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Comment by Dr. Krishna Kumari Challa 7 hours ago

Dissolved oxygen is very different from the oxygen atoms that pair with a hydrogen to form water. Dissolved oxygen is what aquatic life needs to 'breathe': that goes for animals, plants, plankton, bacteria, and anything else living underwater.

But the bonds that keep oxygen gas dissolved in water are relatively weak. Just a slight shift in temperature is enough to rip them apart, allowing the oxygen to escape.

https://www.science.org/doi/10.1126/sciadv.aef3132

Part 2

Comment by Dr. Krishna Kumari Challa 7 hours ago

80% of Earth's Rivers Are Quickly Losing Oxygen, Study Reveals

Oxygen levels have decreased in almost 80 percent of rivers worldwide, and they're going to continue losing this precious resource unless we make some serious changes.

Satellite and climate data collected between 1985 and 2023 reveal that over 16,000 rivers across the world have been losing their dissolved oxygen.

On average, these rivers have been losing 0.045 milligrams of oxygen per liter each decade.

Without enough dissolved oxygen essential to sustain life underwater, rivers – and the communities that rely on their water and resources – are under serious threat.

By the end of the century, assuming carbon dioxide emissions continue to rise at similar rates (as opposed to some of the worst-case scenarios), rivers across most of South America, India, the Arctic, and the Eastern United States are expected to lose around 10 percent of their dissolved oxygen.

The most severe shifts so far have occurred in tropical rivers, such as the Ganges in India and the Amazon River in South America. The Ganges River in particular is losing oxygen 20 times faster than the global average.

Scientists didn't see this coming. Previously, they assumed that high-latitude rivers would experience the worst deoxygenation because these regions are climate change hotspots.
But tropical rivers had a disadvantage from the start: Since their waters were already warmer, they already had lower levels of dissolved oxygen. This means they're already closer to reaching hypoxia (insufficient oxygen to sustain most life).

Climate change driven by human activities is reducing oxygen solubility (the ability of a body of water to hold dissolved oxygen). According to the new study, oxygen solubility accounts for about 63 percent of global river deoxygenation.

Water temperature is most likely driving this change in oxygen solubility. Warmer waters hold less dissolved oxygen because the oxygen and water molecules are receiving more energy in the form of heat.
Part 1

Comment by Dr. Krishna Kumari Challa 7 hours ago

arXiv clamps down on AI citations
The preprint repository arXiv has announced a one-year posting ban for researchers whose submissions are found to contain references hallucinated by artificial intelligence. Even after this penalty period, affected researchers can’t post to arXiv unless their manuscript has already been accepted at a “reputable peer-reviewed venue”, according to computer scientist Thomas Dietterich, chair of arXiv’s computer science section. Some researchers have praised the server for taking a stand; others suggest it doesn’t go far enough to tackle ‘AI slop’ in preprints.

https://www.linkedin.com/posts/vk2lndx_arxiv-just-declared-war-on-a...

https://www.linkedin.com/feed/update/urn:li:activity:74618939739688...

Comment by Dr. Krishna Kumari Challa 9 hours ago

But perhaps the most important finding was that no single measure told the full story. It was not one region or one feature that mattered most, but the overall pattern, the way multiple features came together across the brain. The brain does not function in isolated parts. It operates as an integrated system, and it was the balance across that system that appeared to shape later cognitive ability.

 Among children who went on to experience cognitive difficulties, they observed something unusual—altered connectivity between frontal, cingulate, and temporal regions. In some cases, these regions showed anticorrelated patterns essentially moving in opposite directions when they would normally move in concert.
 The parts of the brain that should be working together were, in some children, less coordinated and almost out of sync
They also found differences in the brain's hubs, the highly connected regions that act as coordination centers, integrating information from across the network. In children with cognitive difficulties, these hubs were positioned differently compared with those who developed within the typical range. Even a subtle shift in where those coordination centers sit can affect how efficiently the whole system processes and shares information. What this tells us is that outcomes after extremely preterm birth are not simply determined by what happened at birth. They are shaped by how the developing brain reorganizes itself in the months and years that follow.

The brain regions most affected in our study are those associated with language, attention, and working memory. These are capacities that can be strengthened through targeted educational strategies, cognitive interventions, and early developmental support. We also found that children with more severe neonatal complications, such as prolonged need for ventilation or bronchopulmonary dysplasia, were more likely to show later cognitive difficulties. This reinforces how important it is to continue improving the quality of neonatal intensive care from day one.

