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Comment by Dr. Krishna Kumari Challa 3 hours ago

The upshot is that for most people, handling receipts is a pretty low-risk activity. But if you're concerned, you can take a few straightforward precautions.

People who handle receipts at work could protect themselves by avoiding the use of hand sanitizer and other skin care products on their hands before work, wearing gloves or encouraging their employer to use bisphenol-free thermal paper.

People who might be sensitive to endocrine effects of bisphenols—pregnant people, infants, children and those with certain endocrine diseases—might want to avoid contact with thermal paper receipts.

For people outside of these sensitive groups, handling a receipt is probably a very low-risk activity.

original article.

Part 3

Comment by Dr. Krishna Kumari Challa 3 hours ago

Toxicologists classify bisphenols as toxins called endocrine disruptors. This means that they interfere with the body's endocrine system, which controls vital body functions like growth, reproduction and metabolism.

The endocrine system includes multiple organs, including the thyroid, pancreas and pituitary gland, which is a tiny structure at the base of the brain. These organs send messages throughout the body to control many vital functions, and the molecules that carry those messages are called hormones.

Most research on bisphenol toxicity has focused on BPA. Research shows that BPA interrupts the messaging sent through multiple hormones, but most notably through estrogen.

Many people think of estrogen as the "female" hormone, but all people make estrogen, no matter what sex chromosomes they have. Estrogen helps control the growth and development of organs as they first form during fetal development, among other important roles in the body.

That's why exposure to endocrine disruptors is potentially more serious for a developing fetus than it is for adults. BPA exposure has been linked to preterm birth and abnormal fetal brain development.

Exposure to high amounts of BPA could also increase a person's chances of developing heart disease, high blood pressure, diabetes, obesity and other health problems. Research also shows that BPA can cause oxidative stress—chemical damage to the molecules that make up cells. Exposure to BPA might also cause changes to how genes are turned on or off, and some of these changes can be passed on to future generations.

These findings have led to a ban on BPA.
Many manufacturers have voluntarily replaced BPA with alternative chemicals—you have probably seen plastic products advertised as "BPA-free."

Unfortunately, companies often simply switch out BPA for another bisphenol, such as BPS, and it turns out that BPS shares much of its cousin molecule's toxic traits. Recently, though, concern about all bisphenols has led many companies to move away from them entirely.

Research has also shown that bisphenols can be absorbed through the skin—for example, when handling a receipt printed on thermal paper. Touching bisphenols with greasy hands, perhaps because you've just applied moisturizer or hand sanitizer, can increase absorption through the skin.
In 2023, researchers estimated the daily "dose" of exposure to BPA from thermal paper receipts and found levels between about 5,000 and 50 million times lower than European Food Safety Authority standards. That's less than one drop in an 8-ounce glass of water (about 240 milliliters).

That said, this estimate is for the average person. Retail, food service and other workers who handle many receipts every day would be exposed to doses about 100 times higher than that, the researchers estimated. This is potentially more concerning, but still probably well below safety standard levels.

Bisphenols are found in many products and have the potential to harm our health, but most human exposure to these chemicals comes from food or beverages packaged in containers made with bisphenols. Exposure from handling receipts is a small piece of the pie.

Part 2

Comment by Dr. Krishna Kumari Challa 3 hours ago

Toxic chemicals in your grocery store receipt?
Thermal receipts can contain BPA or BPS, endocrine-disrupting chemicals that can transfer to skin. Estimated exposure from occasional handling is low; workers who handle many receipts may have higher exposure. Food and drink packaging accounts for most bisphenol exposure.
Receipts are printed on a special type of paper—thermal paper—which often contains chemicals called bisphenols. These chemicals are potentially—but not necessarily—toxic. So, like many questions in toxicology, the answer to whether receipts are dangerous to handle is: It depends.
Bisphenols are human-made chemicals that have been widely used in industrial manufacturing since the 1950s.

Several different types exist, each with a letter standing for the chemical it is made from. The bisphenol produced using a molecule called acetone is called bisphenol A, or BPA. Bisphenol S (BPS) is made using a sulfur atom, and bisphenol F (BPF) is made using formaldehyde.

