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Comment by Dr. Krishna Kumari Challa yesterday

How does gold keep its glitter? Researchers uncover why it resists tarnish

Gold has been prized for thousands of years for its enduring shine, but researchers have discovered that gold's resistance to tarnishing depends on more than its chemistry.

In a new study published in Physical Review Letters, researchers found that atoms on certain gold surfaces naturally rearrange themselves into protective patterns that dramatically suppress reactions with oxygen.

The discovery helps explain why gold jewelry and other gold objects can remain untarnished for centuries—and could also point the way toward designing more effective gold-based catalysts for industrial and energy-related applications.

Using computer simulations that predict how atoms and electrons behave, the researchers studied how oxygen molecules interact with two common gold surface structures. They found that without this atomic rearrangement, oxygen molecules could break apart and react with gold much more easily.

Instead, the rearranged surfaces suppress oxygen reactions by a factor of a billion to a trillion, essentially creating a protective atomic-scale barrier that helps gold stay shiny indefinitely.

The findings offer a new explanation for one of gold's best-known properties while also opening the door to potential advances in catalysis.

Anonymous, Role of reconstruction in the inertness of gold towards oxygen, Physical Review Letters (2026). DOI: 10.1103/g3bc-t1qv

Comment by Dr. Krishna Kumari Challa yesterday

Extraterrestrial life may be slipping past space missions, astrobiologists warn

Current astrobiological detection methods risk false-negative results, potentially missing existing extraterrestrial life due to preservation issues, detection limitations, and insufficiently targeted research strategies. Overlooking such evidence may deprioritize promising environments and lead to premature resource exploitation, risking irreversible loss of undiscovered life. Improved strategies integrating laboratory, modeling, fieldwork, and AI-driven pattern recognition are needed to minimize these risks.

False negatives in the search for extraterrestrial life, Nature Astronomy (2026). DOI: 10.1038/s41550-026-02863-0

Comment by Dr. Krishna Kumari Challa yesterday

Common food preservatives linked to high blood pressure and heart disease

Food preservatives are used in hundreds of thousands of industrially processed foods. Experimental studies suggest that some preservative food additives may be harmful to cardiovascular health.

Eating foods that contain common preservative food additives may increase the risks of high blood pressure and cardiovascular disease, according to research published in the European Heart Journal.

Researchers carried out detailed analyses of the ingredients of all the food and drink, including any preservatives. They also tracked the volunteers' health for an average of seven to eight years to see if they develop high blood pressure or any cardiovascular disease.

Researcher found that 99.5% of the volunteers had consumed at least one food preservative within the first two years of taking part.

Overall, they found that people who ate the largest amounts of "non-antioxidant" preservatives had a 29% higher risk of hypertension, compared to those who ate the least, and a 16% higher risk of cardiovascular disease, including heart attack, stroke, and angina. People who ate the most antioxidant preservatives had a 22% higher risk of hypertension.

Non-antioxidant preservatives are designed to stop harmful microbes, such as mold and bacteria, from growing, whereas antioxidant preservatives are designed to stop oxidation which means the food will not turn brown or become rancid.

Researchers also looked at 17 of the most commonly eaten preservatives and found that eight of these were specifically linked to high blood pressure. These were: potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), ascorbic acid (E300), sodium ascorbate (E301), sodium erythorbate (E316), citric acid (E330) and extracts of rosemary (E392). Ascorbic acid (E300) was also specifically linked to cardiovascular disease.

The findings are based on highly detailed data, and the researchers have taken account of other factors that can increase or lower the risk of cardiovascular disease. Experimental research in the literature consistently suggested that preservatives may cause oxidative stress in the body or affect the way the pancreas works.

These results suggest we need a re-evaluation of the risks and benefits of these food additives by the authorities in charge for better consumer protection.

These findings support existing recommendations to favour non-processed and minimally processed foods, and avoid unnecessary additives.

Preservative food additives, hypertension, and cardiovascular diseases: the NutriNet-Santé study, European Heart Journal (2026). DOI: 10.1093/eurheartj/ehag308

Comment by Dr. Krishna Kumari Challa yesterday

Quantum supremacy just ran into an unexpected rival: An ordinary laptop armed with new math

Using a conventional computer and cutting-edge mathematical tools and code, physicists have cracked a daunting quantum physics problem previously claimed to be solvable only by quantum computers.

The technique is so ground-breaking in its efficiency that the researchers were even able to use a personal laptop to solve the problem.

By enabling scientists to squeeze extra problem-solving power from classical computers, the breakthrough methodology is opening new avenues for research on quantum dynamics and may be useful as a protocol for solving problems about finding the optimal solution amid an abundance of feasible ones.

The problem at hand involves simulating a quantum system composed of hundreds of interacting "qubits"—the quantum computing equivalent of the bits used in classical computers—arranged in square, cubic, or diamond lattices. While bits can have values of 0 or 1, qubits can exist in a superposition of multiple values, making it challenging for traditional computers to simulate their dynamics.

The research team  achieved their breakthrough by developing and implementing new tools based on tensor networks. The tensor networks made the problem feasible for classical computers. The team ran many of their simulations using relatively modest computational resources.

Despite using only modest computational hardware, the researchers demonstrated that their simulations yielded state-of-the-art accuracies. The simulations converged on solutions that matched theoretical predictions and provided accurate results when applied to smaller test problems. The results also agreed with those reported by the quantum computing researchers—but with no quantum computer required.

Joseph Tindall et al, Dynamics of disordered quantum systems with two- and three-dimensional tensor networks, Science (2026). DOI: 10.1126/science.adx2728. www.science.org/doi/10.1126/science.adx2728

Comment by Dr. Krishna Kumari Challa yesterday

Astronomers have discovered the tiniest odd radio circle

Astronomers have identified a possible new member of one of astronomy's strangest classes of objects: Odd radio circles (ORCs), enormous ring-like structures visible only at radio wavelengths. The newly discovered source, J1248+4826, appears to be the most compact ORC candidate identified so far, with a ring only about 30,000 parsecs across. The paper was posted to the arXiv preprint server on May 6.

First reported in 2021, odd radio circles are faint ring-shaped radio emissions that are not detected at other wavelengths. They typically have a massive early-type galaxy with hundreds of billions of solar masses at their center, existing somewhere when the universe was roughly 8–11 billion years old. They span hundreds of kiloparsecs across.

Where they come from is still an open question. Leading ideas include remnants of magnetized plasma ejected roughly a billion years ago by a supermassive black hole, a past starburst episode, merging galaxy groups, or large-scale active galactic nuclei-driven outflows.

This newly discovered one  is a radio ring surrounded by a faint diffuse envelope, located very close to a galaxy group as seen when the universe was 11.2 billion years old.

The team's analysis revealed that the ring's radius is about 9 arcseconds, which corresponds to only 30 kiloparsecs physically. This is well below the previously reported radii of the ring-structure of ORCs, which range from 44 to 365 kiloparsecs. The surrounding diffuse envelope, extending to roughly 100 kiloparsecs, is more in line with the other members of the population.

Despite its compact size, the structure shares many of the same radio properties as previously known ORCs. However, unlike other ORCs that have their host galaxy at their center, this structure's host galaxy was found not at the center but at the edge.

M. Polletta et al, A Compact Radio Ring with a Diffuse Envelope in LOFAR: Odd Radio Circle or Distinct Phenomenon?, arXiv (2026). DOI: 10.48550/arxiv.2605.05174

Comment by Dr. Krishna Kumari Challa on Thursday

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 on Thursday

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 on Thursday

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 on Thursday

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 on Thursday

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.
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