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Comment by Dr. Krishna Kumari Challa 13 hours ago

Closing your eyes might not help you hear better after all

Most people will close their eyes when trying to concentrate on a faint sound. Many of us have been told that keeping our eyes closed helps us hear better—that it frees up our brains' processing abilities and increases our auditory sensitivity. However, that strategy may sometimes backfire, particularly in environments with a lot of loud background noise.
Closing the eyes in noisy environments reduces the ability to detect faint sounds, contrary to common belief. Visual input, especially dynamic videos matching the sound, enhances auditory sensitivity. Eye closure leads to neural filtering that can suppress both noise and target sounds, while visual engagement helps the brain separate signals from background noise.
In The Journal of the Acoustical Society of America, researchers tested whether a person closing their eyes can really hear better in noisy environments.

To test this, volunteers listened to a collection of sounds through headphones amid background noise. Then, the volunteers adjusted the volume of the sounds until they could barely make them out over the background noise.

This test was conducted first with eyes closed, then with eyes open but looking at only a blank screen, then looking at a still picture corresponding to the sound, and finally, looking at a video matching up with the sound they were trying to hear.
To their surprise, the researchers found that, contrary to popular belief, closing one's eyes actually impairs the ability to detect these sounds! Conversely, seeing a dynamic video corresponding to the sound significantly improves hearing sensitivity.
To find an explanation for this result, the researchers attached electroencephalography (EEG) devices to the participants to monitor their brain activity. They determined that closing the eyes puts a participant's brain in a state of neural criticality, which more aggressively filters noises and quiet sounds, including the target sounds those participants were trying to detect.

In a noisy soundscape, the brain needs to actively separate the signal from the background, The researchers found that the internal focus promoted by eye closure actually works against you in this context, leading to over-filtering, whereas visual engagement helps anchor the auditory system to the external world.
The authors emphasize that this result is unique to noisy environments. With a calmer background, the conventional strategy of keeping their eyes closed likely does help people detect faint sounds. But because so much of our lives are spent surrounded by noise, it might be better to face the world with eyes wide open, say the researchers.

Visual engagement modulates cortical criticality and auditory target detection thresholds in noisy soundscapes, The Journal of the Acoustical Society of America (2026). DOI: 10.1121/10.0042380

Comment by Dr. Krishna Kumari Challa 13 hours ago

Engineered bacteria deliver cancer drug directly inside tumors in mice

Engineered Escherichia coli Nissle 1917 (EcN) can be modified to produce and deliver the anticancer drug Romidepsin (FK228) directly within tumors in mice. The bacteria selectively colonize tumors and release the drug in situ, resulting in targeted tumor therapy. This approach demonstrates potential for bacteria-assisted, tumor-targeted delivery of anticancer agents.

Ma C, et al. Engineered romidepsin biosynthetic pathways in Escherichia coli Nissle 1917 improve the efficacy of bacteria-mediated cancer therapy, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003657

Comment by Dr. Krishna Kumari Challa 14 hours ago

Heart disease risk tied to certain molecules made by gut microbes

Bloodstream levels of nine specific metabolites produced by gut microbes are statistically associated with the risk of developing coronary heart disease. These associations persist after accounting for factors such as age, family history, and diet, though some differences appear by race or age. The identified metabolites may serve as potential biomarkers or therapeutic targets for coronary heart disease.
In a study involving data from thousands of people, the risk of a new coronary heart disease diagnosis was statistically associated with bloodstream levels of nine specific molecules that are produced by gut microbes.
The human digestive tract naturally contains a large population of microbes. Different people have different proportions of different species of gut microbes, which produce different molecules during their normal, metabolic chemical reactions.

These metabolites can enter the bloodstream and exert a broad range of impacts, good and bad, on human health. Some gut microbe metabolites may be linked with a person's risk of coronary heart disease—the world's leading cause of death.

Using data from nearly 2,000 of the participants, researchers discovered several gut microbe metabolites associated with the risk of developing coronary heart disease. Then, they used the rest of the data to validate and refine these links—including external and quantitative validations, and accounting for many other factors known to be associated with risk of coronary heart disease, such as age, family health history, and diet.

The final analysis revealed nine specific gut microbe metabolites in the bloodstream that were associated with a higher or lower chance of developing coronary heart disease. These links remained consistent across some participants when stratified by lifestyle or family history. However, some differences in links between specific metabolites and heart disease risk were found when individuals were stratified by race or age.
This study underscores the link between gut microbes and heart health. On the basis of the findings, the researchers call for follow-up research into the nine metabolites they identified to determine whether they represent potentially promising avenues for development of novel ways to treat or prevent coronary heart disease.

Zheng Y, et al. Circulating gut microbial metabolites and risk of coronary heart disease: A prospective multi-stage metabolomics study.PLOS Medicine (2026). DOI: 10.1371/journal.pmed.1004750

Comment by Dr. Krishna Kumari Challa 14 hours ago

Hidden mutagens in your lipstick and water

Substances capable of mutating human genetic material—altering and permanently damaging it—are present in many everyday products. Researchers have, for the first time, detected mutagens and concurrently cytotoxic substances in food, meat, smoke flavourings, personal care products, and even water.
To achieve this, they developed a novel screening procedure enabling the determination of the mutagenicity of individual substances within complex mixtures. Furthermore, the new test procedure detects potential detoxification of mutagens in the body via simulated human liver metabolism. It revealed that detoxification within the body is minimal.

