Comment

Comment by Dr. Krishna Kumari Challa on October 28, 2025 at 7:08am

If faults do indeed become stronger when they move, then these already broken pieces will quietly slip past each other, and in doing so, act as a barrier. That makes it harder for earthquakes to increase in size. This makes it possible to lower the estimated risk of an earthquake, as this risk is primarily determined by the maximum magnitude of an earthquake.

Meng Li et al, Frictional healing and induced earthquakes on conventionally stable faults, Nature Communications (2025). DOI: 10.1038/s41467-025-63482-3

Part 2

Comment by Dr. Krishna Kumari Challa on October 28, 2025 at 7:08am

Why earthquakes sometimes still occur in tectonically silent regions

Earthquakes in some parts of stable world should not be able to occur even if the subsurface has been exploited for decades. This is because the shallow subsurface behaves in such a way that faults there become stronger as soon as they start moving. At least that is what geology textbooks teach us. And so, in theory, it should not be possible for earthquakes to occur. So why do they still occur in such nominally stable subsurfaces?

Geosciences researchers  considered this question. They discovered that as a result of millions of years of inactivity, extra stress can build up on the faults which can result in a single release. This research, recently published in the journal Nature Communications, is vitally important in the search for safe locations for applications such as geothermal energy production and energy storage.

Faults can be found almost everywhere. Faults in the shallow subsurface are usually stable, so we do not expect shock movements to occur along them. Nevertheless, shock movements often do occur in the stable first few kilometers of the subsurface. In such instances, we generally find a correlation with human activities. What exactly explains that paradox of shallow faults, which become stronger with movement, but then suddenly become weak and are subsequently released with a tremor?

Induced earthquakes (those caused by human activities) often take place on inactive faults that have not moved for millions of years. Although these faults do not move, we still observe a very slow growth of the surface that connects them. This sort of 'fault healing' gives rise to additional strength. It is this extra fault strength that can cause an acceleration once a fault has been set in motion. This acceleration is what causes earthquakes to occur in stable subsurfaces, despite textbooks telling us that this ought not to happen there.

As such areas do not have a history of earthquakes, the people living there are more at risk as infrastructure has not been built to withstand earthquakes. "Furthermore, these earthquakes take place at a depth where human activities occur, in other words, no more than several kilometers deep. That is considerably less deep than the majority of natural earthquakes." Therefore, they can be more hazardous and cause more ground shaking.

Interestingly, this potential acceleration, in the form of an earthquake, occurs only once. As soon as that extra fault strength, which has been built up over millions of years, finds a way out, the situation becomes stable again.

As a result, there is no more earthquake activity at that spot. This means that, although the subsurface in such areas will not settle immediately after human operations stop, the strength of the earthquakes—including the maximum expected magnitude—will gradually decrease.

Part 1

Comment by Dr. Krishna Kumari Challa on October 27, 2025 at 6:51am

Life's Ingredients Found Frozen Beyond The Milky Way For First Time

For the first time, astronomers have seen life's building blocks in ice beyond the borders of our galaxy.
Among a mix of complex organic molecules trapped in ice circling a newborn star in the Large Magellanic Cloud, researchers found ethanol, acetaldehyde, and methyl formate – compounds that have never before been spotted in ice form outside the Milky Way.
Moreover, another identified compound, acetic acid, has never before been conclusively identified in ice anywhere in space.

The discovery by astrophysicists suggests that the ingredients for the chemistry that gives birth to life are widespread and robust across the cosmos, and not limited to our own galaxy.
Complex organic molecules (COMs) in an astrophysical context are molecules with at least six atoms, at least one of which is carbon. The category includes molecules such as ethanol (CH₃CH₂OH), methyl formate (HCOOCH₃), and acetaldehyde (CH₃CHO), as well as larger molecules such as iso-propyl cyanide ((CH3)2CHCN).

They're important to scientists because they're the chemical precursors to the molecules that build life, such as amino acids, sugars, and nucleobases. Finding them in space, therefore, sheds light on the origins of prebiotic chemistry and where those precursor compounds were likely forged before Earth was even born.

https://iopscience.iop.org/article/10.3847/2041-8213/ae0ccd

Comment by Dr. Krishna Kumari Challa on October 25, 2025 at 10:59am

Physicists create the smallest pixel in the world 

Smart glasses that display information directly in the field of vision are considered a key technology of the future—but until now, their use has often failed due to cumbersome technology. However, efficient light-emitting pixels are ruled out by classical optics if their size is reduced to the wavelength of the emitted light.

Now, physicists  have taken a decisive step toward luminous miniature displays and, with the help of optical antennas, have created the world's smallest pixel to date.

With the help of a metallic contact that allows current injection into an organic light-emitting diode while simultaneously amplifying and emitting the generated light, they have created a pixel for orange light on an area measuring just 300 by 300 nanometers. This pixel is just as bright as a conventional OLED pixel with normal dimensions of 5 by 5 micrometers.

