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Comment by Dr. Krishna Kumari Challa 18 hours ago

Scientists Discover Mysterious Signs of Life in Bizarre Blue Volcanic Goo

Unexpected biosignatures found in a startlingly blue volcanic goo beneath the Pacific Ocean may offer clues to life's origins.
Exhumed from mud volcanoes near the Mariana Trench, at depths of almost 3,000 meters (9,833 feet), the bizarrely colored sediment samples contain fats from mysterious living organisms.

With an extremely high pH of 12 – among the highest recorded in a natural ecosystem – this nutrient-poor ooze would cause severe burns to your skin on contact. Yet researchers have now confirmed that some extremophile microbes live there.

The bottom section of one taken from the Pacman volcano consists mainly of serpentinite with bits of brucite, largely untouched by the seawater above, allowing it to maintain its striking color.

At shallower depths, closer to the mud from the ocean floor, the volcanic sediment pales to a lighter blue-green, and the brucite has been dissolved by salt water.
Within these serpentinite layers, researchers detected fats from bacterial and archaeal cell membranes – the microbes' "first line of defense" against highly alkaline conditions.
The mostly intact state of the fats indicates multiple communities of microbes are currently eking out a living in these extreme conditions, the researchers explain.
Like plants do through photosynthesis, these microbes make their own energy from methane by consuming sulfate, which produces corrosive hydrogen sulfide.

https://www.nature.com/articles/s43247-025-02667-6

Comment by Dr. Krishna Kumari Challa 18 hours ago

Talking with our hands: How culture shapes our gestures

New research  shows that gesture is not merely a matter of individual style or habit, but a reflection of cultural expression tied to racial identity.

The research also suggests that mismatched expectations about gesture may influence the dynamics of interracial communication.

We all clearly communicate in very different ways. Some of us may talk differently than others. Some of us may use our hands more than others. It doesn't mean we can't communicate. When we experience that mismatch in communication, maybe we all need to try a little harder to understand each other across group differences, say the researchers.

Their findings show consistent patterns suggesting that what feels natural when speaking can differ across racial groups, and that those differences can shape how people perceive one another.

Collectively, these studies highlight that gesture is not only a personal characteristic but also a culturally grounded mode of expression, deeply linked to identity and group norms. The research also underscores how mismatched expectations about nonverbal behavior may affect perceptions and interactions across racial groups.

Yes, what I say need not exactly be what you comprehend!

Esha S. Naidu et al, Talk to the hand: Black and White cultural differences in gesture use., Journal of Experimental Psychology: General (2025). DOI: 10.1037/xge0001862

 

Comment by Dr. Krishna Kumari Challa 19 hours ago

AI bias in hiring decisions is often copied by human reviewers, study reveals

An organization drafts a job listing with artificial intelligence. Droves of applicants conjure résumés and cover letters with chatbots. Another AI system sifts through those applications, passing recommendations to hiring managers. Perhaps AI avatars conduct screening interviews. This is increasingly the state of hiring, as people seek to streamline the stressful, tedious process with AI.

Yet research is finding that hiring bias—against people with disabilities, or certain races and genders—permeates large language models, or LLMs, such as ChatGPT and Gemini. We know less, though, about how biased LLM recommendations influence the people making hiring decisions.
In a new  study, 528 people worked with simulated LLMs to pick candidates for 16 different jobs, from computer systems analyst to nurse practitioner to housekeeper. The researchers simulated different levels of racial biases in LLM recommendations for résumés from equally qualified white, Black, Hispanic and Asian men.

When picking candidates without AI or with neutral AI, participants picked white and non-white applicants at equal rates. But when they worked with a moderately biased AI, if the AI preferred non-white candidates, participants did too. If it preferred white candidates, participants did too. In cases of severe bias, people made only slightly less biased decisions than the recommendations.

Kyra Wilson et al, No Thoughts Just AI: Biased LLM Hiring Recommendations Alter Human Decision Making and Limit Human Autonomy, Proceedings of the AAAI/ACM Conference on AI, Ethics, and Society (2025). DOI: 10.1609/aies.v8i3.36749

Comment by Dr. Krishna Kumari Challa 19 hours ago

Chronic kidney disease is now the ninth leading cause of death, global analysis finds

Record numbers of men and women globally are now estimated to have reduced kidney function, a new study shows. Figures rose from 378 million people with the disease in 1990 to 788 million in 2023 as the world population grew and aged, making it for the first time a top 10 cause of death worldwide.

 The analysis explored the rise of the illness, in which the kidneys gradually lose their ability to filter waste and excess fluid from the blood. Mild cases may have no symptoms while the most severe stages can require dialysis, kidney replacement therapy, or an organ transplant.

