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Comment by Dr. Krishna Kumari Challa on August 7, 2026 at 11:13am

Scientists discover a brain cycle that may explain why learning eventually stalls

For many who have struggled to learn a new language or instrument, it's a familiar pattern: They make rapid progress at first, then hit a plateau that no amount of diligent practice or concentration seems to break.

Biologists identified a physical mechanism in the brain that may help explain why such plateaus occur: A scaffold-like structure surrounding brain cells, called the extracellular matrix, helps control when the brain can change during learning. In the auditory cortex, this matrix loosens within hours of a practice session and rebuilds itself within about a day—a cycle that lets the learning from a session take hold before the next one. As a skill is mastered, the rebuilding cycle fades and eventually stops altogether, as if the brain has decided that learning is finished and it's time to protect what's been gained.
In the adult auditory cortex, extracellular matrix loosens within hours of training and rebuilds by about 24 hours, supporting learning and consolidation. This remodelling declines and ceases as skills are mastered. Enzymatic matrix disruption impaired learning and degraded retained performance, indicating roles in both plasticity and stability.

Caras, Melissa L., Experience-dependent modulation of extracellular matrix integrity supports perceptual skill learning and memory, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2601801123

Comment by Dr. Krishna Kumari Challa on August 7, 2026 at 11:09am

Why do people's pupils dilate when they're surprised?

When people encounter new information that challenges their expectations, their pupils are likely to dilate. This physiological response is a sign that something is happening in the brain to help the person adapt to the new situation, according to a new study.
Surprising events elicit activity in the part of the brain known as the locus coeruleus, which is the primary source of norepinephrine, the chemical messenger that drives the body's fight-or-flight stress response. This activity is correlated with a change in pupil diameter as well as with specific brain waves measured by electroencephalography (EEG).
The researchers found in their experiments that surprising colours—those that didn't match predictions—elicited pupil dilation and amplified certain brain waves. They also found that these measurements were related to reductions in bias and adjustments in learning: When images looked like what the participants thought they were going to see, participants were biased toward their expectations. Yet pupil and brain measurements showed that participants were also able to learn from unexpected results and adjust their subsequent predictions accordingly.

In surprising situations, the researchers found, the norepinephrine spike is almost like a refresh mechanism—it's a sign the brain is adjusting to new information that changes expectations.
The brain holds on to some mental context, and then when it recognizes that you're in a new situation, you replace that context. Changes in pupil diameter, as well as specific EEG readings, are external markers showing that the brain is loading that new context. This both limits the effect that the previous context has on perception and also provides a clean slate, unencumbered by previous expectations, thereby allowing one to learn faster.

Tiantian Li et al, Fluctuations in arousal reflect latent state transitions that facilitate behavioural optimization, Nature Human Behaviour (2026). DOI: 10.1038/s41562-026-02533-1

Comment by Dr. Krishna Kumari Challa on August 7, 2026 at 10:46am

Decades of data reveal who's most at risk of snakebites and how to prevent them

Snakebites aren't random but are predictably correlated with a variety of environmental and socioeconomic factors, according to a study published Aug. 6, 2026, in the journal PLOS Neglected Tropical Diseases .
Snakebite is considered a neglected tropical disease, responsible for as many as 1.4 million deaths per year and disproportionately affecting rural populations in low- and middle-income countries. However, limited information is available on the environmental and socioeconomic factors influencing snakebite incidence.
Across 142 studies (>200,000 cases), nearly 70% of snakebites occurred during outdoor work, especially farming and construction. Risk increased during rainy seasons and evening hours and was associated with poverty-related factors including inadequate footwear, insecure housing, and limited health education. Prevention should complement antivenom through workplace safety, housing, rural development, and education.
In the study, researchers synthesized data from 142 studies documenting more than 200,000 snakebites worldwide dating to the 1800s. The review found that snakebite is strongly related to occupation, with nearly 70% of cases occurring during outdoor work such as farming and construction. It is also related to timing, with most cases occurring during rainy seasons and during the evening and early-night hours. Snakebite cases were also correlated with factors related to poverty, such as lack of adequate footwear, poorly secured homes and limited access to health education.
These results highlight areas where targeted policies might significantly reduce the risk of snakebite, including workplace safety, rural development, housing improvement and health education. The authors note that the dataset is limited because it is mostly focused on South Asia and has inconsistent reporting of variables involved in each snakebite incident.
The authors say, "The scoping review told us something we needed to hear: limiting ourselves to antivenom will never address the behavioural and environmental factors that put people at risk in the first place. The inverse care law is particularly relevant to snakebite; the people most exposed to snakes—because of where they live and the work they do—are also the people furthest from a hospital that can treat them. You cannot fix that gap with antivenom alone; antivenom sits at the wrong end of the problem."