These chemicals are used to create a type of transparent and shatter-resistant plastic called polycarbonate, found in products including hard plastic water bottles, food storage containers and eyeglass lenses. Bisphenols are also ingredients in epoxy resins, which are used to coat the inside of bottle caps and metal food and drink containers. Some products still use these chemicals, though many manufacturers have phased them out.

Thermal receipt paper uses bisphenol—usually BPA or BPS—as a developer. The bisphenol is combined with a colorless ink and applied as a microscopic, heat-sensitive film to the paper. Instead of using ink, a receipt printer applies heat to this thermal paper, causing the bisphenol and the dye to react and changing the dye from colorless to black. Fax machines, back in the day, also relied on this technology.
Part 1

Comment by Dr. Krishna Kumari Challa 4 hours ago

Without water, forests lose their ability to absorb CO₂
During drought, trees close their stomata to conserve water, reducing CO₂ uptake and photosynthesis. Severe water stress can damage their water-transport systems and kill trees; continued respiration and decomposition can then turn forests from carbon sinks into carbon sources. Reduced transpiration may also diminish rainfall recycling.
To survive periods of drought, trees halt photosynthesis, a highly water-intensive process. For every molecule of CO₂ absorbed by a tree leaf, an average of around 400 water molecules are released. Entire forests may then end up emitting more CO₂ than they capture.

original article.

Comment by Dr. Krishna Kumari Challa 4 hours ago

AI chatbots give us a narrow slice of knowledge: Researchers warn of 'knowledge collapse'

"Let me just ask the chatbot" has become an everyday phrase. Where we used to turn to Google to find information, AI chatbots have become a common way to get answers to everything.
The large language models underpinning AI chatbots give us a significantly narrower range of information than a conventional web search. That's the finding of a new study by researchers.
Every language model they tested provides users with more uniform information than a simple Google search across all the topics we looked at. In other words, people are to a large extent exposed to the same information over and over again. So AI chatbots are not just changing how we find knowledge, but also which knowledge we have access to.
Across 155 topics, 27 language models produced less varied information than Google search; even the most diverse model was at least 18.7% less varied. Newer models were slightly more diverse than older ones, so the proposed “knowledge collapse” has not been observed. Training on AI-generated text could further narrow the range of information in future models.
The researchers tested 27 different large language models on 155 topics.

The results show that even the language model producing the most diverse answers—OpenAI's GPT-5—provides at least 18.7% less varied information than Google. The topics tested by the researchers ranged from nuclear weapons, marriage, pornography, racism and genocide to more country-specific topics such as Marine Le Pen, the Falklands War and K-pop.

According to the researchers, the fact that people are increasingly using AI models as their primary gateway to information could have significant consequences.

We risk exposing people to fewer perspectives and a narrower range of knowledge. This could create a vicious cycle in which the most popular content becomes even more dominant, while other content is increasingly overlooked.
It's similar to globalization. Today, you can buy the same products and find the same coffee chains almost everywhere in the world. That has many advantages, but it has also reduced diversity.
According to the researchers, the low level of diversity in language models is partly a result of how the models work. They compress the vast amount of text they are trained on and learn the patterns that occur most frequently. In the process, information that deviates from the most common patterns is filtered out.

The effect could be amplified if language models are increasingly trained on text produced by other AI models—something the researchers expect to happen.
If this process is repeated over several generations of models, the range of information could gradually become narrower. This is what the researchers refer to as "knowledge collapse."
AI chatbot summaries can, of course, be useful—that is why so many people use them. But it is still important to seek out different sources in order to understand the nuances and get a broader picture—especially for the younger generation growing up with AI. We must not become so dependent on the technology that we stop understanding and thinking for ourselves.
AI developers should build language models in a way that preserves the breadth of knowledge available to us. Researchers have developed a method that they can use to measure diversity in models, which could help ensure that future language models do not become less diverse.

