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Comment by Dr. Krishna Kumari Challa on November 18, 2025 at 8:38am

Lethal dose of plastics for ocean wildlife: Surprisingly small amounts can kill seabirds, sea turtles and marine mammals

By studying more than 10,000 necropsies, researchers now know how much plastic it takes to kill seabirds, sea turtles, and marine mammals, and the lethal dose is much smaller than you might think. Their new study titled "A quantitative risk assessment framework for mortality due to macroplastic ingestion in seabirds, marine mammals, and sea turtles" is published in the Proceedings of the National Academy of Sciences.

Led by Ocean Conservancy researchers, the paper is the most comprehensive study yet to quantify the extent to which a range of plastic types—from soft, flexible plastics like bags and food wrappers; to balloon pieces; to hard plastics ranging from fragments to whole items like beverage bottles—result in the death of seabirds, sea turtles, and marine mammals that consume them.

The study reveals that, on average, consuming less than three sugar cubes' worth of plastics for seabirds like Atlantic puffins (which measure approximately 28 centimeters, or 11 inches, in length); just over two baseballs' worth of plastics for sea turtles like Loggerheads (90 centimeters or 35 inches); and about a soccer ball's worth of plastics for marine mammals like harbor porpoises (1.5 meters, or 60 inches), has a 90% likelihood of death.

At the 50% mortality threshold, the volumes are even more startling: consuming less than one sugar cube's worth of plastics kills one in two Atlantic puffins; less than half a baseball's worth of plastics kills one in two Loggerhead turtles; and less than a sixth of a soccer ball kills one in two harbor porpoises.

The lethal dose varies based on the species, the animal's size, the type of plastic it's consuming, and other factors, but overall it's much smaller than you might think, which is troubling when you consider that more than a garbage truck's worth of plastics enters the ocean every minute.

Part 1

Comment by Dr. Krishna Kumari Challa on November 18, 2025 at 8:34am

Reducing arsenic in drinking water cuts risk of death, even after years of chronic exposure: 20-year study

Arsenic is among the most common chemical pollutants of ground water.

Arsenic is a naturally occurring element that accumulates in groundwater, and because it has no taste or odor, people can unknowingly drink contaminated water for years.

A 20-year study of nearly 11,000 adults in Bangladesh found that lowering arsenic levels in drinking water was associated with up to a 50% lower risk of death from heart disease, cancer and other chronic illnesses, compared with continued exposure.

The study provides the first long-term, individual-level evidence that reducing arsenic exposure may lower mortality, even among people exposed to the toxic contaminant for years.

The landmark analysis by researchers is important for public health because groundwater contamination from naturally occurring arsenic remains a serious issue worldwide.

The study shows what happens when people who are chronically exposed to arsenic are no longer exposed. You're not just preventing deaths from future exposure, but also from past exposure.

The results provide the clearest evidence to date of the link between arsenic reduction and lower mortality.

For two decades, the research team followed each participant's health and repeatedly collected urine samples to track exposure, which they say strengthened the accuracy of their findings.

People whose urinary arsenic levels dropped from high to low had mortality rates identical to those who had consistently low exposure throughout the duration of the study. The larger the drop in arsenic levels, the greater the decrease in mortality risk. By contrast, individuals who continued drinking high-arsenic water saw no reduction in their risk of death from chronic disease.

 Arsenic Exposure Reduction and Chronic Disease Mortality, JAMA (2025). jamanetwork.com/journals/jama/ … 1001/jama.2025.19161

Comment by Dr. Krishna Kumari Challa on November 18, 2025 at 8:27am

Ferroelectric materials, first discovered in 1920, have a natural electrical polarization that can be reversed by an electric field. That polarization remains reversed even once the electric field has been removed.

The materials are dielectric, meaning they can be polarized by the application of an electric field. That makes them highly effective in capacitors.

Ferroelectrics are also piezoelectric, which means they can generate electric properties in response to mechanical energy, and vice versa. This quality can be used in sonars, fire sensors, tiny speakers in a cell phone or actuators that precisely form letters in an inkjet printer.