Behavioural and environmental risk factors associated with snake–human conflict: A scoping systematic review, PLOS Neglected Tropical Diseases (2026). DOI: 10.1371/journal.pntd.0014505

Comment by Dr. Krishna Kumari Challa on August 7, 2026 at 9:34am

High-tech techniques, including Raman spectroscopy and scanning electron microscopy, revealed that tiny, irregular plastic fragments floating in blood storage solutions were PVC particles shed from the bags. Raman spectroscopy identified the particles' chemical fingerprints, while scanning electron microscopy captured microscopic changes in blood transfusion bags. The microscopy also showed that plastic particles attached directly to the outer membranes of stored red blood cells.

Tests revealed that storing blood bags at room temperature caused significantly more plastic to break off than storing them at 4 °C did. Simulated transport placed additional physical stress on the bags, causing the plastic to crack and peel and releasing significantly more particles into the liquid than in bags that remained still.

When healthy red blood cells were exposed to these microplastic-containing fluids for 30 days, their intracellular ATP—the chemical energy that keeps them alive and maintains their shape—gradually declined. Some cells also lost their disk shape and became spiky over time.

The researchers also identified a potential solution—ultrafiltration, which passes the storage liquid through extremely fine filters before it is added to blood. It removed 78%–85% of the microplastics. With most of the particles filtered out, red blood cells retained their normal shape, maintained their energy levels and were protected from shape changes.

The findings provide direct evidence that microplastics contaminate blood storage systems and can affect the quality of stored blood.

Ning Li et al, Microplastics Released from Blood Storage Bags: A Hidden Contribution to Red Blood Cell Storage Lesions, Environment & Health (2026). DOI: 10.1021/envhealth.6c00110

Part 2

Comment by Dr. Krishna Kumari Challa on August 7, 2026 at 9:33am

Common blood storage bags may leach microplastics into stored blood

In the 1970s, PVC bags revolutionized the storage of blood and blood products for transfusion. Disposable plastic (PVC) bags replaced reusable glass bottles, making the process more convenient and safer from contamination. Over half a century later, the same disposable plastic bags are creating a new kind of problem because of microplastics (MPs). These tiny particles, less than 5 millimeters in size, are formed by the polymer degradation of plastic materials as they break down and age.

In a recent study published in Environment & Health, researchers from China investigated how microplastics are released from medical storage bags into the blood and preservation fluids used for transfusions.

They found PVC microplastics not only in blood-preservation fluids but also in stored blood samples, with microscopy showing that some particles attached to red blood cells. Their levels rose substantially during storage, increasing by roughly seven- to 20-fold over 30 days compared with freshly opened blood bags in the tested systems.

Storage conditions also played a role in the amount of plastic being shed. Microplastic levels increased with higher storage temperatures, and the bags were shaken to simulate transportation.

Microplastics do not belong anywhere on this planet, but they have made their way to every corner of Earth. There is growing evidence that these microscopic plastic particles have invaded many tissues and organs throughout the human body, including the lungs, liver, placenta, blood and blood vessels.

Studies have already documented that microplastics leach from everyday disposable medical gear, including IV infusion sets, syringes, IV bags and even the tubing used in kidney dialysis. For instance, IV infusion bags alone can shed up to 5,455 plastic particles into every litre of fluid.

Blood bags are typically made of PVC.

Part 1

Comment by Dr. Krishna Kumari Challa on August 7, 2026 at 9:28am

Sunlight-powered setup generates quantum entanglement

Quantum entanglement is crucial for applications such as secure communication, ultra-precise sensing and high-performance computation.

