Comment

Comment by Dr. Krishna Kumari Challa on October 28, 2025 at 9:33am

Humanity rises as wildlife recedes: Two studies show the extent of human domination over nature

Wolves roaming the Mongolian steppes cover more than 7,000 kilometers a year. The Arctic tern flies from pole to pole in its annual migration. Compared to these long-distance travelers of land, sea and sky, humans might seem like the ultimate couch potatoes. But a new study shows otherwise.

In a paper published recently in Nature Ecology & Evolution,  researchers report that the total movement of humans is 40 times greater than that of all wild land mammals, birds and arthropods combined. Since the Industrial Revolution some 170 years ago, human movement has skyrocketed, while animal movement in nature has dwindled to levels that could endanger ecosystems.

Life, by its very nature, is always in motion, shaping both the natural world and human society. Yet until now, no comparison has been made among different species as to the magnitude of their overall movement. Birds, for example, cross vast distances but their overall body mass is tiny. By contrast, deep-sea fish may travel only short distances, but their combined biomass is enormous—about a thousand times greater than that of all birds.

Researchers  have now quantified and compared the movement of different species, shedding light on the power dynamics between humans and the rest of the animal kingdom.

The index they created, called the biomass movement metric, is calculated by multiplying the total biomass of a species—that is, the combined mass of all its members—by the total distance that species travels in a year. Calculating this metric globally made it possible, for the first time, to quantify global movement across animal species—and then compare it to that of humankind.

Part 1

Comment by Dr. Krishna Kumari Challa on October 28, 2025 at 9:24am

How a coral stiffens its skeleton on demand

Touch the branches of Leptogorgia chilensis, a soft coral found along the Pacific coast from California to Chile, and its flexible arms stiffen. Researchers have discovered the mechanism underlying this astonishing ability, one that could advance fields as varied as medicine, robotics and manufacturing.

In a paper in Proceedings of the National Academy of Sciences,

they describe how the coral's skeleton—made of millions of mineral particles suspended in a gelatinous matrix—compacts itself to ward off danger.

When stimulated, the coral's tissues expel water, shrinking the gel and squeezing the particles closer together until they jam in place.

Physicists have long studied this phenomenon, known as "granular jamming," by manipulating grainy substances like sand and coffee grounds, but this marks the first time granular jamming based on hard particles has been observed in a living organism.

They're basically made of chalk- calcium carbonate, the same cheap and plentiful white powder that forms eggshells, sticks of chalk, marble, limestone and pearls. What gives their skeletons interesting properties is how the calcium carbonate is structured and organized.

While marine biologists recognized long ago that soft corals like L. chilensis have skeletons containing granular particles, the grains' shapes had primarily been used to classify different species.

Li, Ling, Mineralized sclerites in the gorgonian coral Leptogorgia chilensis as a natural jamming system, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2504541122. doi.org/10.1073/pnas.2504541122

Comment by Dr. Krishna Kumari Challa on October 28, 2025 at 9:06am

Study links cockroach infestations to higher household allergens and endotoxins

Researchers have shown a link between the size of cockroach home infestations and the levels of both allergens and endotoxins in those homes, with lowering roach infestation numbers through pest control triggering significant declines in the levels of allergens and endotoxins. The study's findings suggest that eliminating cockroach infestations could help improve indoor environmental health by greatly reducing allergens and endotoxins.

Endotoxins are bacterial cellular components that get released when bacteria die. As omnivores that will eat just about anything, cockroaches have a rich and diverse gut microbiome. Previous research has shown that cockroaches shed a lot of endotoxins through their fecal matter, although house pets – and humans – can also shed endotoxins. The researchers in this study found that a large amount of the endotoxins found in household dust was associated with cockroach feces.

Endotoxins are important to human health, as inhalation of these components has been shown to provoke allergic responses. 

The researchers found significant amounts of endotoxins in infested homes, with female cockroaches excreting about twice the amount that males excreted. Female cockroaches eat more than males, so more endotoxins are shed from their fecal matter.  More endotoxins were found in kitchens than in bedrooms, as more cockroaches live in kitchens where they find more food.

When you eliminate cockroaches, you eliminate their allergens. Small decreases in cockroaches don't lower allergen levels because the remaining live cockroaches deposit more allergens. Endotoxins significantly decreased in homes where cockroaches were eliminated. This research shows that the cockroach is the most important depositor of endotoxin in infested homes.

Researchers  also saw that allergens and endotoxins can be airborne. 

There exists the implication that asthma can be worse due to interactions between allergens and endotoxins.

Cockroaches?! Eeek!

I don't have a single cockroach in my home. Because I don't like them, I see to it they don't come inside my home. 

 Madhavi L. Kakumanu et al, Indoor Allergens and Endotoxins in Relation to Cockroach Infestations in Low-Income Urban Homes, Journal of Allergy and Clinical Immunology: Global (2025). DOI: 10.1016/j.jacig.2025.100571

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.

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