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Comment by Dr. Krishna Kumari Challa yesterday

Chaos tamed by thermodynamics : Nonlinear multimode optical systems are often dismissed as chaotic and unpredictable. Their intricate interplay of modes has made them among the hardest systems to simulate—let alone design for practical use. Yet, precisely because they are not constrained by the rules of linear optics, they harbor rich and unexplored physical phenomena.

Recognizing that light in these systems undergoes a process akin to reaching thermal equilibrium—similar to how gases reach equilibrium through molecular collisions—the researchers developed a comprehensive theory of "optical thermodynamics." This framework captures how light behaves in nonlinear lattices using analogs of familiar thermodynamic processes such as expansion, compression, and even phase transitions.
The team's demonstration in Nature Photonics marks the first device designed with this new theory. Rather than actively steering the signal, the system is engineered so that the light routes itself.

The principle is directly inspired by thermodynamics. Just as a gas undergoing what's known as a Joule-Thomson expansion redistributes its pressure and temperature before naturally reaching thermal equilibrium, light in the new device experiences a two-step process: first an optical analog of expansion, then thermal equilibrium. The result is a self-organized flow of photons into the designated output channel—without any need for external switches.

Hediyeh M. Dinani et al, Universal routing of light via optical thermodynamics, Nature Photonics (2025). DOI: 10.1038/s41566-025-01756-4

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Comment by Dr. Krishna Kumari Challa yesterday

First device based on 'optical thermodynamics' can route light without switches

A team of researchers  has created a new breakthrough in photonics: the design of the first optical device that follows the emerging framework of optical thermodynamics.

The work, reported in Nature Photonics, introduces a fundamentally new way of routing light in nonlinear systems—meaning systems that do not require switches, external control, or digital addressing. Instead, light naturally finds its way through the device, guided by simple thermodynamic principles.

Universal routing is a familiar engineering concept. In mechanics, a manifold valve directs inputs to a chosen outlet. In digital electronics, a Wi-Fi router at home or an Ethernet switch in a data center directs information from many input channels to the correct output port, ensuring that each stream of data reaches its intended destination.

When it comes to light, the same problem is far more challenging, however. Conventional optical routers rely on complex arrays of switches and electronic control to toggle pathways. These approaches add technical difficulty, while limiting speed and performance.

The photonics team has now shown that there is another way. The idea can be likened to a marble maze that arranges itself.

Normally, you'd have to lift barriers and guide a marble step-by-step to make sure it reaches its destination—the right hole. In the team's device, however, the maze is built so that no matter where you drop the marble, it will roll on its own toward the right place—no guiding hands needed. And this is exactly how light behaves: it finds the correct path naturally, by following the principles of thermodynamics.

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Comment by Dr. Krishna Kumari Challa yesterday

Easter Island's statues actually 'walked,' and physics backs it up

For years, researchers have puzzled over how the ancient people of Rapa Nui did the seemingly impossible and moved their iconic moai statues. Using a combination of physics, 3D modeling and on-the-ground experiments, a research team has confirmed that the statues actually walked—with a little rope and remarkably few people.

Studying nearly 1,000 moai statues, they found that the people of Rapa Nui likely used rope and "walked" the giant statues in a zig-zag motion along carefully designed roads. The paper is published in the Journal of Archaeological Science.

They 

 had previously demonstrated via experimental evidence that the large statues "walked" from their quarry to ceremonial platforms using an upright, rocking motion, challenging a theory that the statues were moved lying prone on wooden devices.

"Once you get it moving, it isn't hard at all—people are pulling with one arm. It conserves energy, and it moves really quickly," they say.

The hard part is getting it rocking in the first place. The question is, if it's really large, what would it take? Are the things that we saw experimentally consistent with what we would expect from a physics perspective?"

To explore how a larger statue might move, the team created high-resolution 3D models of the moai and identified distinctive design features—wide D-shaped bases and a forward lean—that would make them more likely to be moved in a rocking, zig-zagging motion.

