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Comment by Dr. Krishna Kumari Challa yesterday

Stress gene 'stuck on' in the brains of people with schizophrenia, study finds

Experts  have found that a gene involved in regulating the body's response to stress switches on more easily in the brains of people who live with schizophrenia.
The study, published in the American Journal of Psychiatry, looked at the FKBP5 gene and the corresponding FKBP51 protein, which help regulate how strongly the body responds to stress hormones such as cortisol.

Using donated brain tissue, the researchers found that for people with schizophrenia, the chemical tags that normally keep the FKBP5 gene in check had been stripped away. This change was linked to higher activity of the FKBP5 gene, opening up the possibility of developing new treatments that target it.
For people who have lost the chemical tags that keep their stress gene in check, it is like having the volume on their speaker stuck on high.

Responding to stress so strongly can affect the brain over time, making it more vulnerable to serious psychiatric conditions. Understanding what controls this response gives us fresh insights that will help us to develop more effective treatments.
The researchers also found that changes in the stress-response system become more pronounced with age, potentially affecting the brain's internal circuitry over time. This means that the system may be switched on more easily and stay on for longer. These changes, in turn, increase vulnerability to developing psychiatric disorders such as schizophrenia later in life.
Having a persistently heightened stress response may mean that, as the brain ages, the circuits in the frontal cortex become more vulnerable to damage, increasing susceptibility to serious psychiatric illness.

Age-dependent DNA methylation changes at FKBP5 enhancer sites drive increased gene expression in schizophrenia, American Journal of Psychiatry (2026).

Comment by Dr. Krishna Kumari Challa on Tuesday

How bacteria help plants survive drought
A Flavobacterium strain increased plant drought tolerance by stimulating root-hair formation. The enhanced root hairs increase root surface area for water and nutrient uptake through a plant signaling and gene-regulation pathway, identifying a microbial contribution to drought adaptation.

Arezoo Rahimi et al, Endophytic Flavobacterium promotes root hair development and enhances drought tolerance via an ERF–CEP5 hormonal regulatory module, Nature Plants (2026). DOI: 10.1038/s41477-026-02350-4

Comment by Dr. Krishna Kumari Challa on Tuesday

Antarctic bacteria share 'life‑support' genes to survive extreme conditions

Antarctic soil microbes extensively exchange genes via horizontal transfer; evidence occurred in ~98% of 676 analyzed species. Frequently transferred genes support aerotrophy, enabling energy generation from atmospheric hydrogen and carbon monoxide. Selection retains beneficial genes, supporting survival in cold, dry, nutrient-poor soils.

original article.

Comment by Dr. Krishna Kumari Challa on Tuesday

The researchers argue that it is not enough to simply remove satellite DNA from just one chromosome. With only one "barcode" disrupted, all the other chromosome pairs with intact satellite DNA "barcodes" can find each other. Ultimately, only the pair of chromosomes from which the researchers removed the barcode remains. They find each other like the last two face-down cards in a game of Memory.

Therefore, the ETH researchers removed the satellite DNA barcode from two different chromosomes, leaving the two pairs without any guidance.

And indeed, without their barcode, partner selection went awry and failed, meaning that the chromosomes frequently docked with the wrong partners. "This showed us that satellite DNA functions as a recognition aid and ensures that the chromosomes that belong together can reliably find one another.
Simply recognizing each other, however, is not enough. The researchers went on to discover that chromosome pairing also requires a molecular "glue" to properly "marry" the two partners together. A protein called D1 plays this role. It recognizes the matching barcodes on the chromosomes that belong together, binds them and holds the two together.

However, if the recognition pattern on one of the two chromosomes is altered—for example, if part of the barcode is deleted or changes occur due to natural mutations—the D1 protein can bond two chromosomes together that do not belong together. The pairing then goes wrong.
The new findings also explain how new species arise. Satellite DNA changes a great deal more rapidly than the rest of the genome. As long as individuals of a species produce offspring with one another, the satellite DNA barcodes remain similar across the population. because of the constant mixing of genetic material. Individuals with recognition patterns that differ too greatly suffer from meiosis defects and are unable to reproduce.

However, if a population of an animal species becomes geographically isolated—for example, because of the formation of a mountain range over millions of years—the satellite DNA in both groups evolves independently. When the two groups meet again after a long period, the recognition patterns of the chromosomes no longer match. The result: The animals can no longer reproduce, and one species has become two.

Studies on crosses between Drosophila melanogaster and its relative Drosophila simulans are consistent with this idea. The two species diverged two to three million years ago. The barcodes of their chromosomes now differ so greatly that massive chromosome-pairing defects occur during meiosis in hybrids.

