Comment

Comment by Dr. Krishna Kumari Challa on Thursday

Birds that put more energy into parenthood age faster and die younger, research shows

Selective breeding of Japanese quails for larger egg size resulted in females aging faster and having a 20% shorter lifespan compared to those bred for smaller eggs. This demonstrates a genetic trade-off between reproductive investment and longevity, supporting evolutionary theory that higher reproductive effort accelerates aging. The effect was not conclusively observed in males due to their longer lifespan.

In a new study, appearing in Proceedings of the Royal Society B: Biological Sciences, scientists selectively bred Japanese quails into two groups: laying either relatively large or small eggs. As the quails don't do much "parenting" after eggs hatch, mothers' main contribution is the resources they transfer to their eggs (chicks from larger eggs are more likely to survive).

After five to six generations of selective breeding, females bred to lay larger eggs aged faster and died about 20% younger than females bred for small eggs.

The findings of the study support a fundamental evolutionary theory: that high "investment" in offspring unavoidably leads to faster aging and a shorter life.

All living things have limited energy and resources, and face trade-offs between competing priorities.

Artificial selection for increased reproductive effort accelerates actuarial senescence and reduces lifespan in a precocial bird., Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2025.2908

Comment by Dr. Krishna Kumari Challa on Thursday

To test this idea, the team built computer models of simple neural circuits and examined how they responded to signals at different tempos. According to the models, the circuits respond most strongly to signals within the same 2 hertz range observed across animal communication. That means communication signals may have evolved to match the rhythms that brains process most easily.

Musicologists have long noted that popular songs cluster around 120 beats per minute, which is exactly 2 hertz. That rhythm fits our body.

Guy Amichay et al, A widespread animal communication tempo may resonate with the receiver's brain, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003735

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Comment by Dr. Krishna Kumari Challa on Thursday

Nature might have a universal rhythm

Animal communication can look wildly different—flashing lights, chirping calls, croaking songs and elaborate dances. But new research suggests many of these signals share a surprising feature: They repeat at nearly the same tempo.

In a new study, scientists found that communication signals across a wide range of species tend to repeat at about 2 hertz, or roughly two beats per second.

The researchers propose this tempo might reflect a shared biological constraint. Animal brains, including humans, may be naturally tuned to process signals arriving at that pace. In other words, two beats per second may be a rhythmic "sweet spot" that enables brains to detect signals more easily and process communication more efficiently.

Understanding this potentially universal tempo could help scientists better interpret animal signaling and social behaviour across species. The findings also hint that human perception of rhythms, including beats in popular music and the cadence of speech, may arise from the same neural timing principles found throughout nature.

The study grew out of the researchers' project to understand how synchrony arises in nature. 

 They noticed that the flashing of the fireflies and the chirping of the nearby crickets were in sync with each other and they thought that it was crazy that these two unrelated species would interact in such a way.

After analyzing their own recordings, the team concluded that the species were not synchronizing with one another. Instead, they were sending independent signals at very similar tempos—around two-to-three pulses per second.

To investigate whether the firefly-cricket coincidence reflected a broader pattern, they analyzed previously published studies of animal communication across a wide range of species. These rhythmic signals included: firefly flashes, cricket chirps, frog calls, birds' mating displays, sound and light pulses from fish and vocals and gestures from mammals.

Despite enormous differences in body sizes, habitats and communication methods, the team found that many species repeat signals within a narrow range of roughly 0.5 to 4 hertz (1 to 4 beats per second). The pattern spans animals that communicate through sound, light or movement, suggesting a common underlying principle.

Earlier biophysicists noted that the biophysics of a single neuron operates at the same rhythm. Neurons require time to integrate information before firing again. Because of this biological constraint, neural circuits tend to respond most strongly to signals arriving every few hundred milliseconds—roughly two times per second.

Part 1

Comment by Dr. Krishna Kumari Challa on Thursday

Ribosomal DNA may help explain human size differences

The ribosome is the most basic yet essential part of life on Earth. In humans, ribosomes are made up of about 80 proteins and four types of RNA. To keep up with the high demand for protein-making structures in cells, our bodies carry hundreds of copies of the instructions for making them in the form of rDNA. The number of these copies varies considerably between individuals, ranging from around 200 to 600 copies per human genome.