Putting their theory to the test, the team built a 4.35-ton replica moai with the distinct "forward-lean" design. With just 18 people, the team was able to transport the moai 100 meters in just 40 minutes, a marked improvement over previous vertical transport attempts.

The physics makes sense, say the researchers, "What we saw experimentally actually works. And as it gets bigger, it still works. All the attributes that we see about moving gigantic ones only get more and more consistent the bigger and bigger they get, because it becomes the only way you could move it."

Adding to the support for this theory are the roads of Rapa Nui. Measuring 4.5 meters wide with a concave cross-section, the roads were ideal for stabilizing the statues as they moved forward.

 Carl P. Lipo et al, The walking moai hypothesis: Archaeological evidence, experimental validation, and response to critics, Journal of Archaeological Science (2025). DOI: 10.1016/j.jas.2025.106383

Comment by Dr. Krishna Kumari Challa on Sunday

Menstrual cycle found to affect women's reaction time, but not as much as being active

Women performed best on cognitive tests during ovulation but physical activity level had a stronger influence on brain function, according to a new study .

The study, published in Sports Medicine–Open, explored how the different phases of the menstrual cycle and physical activity level affected performance on a range of cognitive tests designed to mimic mental processes used in team sports and everyday life, such as the accurate timing of movements, attention, and reaction time.

Researchers found that women had the fastest reaction times and made the fewest errors on the day of ovulation, when the ovaries release an egg ready to be fertilized (and when women's fertility is at its peak).

But while cognitive performance fluctuated across the menstrual cycle, much greater differences were observed between those who were active and those who weren't. Compared to active participants, inactive participants had reaction times on average around 70 milliseconds slower and made around three times as many impulsive errors, regardless of cycle phase.

The researchers say the findings are particularly relevant to women's sport, where slightly quicker reaction times of around 20 milliseconds may make the difference between sustaining or avoiding an injury like concussion. Previous research on elite athletes has suggested injuries are more common at certain points during the menstrual cycle, and the authors say that these changes in cognition might partially explain this occurrence.

However, while a difference of 20 milliseconds is likely to be inconsequential in everyday life, the much larger difference between active and inactive groups is more significant, where 70 milliseconds could determine whether we regain balance after tripping over an obstacle or not.

Menstrual cycle and athletic status interact to influence symptoms, mood, and cognition in females, Sports Medicine–Open (2025). DOI: 10.1186/s40798-025-00924-8

Comment by Dr. Krishna Kumari Challa on Sunday

Blood cancer: Scientists reprogram cancer cell death to trigger immune system

The aim of immunotherapy strategies is to leverage cells in the patient's own immune system to destroy tumor cells. Using a preclinical model, scientists successfully stimulated an effective anti-tumor immune response by reprogramming the death of malignant B cells. They demonstrated an effective triple-therapy approach for treating forms of blood cancer such as certain lymphomas and leukemias which affect B cells. The study was published on August 15 in the journal Science Advances. 

Immunotherapy strategies represent a major breakthrough in cancer treatment. They aim to harness the patient's immune system so that their own cells can recognize and specifically eliminate tumor cells. Immune cells can act like sentinels, scanning the body and identifying all residual tumor cells to reduce the risk of relapse. Various novel immunotherapy strategies are emerging, one of which makes use of a cell death mechanism known as necroptosis. Unlike apoptosis, which results in silent cell death, necroptosis releases warning signals that attract and stimulate immune cells so that they can kill any remaining tumor cells.

Scientists set out to explore the effectiveness of this necroptosis-based immunotherapy strategy on hematological malignancies. They began by observing that necroptosis cannot be easily induced in malignant B cells because of the absence of the MLKL protein.

To overcome this hurdle, the scientists combined administration of three drugs already used in clinical practice. They confirmed induction of necroptosis and observed a strong immune response leading to the complete elimination of leukemia in a preclinical model. 

