Comment

Comment by Dr. Krishna Kumari Challa 10 hours ago

Bacteria from gum disease may cause inflammation, harden heart valves

Gum disease bacteria may spur calcium buildup in the heart's aortic valve, leading to a common and serious heart valve disease, according to preliminary, independent research presented at the American Heart Association's Basic Cardiovascular Sciences Scientific Sessions 2026, held in Boston, July 13–16, 2026.

Porphyromonas gingivalis, a key periodontal pathogen, was enriched in calcified aortic valves and, in mice, accumulated in valves, increased calcification, and induced aortic stenosis–like changes. These effects were reduced by antibiotics and markedly attenuated when IL‑1β was deleted, implicating an IL‑1β–mediated inflammatory pathway linking periodontal disease to calcific aortic valve stenosis.

Comment by Dr. Krishna Kumari Challa 12 hours ago

Scientists strike invisible gold in the deep sea—locked inside fool's gold

Pyrite, an iron sulfide ore, is often known as fool's gold because its shiny metallic luster and pale brass-yellow color can easily fool the untrained eye into mistaking it for real gold. This time, however, 360 kilometers (220 miles) south of Tokyo, scientists have uncovered invisible gold within pyrite structures found deep beneath the ocean at the Higashi-Aogashima Knoll Caldera hydrothermal field.
With the help of robotic submarines that dived more than 700 meters (2,300 feet) below sea level, researchers collected rock samples from volcanic vents and underwater mounds scattered across the floor of a deep-sea caldera. Peering inside these rocks using secondary-ion mass spectrometry through tiny drill holes, they discovered that the minerals at this site contain record-breaking concentrations of gold, reaching as high as 1.9 wt% (19,231 ppm).
Instead of being present as gold granules or nodules, as found in conventional gold mines, the metal was locked as a solid solution within the crystal lattice of seafloor pyrite. This discovery, published in Scientific Reports, could give geologists a new way to identify promising mining sites around the world.
What surprised the researchers most was how the gold existed. Instead of forming tiny nuggets trapped inside the mineral, the gold was woven directly into pyrite's crystal structure, atom by atom. They also found that this could only happen when elements such as arsenic, lead and copper were present. These elements cause structural distortions in the pyrite lattice, creating vacancies that allow gold atoms to fit within the crystal and become trapped.

This was reflected in the positive gold-arsenic correlation, in which gold concentrations increased alongside arsenic concentrations. This occurs because arsenic substitutes for sulfur in the pyrite structure, creating space for the larger gold ions to enter.
Not all pyrite, however, was equally rich in gold. The concentration depended on where it was found and under what conditions it formed.

Yuichi Morishita et al, SIMS discovers invisible gold in pyrite from the high-grade seafloor hydrothermal deposits in the Higashi-Aogashima knoll caldera, Izu-Ogasawara arc, Japan, Scientific Reports (2026). DOI: 10.1038/s41598-026-58760-z

Comment by Dr. Krishna Kumari Challa 13 hours ago

The heart works as a one-way pump, moving blood into the organ with every beat. Heart valves help maintain this steady flow by opening to let blood pass through and closing to keep it from moving in the wrong direction. Each valve responds to pressure changes within the heart, causing its thin flaps to open at the right moment and then seal shut once blood has passed.

Valve disorders take two main forms. The first is regurgitation, in which the valve doesn't close completely, so blood leaks backward instead of flowing forward. This means less blood moves in the right direction and puts extra strain on the heart.

The second is stenosis, in which the valve opening narrows or stiffens, blocking blood flow and forcing the heart to pump harder to push blood through the tight opening. Depending on the severity of the condition, doctors decide whether it can be treated with medication, repair or replacement.

Aortic stenosis is one of the most common heart valve diseases, affecting millions of people worldwide. It is typically treated by replacing the aortic valve through either open-heart surgery (SAVR) or the less invasive TAVR.

While surgical bioprosthetic valves are designed to last 10 years or more, some can wear out much sooner, within five to seven years, with certain valve types showing a higher risk of early failure. There is still limited information comparing how well TAVR valves perform beyond five years, especially in low-risk patients.
In this study, the researchers sought to understand whether a less invasive procedure could provide results comparable to traditional surgery over time. They recruited 1,000 patients considered low-risk, meaning they were healthy enough to undergo open-heart surgery safely.