Ribosomal RNA (rRNA), made from many copies of ribosomal DNA (rDNA), is the core component that powers ribosomes—protein-building machines in our body. It helps build proteins by linking amino acids together, and can also fine-tune this process by interacting with other proteins and messenger RNA (mRNA). For a long time, scientists assumed ribosomes were more or less identical within a species. A new study in Cell Genomics is challenging that idea.

The work shows that rDNA can vary quite a bit, not just between species, but even from one person to another, and these small genetic differences can subtly change the shape of ribosomes, which may influence diversity in human size traits such as height and weight.

Recent studies reveal that rDNA can vary not only in how many copies people have, but also in its sequence, with small changes such as single-letter differences and insertions or deletions. 

Researchers discovered a cluster of genetic variations in a region of 28S rRNA called expansion segment 15L (ES15L) that is strongly linked to body size traits such as height, weight, and birth weight. These genetic differences are not just passive markers built into the ribosomes and could change their physical shape and structure. These effects appeared to be independent of the number of rDNA copies a person has.

This study uncovers a previously overlooked source of genetic variation that shapes human traits such as height and weight, while also highlighting the ribosome as an unexpected contributor to human diversity. 

Francisco Rodriguez-Algarra et al, Germline sequence variation within the ribosomal DNA is associated with human complex traits, Cell Genomics (2026). DOI: 10.1016/j.xgen.2026.101213

Comment by Dr. Krishna Kumari Challa on April 14, 2026 at 9:20am

The central idea is that if a small black hole forms at the core of a strongly magnetized star, it does not grow in isolation. Instead, it is embedded in a medium where magnetic forces are significant. These fields can exert pressure and tension that oppose the inward flow of matter toward the black hole.

As a result, the accretion process—the mechanism that drives black hole growth—can be substantially reduced.
In this picture, the black hole may still form, but its growth is effectively slowed or even halted. Instead of a runaway process in which the star is inevitably consumed, the system becomes regulated. The star could survive for much longer timescales, potentially remaining observable.

This mechanism is referred to as magnetically arrested transmutation (MAT).

MAT provides a natural way to understand the contrasting observations in the galactic center. Stars with strong internal magnetic fields, such as magnetars or highly magnetized white dwarfs, may be protected from rapid destruction.

Their magnetic fields act as a barrier that limits the growth of any black hole forming inside them. On the other hand, stars with weaker magnetic fields may lack this protection, making them more vulnerable to being consumed from within.

In this way, magnetic fields may effectively decide the fate of compact stars in extreme environments.

H. A. Adarsha et al, Magnetically arrested transmutation of a compact star, The European Physical Journal C (2026). DOI: 10.1140/epjc/s10052-026-15515-4

Part 2

Comment by Dr. Krishna Kumari Challa on April 14, 2026 at 9:17am

Why do some stars in the galactic center survive while others are destroyed?
Strong internal magnetic fields in compact stars near the galactic center can suppress the accretion of stellar material onto nascent black holes, slowing or halting their growth and allowing the stars to survive. This mechanism, termed magnetically arrested transmutation, explains the survival of magnetars and highly magnetized white dwarfs, while stars with weaker magnetic fields are more likely to be destroyed.
The center of our galaxy is an extreme place. Surrounding the supermassive black hole Sagittarius A, stars are packed densely into a region where gravity, radiation, and dark matter all interact in complex ways. It is a natural laboratory for testing some of the deepest ideas about astrophysics.
Compact stars—such as neutron stars and white dwarfs—are expected to accumulate dark matter over time, especially in such dense environments. Under the right conditions, this accumulation can trigger the formation of a tiny black hole at the very center of the star.

Once formed, the black hole should begin to grow by accreting the surrounding stellar material. The expected outcome is dramatic: The star is gradually consumed from within and eventually collapses entirely into a black hole.

If this picture were complete, many compact stars in the galactic center should already have been destroyed. But observations suggest otherwise.
Some stars clearly survive. Others appear to be missing. This uneven outcome raises a fundamental question: What determines whether a star lives or dies in such an environment?

One particularly intriguing clue comes from the magnetar PSR J1745-2900, located remarkably close to Sagittarius A*. Magnetars are neutron stars with extremely strong magnetic fields, and this object is both highly magnetized and stable. Its survival is not easy to reconcile with the expectation of rapid destruction driven by internal black hole growth.

At the same time, there is evidence for an overabundance of strongly magnetized white dwarfs near the galactic center.

In contrast, ordinary pulsars—neutron stars with comparatively weaker magnetic fields—appear to be underrepresented, a long-standing issue often referred to as the "missing pulsar problem."