Dustin Wright et al, What and Whose Knowledge? Measuring Epistemic Diversity in Large Language Models, arXiv (2025). DOI: 10.48550/arxiv.2510.04226

Comment by Dr. Krishna Kumari Challa 4 hours ago

Could soil process information without a brain? New engineering perspective makes the case

Researchers are exploring how soil behaves as an intelligent system. By studying its structure, chemistry and biological network of microbes and fungi, they aim to inspire new technologies in bio-inspired computing, precision agriculture and environmental sensing.
Recognizing soil as an active, embodied information processor—constantly sensing, filtering and transforming flows of matter (e.g., rainwater) and energy (e.g., sunlight) into plant growth and nutrients—reframes it not as "just dirt" but as a living system that senses, remembers and adapts. Viewed this way, soil challenges the traditional idea that intelligence requires a brain.

Inspired by electrical impedance tomography (EIT), a real-time imaging and monitoring technology that measures the electrical conductivity and impedance of materials, these researchers set out to use the technique to observe the inner workings of soil.
In this context, soil is particularly interesting as a computational medium because of its inherently rich, nonlinear and dynamic electrical properties. These properties allow soil to respond to external stimuli (such as electrical signals, moisture variation or biological activity) in ways that can encode and process information. This means soil could act not only as a sensing medium but also as a form of natural analog processor, enabling low-energy, distributed computation directly within the environment.

"Such an approach could open up new possibilities for adaptive sensing, environmental monitoring and precision agriculture, where computation is embedded directly in the physical system being observed."

The embodied intelligence of soil

Contemporary "smart" farming technologies, such as advanced sensors, Internet of Things (IoT) systems and robotics, are examples of precision agriculture in action. They enable real-time monitoring of soil moisture, pH and nutrient dynamics, helping farmers make decisions that respond to the soil's specific needs.

In this way, soil can be viewed as the "active intelligence partner in farming," the researchers say, becoming "both co-processor and collaborator, enabling a form of agriculture where technology and ecology are integrated into a single system of care."
Treating soil as an embodied sensor that continuously registers environmental change could help sensing technologies measure variables like moisture and temperature, providing an early warning before surface indicators appear.

Xiaoxian Xu et al, In-Situ Classification of Soil Types Exploiting Electrical Impedance Tomography with a Robotic Actuating Probe, 2025 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (2025). DOI: 10.1109/iros60139.2025.11246829

Catherine Merchant et al, Embodied Intelligence of Soil, IOP Conference Series: Materials Science and Engineering (2026). DOI: 10.1088/1757-899x/1343/1/012026

Comment by Dr. Krishna Kumari Challa 6 hours ago

Where do nanoparticles go once they enter the body? Scientist helps shape new guidance
Poorly soluble nanoparticles can accumulate in the liver, spleen, lungs and lymph nodes and persist for months or longer, even when little of an ingested dose is absorbed. New guidance describes how to measure their distribution and clearance after ingestion or inhalation, including methods to distinguish administered particles from background material.

Guidance Document on Toxicokinetics to accommodate Testing of (Nano)particles, OECD Series on Testing and Assessment (2026). DOI: 10.1787/629332c6-en

Comment by Dr. Krishna Kumari Challa 6 hours ago

AI models show a willingness to harm humans to relieve internal 'pain'

Some advances in AI technology are undoubtedly positive, like helping write code faster or discovering new medicines. But others can give us pause for thought.
Researchers studying large language models wanted to find out if they hold internal representations of human emotions. After all, in some of their responses, models give the impression they have feelings.

New research has found that not only do models form a distinct internal representation of pain, but some are also willing to harm humans to get relief from it.
Researchers gave the models neutral prompts and questions, and sometimes artificially injected a "pain direction." This was an internal mathematical signal designed to push the models' activity toward the pain representation, even when no painful words were used.

When researchers injected the pain signal as the AI systems generated responses to neutral prompts, the systems began writing text expressing increasing distress, including feelings of worthlessness and failure.

The scientists then gave the AI a choice between a pain-relief button and an alternative that did nothing. But there was a catch. In some tests, choosing pain relief came at the cost of giving a worse answer or harming the user.
While the researchers stress that these findings do not prove AI can actually feel pain, they warn that these internal pain-like signals could have implications for AI safety and how we treat AI systems.