To put this into perspective, a nanometer is one millionth of a millimeter. This means that a display or projector with a resolution of 1,920 x 1,080 pixels could easily fit onto an area of just one square millimeter. This, for example, enables integration of the display into the arms of a pair of glasses from where the light generated would be projected onto the lenses.

Cheng Zhang et al, Individually addressable nanoscale OLEDs, Science Advances (2025). DOI: 10.1126/sciadv.adz8579

Comment by Dr. Krishna Kumari Challa on October 25, 2025 at 10:47am

How the brain's activity, energy use and blood flow change as people fall asleep

A new study by investigators  has used next-generation imaging technology to discover that when the brain is falling asleep, it shows a coordinated shift in activity.

The researchers found that during NREM (non-rapid eye movement) sleep, parts of the brain that handle movement and sensory input stay active and keep using energy, while areas involved in thinking, memory and daydreaming quiet down and use less energy. Their results are published in Nature Communications.

This research helps explain how the brain stays responsive to the outside world even as awareness fades during sleep.

By revealing how brain activity, energy use, and blood flow interact during sleep, these findings, and the imaging tools scientists used to uncover them, offer new insights into the mechanisms of neurological and sleep-related diseases.

The body cycles through two types of sleep several times each night: NREM and REM (rapid eye movement). NREM is the deep, restorative stage of sleep that plays a key role in physical health, brain function and disease prevention. Yet, many of its underlying processes and impacts on long-term health remain poorly understood. Previous studies have suggested that NREM helps clear waste from the brain.

Using a new tri-modal EEG-PET-MRI technique that combines EEG to study brain activity, fMRI to analyze blood flow, and functional PET (fPET)-FDG to monitor glucose metabolic dynamics, researchers examined the brains of 23 healthy adults during brief afternoon sleep sessions.

The researchers found that energy use and metabolism decrease as sleep deepens, while blood flow becomes more dynamic, especially in sensory areas that stay relatively active. At the same time, higher-order cognitive networks quiet down, and cerebrospinal fluid flow increases. Together, these findings support the idea that sleep helps clear waste from the brain while maintaining sensitivity to sensory cues that can trigger awakening.

Simultaneous EEG-PET-MRI identifies temporally coupled and spatially structured brain dynamics across wakefulness and NREM sleep", Nature Communications (2025). DOI: 10.1038/s41467-025-64414-x

Comment by Dr. Krishna Kumari Challa on October 25, 2025 at 10:18am

Instead of pathogens for typhus, the team found traces of Salmonella enterica, a bacterium that causes enteric fever, and Borrelia recurrentis, responsible for relapsing fever, which is also transmitted by body lice.

The researchers did not detect R. prowazekii or Bartonella quintana, the cause of trench fever, which has been identified in previous research on different soldiers from this site. Researchers say this discrepancy could be explained by the usage of different sequencing technologies. Earlier studies relied on polymerase chain reaction, or PCR, a technology that makes many copies of a specific DNA segment from limited starting material.
Ancient DNA gets highly degraded into pieces that are too small for PCR to work. New method now used is able to cast a wider net and capture a greater range of DNA sources based on these very short ancient sequences.

Paratyphoid Fever and Relapsing Fever in 1812 Napoleon's Devastated Army, Current Biology (2025). DOI: 10.1016/j.cub.2025.09.047. www.cell.com/current-biology/f … 0960-9822(25)01247-3

Part 2

Comment by Dr. Krishna Kumari Challa on October 25, 2025 at 10:14am

Rewriting history using modern technology

DNA from Napoleon's 1812 army identifies pathogens likely responsible for the army's demise during retreat from Russia

It's very exciting to use a technology we have today to detect and diagnose something that was buried for 200 years

In the summer of 1812, French emperor Napoleon Bonaparte led about half a million soldiers to invade the Russian Empire. But by December, only a fraction of the army remained alive. Historical records suggest that starvation, cold, and typhus led to their demise.

In a new study published in Current Biology, a team of microbial paleogenomicists extracted DNA from the soldiers' teeth and found no trace of typhus. Instead, they identified two pathogens known to cause enteric fever and relapsing fever—ailments which likely contributed to the army's downfall.

For centuries, historians have debated the factors that contributed to Napoleon's army's demise. Accounts from doctors and army officers suggested it was likely the result of typhus, an infectious disease that was common among armies of the time.
The discovery of body lice—the main vector of typhus—on the remains of Napoleon's soldiers, and the DNA of Rickettsia prowazekii—the bacterium responsible for typhus—further bolstered this assumption.

With new technology in hand capable of analyzing ancient DNA, researchers set off to reanalyze samples from Napoleon's fallen soldiers to see whether typhoid was indeed the culprit.

The researchers extracted and sequenced DNA from the teeth of 13 soldiers buried in a mass grave in Vilnius, Lithuania, which was along the route of the French army's retreat from Russia. They then removed all environmental contamination to isolate and identify DNA fragments from bacterial pathogens.