The triple therapy they used forces cancer cells to die in a way that activates the immune system.

The results were observed in preclinical models using an innovative intravital imaging technique. The scientists were able to monitor the interactions between immune cells and cancer cells in real time for the different types of cell death induced.

"This novel immunotherapy strategy, successfully tested in preclinical models, turns tumor cells into triggers for the immune system, pointing to a potential therapeutic avenue for certain cancers, such as lymphomas or leukemias affecting B cell.

Ruby Alonso et al, Reprogramming RIPK3-induced cell death in malignant B cells promotes immune-mediated tumor control, Science Advances (2025). DOI: 10.1126/sciadv.adv0871

Comment by Dr. Krishna Kumari Challa on Friday

The researchers then examined the underlying mechanisms driving these changes. They found that air pollution had triggered significant changes in the regulation of DNA in brown fat cells.

This included modifications in DNA methylation patterns and changes in how accessible certain genes were for being turned on or off—a process known as chromatin remodeling. These epigenetic changes affect how cells function by regulating gene activity without altering the genetic code itself.

Two enzymes were identified as main drivers of this process: HDAC9 and KDM2B. These enzymes are involved in modifying histones, the proteins around which DNA is wrapped. They were found to bind to specific regions of the DNA in brown fat cells of the mice exposed to PM2.5, leading to a reduction in key chemical tags, or methyl groups, that normally promote gene activity.

When these enzymes were experimentally suppressed, brown fat function improved, whereas increasing their activity led to further declines in metabolism.
The study shows that long-term exposure to fine air pollution can impair metabolic health by disrupting the normal function of brown fat. This occurs through complex changes in gene regulation controlled by epigenetic mechanisms.

Rengasamy Palanivel et al, Air pollution modulates brown adipose tissue function through epigenetic regulation by HDAC9 and KDM2B, JCI Insight (2025). DOI: 10.1172/jci.insight.187023

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Comment by Dr. Krishna Kumari Challa on Friday

Study suggests air pollution can contribute to obesity and diabetes

Long-term exposure to fine air pollution can impair metabolic health by disrupting the normal function of brown fat in mice. A study co-led by the University of Zurich shows that this occurs through complex changes in gene regulation driven by epigenetic mechanisms. The results demonstrate how environmental pollutants contribute to the development of insulin resistance and metabolic diseases.

There is growing evidence that air pollution is not just harmful to our lungs and heart, but also plays a significant role in the development of metabolic disorders like insulin resistance and type 2 diabetes.

For their investigation, the researchers exposed laboratory mice to either filtered air or concentrated PM2.5 for six hours a day, five days a week, over a period of 24 weeks. This setup was designed to closely mimic chronic urban exposure in humans.
Particular attention was paid to brown adipose tissue, a special type of fat that helps the body generate heat and burn calories, and therefore plays a key role in energy balance and glucose metabolism. After the exposure period of about five months, the mice that had inhaled PM2.5 showed signs of disrupted metabolism, including impaired insulin sensitivity.

Further examination revealed that the function of brown fat had been significantly altered. In particular, they found that the expression of important genes in brown adipose tissue which regulate its ability to produce heat, process lipids and handle oxidative stress were disturbed. These changes were accompanied by increased fat accumulation and signs of tissue damage and fibrosis within the tissue.

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Comment by Dr. Krishna Kumari Challa on Friday

For cancer patients, this discovery suggests simple changes, like eating more foods rich in OA (such as olive oil, avocados and nuts) and cutting back on PA (found in processed foods, palm oil and fatty meats), could improve the effectiveness of cancer treatments. The study also points to novel strategies, like combining dietary changes with specific drugs to further boost the immune system.

