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Comment by Dr. Krishna Kumari Challa on May 6, 2026 at 9:50am

At first, swapping in a similar building block worked only about 43% of the time. To improve this, the researchers turned to AI, which helped them select the best replacement for a missing amino acid based on its surrounding context, ensuring the protein didn't fold incorrectly or collapse. They redesigned ribosomes that were capable of producing 52 Ile-free proteins. They eventually combined 21 of these redesigned parts into a single E. coli strain, which they named Ec19.

The results showed that the so-called universal 20-letter (amino acid) code of life isn't an absolute requirement for survival, and it is indeed possible to create a living organism that gets by with just 19 amino acids.

The researchers noted that as genome-scale modeling and DNA synthesis improve, scientists will be able to test many engineered genomes by swapping amino acids, creating cells with new traits and pushing the limits of synthetic biology.

Liyuan Liu et al, Toward life with a 19–amino acid alphabet through generative artificial intelligence design, Science (2026). DOI: 10.1126/science.aeb5171. www.science.org/doi/10.1126/science.aeb5171

Part 2

Comment by Dr. Krishna Kumari Challa on May 6, 2026 at 9:48am

Engineered bacteria break the 20-amino-acid rule

There are over 500 different types of amino acids found in nature, yet protein synthesis in life forms uses only the canonical 20. Some bacteria are known to use extra amino acids, bringing the total to 21 or even 22, but no naturally occurring organism has been found that uses fewer than these 20 amino acids. Large-scale genetic studies are a testament to it.

One of life's many mysteries is how it ended up choosing only a set of 20 amino acids to build proteins for its wide catalog of organisms, from single-celled bacteria to behemoth whales. From a chemical standpoint, many of the canonical amino acids share similar chemical structures and properties, which might make them expendable. This raises an intriguing question: could life manage with one less amino acid?

In a recent study in Science, researchers used generative AI and deep-learning models like AlphaFold2, which can predict protein 3D structures, to design Ec19 —a genetically engineered strain of E. coli that functions using just 19 amino acids instead of the usual 20.

In Ec19, the researchers set out to see if they could remove isoleucine (Ile) and still obtain a living, healthy cell. The resulting strain remained genomically stable and grew at nearly the same rate as normal bacteria for over 450 generations in the laboratory, and whole-genome sequencing found no evidence of Ec19 attempting to restore Ile and revert to the 20-amino acid system.

Scientists also suggest that before the single-celled organism considered our last universal common ancestor (LUCA), early life forms likely used a smaller set of amino acids than the one we see today. Since many canonical amino acids have similar biochemical properties, their role might be redundant.

Computational studies have suggested that as few as 9 to 12 amino acids may be enough to build almost every known protein shape. Even the cell's own protein-making machinery isn't perfect, where every so often it slips, and about 8% of proteins end up with at least one wrong amino acid. Yet most of them still work just fine.
For this study, the researchers began by analyzing the 20 amino acids to determine which one was most replaceable, and isoleucine (Ile) emerged as a contender because it is chemically very similar to another amino acid, valine. So they followed a careful step-by-step approach known as the design-build-test framework to see if they could create a living cell that functions without the amino acid Ile.

Part 1

Comment by Dr. Krishna Kumari Challa on May 5, 2026 at 10:24am

People who are blind from birth never develop schizophrenia—what this tells us about the psychiatric condition
Congenital cortical blindness appears to confer strong protection against schizophrenia, with no reported cases among individuals blind from birth due to visual cortex damage. This protection is not seen in those who lose vision later or have blindness from eye damage, suggesting early absence of visual input alters brain development and prediction processes implicated in schizophrenia. Insights from this phenomenon may inform new approaches targeting perception and brain organization in schizophrenia treatment.

https://www.frontiersin.org/journals/psychology/articles/10.3389/fp...

original article.

Comment by Dr. Krishna Kumari Challa on May 5, 2026 at 9:48am

Why your face doesn't perceive itchiness the same way your body does

In a new study, researchers show that itch sensations in the face are perceived differently from those in the body due to differences in signalling between trigeminal (located in the brain) and spinal pain pathways. The work could lead to the development of specific molecular targets for treating facial pain or itch. The study appears in Communications Biology.
On the body, itch signals go from neuronal projections in the skin through the dorsal root ganglia (DRG)—which are clusters of sensory cells located at the root of the spinal nerves—then to the spinal cord. But on the face and head, those signals travel to the trigeminal ganglia (TG)—which are clusters of sensory cells located in a small structure below the brain where it sits atop the skull."

We know that in terms of itch, the face and torso have different thresholds—in mice, for example, they have lower itch response to histamine exposure on the cheek as compared to the nape of the neck.
The researchers first looked at itch response in mice exposed to histamine on the cheek and nape. They observed that itch response on the cheek was significantly reduced when compared with the neck. Next, they looked at innervation—or how many nerves were present—in the face versus the neck to rule out structural causes for the difference in response.