Lena Skrutl et al, Meiotic pairing through barcode-like satellite DNA repeats, Nature Communications (2026). DOI: 10.1038/s41467-026-74398-x

Part 2

Comment by Dr. Krishna Kumari Challa on Tuesday

How chromosomes find their partners

For a long time, so-called satellite DNA was considered largely worthless. Now, researchers have shown in fruit flies that these repetitive sections of genetic material act as a kind of barcode, enabling the correct chromosomes to recognize one another.
The body cells of humans and animals contain a double set of chromosomes. One-half of the genetic material comes from the mother; the other stems from the father.

During the formation of sperm or egg cells, this double set of chromosomes must be halved to form a single set. This takes place during what is known as meiosis. In this process, a cell with a double set of chromosomes gives rise to daughter cells with a single set of chromosomes. This halving is necessary because, during fertilization, two germ cells—and thus their genetic material—fuse together.

Afterwards, there is once again a double set of chromosomes. If this did not happen, the number of chromosomes would double from one generation to the next as the germ cells fuse.

To ensure that chromosomes can be distributed evenly during meiosis, the maternal and paternal versions of the same chromosome must locate one another within a cell and temporarily pair up. This is no easy task amid the vast jumble of the cell nucleus. Mismatches must be avoided at all costs during the pairing phase to prevent chromosomes from being distributed incorrectly.
But how do the matching chromosome pairs actually find each other?
Researchers have now investigated—using the example of egg cell formation in female fruit flies (Drosophila)—how this "matchmaking" process takes place in the cell nucleus and have made a surprising discovery.
For a long time, scientists have known that large swaths of animal genomes consist of repetitive DNA sequences. Known as satellite DNA, experts regarded these repeats as useless "junk DNA" because they do not contain blueprints for proteins. Nor were other researchers able to attribute any role to satellite DNA during meiosis. Indeed, when they removed these satellite DNA repeats from just one chromosome, chromosome pairing still proceeded without error.

In Nature Communications, researchers demonstrate that unique satellite DNA patterns on each pair of chromosomes, comparable to a barcode on a product in a supermarket, help matching chromosomes find each other.
Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

How space rocks become meteorites

What happens to a space rock as it falls through Earth's atmosphere and becomes a meteorite? By studying 75 meteorite falls captured on video and in photographs, researchers identified seven distinct phases in the journey from space rock to meteorite. Their findings show that melting and fragmentation, rather than simply evaporation and "burning up," control how a rock loses mass, slows down and ultimately reaches the ground.
Phase 1 starts high in the atmosphere, when the air is dense enough to create a shock wave in front of the falling rock. Collisions with air molecules heat the rock and the gas around it until they glow. This is what we see as a meteor or "shooting star."

As the rock falls into thicker air, Phase 2 begins and the meteor gets brighter. Some meteors show that the rock is spinning rapidly by changing brightness in a regular pattern. The fastest-spinning rocks in the study made a full turn every 0.5 to 5 seconds.

In Phase 3, the meteor gets much brighter and turns into a fireball. The researchers found that melting now causes most of the rock's mass loss. The fast-moving air pulls melted material off the surface, leaving droplets behind that keep evaporating.
At around 60 kilometers (around 40 miles) above Earth, the fireball reaches Phase 4 by settling into a melting equilibrium. Its brightness stays the same or grows at a steady pace. The rock ultimately can lose up to 40% of its mass just from melting.
Deeper in the atmosphere, higher pressure makes the rock break apart, starting Phase 5. The fireball may flare up several times as pieces break off.

The researchers discovered that rocks start to break apart when the air pressure in front of the rock is only about one-fifth of the strength measured in meteorites found on Earth. They think that heat and cracks from earlier collisions in space can explain why the rocks break earlier than expected.

Only at this time does the remaining rock quickly become smaller and slow down significantly, more rapidly if the rock breaks aggressively.
If the back of the main rock stays whole, it creates a low-pressure area behind it that pulls smaller pieces along.
When the back of the rock finally breaks apart in Phase 6, the fireball gives off a last bright flare and sends pieces flying out faster. Since the rock has already slowed down, these late flares are usually red instead of the bright green seen earlier.

That final disruption sends fragments flying at higher relative speeds.
In Phase 7, melting and fragmentation keep happening until the last pieces slow down enough to stop glowing. Melting ends, leaving a thin fusion crust on their surfaces. Winds can then blow the darkened fragments off course as they finish falling to the ground as meteorites.
The 75 investigated meteorite falls included several different meteorite types. The study identified the altitudes at which these different materials went through the seven phases.