All these properties can be enhanced by manipulating the phase boundary of ferroelectric materials.
In a lead-based ferroelectric, such as lead zirconate titanate, one can chemically tune the compositions to land right at the phase.
Lead-free ferroelectrics, however, contain highly volatile alkaline metals, which can become a gas and evaporate when chemically tuned.
The researchers instead created a thin film of the lead-free ferroelectric material sodium niobate (NaNbO3). The material is known to have a complex crystalline ground state structure at room temperature. It is also flexible. Scientists have long known that changing the temperature of sodium niobate can produce multiple phases, or different arrangements of atoms.
Instead of a chemical process or manipulating the temperature, the researchers changed the structure of the atoms in sodium niobate by strain.

They grew a thin film of sodium niobate on a substrate. The structure of the atoms in the sodium niobate contract and expand as they try to match the structure of the atoms in the substrate. The process creates strain on the sodium niobate.

"What is quite remarkable with sodium niobate is if you change the length a little bit, the phases change a lot.
To the researchers' surprise, the strain caused the sodium niobate to have three different phases at once, which optimizes the useful ferroelectric properties of the material by creating more boundaries.
The experiments were conducted at room temperature. The next step will be seeing if sodium niobate responds to strain in the same way at extreme temperatures ranging from minus 270 C to 1,000 C above.

Reza Ghanbari et al, Strain-induced lead-free morphotropic phase boundary, Nature Communications (2025). DOI: 10.1038/s41467-025-63041-w

Part 2

Comment by Dr. Krishna Kumari Challa on November 18, 2025 at 8:25am

Lead-free alternative discovered for essential electronics component

Ferroelectric materials are used in infrared cameras, medical ultrasounds, computer memory and actuators that turn electric properties into mechanical properties and vice-versa. Most of these essential materials, however, contain lead and can therefore be toxic.

Therefore, for the last 10 years, there has been a huge initiative all over the world to find ferroelectric materials that do not contain lead.

The atoms in a ferroelectric material can have more than one crystalline structure. Where two crystalline structures meet is called a phase boundary, and the properties that make ferroelectric materials useful are strongest at these boundaries.

Using chemical processes, scientists have manipulated the phase boundaries of lead-based ferroelectric materials to create higher performance and smaller devices. Chemically tuning the phase boundaries of lead-free ferroelectric material, however, has been challenging.

New research found a way to enhance lead-free ferroelectrics using strain, or mechanical force, rather than a chemical process. The discovery could produce lead-free ferroelectric components, opening new possibilities for devices and sensors that could be implanted in humans.

Part 1

Comment by Dr. Krishna Kumari Challa on November 18, 2025 at 7:14am

Parasitic ant tricks workers into killing their queen, then takes the throne

Scientists document a new form of host manipulation where an invading, parasitic ant queen "tricks" ant workers into killing their queen mother. The invading ant integrates herself into the nest by pretending to be a member of the colony, then sprays the host queen with fluid that causes her daughters to turn against her. The parasitic queen then usurps the throne, having the workers serve her instead as the new queen regent. This work was published in Current Biology on November 17.

Matricide, a behavior where offspring kill or eat their mother, is a rarely seen phenomenon in nature. Despite appearing maladaptive at first glance, it does offer advantages by either nourishing the young and giving the mother indirect benefits through increased offspring survival or allowing the young to invest in offspring of their own.

Up until now, only two types of matricide have been recorded in which either the mother or offspring benefit. In this novel matricide that researchers reported, neither profit; only the parasitic third party.

The ants Lasius orientalis and umbratus, commonly referred to as the "bad-smell ants" in Japanese, are so-called "social parasites" that execute a covert operation to infiltrate and eventually take over the colony of their unsuspecting ant queen hosts, Lasius flavus and japonicus, respectively. The parasitic queen takes advantage of ants' reliance on smell to identify both friends and foes to dupe unsuspecting worker ants into believing she is part of the family.

Ants live in the world of odors. 

Before infiltrating the nest, the parasitic queen stealthily acquires the colony's odor on her body from workers walking outside so that she is not recognized as the enemy.