Participants were then randomly assigned to one of two groups: One received TAVR using the SAPIEN 3 valve, while the other underwent traditional open-heart surgical valve replacement. Over the seven years, patients had regular echocardiograms at set intervals: 30 days, one year, annually through year five, and again at year seven.
They found that only a small number of patients experienced significant valve deterioration, with similar rates between the two groups—7.3% for TAVR and 7.6% for surgery. Valve failure also occurred at similar rates, affecting 6.9% of TAVR patients and 7.5% of surgical patients, with 6% of TAVR patients and 5.5% of surgical patients needing a second valve procedure.

Overall, about 75% of patients in both groups were alive with a fully functioning replacement valve at the end of the study.

The results strengthen the case for TAVR, alongside conventional surgery, as a long-term alternative for low-risk patients. The researchers noted that these findings could help guide treatment choices based on each patient's needs and preferences. However, they suggested that if TAVR is chosen, patients should be monitored for early valve thrombosis so it can be identified and managed when needed.

Julien Ternacle et al, Seven-Year Valve Durability With Transcatheter or Surgical Aortic Valve Replacement, JAMA Cardiology (2026). DOI: 10.1001/jamacardio.2026.2299

Part 2

Comment by Dr. Krishna Kumari Challa 13 hours ago

Seven-year study finds non-surgical valve replacement holds up as well as open-heart surgery
The incidence of cardiovascular disease is rising across the globe, with more than 28 million people worldwide living with heart valve disease. Each year, surgeons perform thousands of heart valve replacement procedures.
As treatment options evolve, the profile of patients undergoing these surgeries is also changing. As transcatheter aortic valve replacement (TAVR) is increasingly considered for younger, lower-risk patients, researchers sought to explore a broader question: Which heart valve replacement approach offers better long-term durability and healthier valve function?

In the recent randomized PARTNER 3 trial, researchers compared TAVR, a minimally invasive procedure, with traditional open-heart surgery to see how the two approaches performed over the long term.

The study followed low-risk patients for seven years after their procedures and found encouraging results for both TAVR and surgery, with excellent outcomes and comparable valve durability. Both groups experienced very few valve-related problems over seven years, with similarly low rates of valve failure, valve wear and tear, and the need for another procedure.

The long-term follow-up revealed one important difference: Blood clots (thrombosis) occurred more frequently after TAVR, affecting 5.2% of patients compared with 0.9% of those who underwent traditional heart surgery.
Part 1

Comment by Dr. Krishna Kumari Challa 13 hours ago

Study reports the first detection of a sugar in interstellar space

Sugars are key biomolecules in living organisms, as they form the backbone of DNA and RNA and play a fundamental role in metabolic processes. In theories of the origin of life, sugars are also essential for the synthesis of the first nucleic acids. Despite their importance, one of the major questions in origin-of-life research is how the first sugars formed on Earth, since laboratory experiments show that they do not form in sufficient quantities under prebiotic conditions.
Sugars such as ribose and glucose have previously been detected in meteorite and asteroid samples, suggesting that some of these molecules may have originated in the primordial molecular cloud from which our solar system formed. However, until now, no sugar had ever been directly detected in the interstellar medium.
An international team has now identified the first sugar in interstellar space: erythrulose. This molecule is the only possible four-carbon ketose, and on Earth, it is commonly found in raspberries and sunless tanning products. Erythrulose was detected toward the molecular cloud G+0.693−0.027, located near the center of our galaxy, the Milky Way.

The discovery was made possible by ultrasensitive, broadband spectroscopic surveys carried out with the 40-m Yebes radio telescope and the 30-m telescope of the Institute for Radio Astronomy in the Millimeter Range (IRAM).
The team identified 12 spectral lines matching the laboratory spectrum of erythrulose measured at the University of the Basque Country. The study also shows that this sugar is at least eight times more abundant than similar three-carbon sugars, none of which were detected in the same region.
Based on the abundance of erythrulose measured in the G+0.693−0.027 molecular cloud, the researchers estimate that between 0.5 and 50 million metric tons of this sugar could have reached Earth's surface during the Late Heavy Bombardment, which occurred approximately 4.1–3.8 billion years ago.

The presence of erythrulose in interstellar space therefore provides an alternative source of sugars that may have contributed to the emergence of the first metabolic and replication processes on early Earth.