By studying the atmospheric slowdown of small, solid space rocks of different types, researchers also gained insight into what happens to more dangerous airbursting asteroids the size of cars to city blocks.

Asteroids up to tens of meters in size are also solid rocks because they tend to spin faster than do the larger rubble-pile asteroids.

Peter Jenniskens et al, Bolide Light Curve Systematics from 75 Recovered Meteorites, Meteoritics & Planetary Science (2026). DOI: 10.1111/maps.70203

Comment by Dr. Krishna Kumari Challa on Tuesday

A 4-star system caught eclipsing itself in a way never seen before
Astronomers have found a four-star system doing something that has never been confirmed before. The system, TIC 433545934, has two close pairs of stars orbiting each other. While each pair eclipses its own two stars, as usual, only one pair eclipses the other. A paper outlining the properties of this unique system was submitted to the arXiv preprint server on Aug. 13. It has been accepted for publication in the journal Astronomy & Astrophysics.

Tamás Borkovits et al, TIC 433545934: The first 2+2 type doubly eclipsing binary with extra, mutual eclipses, arXiv (2026). DOI: 10.48550/arxiv.2608.13034

Comment by Dr. Krishna Kumari Challa on Tuesday

In simpler terms, a small group of brain cells suddenly becomes highly active and moves to the same fast beat. The entire event is over almost as soon as it begins.

Across 43 recording sessions, the researchers followed the activity of 1,373 brain cells. They discovered that ripples often appeared at the same time in two distant brain regions.

When that happened, cells in those regions were about 30 percent more likely to send signals together. In some parts of the task, the increase reached 49 percent.

This may help explain how information stored across the brain can be combined into one experience.

A face may be processed in one area, a name in another, and the place where you met that person somewhere else. The shared rhythm could briefly open a line of communication between those areas, allowing them to work as one team.

That matters because 'firing together' may be the brain's basic currency for linking information.

The most surprising result was how far this coordination reached. The shared ripples linked areas separated by as much as 220 millimeters and even appeared across the brain's two halves.

Ordinarily, direct connections between brain regions become less common as the distance between them increases. If the ripples depended only on direct wiring, their coordination should have weakened over longer distances. It did not.

The results suggest this coordination may not require a single brain region acting as a conductor. Instead, the effect may resemble a crowd gradually beginning to clap to the same beat without anyone directing it.

The rhythm also became more prominent when the memory task grew harder.

Previous research has connected similar ripples with the replay and storage of memories. One recent study found that even one exercise session could change memory-related ripples in the human brain.

The new findings suggest these brief rhythms may also help the brain keep a thought together while we are actively using it.

https://www.nature.com/articles/s41593-026-02403-z

Part 2

Comment by Dr. Krishna Kumari Challa on Tuesday

Hidden Pulses Within Your Brain May Hold Your Thoughts Together
When you recognize a familiar face, your brain must connect that face with a name, a place, and perhaps a memory.

Those pieces of information are not necessarily handled in the same part of the brain. Yet they come together so smoothly that you experience them as a single thought.

Scientists may now have found one way the brain pulls off this trick.

A new study suggests that distant parts of the brain briefly fall into the same rhythm when we hold and retrieve information. During these fleeting moments, their cells become more likely to send signals together, potentially allowing separate pieces of a thought to be joined.

Researchers were especially interested in extremely brief bursts of electrical activity called ripples. A ripple is a very brief burst of rhythmic oscillations in neuron excitability – roughly 90 cycles per second, lasting only about a tenth of a second.
Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

Getting pregnant while already pregnant is an extremely rare phenomenon known as superfetation. It happens when a second egg is released, fertilized, and implants in the uterus weeks after an initial pregnancy has already begun, resulting in two fetuses with different gestational ages.
How It Normally Blocked
Your body has strong natural barriers to prevent this:
No Ovulation: Pregnancy hormones like progesterone stop your ovaries from releasing more eggs.
Cervical Plug: Thick mucus blocks sperm from entering the uterus.
Uterine Lining Changes: The lining changes so a new embryo cannot implant.
Why It Is So Rare
For superfetation to happen, all natural body blocks must fail at the same time.
Only a tiny number of natural cases are documented worldwide.
Most reported cases involve fertility treatments or assisted reproductive technology.
However, some people of science that different fetal sizes on early scans are usually just fraternal twins or normal growth variations rather than true superfetation.

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