Once these "bad-smell" ants have been accepted by the colony's workers and locate the queen, the parasitic ant douses her with a foul-smelling chemical researchers presume to be formic acid—a chemical unique to some ants and stored in a specialized organ.

The parasitic ants exploit that ability to recognize odors by spraying formic acid to disguise the queen's normal scent with a repugnant one. This causes the daughters, who normally protected their queen mother, to attack her as an enemy.

Then, like fleeing the scene of the crime, the parasitic queen immediately (but temporarily) retreats. "She knows the odor of formic acid is very dangerous, because if host workers perceive the odor they would immediately attack her as well.

She will periodically return and spray the queen multiple times until the workers have killed and disposed of their mother queen. Then, once the dust has settled, the parasitic ant queen returns and begins laying eggs of her own. With this newly accepted parasitic queen in the colony and no other queen to compete with, the matricidal workers begin taking care of her and her offspring instead.

 Host daughter ants manipulated into unwitting matricide by a social parasitic queen, Current Biology (2025). DOI: 10.1016/j.cub.2025.09.037. www.cell.com/current-biology/f … 0960-9822(25)01207-2

Comment by Dr. Krishna Kumari Challa on November 16, 2025 at 10:01am

The results are consistent with recent archaeological discoveries and align with a body of evidence that suggests the decline of Neanderthals in Europe was gradual rather than sudden.

Homo sapiens seem to have started migrating out of Africa much earlier than scientists previously thought, and they arrived in Europe in several influxes, possibly starting more than 200,000 years ago.
As each wave of migration came crashing into the region, it engulfed local Neanderthal communities, diluting their genes, like sand pulled into the sea.
Today, some scientists argue that there is more to unite Homo sapiens and Neanderthals than there is to differentiate us. Our lineages, they say, should not be regarded as two separate species, but rather as distinct populations belonging to a "common human species.".

Neanderthals were surprisingly adaptable and intelligent. They made intricate tools, created cave art, and used fire – and when it came to communication, they were probably capable of far more than simple grunting.
Neanderthal populations and cultures may no longer exist, but their genetic legacy lives on inside of us.
These are not just our cousins; they are also our ancestors.

https://www.nature.com/articles/s41598-025-22376-6

Part 2

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Comment by Dr. Krishna Kumari Challa on November 16, 2025 at 9:59am

Neanderthals May Never Have Truly Gone Extinct

Neanderthals may have never truly gone extinct, according to new research – at least not in the genetic sense.

A new mathematical model has explored a fascinating scenario in which Neanderthals gradually disappeared not through "true extinction" but through genetic absorption into a more prolific species: Us.
According to the analysis, the long and drawn-out 'love affair' between Homo sapiens and Neanderthals could have led to almost complete genetic absorption within 10,000–30,000 years.
The model is simple and not regional, but it provides a "robust explanation for the observed Neanderthal demise, say researchers.
Once, the idea that Neanderthals and Homo sapiens interbred was a radical notion, and yet now, modern genome studies and archaeological evidence have provided strong evidence that our two lineages were hooking up and reproducing right across Eurasia for tens of thousands of years.

Today, people of non-African ancestry have inherited about 1 to 4 percent of their DNA from Neanderthals.
No one knows why Neanderthals disappeared from the face of our planet roughly 40,000 years ago, but experts tend to agree that there are probably numerous factors that played a role, like environmental changes, loss of genetic diversity, or competition with Homo sapiens.
Now researchers present a model that does not rule out these other explanations.
It does suggest that genetic drift played a strong role – even with the researchers assuming the Neanderthal genes our species 'absorbed' had no survival benefit.

If the model were to include the potential advantages of some Neanderthal genes to the larger Homo sapiens population, then mathematical support for genetic dilution may become even stronger.

Like all models, this new one is based on imperfect assumptions. It uses the birth rates of modern hunter-gatherer tribes to predict how quickly small Neanderthal tribes would be engulfed by a much larger human population, given how frequently it seems we were interbreeding.
Part 1

Comment by Dr. Krishna Kumari Challa on November 16, 2025 at 8:57am

Direct link between peak air pollution and cardiac risk revealed

The risk of suffering cardiac arrest may increase on days recording high levels of air pollution in some parts of the world. This emerges from a study conducted by researchers and published in the journal Global Challenges.