The detection of erythrulose is very exciting because it opens up the possibility of discovering in space other sugars such as ribose, which is part of RNA, and other important molecules for the origin of life.

Izaskun Jiménez-Serra, Detection of a four-carbon sugar in interstellar space, Nature Astronomy (2026). DOI: 10.1038/s41550-026-02905-7. www.nature.com/articles/s41550-026-02905-7

Comment by Dr. Krishna Kumari Challa on Saturday

Your Medicine Cabinet Is Polluting The Ocean

Over-the-counter medication makes up the majority of pharmaceutical pollution in several rivers across the world, and may persist in rivers long enough to spread into coastal waters.

The everyday medications in our homes may be a major source of water pollution. A recent study of Hong Kong’s major rivers revealed that common over-the-counter (OTC) drugs accounted for 85 percent of pharmaceutical pollution in the wet season compared to just 13 percent for prescription medicines.

We often assume that complex or restricted prescription medications pose the greatest environmental risk, but our findings shine a new light on everyday household medicines.

Because medicines are designed to be effective when taken orally, they often have molecular properties that make them mobile in water.

However, these properties also allow them to easily travel in river environments, through estuaries and eventually enter the ocean, where they can pose threats to marine ecosystems. Pharmaceutical residues have been found even in deep seas and remote marine environments.

Pharmaceutical pollution is not a local pollution issue at a specific site. Hence, we should adopt a river-estuary-sea perspective to prioritise pollutants for control and management.

https://www.sciencedirect.com/science/article/pii/S2590182626000500...

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Comment by Dr. Krishna Kumari Challa on Saturday

Children back group claims over evidence, but privacy reduces bias, experiments reveal

A team of psychology researchers has found evidence of partisan behavior in children ages 5 to 9—they frequently endorsed their own group's claims even when evidence suggested otherwise, indicating group affiliation influenced their responses. However, the scientists also uncovered a potential remedy to such responses: When incentivized to tell the truth about what they had seen or when they could provide answers under the veil of privacy, the children were much less likely to adopt their own group's claims. The paper is published in the journal Cognition.

Even young children will side with their group over the evidence of their own eyes, but mainly when they're responding publicly and when being accurate doesn't count for much.
However, if you allow them to respond in private or give them a reason to care about accuracy, the partisanship effect disappears.
Partisanship may start not as a conviction about what's true, but as a way of showing you belong or you're loyal to your group. But there's an encouraging implication here, too: Conditions that reward accuracy or that lower the social stakes of an answer can pull people back toward the evidence.
The impact of privacy and "truth incentives" was clear: Children who answered privately were more likely to accurately report what they saw than those who answered publicly. Similarly, those in the truth-incentive group were more likely to accurately report what they saw than those who received no such incentive.

Belonging, not belief, drove bias
Taken together, the experiments indicated that children's partisanship appears to be less about a search for truth and more about a desire for social connection, the authors conclude—and point to potential remedies for diminishing responses not supported by evidence.

Bethany Lassetter et al, Investigating the origins of partisanship: What motivates children to preferentially endorse their ingroups' claims?, Cognition (2026). DOI: 10.1016/j.cognition.2026.106629

Comment by Dr. Krishna Kumari Challa on Saturday

Natural forests survive heat waves better than planted forests

When a record-breaking drought and heat wave swept across China's Yangtze River Basin in 2022, forests across the region faced an extreme test. The event provided a rare opportunity for researchers to test how different forests respond when rising temperatures and water shortages strike at the same time.
The basin is home to some of China's most important forests, which help prevent soil erosion, regulate water supplies and support biodiversity. As China's largest river basin, the Yangtze is also a major hub for water resources and economic activity, meaning healthy forests play a crucial role.

Following widespread deforestation and major flooding events, including the devastating 1998 Yangtze River flood, China launched large-scale tree-planting programs to restore forests and reduce soil erosion.

But as climate change drives more frequent and intense combinations of drought and extreme heat, researchers wanted to understand whether these planted forests could cope with increasingly challenging conditions and how they respond compared with forests that developed naturally. The study focused on compound drought–heat wave events, where unusually hot and dry conditions occur at the same time.

These events can be particularly damaging because plants face two stresses at once: a lack of water in the soil and increased water loss through their leaves. These combined stresses can threaten not only forest health but also the wider services forests provide, such as storing water and regulating runoff.