Part 1

Comment by Dr. Krishna Kumari Challa on October 25, 2025 at 10:07am

Furthermore, while AsEVs from control astrocyte cultures tend to favor an anti-inflammatory profile of the GALT (i.e., increased Treg/Th17 ratio), AsEVs derived from corticosterone-treated astrocytes have an opposite action. Similarly, in vitro experiments with disaggregated mesenteric lymph nodes reveal the immunomodulatory functions of AsEVs from corticosterone-treated astrocytes."

The results of this recent study uncover a new brain-to-gut communication pathway mediated by AsEVs via which stress could worsen the symptoms of IBDs.

Liliana Yantén-Fuentes et al, A novel brain-to-gut communication pathway mediated by astrocyte-derived small extracellular vesicles modulates stress-induced intestinal inflammation, Molecular Psychiatry (2025). DOI: 10.1038/s41380-025-03289-2.

Part 2

Comment by Dr. Krishna Kumari Challa on October 25, 2025 at 10:07am

Astrocyte-derived vesicles could link stress to intestinal inflammation

Inflammatory bowel diseases (IBDs), such as Crohn's disease and ulcerative colitis, are chronic and autoimmune conditions characterized by the inflammation of the intestinal tract. This inflammation can cause nausea or vomiting, diarrhea, abdominal pain and cramping, fatigue, fever, and various other debilitating symptoms.

While the underpinnings of IBDs have been widely investigated, the factors that can contribute to its emergence have not yet been clearly elucidated. Past findings suggest that the symptoms of these diseases are often exacerbated by psychological and emotional stress.

Researchers recently carried out a study aimed at shedding new light on the neurobiological mechanisms via which stress could worsen IBDs. Their findings, published in Molecular Psychiatry, hint at the existence of a brain-to-gut communication pathway that is mediated by small communication vehicles known as small extracellular vesicles (sEVs), which are released by astrocytes.

The researchers now hypothesize that psychological stress regulates intestinal inflammation through the release of small extracellular vesicles derived from astrocytes (AsEVs).

The researchers carried out various experiments involving rats, aimed at understanding how stress affected immune responses in their gut. Their study specifically focused on the role of astrocytes, star-shaped glial cells that help to maintain a balanced and healthy environment in the brain, and of small EVs released by these cells.

They  marked astrocytes with a special "tag" protein, using a technique known as in-utero electroporation. This technique allowed them to monitor where signals originating from these cells traveled within the rats' body.

"In-utero electroporation performed to selectively express an AsEV-associated membrane recombinant protein in rat forebrain astrocytes reveals that this protein is transferred to the gut-associated lymphoid tissue (GALT)," wrote the authors.

Similarly, AsEVs isolated from primary astrocyte cell cultures that were stimulated with vehicle or corticosterone (to emulate a stress condition) trafficked to the GALT. Interestingly, the membrane gut homing receptor CCR9 is present on AsEVs and mediates their association with the CCR9-endogenous ligand CCL25."

Interestingly, the researchers discovered that signals originating from astrocytes traveled to immune tissues in the rats' gut. Subsequently, they grew astrocytes in their lab and increased the levels of corticosterone within them. This is a hormone that is naturally released in the animals' body when they are stressed.

The team then injected vesicles released by these cells, as well as vesicles released by "non-stressed" astrocytes into rats and observed their gut responses. They found that vesicles derived from "stressed" astrocytes led to greater gut inflammation, while those released by 'non-stressed' astrocytes helped to calm the gut's immune system.

At the histological level, inflammatory parameters (such as lymph vessel diameter or cell number in them), induced by a stress protocol based on movement restriction, increased by treatment with AsEVs from corticosterone-treated astrocytes.

Part 1

Comment by Dr. Krishna Kumari Challa on October 24, 2025 at 2:35pm

'Forever Chemicals' in Mothers' Blood Linked to Brain Changes in Their Kids

'Forever chemicals' already have a shocking reputation, and now new research has linked these substances – named for the way they stick around in the environment for so long – to brain changes in children born to mothers exposed to common PFAS (per- and polyfluoroalkyl substances).
To reach that conclusion, researchers looked at 51 mother-and-child pairs, measuring PFAS levels in the mother's blood during pregnancy, and then running brain scans on the kids once they reached 5 years old.
These records meant the research team was able to compare different types of PFAS against changes in brain structure and connections between brain regions. Several distinct patterns were revealed, enough to suggest (but not prove) a strong influence.
They were able to measure seven different PFAS in this study, and found that individual compounds had specific associations with offspring brain structure.
In some cases two different PFAS had opposite relationships with the same brain region
For example, perfluorononanoic acid (PFNA) and perfluorooctanoic acid (PFOA) were linked to changes in the corpus callosum, the tract of white matter that connects the brain's left and right hemispheres.
Substantial changes connected to PFAS levels were also detected in the hypothalamus, a part of the brain that controls many of the body's core functions, and in the volume and surface area of posterior grey matter in the occipital lobe, the brain's visual processing centre.
The researchers also found certain types of PFAS more likely to influence brain structure and brain connectivity than others, based on their chemical composition. It's not immediately evident what these changes might mean – but the changes are there.

https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(25)00187-1/fulltext

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