Finally, they looked at the neuronal populations within the DRG and TG, and the neuropeptides they express.

The neurons within the DRG and TG differ, mainly because the sensory environments they work in differ. Skin doesn't need to be able to sense taste or smell, for example. But it also seems as though the neuronal populations don't handle signals the same way, either.

Wheeler, J.J. et al, Substance P and somatostatin neurons limit facial itch by recruiting distinct nociceptive circuits in the brainstem, Communications Biology (2026). DOI: 10.1038/s42003-026-10128-9 www.nature.com/articles/s42003-026-10128-9

Comment by Dr. Krishna Kumari Challa on May 5, 2026 at 9:33am

A 'living plastic' activates and self-destructs on command

A living plastic incorporating dormant Bacillus subtilis spores and two cooperative polymer-degrading enzymes fully degrades polycaprolactone into monomers within six days upon activation with nutrient broth at 50 °C, without generating microplastics. The material retains mechanical properties similar to conventional polycaprolactone and demonstrates potential for programmable, on-demand biodegradation in various plastic types.

Chenwang Tang et al, Degradable Living Plastics Programmed by Engineered Microbial Consortia, ACS Applied Polymer Materials (2026). DOI: 10.1021/acsapm.5c04611

Comment by Dr. Krishna Kumari Challa on May 5, 2026 at 9:25am

While these studies do not imply that there are no reflex responses to approaching dangers, visual looming stimuli and other types of auditory stimuli (echoes, higher frequencies) will trigger an involuntary reaction whenever danger is near. Yet, the most significant finding is that when sound serves as a basis for determining the distance of an approaching stimulus, people apply an unambiguous rule.

More importantly, these results refute one of the widespread beliefs about our response mechanisms. According to the researchers' claims, once loudness becomes a key indicator of the distance of the approaching stimulus, all distance decisions "are based on loudness." The authors conclude that this approach is not grounded in some auditory looming bias.

Asymmetries in human judgements of distance for approaching and receding sounds are predicted by a loudness model for time-varying sounds, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2026.0157. doi.org/10.1098/rspb.2026.0157

Part 2

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Comment by Dr. Krishna Kumari Challa on May 5, 2026 at 9:25am

That split-second panic when something rushes toward you may hinge on one deceptively simple sound cue

Those jolts of terror that seem to occur whenever a noise comes closer? While we assume that this is an age-old survival reaction, modern revelations show that there may be an easier explanation for what's occurring.

Many of us have experienced the heart-jolt of an approaching car horn or booming footsteps from behind. By the time we realize what's happening, the sound already seems much closer than it really is—as if our brains had an extra warning system.

It's long been thought that humans possess an adaptive looming bias—an inborn tendency to perceive advancing sounds as nearer or more urgent than receding ones. In fact, one hearing expert suggests we evolved an "auditory looming bias" that provides "advanced warning of approaching sound sources." That sounds logical: in nature, an approaching noise usually signals danger (or opportunity), and getting a head start to react is valuable. But what if this accepted wisdom isn't the whole story?

Then researchers conducted some experiments to find out the truth.

In a recent study published in the journal Proceedings of the Royal Society B: Biological Sciences, blindfolded volunteers with normal hearing listened through headphones to sounds that either approached or receded. The sounds—pure tones or broadband noise—were simulated to move over an 11-meter path, starting from three different distances (near, middle, far). After each sound, participants reported how far away it began and ended.

Because the experiments took place in an anechoic chamber with blindfolded listeners, the only distance cues came from changes in loudness as the sound moved. With vision eliminated and no echoes, any looming illusion would have to come from volume. Would approaching sounds still feel closer under those conditions?

The answer was yes—partially at least. On average, the approaching sounds were perceived to be closer both when they started and when they ended, compared to the receding sounds, particularly if the approaching sound was close at the start. This is in line with the classical phenomenon of looming.

However, a number of predictions based on the hypothesis of the hard-wired alarm system turned out to be incorrect. For example, there was no significant difference between judgments of distance when the sound stimulus was either a pure tone or noise. Also, surprisingly, the distance travelled by the approaching sound was roughly equal to that of the receding sound.

So if it's not a special bias, what is going on? It turns out the answer lies in simple acoustics. As a sound draws nearer, it naturally gets louder, and louder sounds tend to be interpreted as closer. The researchers ran the same sounds through a standard loudness model for time-varying signals. The result was striking: the model's predictions matched the human judgments almost perfectly.

The authors explain, "The pattern of results was accurately predicted using a model of loudness for time-varying sounds," adding that "it is not necessary to invoke the adaptive perceptual bias theory to account for asymmetries in loudness and distance judgements between approaching and receding sounds."

They even note that this is "the first time that auditory distance estimates are predicted using a loudness model." In other words, no mysterious looming detector was needed—just basic hearing.