Today's quantum technologies rely on energy-intensive lasers, raising concerns that scaling them up could further increase energy demands. In new work, researchers have demonstrated that quantum entanglement between photons can be generated directly from sunlight, offering a potential alternative.
In Optica, the researchers report that the entanglement they achieved using sunlight was comparable to laser-based approaches after accounting for differences in the bandwidth of the input light.
This technology could one day enable satellites to create secure encryption keys using the sunlight already abundant in space, reducing the need for onboard lasers and much of the supporting hardware.
Sunlight-driven entanglement generation could also provide the crucial ingredient needed to scale up quantum computing without adding to the energy burden.
Researchers conducted an outdoor experiment at MPL. Using quantum state tomography to characterize the resulting quantum state, they found that the entanglement generated from sunlight was about 94% similar to a perfectly entangled state. Additionally, the photons produced during the experiment were correlated in a way that violated Bell's inequality, indicating that the correlation has no classical explanation and must be a result of quantum entanglement.

Now that the proof-of-principle demonstration is complete, the researchers are working toward a field-deployable product by making improvements in brightness and the quality of entanglement.

Cheng Li et al, Generating quantum entanglement from sunlight, Optica (2026). DOI: 10.1364/optica.601797

Comment by Dr. Krishna Kumari Challa on August 6, 2026 at 9:20am

Even light activity may lower risk of stroke and death in people with atrial fibrillation

AFib is a quivering or irregular heartbeat that occurs in the heart's upper chambers, known as the atria. According to the American Heart Association, it can lead to blood clots, stroke and other heart-related conditions.
Being physically active was linked to a lower risk of stroke and death for adults with atrial fibrillation, or AFib, according to new, independent research published this week in the Journal of the American Heart Association.

Among 87,340 adults followed for about 15 years, higher self-reported physical activity was associated with 9–19% lower stroke risk and 11–22% lower all-cause mortality. Associations were similar with and without atrial fibrillation; among those with atrial fibrillation, activity corresponded to 0.5–1.2 additional years of life.

The results from this study indicate that physical activity was associated with a reduced risk of stroke and death in individuals with and without atrial fibrillation. So, regular physical activity is important for all and could be an important preventive strategy for people with AFib.

The American Heart Association recommends that all adults spend less time sitting and get at least 150 minutes of moderate-intensity aerobic activity or 75 minutes of vigorous aerobic activity per week. In addition, adults should participate in moderate muscle-strengthening activity at least twice a week.

What did the analysis find?

Compared to adults who were inactive, adults with a low, moderate or high level of physical activity had a 9%, 19% and 18% lower risk of stroke, respectively.
Having a low, moderate or high level of physical activity was associated with an 11%, 18% and 22% lower risk of death from any cause, respectively.
These benefits were similar regardless of whether a person had AFib. This suggests that having AFib does not change the relationship between physical activity and stroke.
For people with AFib, staying active was tied to living an average of 0.5 to 1.2 years longer compared with those who were inactive.

www.ahajournals.org/doi/10.1161/JAHA.126.048812

Comment by Dr. Krishna Kumari Challa on August 6, 2026 at 9:19am

Act now on microplastic risks, businesses urged

A new white paper released by experts at the UTS Business School highlights the risks businesses face if they ignore growing scientific evidence and consumer awareness of the dangers posed by microplastics.

Microplastics are tiny plastic fragments, or synthetic polymers, that exist throughout supply chains and in the wider environment. They've been found in even the most remote places on Earth.

Primary microplastics are purposely added to products such as paint, cosmetics or cleaning products such as handwash. Secondary microplastics result from the breakdown of plastics in the environment, such as a plastic bag breaking down in a landfill.

All available evidence points to both types of microplastics being pervasive and persistent. Evidence is emerging that they're implicated in harm to human health and global ecosystems."

The white paper, "Microplastics: Preparing for Australia's Next Regulatory Shift," highlights evidence that global plastic production now exceeds 450 million tonnes (496 million tons) per year and could almost triple to 1.2 billion tonnes (1.3 billion tons) under a business-as-usual scenario.

Microplastics are pervasive in products, supply chains and ecosystems, with emerging evidence of human-health and environmental harm. Plastic production exceeds 450 million tonnes annually and may nearly triple without intervention. Businesses face increasing regulatory, reputational and litigation risks, requiring monitoring, reporting and reduction of primary and secondary microplastic pollution.

As the science and engineering behind industrial monitoring advance, businesses will be expected to track the level of microplastics in their products and control secondary microplastic pollution."

The white paper highlights many actions businesses can take now to proactively manage risks related to microplastic exposure.

Increased monitoring and transparent reporting, circular business models, recycled-content products and materials innovation can build trust and generate efficiencies in the face of consumer concern.