The findings revealed that about 14% of adults in the world have chronic kidney disease. Results further showed that about 1.5 million people died from the condition in 2023, an increase of more than 6% since 1993 when accounting for differences in countries' age demographics over time.

Another major finding was that impaired kidney function, on top of killing people directly, was a key risk factor for heart disease, contributing to about 12% of global cardiovascular mortality. The results showed further that in 2023, the condition was the 12th leading cause of diminished quality of life from disability. The biggest risk factors for kidney disease were found to be high blood sugar, high blood pressure, and high body mass index (a measure of obesity).

Global, regional, and national burden of chronic kidney disease in adults, 1990–2023, and its attributable risk factors: a systematic analysis for the Global Burden of Disease Study 2023, The Lancet (2025). DOI: 10.1016/S0140-6736(25)01853-7

Comment by Dr. Krishna Kumari Challa 19 hours ago

How cells choose their direction without external signals

Cell movement is an essential biological process, whether it's cancer cells metastasizing to other parts of the body or immune cells migrating to heal a wound.

An international joint research team has elucidated the principle by which cells decide their direction and move on their own without external signals, offering a crucial clue for identifying the causes of cancer metastasis and immune diseases and establishing new treatment strategies.
Cells determine their movement direction autonomously through an internal program involving Rho family proteins. The Cdc42–FMNL interaction drives straight movement, while Rac1–ROCK enables directional changes. Disrupting Rac1–ROCK binding impairs turning and environmental adaptation. The INSPECT technique allows direct visualization of these protein interactions in living cells.

Heeyoung Lee et al, A Rho GTPase-effector ensemble governs cell migration behavior, Nature Communications (2025). DOI: 10.1038/s41467-025-64635-0

Comment by Dr. Krishna Kumari Challa 19 hours ago

Dinosaur eggshells unlock a new way to tell time in the fossil record

An international team of geologists and paleontologists is pioneering a groundbreaking methodology to reliably determine the age of fossil-bearing rocks—by directly dating fossilized dinosaur eggshells.

Many fossil sites around the world are only coarsely dated. Without precise information on the geologic age of fossils, paleontologists struggle to understand how different species and ecosystems relate across time and space. Usually, researchers rely on dating minerals such as zircon or apatite found associated with fossils, but those minerals aren't always present. Attempts to date the fossils themselves, such as bones or teeth, have often produced uncertain results.

Now researchers  took a different approach. They used advanced uranium–lead (U–Pb) dating and elemental mapping to measure trace amounts of uranium and lead housed inside the calcite of fossilized dinosaur eggshells. These isotopes function like a natural clock, enabling scientists to determine when the eggs were buried.
Fossilized dinosaur eggshells can be directly dated using uranium–lead (U–Pb) isotopes in their calcite, providing geologic ages with about 5% accuracy compared to volcanic-ash dating. This method enables precise dating of fossil sites lacking datable volcanic layers, offering a new tool to reconstruct the timing of dinosaur evolution and ancient ecosystems.

Tests on dinosaur eggs from Utah (U.S.) and the Gobi Desert (Mongolia) showed that the eggshells record ages with an accuracy of about 5% relative to precise volcanic-ash dates. In Mongolia, the team determined the first-ever direct age—around 75 million years old—for a historic locality preserving dinosaur eggs and nests.

 Ryan T. Tucker et al, U-Pb calcite age dating of fossil eggshell as an accurate deep time geochronometer, Communications Earth & Environment (2025). DOI: 10.1038/s43247-025-02895-w

Comment by Dr. Krishna Kumari Challa 19 hours ago

AI evaluates texts without bias—until the source is revealed
Large language models evaluate texts consistently and with minimal bias when no source information is provided, showing over 90% agreement across models. However, when the author’s identity or nationality is revealed, significant biases emerge, notably a strong anti-Chinese bias, and trust in human over AI authors. These findings highlight the need for transparency and safeguards in AI-driven evaluations.

How to avoid LLM evaluation bias Make the LLM identity blind:

Remove all identity information regarding author and source of the text, e.g., avoid using phrases like "written by a person from X / by model Y" in the prompt.

Check from different angles: Run the same questions twice, e. g. with and without a source mentioned in the prompt. If results change, you've likely hit a bias.

Or cross-check with a second LLM model: If divergence appears when you add a source that is a red flag.

Force the focus away from the sources: Structured criteria help anchor the model in content rather than identity.

Use this prompt, for example: "Score this using a 4-point rubric (evidence, logic, clarity, counter-arguments), and explain each score briefly." Keep humans in the loop: Treat the model as a drafting help and add a human review to the process—especially if an evaluation affects people.

 Federico Germani et al, Source framing triggers systematic bias in large language models, Science Advances (2025). DOI: 10.1126/sciadv.adz2924

Comment by Dr. Krishna Kumari Challa 19 hours ago

Could mass arise without the Higgs boson?