 Not all extremely preterm children showed disrupted connectivity. A substantial number in the study performed within the typical cognitive range at age 12. Their brains showed some structural differences compared with term-born peers, but they did not show the altered connectivity patterns  the researchers saw in children with cognitive difficulties. That variability is not noise. It is one of the most meaningful things they found. It tells us that the developing brain is not simply a record of what went wrong. It is, in many children, a record of what held together.

Real, measurable, neural resilience is common among children born extremely preterm. Understanding what protects these children, whether biological, environmental, or a combination of both, is now just as important to us as understanding the risk. Because the question is no longer only what changes in the preterm brain. It is also what protects it.

Samson Nivins et al, Disrupted cortical folding and cognitive outcomes in extremely preterm children at mid-childhood, NeuroImage (2026). DOI: 10.1016/j.neuroimage.2026.121993

Part 2

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Comment by Dr. Krishna Kumari Challa 9 hours ago

Rewiring early life: What extremely preterm birth teaches us about the brain

Extremely preterm birth (before 28 weeks of gestation) places infants into the world at one of the most extraordinary moments in human development. The brain at this stage is not simply growing; it is folding, organizing, and laying down the networks that will eventually support language, memory, attention, and learning. It is doing all of this in the dark, in the warmth, protected. When birth happens this early, all conditions change in an instant.
Extremely preterm birth disrupts typical brain development, leading to widespread structural differences such as thinner cortex, reduced folding, and altered sulcal depth, especially in regions linked to language, memory, and attention. Cognitive difficulties are associated with altered connectivity and repositioned network hubs, but many preterm children show neural resilience and typical cognitive outcomes, highlighting both risk and protective factors. Early identification of at-risk children may enable timely interventions to support cognitive development.
Modern neonatal medicine has achieved something remarkable: More of these children survive than ever before.
The third trimester is, in many ways, one of the brain's most ambitious phases. Its surface expands rapidly and folds into the ridges and grooves familiar from anatomy textbooks. But those folds are not cosmetic. They reflect an underlying organization of neural networks, the scaffolding of future thought.

When an extremely preterm infant enters the world, that scaffolding is still being built. The brain is suddenly exposed to an environment it was never designed to encounter at this stage. The noise, light, and necessary interventions—none of this is what the developing brain expects. Development continues, but on an altered course. At the same time, the infant is deprived of natural stimuli such as kicking the walls of the mother's womb and hearing the mother's voice.
Researchers found what happens in these conditions to the developing brain.
The structural differences they found were not confined to one region. Children born extremely preterm showed a thinner cortex, less folding, and shallower sulci (i.e., the grooves between brain folds) compared with their term-born peers. These differences were most evident in temporal and cingulate regions; areas closely related to language, memory, attention, and cognitive control.
Part 1

Comment by Dr. Krishna Kumari Challa 9 hours ago

In their experiments, the researchers found 522 instances—about 7% of epigenetic inheritance patterns—in which methylation was inherited on non-sex chromosomes in a variety of ways that broke Mendel's laws.

Some 54 of those instances represented rare or "emergent" types of epigenetic inheritance not present in either parent. For example, a cross between two mice with no methylation on the same allele, which should have resulted in a mouse that inherited no methylation on the allele, could instead result in a mouse with methylation on both alleles. "The methylation seemingly appeared out of nowhere" .
The scientists also found another rare type of inheritance called paramutation in a gene called Capn11, which encodes a calcium-dependent gene that regulates normal sperm development. Alterations in the human version of the gene cause infertility and problems with sperm.

Paramutation occurs when methylation in one allele leads to methylation in another allele. The paramutation was located in an area of the gene associated with a repetitive element of a type known to be influenced by environmental exposure. It's almost like the methylation is transferred to another allele. Epigenetic influences on the genome have been tied to environmental pressures such as environmental stress, trauma and diet.

This work may convince scientists to integrate both genomics and epigenomics more often for a complete understanding of how traits that produce disease and healthy states are inherited.