Katharina Schmidtmann et al, High-Throughput Testing for Unknown Mutagens and Cytotoxica via Duplex Planar Ames–Cytotoxicity Bioassay Including Metabolic S9 Activation, Analytical Chemistry (2026). DOI: 10.1021/acs.analchem.5c06690

Comment by Dr. Krishna Kumari Challa 15 hours ago

Scientists discover new heavy proton-like particle at CERN

A new heavy proton-like particle, Ξ_cc⁺, containing two charm quarks and one down quark, has been observed at CERN's LHC using the upgraded LHCb detector. The particle was identified via its decay into Λ_c⁺, K⁻, and π⁺, with a measured mass of 3,619.97 MeV/c², consistent with theoretical predictions and resolving previous uncertainties about its existence.

Details of the Ξ_cc⁺ discovery were presented at the Rencontres de Moriond Electroweak conference.

Comment by Dr. Krishna Kumari Challa 15 hours ago

In their new study, the researchers used the same technique to measure how the brain responds to not only propofol but two additional anesthesia drugs—ketamine and dexmedetomidine. Animals were given one of the three drugs while their brain activity was analyzed, including their response to auditory tones.

This study showed that the same destabilization induced by propofol also appears during administration of the other two drugs. This "universal signature" appears even though the three drugs have different molecular mechanisms: propofol binds to GABA receptors, inhibiting neurons that have those receptors; dexmedetomidine blocks the release of norepinephrine; and ketamine blocks NMDA receptors, suppressing neurons with those receptors.

Each of these pathways, the researchers hypothesize, affect the brain's balance of stability and excitability in different ways, and each leads to an overall destabilization of this balance.
All three of these drugs appear to do the exact same thing. In fact, you could look at the destabilization measure we use and you can't tell which drug is being applied.
Now that the researchers have shown that three different anesthesia drugs produce similar destabilization patterns in the brain, they think that measuring those patterns could offer a valuable way to monitor patients during anesthesia. While anesthesia is overall a very safe procedure, it does carry some risks, especially for very young children and for people over 65.

Similar destabilization of neural dynamics under different general anesthetics, Cell Reports (2026). DOI: 10.1016/j.celrep.2026.117048. www.cell.com/cell-reports/full … 2211-1247(26)00126-9

Part 2

Comment by Dr. Krishna Kumari Challa 15 hours ago

Three anesthesia drugs all have the same effect in the brain

When patients undergo general anesthesia, doctors can choose among several drugs. Although each of these drugs acts on neurons in different ways, they all lead to the same result: a disruption of the brain's balance between stability and excitability, according to a new  study published in the journal Cell Reports.

This disruption causes neural activity to become increasingly unstable, until the brain loses consciousness, the researchers found. The discovery of this common mechanism could make it easier to develop new technologies for monitoring patients while they are undergoing anesthesia.

What's exciting about that is the possibility of a universal anesthesia-delivery system that can measure this one signal and tell how unconscious you are, regardless of which drugs they're using in the operating room.

This work could help doctors ensure that patients stay unconscious throughout surgery without becoming too deeply unconscious, which can have negative side effects following the procedure.

Exactly how anesthesia drugs cause the brain to lose consciousness has been a longstanding question in neuroscience. In 2024, a study suggested that for propofol, the answer is that anesthesia works by disrupting the balance between stability and excitability in the brain.

It has to be excitable enough so different parts can influence one another, but if it gets too excited it goes off into chaotic activity.

When someone is awake, their brain is able to maintain this delicate balance, responding to sensory information or other input and then returning to a stable baseline.

"The nervous system has to operate on a knife's edge in this narrow range of excitability

In that 2024 study, the researchers found that propofol knocks the brain out of this state, known as "dynamic stability." As doses of the drug increased, the brain took longer and longer to return to its baseline state after responding to new input. This effect became increasingly pronounced until consciousness was lost. For that study, the researchers devised a computational model that analyzes neural activity recorded from the brain. This technique allowed them to determine how the brain responds to perturbations such as an auditory tone or other sensory input, and how long it takes to return to its baseline stability.

Part 1

Comment by Dr. Krishna Kumari Challa 15 hours ago

Why some moments endure: Episodic memory encoding fluctuates with brain's theta rhythms

For almost a century, psychologists and neuroscientists have been trying to understand how humans memorize different types of information, ranging from knowledge or facts to the recollection of important events. Past studies consistently showed that humans recall some experiences for longer and in greater detail than others.

Some psychological theories suggest that the encoding and retrieval of past event-related memories is not a continuous process. Instead, these two aspects of memory could be separate and could manifest at different times.

One memory-related theoretical framework, rooted in behavioral science, is the Separate Phases for Encoding and Retrieval (SPEAR) model. This model outlines the idea that the human brain rapidly switches between the encoding of information and the retrieval of stored information.