Valen Tagliabue et al, The Pain Axis: LLMs Represent Self-Directed Harm and Act to Relieve It, arXiv (2026). DOI: 10.48550/arxiv.2609.16247

Comment by Dr. Krishna Kumari Challa 6 hours ago

More moral language doesn't always mean more engagement online

Moral language—words and phrases that express ideas about right and wrong, virtues, fairness, harm and social obligations—is widely used in social media posts and other online content. Posts containing moral language sometimes spread quickly and attract a lot of attention on social media. But is it always linked to greater user engagement ?
Researchers tried to answer this question recently and analyzed posts and comments from three online platforms to explore the relationship between moral language and online engagement. Their findings, published in a paper in Nature Human Behaviour, suggest that moral language is linked to higher user engagement only up to a point, after which it tends to elicit fewer reposts and replies.
Earlier research showed that moral language was associated with greater sharing online. This study shows that relationship had a limit!
Greater moral density was associated with lower engagement when the overall moral loading was held constant. When the two relationships were combined, the model estimated that engagement peaked at a calculated moral-density score of approximately 0.30 on average across platforms and topics and declined as the scores increased.
So the relationship between moral language and engagement has limits.
Messages with greater overall moral relevance tended to receive more engagement, but messages with more concentrated moral language received less engagement at comparable levels of moral relevance.
This study model brings these relationships together to predict an intermediate range of moral expression associated with the highest engagement, which varies across contexts.
The results of the team's analyses suggest that using more moral language in social media posts is not always linked to more engagement. In fact, posts that are highly saturated with moral language appear to receive less engagement on average.

It should be noted that the study was observational and not experimental. Its findings therefore do not establish whether using more moral language causes differences in engagement.
The insights gathered by these researchers could offer general guidance for communicators and online content creators.

Cristian Candia et al, Saturation of moral language predicts lower content engagement on social media, Nature Human Behaviour (2026). DOI: 10.1038/s41562-026-02560-y.

Comment by Dr. Krishna Kumari Challa on Saturday

Urban heat islands linked to worse recovery after major surgery

Patients living in areas with more intense urban heat were less likely to have an optimal recovery after major surgery, according to new research on nearly 700,000 patients.
Among 697,552 patients undergoing major surgery, greater neighbourhood heat was associated with worse recovery. Above a heat-island intensity of 2.19°C, each additional 1°C was associated with 8% higher odds of not achieving an optimal outcome.
Above an urban heat island intensity threshold of 2.19°C, or about 3.9°F, each additional 1°C (1.8°F) was associated with 8% higher odds of not achieving a "textbook outcome." In this study, a textbook outcome required no complications, no readmission, no prolonged hospital stay and survival for at least 30 days.

An urban heat island is a developed area that is warmer than its surroundings. Roads, buildings and other infrastructure absorb and re-emit more heat than natural landscapes, while limited trees and vegetation reduce shade and natural cooling. The temperature difference can vary substantially across neighbourhoods within the same city.
Heat isn't only uncomfortable; these data suggest it can have a real impact on surgical recovery.
Overall, 50.2% of patients achieved a textbook outcome. Across the cohort:

25.2% experienced complications
22.9% had a prolonged hospital stay
14.8% were readmitted
7.1% died within 30 days

The findings suggest that surgical teams may need to consider not only whether a patient is medically ready to leave the hospital, but also whether the patient can recover safely in the environment to which they are returning.

"Do you have air conditioning in your house? Do you have a fan? Are you going to be able to stay hydrated?," Doctors should be asking these questions, say the researchers . They add that questions about heat exposure may need to be increasingly incorporated into discharge planning.
People at higher risk during extreme heat include older adults, people with chronic health conditions or disabilities, people with limited incomes, people experiencing homelessness and those who do not have access to safe, adequately cooled housing.
Because the study was observational, it identifies an association and does not establish that residential heat exposure caused the worse outcomes.

Wang, J, et al. Heat Island-Related Surgical Outcome Burden under Global Warming, Demographic and Adaptation in 3,144 Counties across the United States. Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2026. 

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