The results revealed a trade-off. Natural forests were better able to withstand the harsh conditions, suffering less damage during the event, while planted forests experienced greater vegetation loss but recovered more quickly once the extreme weather had passed.
The findings, published in Water Resources Research, reveal a balance between two important aspects of forest resilience: the ability to resist damage during a weather event and the ability to recover afterward.
During the extreme weather, natural forests proved more resilient in the short term. They suffered less damage from the drought and heat wave, with more than 70% of areas analyzed showing that natural forests were better able to withstand the conditions.

The researchers suggest this stronger resistance may be linked to the greater complexity of natural forests. They typically contain a wider variety of tree species that respond differently to drought and heat, different tree ages and more layered canopies, creating a varied ecosystem that can better buffer extreme conditions.

Planted forests, by contrast, are often made up of fewer species and trees of similar ages. This simpler structure can make them more vulnerable to extreme conditions because they respond to stress in the same way.
The study highlights that there is no single measure of a forest's ability to cope with climate extremes and shows why protecting remaining natural forests remains crucial, even as tree planting continues to be an important tool for restoring degraded landscapes.

The researchers suggest that improving the diversity and structure of planted forests could help make them more resistant to future climate extremes.

Yong Su et al, Higher Vulnerability But Faster Recovery in Planted Than Natural Forests During the 2022 Compound Drought–Heatwave in China's Yangtze River Basin, Water Resources Research (2026). DOI: 10.1029/2026wr044482

Comment by Dr. Krishna Kumari Challa on Friday

Eye Movements Form a Unique Gaze Fingerprint

Eye movements reveal personal 'fingerprints' as people explore unfamiliar scenes
Eye-tracking during exploration of virtual scenes showed that individuals have stable, distinctive gaze patterns that reflect personal conceptual priorities. Machine-learning models, especially those using large language model–derived conceptual descriptions of viewed objects, reliably identified individuals from these patterns, even across sessions one week apart. Results suggest gaze can act as a persistent biometric and potential clinical marker, while raising privacy concerns in VR/AR contexts.

“Conceptual priorities shape individual gaze patterns during natural...” by Amanda J. Haskins, Katherine O. Packard, and Caroline E. Robertson. PNAS
DOI:10.1073/pnas.2604369123

Comment by Dr. Krishna Kumari Challa on Friday

Why some people are more bothered by low-frequency sounds

Some people are more sensitive to low-frequency noise, such as from ventilation systems, heat pumps, wind turbines and transformers. Why is that?
The brain perceives low-frequency sounds in a completely different way from other sounds. Maybe that's why some people react more strongly to them.

Sound below 16 Hz is what professionals like to call infrasound. This is sound that is often considered impossible to hear. But that's not the case.

Humans can actually perceive infrasound if the sound level is high enough.
Some people are more sensitive to low-frequency noise. It can come from ventilation systems, heat pumps, wind turbines, industry, transport, generators or transformers. But this is difficult to measure because the sound is often perceived more as a hum or physical sensation than higher-frequency sound is.

Low-frequency sound and infrasound are detected via a mechanism in the inner ear that differs from normal hearing. When frequencies are very low, conventional sensory hair cells respond weakly, and supporting cells instead generate electric fields sufficient to activate auditory nerve signals. This nonlinear mechanism can make small pressure increases seem much louder and may vary between individuals, explaining differing sensitivity to low-frequency noise.

Now new research suggests that infrasound is registered in the inner ear in a different way than normal sound.

Inside the inner ear, there are specialized sensory hair cells that are crucial for transmitting sound signals to the brain.

But at very low frequencies, the signals to these hair cells become too weak, and other hair cells, which normally contribute to the hearing process, can still pick them up.
These support cells, which normally receive signals from the brain to regulate hearing sensitivity, generate electric fields that are strong enough to trigger nerve signals sent to the brain, so that infrasound is perceived.
Maybe that's why very low-frequency sounds feel different from other sounds.

This may explain why infrasound is experienced differently than normal sound. Small increases in sound pressure quickly make the sound much louder.
The findings may also help explain why some people are bothered by low-frequency noise while others are not, as the newly discovered mechanism may vary from person to person.

Carlos Jurado et al, Infrasound sensation is mediated by intracochlear electrical potentials, Scientific Reports (2026). DOI: 10.1038/s41598-026-50179-w

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