The switch between encoding and retrieval could be associated with a particular type of brainwaves, known as theta rhythms, which repeat several times per second, typically between 3 and 10 hertz (Hz). These brain waves have been hypothesized to support the coordination of memory processes.

Researchers  recently carried out a study aimed at testing this theory and the possibility that memory processes change moment-by-moment following this rhythmic pattern. Their findings, published in Nature Human Behavior, are aligned with the SPEAR model's predictions and suggest that the brain is only disposed to learn new information during brief time windows.

Why do some experiences endure in memory better than others?

Learning fluctuates rhythmically several times per second, with fortuitously timed experiences being more memorable. Although such fleeting opportunities for encoding would evade our awareness, they are predicted by a prominent model describing how theta rhythms in the brain coordinate memory—the SPEAR model.

The researchers found that memory encoding fluctuated at a theta rhythm (3–10 Hz), that these rhythms were not a by-product of rhythmic attention and that—like theta rhythms in the brain—memory rhythms were modulated by putative markers of acetylcholine. The findings provide behavioural evidence consistent with the SPEAR model of episodic memory.

They found that people's ability to memorize information did not stay constant, but it instead fluctuated rhythmically several times per second. This recorded rhythm was consistent with the frequency of theta brain waves, as predicted by the SPEAR model.

Interestingly, the results gathered by the researchers also suggest that the brain rhythms associated with the encoding of episodic memories are modulated by a chemical known as acetylcholine. This is a neurotransmitter known to play a role in attention, learning and memory processes.

This study offers evidence that supports the SPEAR model, suggesting that the encoding and retrieval of information occurs at alternating phases.

Thomas M. Biba et al, Episodic memory encoding fluctuates at a theta rhythm of 3–10 Hz, Nature Human Behaviour (2026). DOI: 10.1038/s41562-026-02416-5.

Comment by Dr. Krishna Kumari Challa yesterday

A brain pathway that allows people to quickly detect scary sounds and respond

Preclinical studies on animals have identified brain pathways that drive quick, protective fear responses to "scary" sounds.
Analysis of human brain imaging data identifies a pathway connecting auditory regions with a fear-related area, associated with both enhanced hearing in noisy settings and higher self-reported fearfulness. This pathway may facilitate rapid, unconscious responses to threatening sounds, similar to mechanisms known for visual fear processing.
Researchers examined links between different pathways in the brain and behavioral measures for emotion and sound processing. A pathway linking two auditory brain areas and a brain region involved in fear was associated with better hearing ability in noisy environments and increased self-reported fearfulness.

While a part of this pathway in the brain was previously described in humans, according to the researchers, this work reveals a new role for this pathway in quickly responding to "scary" sounds.
This pathway may be involved in the unconscious processing of acoustic fear, paralleling an already established pathway for unconscious processing of visual fear.

A Direct Auditory Subcortical Route to the Amygdala Associated with Fear in Humans, JNeurosci (2026). DOI: 10.1523/JNEUROSCI.1431-25.2026

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Comment by Dr. Krishna Kumari Challa yesterday

The seven hour cosmic explosion

Gamma-ray bursts are the most violent explosions in the universe. In a fraction of a second, they can release more energy than the sun will emit across its entire 10-billion-year lifetime. Most are over before you've had time to register them, gone in seconds, minutes at most. So when something arrived on 2 July 2025 that kept going for seven hours, fired three distinct bursts spread across an entire day, and then left behind an afterglow lasting months, astronomers knew immediately they were looking at something completely new.

GRB 250702B, detected by NASA's Fermi Gamma-ray Space Telescope, is the longest gamma-ray burst ever recorded and it dwarfs all others in duration.

A new paper published in Monthly Notices of the Royal Astronomical Society focuses on one of the most intriguing possibilities, an intermediate mass black hole. Black holes come in dramatically different sizes. At one end, you have stellar mass black holes, a few times heavier than the sun, formed when massive stars die. At the other, you have the supermassive monsters lurking at the centers of galaxies, millions or billions of solar masses across. In between sits a largely missing population, intermediate mass black holes, ranging from a few hundred to a hundred thousand solar masses. Theory says they should be common. Finding them has proven stubbornly difficult.

The researchers propose that GRB 250702B was produced when an ordinary star like our sun wandered too close to one of these intermediate mass black holes and was torn apart by its tidal forces. As the shredded stellar material spiraled inward and was consumed, it powered a relativistic jet of particles firing outward at close to the speed of light, generating the extraordinary gamma-ray emission Fermi detected.

Crucially, the repeating nature of the bursts fits this picture neatly. The star wasn't necessarily destroyed in one go. Models suggest it could have been partially stripped across multiple close passes before final disruption, each encounter generating a fresh burst of emission which would explain the near regular spacing of the three Fermi triggers.

Jonathan Granot et al, A milli-tidal disruption event model for GRB 250702B: main-sequence star disrupted by an IMBH, Monthly Notices of the Royal Astronomical Society (2026). DOI: 10.1093/mnras/stag328

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