significant threat in sub-Saharan Africa, accounting for 30,000 deaths annually.

A breakthrough study has discovered a hidden dangerous feature of the black mamba, one of the most venomous snakes in the world.

The study revealed the venoms of three species of mamba were far more neurologically complex than previously thought, explaining why antivenoms were sometimes ineffective. This research was published in Toxins.

The black mamba, western green mamba and Jamesons mamba snakes aren't just using one form of chemical weapon, they're launching a coordinated attack at two different points in the nervous system.

If you're bitten by 3 out of 4 mamba species, you will experience flaccid or limp paralysis caused by postsynaptic neurotoxicity.

Current antivenoms can treat the flaccid paralysis but this study found the venoms of these three species are then able to attack another part of the nervous system causing spastic paralysis by presynaptic toxicity.

Researchers previously thought the fourth species of mamba, the eastern green mamba, was the only one capable of causing spastic paralysis.

This finding resolves a long-standing clinical mystery of why some patients bitten by mambas seem to initially improve with antivenom and regain muscle tone and movement only to start having painful, uncontrolled spasms.

The venom first blocks nerve signals from reaching the muscles, but after the antivenom is administered, it then overstimulates the muscles.

It's like treating one disease and suddenly revealing another.

Researchers  also found the venom function of the mambas was different depending on their geographic location, particularly within populations of the black mamba from Kenya and South Africa.

This further complicates treatment strategies across regions because the antivenoms are not developed to counteract the intricacies of the different venoms.

By identifying the limitations of current antivenoms and understanding the full range of venom activity, we can now directly inform evidence-based snakebite care.

 Lee Jones et al, Neurotoxic Sleight of Fang: Differential Antivenom Efficacy Against Mamba (Dendroaspis spp.) Venom Spastic-Paralysis Presynaptic/Synaptic vs. Flaccid-Paralysis Postsynaptic Effects, Toxins (2025). DOI: 10.3390/toxins17100481

Comment by Dr. Krishna Kumari Challa on September 30, 2025 at 6:21am

Endotoxin concentrations were measured using the Limulus Amebocyte Lysate (LAL) assay, then researchers used DNA sequencing and source tracking to identify the Gram-negative bacteria they came from. Finally, they applied mixture-toxicity modeling to estimate how much these endotoxins contributed to the overall harmful effects of PM2.5 exposure.

They found that despite making up only a minuscule fraction of the total PM2.5 mixture, it drove about 0.1 to 17% of the IL-8 release triggered by PM2.5.

Among all reported PM2.5 components, endotoxin demonstrated the highest toxicity-to-mass contribution ratio, 10,000:1 to 100,000:1, establishing its extreme biological potency. These findings show that less is indeed more.

The researchers note that this study brings to light the importance of identifying highly toxic components present in low concentrations and tracing their sources. Pinpointing these toxicity drivers can help us design cost-effective strategies in which even modest reductions in PM2.5 mass could yield substantial decreases in overall toxicity.

 Jinyan Yu et al, Disproportionately Higher Contribution of Endotoxin to PM_2.5 Bioactivity than Its Mass Share Highlights the Need to Identify Low-Concentration, High-Potency Components, Environmental Science & Technology (2025). DOI: 10.1021/acs.est.5c07255

Part 2

Comment by Dr. Krishna Kumari Challa on September 30, 2025 at 6:20am

Bacterial endotoxins are high-potency, low-mass drivers of PM₂.₅ toxicity, sampling study reveals

Endotoxin, a toxic chemical found in bacteria, makes up only 0.0001% of PM_2.5 fine particles but packs a serious punch when it comes to its bioactivity.

According to a study by researchers endotoxin drives 0.1–17% of the inflammatory responses triggered by these airborne particles, with its toxicity contribution being three to five orders of magnitude higher than its mass contribution.

Air pollution is now the world's leading environmental health threat, linked to more than three million premature deaths every year. One of the key culprits is PM2.5, which refers to airborne particles smaller than 2.5 micrometers, small enough to slip deep into the lungs and even seep into the bloodstream.

Scientists have long been focusing on PM2.5 because evidence consistently links it to respiratory illnesses, such as asthma, chronic obstructive pulmonary disease, and airway inflammation. Studies suggest that the damage caused by PM2.5 could be due to oxidative stress and the triggering of immune responses in the lungs following exposure.

PM2.5 is a complex atmospheric cocktail of natural and anthropogenic particles containing biological, inorganic, and organic constituents. For decades, researchers have extensively studied the impact of chemicals—including transition metals, polycyclic aromatic hydrocarbons, and industrial smoke—produced by human activities. These components, however, contribute to less than half of the respiratory damage inflicted by PM2.5, leaving roughly 60% of its impact still unexplained.

