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Comment by Dr. Krishna Kumari Challa on Tuesday

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 on Tuesday

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 on Tuesday

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 on Tuesday

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.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

Neanderthal DNA helps explain how faces form

Every human face is unique, allowing us to distinguish between individuals. We know little about how facial features are encoded in our DNA, but we may be able to learn more about how our faces develop by looking at our ancient relatives, the Neanderthals. Neanderthal faces were quite distinctive from our own, with large noses, pronounced brows and a robust lower jaw.

Now, scientists are using the DNA of our extinct distant relatives to learn more about how faces develop and evolve.

Published in the journal Development, they show how a region of Neanderthal DNA is better at activating a jaw-forming gene than the human counterpart, revealing one potential reason for Neanderthal's larger lower jaws.

Scientists have sequenced the Neanderthal genome using DNA extracted from ancient bone. The Neanderthal genome is 99.7% identical to the genome of modern-day humans and the differences between species are likely responsible for altering appearance. Both human and Neanderthal genomes consist of about 3 billion letters that code for proteins and regulate how genes are used in the cell, which makes finding regions that impact appearance like looking for a needle in a haystack.

But still they decided on a region of the genome that is linked to Pierre Robin sequence, a syndrome in which the lower jaw is disproportionately small. Some individuals with Pierre Robin sequence have large deletions or DNA rearrangements in this part of the genome that change face development and limit jaw formation. They predicted that smaller differences in the DNA might have more subtle effects on face shape.

By comparing human and Neanderthal genomes, the team found that in this region, roughly 3000 letters in length, there were just three single-letter differences between the species. Although this region of DNA doesn't contain any genes, it regulates how and when a gene is activated, specifically a gene called SOX9, a key coordinator of the process of face development.

To demonstrate that these Neanderthal-specific differences are important for the development of the face, the researchers needed to show that the Neanderthal region could activate genes in the right cells at the right time as the embryo develops.

The researchers simultaneously inserted the Neanderthal and human versions of the region into the DNA of zebrafish and programmed the zebrafish cells to produce different colors of fluorescent protein depending on whether the human or Neanderthal region was active.

Watching the zebrafish embryos develop, the researchers found that both the human and Neanderthal regions were active in the zebrafish cells that are involved in forming the lower jaw and the Neanderthal region was more active than the human version.

This led them to think about what the consequences of these differences could be, and how to explore these experimentally.

Knowing that the Neanderthal sequence was more powerful at activating genes, the researchers then asked if the resulting increased activity of its target, SOX9, might change the shape and function of the adult jaw. To test this theory, they provided the zebrafish embryos with extra SOX9 and found that cells that contribute to forming the jaw occupied a larger area.

This research shows that by studying extinct species we can learn how our own DNA contributes to face variation, development and evolution.

Kirsty Uttley et al, Neanderthal-derived variants increase SOX9 enhancer activity in craniofacial progenitors that shape jaw development, Development (2025). DOI: 10.1242/dev.204779

Comment by Dr. Krishna Kumari Challa on Monday

We're Still Evolving: Human Arms Keep Growing an Extra Artery

Subtle shifts in our anatomy today demonstrate how unpredictable evolution can be. Take something as mundane as an extra blood vessel in our arms, which, going by current trends, could be commonplace within just a few generations.

An artery that temporarily runs down the center of our forearms while we're still in the womb isn't vanishing as often as it used to, according to a study published in 2020 by researchers.

That means there are more adults than ever with what amounts to an extra channel of vascular tissue flowing under their wrist.

Since the 18th century, anatomists have been studying the prevalence of this artery in adults and our study shows it's clearly increasing.

The prevalence was around 10 percent in people born in the mid-1880s compared to 30 percent in those born in the late 20th century, so that's a significant increase in a fairly short period of time, when it comes to evolution

https://onlinelibrary.wiley.com/doi/10.1111/joa.13224

Comment by Dr. Krishna Kumari Challa on Monday

First ever atlas of brain development

First-ever atlas of brain development shows how stem cells turn into neurons

A collection of studies that chart how mammalian brain cells grow and differentiate is a ‘very valuable’ tool for neuroscientists.

Scientists have created the most detailed maps yet of how our brains differentiate from stem cells during embryonic development and early life. In a collection of five papers, they tracked hundreds of thousands of early brain cells in the cortices of humans and mice, and captured with unprecedented precision the molecular events that give rise to a mixture of neurons and supporting cells. It's really the initial first draft of any ‘cell atlases’ for the developing brain.

https://www.nature.com/articles/d41586-025-03641-0?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on November 8, 2025 at 11:15am

Good Social Interactions Slow Cancer Via an Anxiety-Reducing Neural Circuit

Just an hour of socializing per day helped mice fight tumors. Now scientists have traced the brain circuitry that turns companionship into a cancer-fighting signal.