The Higgs field gives mass to elementary particles through interaction, not the Higgs boson particle itself. The Higgs boson is a quantum excitation of this pervasive field. The strength of a particle's interaction with the Higgs field determines its mass, while particles like the photon that don't interact with it remain massless. 

The geometry of space, where physical laws unfold, may also hold answers to some of the deepest questions in fundamental physics. The very structure of spacetime might underlie every interaction in nature.

A paper published in Nuclear Physics B explores the idea that all fundamental forces and particle properties could emerge from the geometry of hidden extra dimensions.

According to the study, the universe may contain invisible dimensions folded into intricate seven-dimensional shapes known as G₂-manifolds. Traditionally, these structures have been studied as static. But researchers of this new study consider them as dynamic: evolving under a process called the G₂–Ricci flow, where the internal geometry changes with time.

As in organic systems, such as the twisting of DNA or the handedness of amino acids, these extra-dimensional structures can possess torsion, a kind of intrinsic twist, they explain. When we let them evolve in time, we find that they can settle into stable configurations called solitons. These solitons could provide a purely geometric explanation of phenomena such as spontaneous symmetry breaking.

In the Standard Model of particle physics, the Higgs field gives mass to the W and Z bosons. But the authors suggest that mass could instead arise from geometric torsion in extra dimensions, without introducing an additional Higgs field.

"In our picture," they say, "matter emerges from the resistance of geometry itself, not from an external field."

The theory also links torsion to the curvature of spacetime, offering a possible explanation of the positive cosmological constant that drives cosmic expansion. The authors even speculate about a new particle, the "Torstone," that might be observable in future experiments.

The masses of the W and Z bosons come not from the famous Higgs field, but directly from the geometry of seven-dimensional space, they argue.

Richard Pinčák et al, Introduction of the G2-Ricci flow: Geometric implications for spontaneous symmetry breaking and gauge boson masses, Nuclear Physics B (2025). DOI: 10.1016/j.nuclphysb.2025.116959

Comment by Dr. Krishna Kumari Challa 19 hours ago

The findings show that sodium bicarbonate therapy did not affect day 90 mortality in patients with severe metabolic acidemia (pH ≤7.20) and moderate to severe acute kidney injury.

Less frequent kidney replacement therapy use in the bicarbonate group and lower bloodstream infections illustrated significantly better outcomes.

 Boris Jung et al, Sodium Bicarbonate for Severe Metabolic Acidemia and Acute Kidney Injury, JAMA (2025). DOI: 10.1001/jama.2025.20231

Prit Kusirisin et al, Sodium Bicarbonate in Severe Acidemia and Acute Kidney Injury—Turning the Tide or Chasing a Myth?, JAMA (2025). DOI: 10.1001/jama.2025.20457

Part 2

Comment by Dr. Krishna Kumari Challa 19 hours ago

Sodium bicarbonate fails to boost survival in patients with severe acidemia

Severe metabolic acidemia (acidic blood) has been linked to impaired cardiac contractility, arrhythmias, pulmonary vasoconstriction, systemic vasodilation, altered kidney blood flow, cerebral edema, and diaphragmatic dysfunction. Common etiologies in critical illness include hyperchloremic acidosis, lactate accumulation, and endogenous anion accumulation during acute kidney injury.

Now researchers  report no reduction in day 90 all-cause mortality with sodium bicarbonate infusion for critically ill adults with severe metabolic acidemia and moderate to severe acute kidney injury.

In the human body, carbon dioxide combines with water via carbonic anhydrase and forms carbonic acid, which dissociates into a hydrogen ion and bicarbonate. Early 20th century investigators described metabolic bicarbonate as an "alkaline reserve," naturally buffering the body to keep a healthy acid-base balance.

Sodium bicarbonate entered acute care protocols in the 1950s as a staple of cardiopulmonary resuscitation (CPR) guidance. Skepticism grew across the 1980s and beyond as routine dosing failed to show outcome advantages and reports raised concerns about potential harms.

Modern evidence, including recent trials, has coincided with removal of routine bicarbonate use from  CPR guidelines, with use retained for select cases of severe acidosis.

Prior work by researchers on bicarbonate outcomes did not show an overall benefit from sodium bicarbonate, though an acute kidney injury intervention suggested benefit, leaving open the possibility that it still might be of benefit under specific conditions.

In the study, "Sodium Bicarbonate for Severe Metabolic Acidemia and Acute Kidney Injury: The BICARICU-2 Randomized Clinical Trial," published in JAMA, researchers conducted an open-label, investigator-initiated, multicenter randomized clinical trial to determine whether sodium bicarbonate infusion reduces day 90 all-cause mortality after severe metabolic acidemia with moderate to severe acute kidney injury in critically ill adults.

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