Researchers of this study conducted daily 24-hour PM_2.5 sampling for a year across an urban and coastal area of Hong Kong. To assess inflammatory responses, the researchers exposed human bronchial epithelial cells to PM_2.5 and measured the release of interleukin-8 (IL-8)—a small protein, called a cytokine, that is released by the immune system— as a marker of inflammation.

Part 1

Comment by Dr. Krishna Kumari Challa on September 27, 2025 at 7:20am

Researchers then adapted these into five scenarios for children to see if they could elicit information avoidance. For example, each child was asked to imagine their favorite and least favorite candy. They were then asked if they wanted to watch a video about why eating that candy was bad for their teeth.

They found that, whereas younger children really wanted to seek information, older children started to exhibit these avoidance tendencies. For example, they didn't want to know why their favorite candy was bad for them, but they were totally fine learning why their least favorite candy is bad for them.
This finding held for all motivations except for competency. Children of all ages were not afraid to learn if they'd done badly on a test, for example.

To avoid avoidance, she suggests thinking through why you might be avoiding something—possibly prioritizing short-term comfort over long-term benefits. Researchers posit that it could help to reframe uncomfortable information as useful and valuable.

Research suggests that intervening while children are still young could keep them from falling into avoidance traps and have compounding benefits.
Humans have this propensity to want to resolve uncertainty, but when the resolution is threatening, people might flip to avoidance instead.
If all else fails, she advises, mimic what children do best: Follow your curiosity.

Radhika Santhanagopalan et al, Becoming an Ostrich: The Development of Information Avoidance, Psychological Science (2025). DOI: 10.1177/09567976251344551

Part 2

Comment by Dr. Krishna Kumari Challa on September 27, 2025 at 7:09am

Origins of the 'Ostrich Effect': Researchers pinpoint the age we start avoiding information—even when it's helpful

In a world of information overload, it can feel soothing to stick your head in the sand.

According to psychologists, avoiding information when it's uncomfortable is a common adult behavior, often referred to as the "Ostrich Effect."

But how do we become an ostrich? Children are notorious for seeking out information, often in the form of endless questions. So when do we sprout feathers and decide that, actually, the number of calories in a slice of cake is none of our business?

This behavioral origin point was exactly what researchers wanted to pin down.

In a study published in Psychological Science, a research team discovered that as children aged, the tendency to avoid information grew stronger.

Though 5- and 6-year-olds still actively sought information, 7- to 10-year-olds were much more likely to strategically avoid learning something if it elicited a negative emotion.

Why is it that children are these super curious people, but then we somehow end up as these information avoiders as adults?

In their initial experiment, the researchers looked at five reasons why we might willfully choose to remain ignorant:
To avoid negative emotions like anxiety or disappointment
To avoid negative information about our own likability or competence
To avoid challenges to our beliefs
To protect our preferences
To act in our own self-interest (perhaps while trying to appear not self-interested)
Part 1

Comment by Dr. Krishna Kumari Challa on September 27, 2025 at 7:00am

Million-year-old skull could change human evolution timeline

A digital reconstruction of a million-year-old skull suggests humans may have diverged from our ancient ancestors 400,000 years earlier than thought and in Asia not Africa, a study said this week.

The findings are based on a reconstruction of a crushed skull discovered in China in 1990, and have the potential to resolve the longstanding "Muddle in the Middle" of human evolution, researchers said.

But experts not involved in the work cautioned that the findings were likely to be disputed, and pointed to ongoing uncertainties in the timeline of human evolution.

The skull, labeled Yunxian 2, was previously thought to belong to a human forerunner called Homo erectus.

But modern reconstruction technologies revealed features closer to species previously thought to have existed only later in human evolution, including the recently discovered Homo longi and our own Homo sapiens.

It suggests that by one million years ago, our ancestors had already split into distinct groups, pointing to a much earlier and more complex human evolutionary split than previously thought.

If the findings are correct, it suggests there could have been much earlier members of other early hominins, including Neanderthals and Homo sapiens, the study says.

It also "muddies the waters" on longstanding assumptions that early humans dispersed from Africa.

There's a big change potentially happening here, where east Asia is now playing a very key role in hominin evolution.

The research, published in the journal Science, used advanced CT scanning, structure light imaging and virtual reconstruction techniques to model a complete Yunxian 2.

The scientists relied in part on another similar skull to shape their model, and then compared it to over 100 other specimens.

The resulting model "shows a distinctive combination of traits," the study said, some of them similar to Homo erectus, including a projecting lower face.

But other aspects, including its apparently larger brain capacity, are closer to Homo longi and Homo sapiens, the researchers said.

"Yunxian 2 may help us resolve what's been called the 'Muddle in the Middle,' the confusing array of human fossils from between 1 million and 300,000 years ago.

The findings are only the latest in a string of recent research that has complicated what we thought we know about our origins.