Taken together, these observations suggest that not all stars share the same fate. Something must be influencing the outcome.
A natural candidate is magnetism.

Compact stars can host some of the strongest magnetic fields in the universe. In many astrophysical environments, magnetic fields are known to regulate how matter moves, especially in accretion processes. They can channel, redistribute, or even suppress the flow of matter onto compact objects. This raises an important possibility: Could magnetic fields also influence the growth of a black hole forming inside a star?

In recent work, this possibility was explored in detail. The findings are published in The European Physical Journal C.
Part 1

Comment by Dr. Krishna Kumari Challa on April 14, 2026 at 8:49am

How the US Will Blockade Iran in the Strait of Hormuz

Comment by Dr. Krishna Kumari Challa on April 11, 2026 at 1:27pm

Too young for the MMR shot, babies become 'sitting ducks' in measles outbreaks
Infants too young for measles vaccination are highly vulnerable during outbreaks, relying on herd immunity, which requires ≥95% community vaccination coverage. Declining vaccination rates and increased exemptions have eroded this protection, leading to significant outbreaks and increased risk of severe illness or death in infants. Legislative efforts to restrict vaccine requirements may further reduce coverage and increase disease spread.
Source: News agencies

Comment by Dr. Krishna Kumari Challa on April 11, 2026 at 1:21pm

The team also showed that an infant's epigenome at birth impacted how their microbiome developed during their first year. Specifically, infants developed less diverse gut microbiomes at 12 months of age when they showed higher rates of DNA methylation in immune genes involved in recognizing pathogens.

The behavioral survey revealed that signs of ASD and ADHD in 3-year-olds were associated with specific epigenetic patterns and the presence of certain gut microbes.

However, other microbial species seemed to mitigate these effects: infants with epigenetic patterns associated with ASD or ADHD were less likely to show signs of the disorders if they acquired Lachnospira pectinoschiza and Parabacteroides distasonis, respectively, during their first year.

Epigenome–microbiome interplay in early life associates with infants' neurodevelopmental outcomes, Cell Press Blue (2026). DOI: 10.1016/j.cpblue.2026.100009. www.cell.com/cell-press-blue/f … 3051-3839(26)00007-1

Part 2

Comment by Dr. Krishna Kumari Challa on April 11, 2026 at 1:20pm

Epigenetic changes at birth are associated with an infant's microbiome and neurodevelopment
Epigenetic patterns at birth influence the development of the infant gut microbiome during the first year and are associated with later neurodevelopmental signs, including ASD and ADHD. Specific gut microbes, such as Lachnospira pectinoschiza and Parabacteroides distasonis, may mitigate the risk of these neurodevelopmental conditions in children with certain epigenetic profiles.
The gut microbiome and epigenetics—molecular switches that turn genes on or off—are intertwined, and both contribute to neurodevelopment, finds a study published in Cell Press Blue. The researchers showed that epigenetic changes present at birth can impact how an infant's gut microbiome develops during their first year.
They also identified specific epigenetic changes and gut microbes that were associated with signs of autism spectrum disorder (ASD) and Attention-Deficit/Hyperactivity Disorder (ADHD) when the children were three years old.

Certain bacteria seem to offer protection, which is exciting because it suggests there could be ways to support a child's development through diet or probiotics in the future.
Early life biology matters:
The first years of life are critical for brain development and immune system maturation. Though previous studies have shown that both early epigenetic changes and gut microbiome development can impact health in later life, little is known about how these two systems interact.
Researchers discovered a kind of conversation happening: a baby's epigenetic setting at birth can influence their risk for neurodevelopmental disorders, but the presence of certain 'good' bacteria in their gut can step in and modify the risk.
The researchers characterized DNA methylation patterns—a type of epigenetic change—from the umbilical cord blood of 571 infants. They paired this information with gut microbiome data collected from 969 infants at 2, 6, and 12 months of age, and from their parents during the third trimester of pregnancy.

When the children reached 36 months of age, the researchers used a behavioral questionnaire to assess their neurodevelopment and investigate links between the microbiome, epigenome, and early signs of ASD and ADHD.
They found that an infant's epigenome at birth was associated with birth mode, length of gestation, having older siblings, and maternal allergies, but it was not affected by their parents' gut microbiomes.

Microbiome development, on the other hand, was associated with birth mode, antibiotics, having older siblings, and breastfeeding. Infants who were born by cesarean section showed different patterns of DNA methylation for several genes involved in immune responses and brain development.
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