Yanmei Zhang et al, Oleic acid restores the impaired antitumor immunity of γδ-T cells induced by palmitic acid, Signal Transduction and Targeted Therapy (2025). DOI: 10.1038/s41392-025-02295-8

Part 2

Comment by Dr. Krishna Kumari Challa on Friday

Certain dietary fatty acids can supercharge cancer-fighting immune cells

A research team has discovered that certain dietary fatty acids can supercharge the human immune system's ability to fight cancer. The team found that a healthy fatty acid found in olive oil and nuts, called oleic acid (OA), enhances the power of immune γδ-T cells, specialized cells known for their cancer-fighting properties.

Conversely, they found that another fatty acid, called palmitic acid (PA), commonly found in palm oil and fatty meats, diminishes the ability of these immune cells to attack tumors.

Their study, published in the journal Signal Transduction and Targeted Therapy, offers an innovative approach using dietary OA supplementation to strengthen the antitumor immunity of γδ-T cells.

Dietary fatty acids are essential for health, helping with growth and body functions. They may also play a role in cancer prevention and treatment, but understanding how they affect cancer is challenging because of the complexity of people's diets and the lack of detailed studies.
Recently, scientists have learned that fatty acids can influence the immune system, especially in how it fights cancer. Specialized immune cells, called γδ-T cells, are particularly good at attacking tumors. These cells, once activated, have helped some lung and liver cancer patients live longer.
However, this therapy is not effective for all patients, partly because the variation of metabolic status, such as fatty acid metabolism, can influence its efficacy in the patients.

The research team identified a correlation between PA and OA levels and the efficacy of cancer therapies. The research suggests that dietary fatty acid supplementation, particularly with foods rich in OA, such as olive oil and avocados, could enhance γδ-T cell immunosurveillance, leading to more effective cancer treatments.

The team also discovered that another fatty acid, called PA, can weaken these immune cells and how OA can counteract this.

The results indicate that cancer patients should avoid PA and consider OA supplementation in their diets to improve clinical outcomes of γδ-T cell-based cancer therapies.

By analyzing blood samples, the researchers confirmed that the levels of these fatty acids are linked to the outcome of cancer immunotherapy.

Part 1

Comment by Dr. Krishna Kumari Challa on Friday

Nanoparticle vaccine prevents multiple cancers and stops metastasis in mice

A new study by researchers demonstrates that their nanoparticle-based vaccine can effectively prevent melanoma, pancreatic and triple-negative breast cancer in mice. Not only did up to 88% of the vaccinated mice remain tumor-free (depending on the cancer), but the vaccine reduced—and in some cases completely prevented—the cancer's spread.

By engineering these nanoparticles to activate the immune system via multi-pathway activation that combines with cancer-specific antigens, they could prevent tumor growth with remarkable survival rates.

The first test paired their nanoparticle system with well-characterized melanoma peptides (called an antigen, similar to how a flu shot typically contains parts of the inactivated flu virus). The formulation activated immune cells called T cells, priming them to recognize and attack this type of cancer. Three weeks later, the mice were exposed to melanoma cells.

Eighty percent of these "super adjuvant" vaccinated mice remained tumor-free and survived until the completion of the study (250 days). In comparison, all of the mice vaccinated with traditional vaccine systems, non-nanoparticle formulations or unvaccinated mice developed tumors; none survived longer than 35 days.

The vaccine also protected against the spread of cancer to the lungs. When exposed to melanoma cells systemically, which mimics how cancer metastasizes, none of the nanoparticle-vaccinated mice developed lung tumors, while all of the other mice did.

The tumor-specific T-cell responses that the researchers are able to generate—that is really the key behind the survival benefit. 

There is really intense immune activation when you treat innate immune cells with this formulation, which triggers these cells to present antigens and prime tumor-killing T cells. This robust T-cell response is possible because of the particular nanoparticle design of the vaccine.

The researchers say that their design offers a platform approach that could be used across multiple cancer types.

"Super adjuvant" nanoparticles for platform cancer vaccination, Cell Reports Medicine (2025). DOI: 10.1016/j.xcrm.2025.102415. www.cell.com/cell-reports-medi … 2666-3791(25)00488-4

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