Xiaobo Feng et al, The phylogenetic position of the Yunxian cranium elucidates the origin of Homo longiand the Denisovans, Science (2025). DOI: 10.1126/science.ado9202

Comment by Dr. Krishna Kumari Challa on September 26, 2025 at 9:10am

Mucus contains molecules that block Salmonella infection, study reveals

Mucus is more than just a sticky substance: It contains a wealth of powerful molecules called mucins that help to tame microbes and prevent infection. In a new study,  researchers have identified mucins that defend against Salmonella and other bacteria that cause diarrhea.

The researchers now hope to mimic this defense system to create synthetic mucins that could help prevent or treat illness in soldiers or other people at risk of exposure to Salmonella. It could also help prevent "traveler's diarrhea," a gastrointestinal infection caused by consuming contaminated food or water.

Mucins are bottlebrush-shaped polymers made of complex sugar molecules known as glycans, which are tethered to a peptide backbone. In this study, the researchers discovered that a mucin called MUC2 turns off genes that Salmonella uses to enter and infect host cells.

Mucus lines much of the body, providing a physical barrier to infection, but that's not all it does.

Researchers identified mucins that can help to disarm Vibrio cholerae, as well as Pseudomonas aeruginosa, which can infect the lungs and other organs, and the yeast Candida albicans.

The researchers found in the new study that when they exposed Salmonella to a mucin called MUC2, which is found in the intestines, the bacteria stopped producing the proteins encoded by SPI-1, and they were no longer able to infect cells.

Further studies revealed that MUC2 achieves this by turning off a regulatory bacterial protein known as HilD. When this protein is blocked by mucins, it can no longer activate the T3SS genes.

Using computational simulations, the researchers showed that certain monosaccharides found in glycans, including GlcNAc and GalNAc, can attach to a specific binding site of the HilD protein. However, their studies showed that these monosaccharides can't turn off HilD on their own—the shutoff only occurs when the glycans are tethered to the peptide backbone of the mucin.

The researchers also discovered that a similar mucin called MUC5AC, which is found in the stomach, can block HilD. And, both MUC2 and MUC5AC can turn off virulence genes in other foodborne pathogens that also use HilD as a gene regulator.

The researchers now plan to explore ways to use synthetic versions of these mucins to help boost the body's natural defenses and protect the GI tract from Salmonella and other infections.

Kelsey M. Wheeler et al, Mucus-derived glycans are inhibitory signals for Salmonella Typhimurium SPI-1-mediated invasion, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.116304

Comment by Dr. Krishna Kumari Challa on September 26, 2025 at 9:03am

Squirrels bite when they feel threatened, cornered, or are aggressively seeking food. They can also bite inadvertently by mistaking a finger for a treat or startling when a hand is presented to them. While usually a defensive action or a form of play, squirrels lack the bite inhibition of domesticated animals, and their bites, though not typically malicious, can be deep and pose a risk of infection. 

Reasons for biting:

Self-defense: Like any wild animal, squirrels will bite to protect themselves if they feel endangered.
Aggression for food: Squirrels may become aggressive if they are accustomed to being fed by humans and approach to get a meal, according to Critter Control.
Accidental bites: Squirrels don't have the same depth perception as humans and can mistakenly bite a finger when trying to take a treat.
Nesting: A mother squirrel in a nesting area, such as an attic, may bite if she feels cornered or threatened.
Play behaviour: Squirrels also "play bite" to practice skills they will use as adults, similar to how siblings interact.
Risks of a squirrel bite:
Infection: Because squirrels are wild rodents, a bite can lead to an infection.
Diseases: Though rabies is rare in squirrels, they can carry other diseases, such as the plague, which is transmitted by fleas.
What to do if a squirrel bites:
Wash the wound: Immediately wash the wound thoroughly with soap and water to reduce the risk of infection.
Seek medical attention: Consult a healthcare professional to determine if a tetanus shot is needed and to monitor for any signs of infection.

Comment by Dr. Krishna Kumari Challa on September 26, 2025 at 8:59am

Trees are dying at an alarming rate

The rise in tree mortality is troubling for local forest ecosystems. As a global phenomenon, however, it has a significant social impact that remains poorly understood.

We don't currently know whether climate change will lead to the death of 10% or 50% of all trees worldwide.

An international group of more than 100 forest researchers are reviewing almost 500,000 forest monitoring studies from 89 countries and five continents. The researchers found that the main cause of tree mortality is anthropogenic (human-induced) climate change and its consequences: heat, dry air and soil, forest fires, storms, and increased insect damage and plant diseases.  

In the article published in New Phytologist, the researchers aimed to identify methods, requirements and data gaps in monitoring tree mortality trends. 

Towards a global understanding of tree mortality, New Phytologist (2025). DOI: 10.1111/nph.20407

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