Researchers analyzed 37,613 cases of out-of-hospital cardiac arrest in Lombardy between 2016 and 2019 by assessing, for each episode, the daily concentrations of various pollutants (PM₂.₅, PM₁₀, NO₂, O₃ and CO) obtained from satellite data of the European Copernicus program (ESA). The study used advanced spatio-temporal statistical models to identify the relationship between pollution peaks and increased risk of cardiac events.

They observed a strong association with nitrogen dioxide (NO₂). Indeed, for every 10 micrograms per cubic meter increase, the risk of cardiac arrest rises by 7% over the next 96 hours.

Even particulate matter PM₂.₅ and PM₁₀ present a 3% and 2.5% increase in the risk rate, respectively, on the same day of exposure.

The effect is more pronounced in urban areas but significant associations are also observed in rural towns. The risk particularly marks an upswing in the warm months, suggesting a possible interaction between heat and pollutants. The association was also observed at levels below legal limits, suggesting that there is no safe exposure threshold.

The link between air quality and out-of-hospital cardiac arrest is a wake-up call for local health systems.

 Amruta Umakant Mahakalkar et al, Short‐Term Effect of Air Pollution on Out of Hospital Cardiac Arrest (OHCA) in Lombardy—A Case‐Crossover Spatiotemporal Study, Global Challenges (2025). DOI: 10.1002/gch2.202500241

Comment by Dr. Krishna Kumari Challa on November 16, 2025 at 8:46am

AI at the speed of light just became a possibility

Researchers have demonstrated single-shot tensor computing at the speed of light, a remarkable step towards next-generation artificial general intelligence hardware powered by optical computation rather than electronics.

Tensor operations are the kind of arithmetic that form the backbone of nearly all modern technologies, especially artificial intelligence, yet they extend beyond the simple math we're familiar with. Imagine the mathematics behind rotating, slicing, or rearranging a Rubik's cube along multiple dimensions. While humans and classical computers must perform these operations step by step, light can do them all at once.

Today, every task in AI, from image recognition to natural language processing, relies on tensor operations. However, the explosion of data has pushed conventional digital computing platforms, such as GPUs, to their limits in terms of speed, scalability and energy consumption.

Motivated by this pressing problem, an international research collaboration has unlocked a new approach that performs complex tensor computations using a single propagation of light. The result is single-shot tensor computing, achieved at the speed of light itself.

The new method performs the same kinds of operations that today's GPUs handle, like convolutions and attention layers, but does them all at the speed of light.

To achieve this, the researchers encoded digital data into the amplitude and phase of light waves, effectively turning numbers into physical properties of the optical field. When these light fields interact and combine, they naturally carry out mathematical operations such as matrix and tensor multiplications, which form the core of deep learning algorithms.

By introducing multiple wavelengths of light, the team extended this approach to handle even higher-order tensor operations.

Another key advantage of this method is its simplicity. The optical operations occur passively as the light propagates, so no active control or electronic switching is needed during computation.

Direct tensor processing with coherent light, Nature Photonics (2025). DOI: 10.1038/s41566-025-01799-7.

Comment by Dr. Krishna Kumari Challa on November 14, 2025 at 10:13am

What puts the ‘cable’ in cable bacteria
The ‘wires’ that cable bacteria use to conduct electricity seem to be made of repeating units of a compound that contains nickel and sulfur. Researchers found that these units make up ‘nanoribbons’, which are woven together like a plait to form the larger wires. The work has yet to be peer reviewed, but if confirmed, the finding could be the first known example of a biologically produced metal–organic framework. “If it holds true, this is a major step in our understanding of what cable bacteria can accomplish,” says electromicrobiologist Lars Peter Nielsen, who co-discovered the microorganisms in 2009.

https://www.biorxiv.org/content/10.1101/2025.10.10.681601v1

https://www.science.org/content/article/metal-scaffolds-turn-bacter...

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