In the 1970s and ‘80s, scientists began noticing that people who had few or poor social relationships had a higher risk of developing illnesses and all-cause mortality. A slew of follow-up studies suggested that social support could protect people from pathological conditions like arthritis, alcoholism, depression, and even death. This link holds true for cancer as well. Upon analyzing disease progression and survival rates in thousands of breast cancer patients, researchers observed a negative impact of social isolation and a positive impact of interpersonal connections on prognosis.

One of the popular theories explaining these effects states that being social eases anxiety, a well-established driver of tumor growth, and consequently inhibits cancer progression. But how exactly does the body sense these stimuli and pump the brakes on cancer?

In a recent study published in Neuron, researchers uncovered the neural circuitry that drives the therapeutic effects of social connections on cancer, in mice. It demonstrates a real biological pathway by which this nebulous subject of social interaction can influence cancer.

That means that now it's technically targetable, by drugs or by neuromodulation techniques, when before, we wouldn't even know what to target or if there was something to target.

 These findings establish a new paradigm for how psychosocial factors influence cancer via neural circuits and could potentially lead to therapies that complement existing treatments.

Wen HZ, et al. Social interaction in mice suppresses breast cancer progression via... Neuron. 2025;113(20)3374-3389.e9.

Comment by Dr. Krishna Kumari Challa on November 8, 2025 at 9:09am

Urolithin A nudges aging immune cells toward a youthful profile in 28 days

An international research team focused on aging reports that urolithin A at 1,000 mg per day shifted human immune profiles toward a more naive-like, less exhausted CD8⁺ state and increased fatty acid oxidation capacity, with additional functional gains.

Urolithin A is a metabolite produced by gut bacteria after breaking down ellagic acid from certain foods, such as pomegranates and walnuts. While produced naturally through microbial digestion, it is in much smaller quantities than available as a supplement or used in the study.

Aging bodies face reduced production of mature T cells, shrinking naive T cell pools and chronic low-grade inflammation. Mitochondrial dysfunction and waning autophagy sit at the core of these shifts, with mitophagy failure linked to immune dysregulation and disease.

Preclinical evidence identified urolithin A as a potent inducer of mitophagy, clearing out damaged mitochondria, in rodents and humans. Previous clinical trials have reported improved physical performance following supplementation.

Improving mitochondrial quality control with a positive influence on immune function would represent a turning back of the aging biological clock, if it can have a meaningful and prolonged effect in humans.

Conclusion: Short-term urolithin A supplementation modulated human immune cell composition and metabolism and improved selected functional responses, supporting the body's potential to counteract age-related immune decline.

Dominic Denk et al, Effect of the mitophagy inducer urolithin A on age-related immune decline: a randomized, placebo-controlled trial, Nature Aging (2025). DOI: 10.1038/s43587-025-00996-x

A natural compound revitalizes the aging human immune system, Nature Aging (2025). DOI: 10.1038/s43587-025-01012-y

Comment by Dr. Krishna Kumari Challa on November 8, 2025 at 8:44am

Coordinated brain network activity during emotional arousal may explain vivid, lasting memories

Past psychology studies suggest that people tend to remember emotional events, such as their wedding, the birth of a child or traumatic experiences, more vividly than neutral events, such as a routine professional meeting. While this link between emotion and the recollection of past events is well-established, the neural mechanisms via which emotional states strengthen memories remain poorly understood.

So researchers now carried out a study aimed at better understanding these mechanisms. Their findings, published in Nature Human Behaviour, suggest that emotional states facilitate the encoding of memories by increasing communication between networks of brain regions.

Emotional experiences tend to be 'sticky,' meaning that they endure in our memories and shape how we interpret the past, engage with the present, and anticipate the future. 

The primary objective of the recent study 's to study the neural processes that make emotional memories become more persistent. To do this, they used brain imaging techniques combined with computational models that can analyze and generate texts, known as natural language processing (NLP) models.

The analyses carried out by the researchers revealed that when participants were emotionally aroused, the activity of various brain networks was more coordinated than when they were in neutral or mild emotional states. Notably, this greater coordination between brain networks was found to predict how well participants remembered the scenes that they viewed during the experiment.

It is more like an orchestra, where different sections work together to create a unified performance, with arousal serving as a conductor that coordinates their activity. This perspective suggests that whether we remember an emotional memory depends not only on the strength of activity in any single region, but also on how effectively different systems communicate and share information.

Overall, the results of this research team's analyses suggest that emotions strengthen the synchronization between brain networks, which in turn supports the encoding of memories. Their paper thus introduces a new way of thinking about emotional memories, suggesting that it is supported by the coordinated activity of various brain regions.

 Jadyn S. Park et al, Emotional arousal enhances narrative memories through functional integration of large-scale brain networks, Nature Human Behaviour (2025). DOI: 10.1038/s41562-025-02315-1.

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