Businesses that communicate credibly about their microplastic footprints and align marketing practices with actual reduction commitments will be better placed to build durable brand equity.

The question is not whether supply chains including plastics will change but how quickly, and who will lead it.

Martina Linnenluecke et al, Microplastics: Preparing for Australia's Next Regulatory Shift, University of Technology Sydney (2026). DOI: 10.71741/4pyxmbnjaq.32583060

Comment by Dr. Krishna Kumari Challa on August 6, 2026 at 9:18am

Birth order may influence your disease risk later in life, study finds

Whether you are first-born or second-born may be associated with your risk of developing certain diseases, according to a new study published in Nature Health.

Previous research has found that younger siblings often have lower rates of allergies and asthma, which may be because their older brothers or sisters bring more microbes into the home. But it was unclear whether birth order was linked more broadly to health risks across the body.

In this study, scientists analyzed a health records database of more than 10 million individuals from more than 5 million two-child families. The data were collected over two decades from commercial insurance claims.

The team screened for 569 disease categories using two approaches. First, they compared 1.6 million first-borns with second-borns from different families who were matched by sex, birth year, location and similar parental ages. They also directly compared first-born and second-born siblings within the same household across all families. This helped account for shared genetics, parenting and home environments.

Of 418 diseases with enough cases to analyze, the scientists found that 150 showed significant birth-order associations. First-borns were more often diagnosed with neurodevelopmental and some mental health conditions, including autism and ADHD, tics and Tourette syndrome, depression and anxiety. They also had higher diagnosis rates for allergy-related conditions like asthma, allergic rhinitis and food allergies.

Meanwhile, second-born children more often had diagnoses of substance abuse, migraines, digestive issues like gastritis, shingles and some joint conditions. "Birth order is associated with disease risk more broadly than previously appreciated," the study authors wrote.

The researchers suggested several possible reasons birth order might influence disease risk. One possibility is that first-time parents may watch their first child more closely, leading to earlier diagnoses of conditions like autism and ADHD.

Second-borns may also be exposed to everyday microbes brought home by older siblings, which may help their immune systems develop greater tolerance and lower the risk of allergies. For behavioral risks like substance abuse, younger siblings may also be exposed to older peer groups at an earlier age.

"The most conservative interpretation is that neurodevelopmental associations probably reflect a mixture of pregnancy-order biology, parental surveillance, diagnostic timing, and residual confounding rather than one uniform mechanism."

The findings show that these statistical links are clear across millions of people, but the actual risk difference for any single child is quite small.

It is also worth noting that these are statistical associations and cannot be interpreted as direct evidence that birth order causes a particular disease.

Benjamin Kramer et al, Birth order and disease risk across the human phenome, Nature Health (2026). DOI: 10.1038/s44360-026-00177-z

Comment by Dr. Krishna Kumari Challa on August 5, 2026 at 10:21am

Brain scans reveal tau buildup in late-onset psychosis

Hallucinations and delusions that appear for the first time in midlife or later are often treated as psychiatric symptoms whose biological cause is unclear. The study, published in Molecular Psychiatry suggests that, for many patients, these symptoms may be linked to brain changes also seen in dementia.
Among 37 people with psychosis onset after age 40, 65% had tau PET positivity and 35% had amyloid positivity, versus 15% and 2% of 47 healthy controls. Tau patterns included amyloid-positive Alzheimer-type and amyloid-negative forms; greater parietal tau in amyloid-positive patients correlated with poorer executive function.
Using positron emission tomography, or PET, the research team found that about 65% of patients who developed psychosis after age 40 showed abnormal buildup of tau, a protein associated with Alzheimer's disease and other forms of dementia. By comparison, tau PET positivity was seen in about 15% of healthy older controls. The study also found amyloid PET positivity in 35% of patients, compared with 2% of controls.

The findings provide the first in vivo evidence that diverse tau-related brain changes may be involved in late-onset psychosis. Until now, earlier epidemiological and postmortem studies had suggested a possible relationship between late-life psychotic symptoms and neurodegeneration, but direct evidence in the living brain had been limited.

Patients can show the same symptoms, such as hallucinations or delusions, but their clinical course and response to treatment can be very different.

Manabu Kubota et al, High prevalence of tau pathologies in late-onset psychosis: A PET study, Molecular Psychiatry (2026). DOI: 10.1038/s41380-026-03749-3

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