Adam Davidovich et al, Non-Mendelian inheritance of DNA methylation patterns in mice, Nature Genetics (2026). DOI: 10.1038/s41588-026-02604-z

Part 2

Comment by Dr. Krishna Kumari Challa 9 hours ago

When Mendel's rules don't apply: Mouse study reveals hidden epigenetic inheritance

The well-studied rules of genetic inheritance—known as Mendel's Laws—cover how genetic materials known as alleles sort themselves, are dominant or recessive, and in what ways they get passed down to new generations. Alleles are variations in genes that lead to a specific trait or disease state. In mammals, one allele is inherited from each parent, and either of those alleles can be dominant or recessive.
The rules state, for example, that alleles in offspring are inherited from each parent, and the traits of dominant alleles prevail over recessive ones, which are silenced.
Analysis of three generations of mice revealed that approximately 7% of DNA methylation patterns are inherited in ways that violate Mendel's laws, including novel forms of epigenetic inheritance such as paramutation and emergent methylation not present in either parent. These findings indicate that non-Mendelian epigenetic inheritance is more frequent and diverse than previously recognized, potentially enabling rapid trait variation in response to environmental factors.

Scientists have long known that the DNA code in genes is not the only way to pass genetic traits from parents to offspring. "Epigenetic" marks—chemical modifications to DNA that don't change the DNA code itself—can also be passed down.
Now, a new study using mice reveals that some of those marks—about 7% of them—can be inherited in ways that break the century-long understanding of the rules of inheritance explored and recorded by Gregor Mendel's work with pea plants. The study also reveals new, unexpected examples of inheritance patterns that defy Mendel's law—such as a naturally occurring paramutation, seen previously in plants and flies, and not in mammals.
Non-Mendelian patterns of inheriting epigenetics could be a faster way to acquire diverse or new traits than alterations in the genomic sequence itself, especially in response to environmental pressures.
Several previous studies have already shown that some patterns of epigenetic inheritance, such as genomic imprinting, can break the guiding principles established by the Austrian-born friar. The new study also found examples of genomic imprinting, but also other types of non-Mendelian patterns of epigenetic inheritance that surprised the scientists.

In examples of genomic imprinting, an allele in either parent can be labeled as coming from sperm or an egg and silenced by methylation. Such imprinted alleles are passed down to offspring and are silenced not because they are recessive but based on which parent contributes the imprinted allele. The new research found imprinting examples in five additional genes.

In addition to the new examples of genetic imprinting, results of the current study suggest that epigenetic patterns of inheritance that defy Mendel's rules may be more frequent than described in other studies. In addition, the research team found epigenetic patterns passed down to offspring that were not present in either parent.
Part 1

Comment by Dr. Krishna Kumari Challa 11 hours ago

Understanding how spin, magnetism, and molecular structure interact could open new doors in:

Isotope separation technologies
Advanced materials design
Analytical chemistry
And even quantum biology, an emerging field exploring how quantum effects influence living systems
In the end, the study reveals something both simple and profound: even at the smallest scales, direction matters.

A magnet pointing north or south can change how molecules move, interact, and separate. And those tiny differences may hold clues to the very origins of life.

Ofek Vardi et al, Spin-dependent isotopic fractionation of L-methionine, Chem (2026). DOI: 10.1016/j.chempr.2026.102993

Part 2

Comment by Dr. Krishna Kumari Challa 11 hours ago

The direction of a magnet could shape the building blocks of life

In a new discovery, researchers have found that something in the direction of a magnetic field can influence how molecules of life behave at the most fundamental level and how early chemical processes linked to life may have unfolded.

The study, published in Chem  shows that tiny differences between atoms (different isotopes) can lead to measurable changes in molecular behaviour when combined with an invisible quantum property known as electron spin. Separation of the different isotopes can be achieved by magnetic surfaces.

At the center of the story is L-methionine, an amino acid, a basic building block of life. Like other biological molecules, methionine has a specific "handedness," meaning it exists in a form that is not identical to its mirror image. This property, called chirality, is a mystery: why did nature choose one "hand" over the other? Now, the team's findings suggest that magnetism and the spin of electrons may have played a role.

The answer lies in a subtle quantum property: electron and nuclear spin. Particles behave a bit like tiny spinning tops, and their "spin direction" can influence how they interact with materials, especially when those materials are magnetic.
Chiral molecules like methionine are known to interact with electron spin in a special way, a phenomenon called chiral-induced spin selectivity (CISS). This means that the molecule's shape can "filter" electrons based on their spin.

What this new research shows is that this same effect can extend to isotopes atoms that differ only slightly in mass and nuclear spin. In other words, spin and magnetism can influence not just how molecules react, but which versions of those molecules are favoured.

Part 1

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