Part 1

Comment by Dr. Krishna Kumari Challa on May 5, 2026 at 8:59am

Rising temperatures could be driving up antibiotic resistance in soil, 11-year study finds

Every year, millions suffer, and thousands lose their lives to infections that were once easily treatable with the right dose of medication. The drugs are the same; human physiology is the same; the only difference is that microbes, such as bacteria, viruses, and fungi, have now developed resistance to drugs designed to kill them. This phenomenon, known as antimicrobial resistance, is rapidly rising, ringing sirens for emergency action across the globe.

It is predicted that by 2050, antimicrobial resistance (AMR) could cause up to 10 million deaths each year if it is not addressed seriously. 

A new 11-year study found that, in addition to the misuse and overuse of antibiotics, long-term climate warming can also increase the abundance of antibiotic resistance genes (ARGs) in grassland soils by nearly 24%.

Higher temperatures favour the growth of Actinomycetota—a group of mostly Gram-positive bacteria that naturally carry many resistance genes. As these bacteria become more abundant, the overall concentration of ARGs in the soil increases. The findings are published in Nature.

Our water bodies and soil around us are a major source of antibiotic resistance genes (ARGs), which pathogens can acquire to survive antibiotic treatment. So far, research has not clearly shown how long-term warming influences antibiotic resistance in soils. Understanding this link is important for anticipating potential risks to human health and agriculture as the climate continues to change.

The experiments of researchers  showed that warming makes resistance genes more mobile, allowing them to move more easily between different bacteria. It also increased genes linked to resistance against glycopeptides and rifamycins—antibiotics that target bacteria.

At the same time, resistance genes associated with plant pathogens became more common, suggesting that in a warmer world, controlling crop diseases with traditional methods may become more difficult.

The study indicates that climate warming accelerates antimicrobial resistance in soil microbes at genetic and ecological levels, with significant implications for public health and environmental sustainability. 

Linwei Wu et al, Decade-long warming accelerates antibiotic resistance in grassland soils, Nature (2026). DOI: 10.1038/s41586-026-10413-x

Comment by Dr. Krishna Kumari Challa on May 2, 2026 at 10:00am

Bigger, faster, but still outfoxed: How prey escape predators

Predators are typically larger, faster, and more powerful than the animals they hunt. Yet in nature, most attacks fail. A new study published in the Proceedings of the National Academy of Sciences, by researchers asks: why do prey get away so often? The key, the researchers found, lies in something the original model overlooked: reaction times.
For decades, scientists have explained this using a simple idea: maneuverability. Because prey are smaller, they can often turn more sharply. A classic model, known as the turning gambit, proposes that a well-timed evasive turn allows prey to slip out of a predator's path, even if the predator is faster. The model even specifies exactly how much more maneuverable prey need to be for this to work. But in the half-century since this model was proposed, no one had tested whether its predictions hold across land, air, and water.
The new study compiled data on animal traits such as body mass, speed, and turning ability, to test the model's predictions. The results revealed a mismatch between theory and reality. Across all environments, prey are generally not maneuverable enough to compensate for their speed disadvantage. Paradoxically, aquatic environments, where the model predicted predators should hold a huge advantage, turned out to have the lowest capture success in nature. Predators caught prey in only around 1 in 10 attacks.

So if not maneuverability, what explains how prey get away so often? The key, the researchers found, lies in something the original model overlooked: reaction times. No predator can respond instantaneously to a prey's evasive turn. Seeing, processing, and reacting all take time. While these delays are short—just a small fraction of a second—they can make a huge difference.
It's this little head start, or benefit of starting to turn earlier, that gives prey enough space to evade. This exceptional maneuverability has a simple physical explanation: water is roughly 1,000 times denser than air, giving aquatic animals something far more substantial to push against to generate a sharp turn.
Prey escape predators not primarily through superior maneuverability, as previously thought, but due to reaction time delays in predators. These brief delays allow prey to initiate evasive maneuvers before predators can respond, significantly increasing escape success, especially in aquatic environments. Predator–prey dynamics are thus influenced by both biomechanical and neural factors.

Lars Koopmans et al, The allometry of vertebrate pursuit predation, Proceedings of the National Academy of Sciences (2026). DOI: 10.1073/pnas.2534397123

Comment by Dr. Krishna Kumari Challa on May 2, 2026 at 9:54am

How oak trees outwit their predators
Oak trees delay leaf emergence by about three days following heavy caterpillar infestation, reducing caterpillar survival and leaf damage by 55%. This adaptive timing, detected via satellite data, demonstrates that trees respond not only to weather but also to biological threats, challenging models that consider only abiotic factors. The delay is a reversible defense, maintaining resilience amid climate change and insect pressure.

Satellite data show trees delay budburst across landscapes to escape herbivores., Nature Ecology & Evolution (2026). DOI: 10.1038/s41559-026-03071-9

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