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Comment by Dr. Krishna Kumari Challa 13 hours ago

How time and space become one inside your brain—and what it means for Alzheimer's

If you develop Alzheimer's disease, you not only lose your sense of time, but you also lose your sense of place.

Neural circuits in the retrosplenial cortex process time and space using similar activity patterns, indicating these dimensions are integrated in the brain. This shared mechanism helps explain why both temporal and spatial orientation deteriorate together in Alzheimer's disease, highlighting the need to understand healthy episodic memory networks to address dementia.

All memories are made up of different components. You don't just remember what you had for dinner yesterday, but also the time and place. We often think of time and space as separate categories, a distinction created by philosophers and physicists that is incredibly practical for organizing our lives. But our brain cells don't see it that way.
These cells don't distinguish between a step forward in space or a second passing in time. Instead, they simply record a continuously changing stream of information from our senses, tracking events as they unfold. To the brain's internal network, time and place are effectively two sides of the same coin.
In Alzheimer's disease, it is therefore not surprising that both are affected; when the neural network is damaged, our sense of 'where' and 'when' begins to unravel together.
Remembering where, when and how something happened is called episodic memory. In your brain, billions of nerve cells form large networks, passing signals like a relay race to process information from your senses, the sounds, smells, and sights of your life.

We already know that cells which link memories to time and space are found in the hippocampus.
But this group of researchers had a theory that another area of the brain is also involved, namely the retrosplenial cortex. Located at the back of the cerebral cortex near the hippocampus, this area was previously only known for linking memories to place.
To test if this area also tracks time, the team designed a memory challenge for mice. The task required them to hold a specific odor in their "working memory" during a brief period. Their study is published in Cell Reports.
The most striking discovery was that the retrosplenial cortex uses the same "neural script" for both space and time. The researchers found that the sequence of neuronal activity in the retrosplenial cortex looks almost identical whether a mouse is physically running through a room or simply holding a memory in its mind for five seconds.
This discovery brings us back to the tragic reality of Alzheimer's disease, where those affected struggle to anchor themselves in both time and place. By showing that the brain uses the same "neural script" for both, this research explains why these two senses often fail together.
This work also challenges how we perceive the world around us. While we use the concepts of time and space to organize our lives, this distinction is largely a human construct. In fact, some modern theories in physics are moving away from using time and space as the fundamental building blocks of the universe. It appears the brain's internal wiring mirrors this deeper reality.

Anna Christina Garvert et al, Area-specific encoding of temporal information in the neocortex, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.115363

Comment by Dr. Krishna Kumari Challa 13 hours ago

Premature and small births are linked to lifelong learning problems

Preterm birth and low birth weight are consistently associated with lower IQ and persistent educational disadvantages, particularly in mathematics, from early childhood into adulthood. The severity of these challenges increases with earlier gestational age and lower birth weight, underscoring the importance of early identification and ongoing support to improve long-term outcomes.
Being born early or at a lower weight is linked to lower IQ scores and poorer educational outcomes in school and beyond, according to a new study published in the journal JAMA Pediatrics.
In this research, known as an umbrella review, the team examined what previous studies had discovered about preterm birth and low birth weight and long-term development. This involved going back to the original numbers and recalculating the results using a single, consistent method to ensure accuracy. They looked at five different life stages, from babies under two years old to adults over 18.

This meta-analysis confirmed that both preterm birth and low birth weight are linked to disadvantages that persist over time. In particular, babies born before 28 weeks or weighing less than 1 kg at birth showed larger academic disadvantages on average than babies born at term with normal birth weight.

The most affected subject was math, with significant gaps in calculation and problem-solving skills. Stark differences were also seen in reading, comprehension, spelling and identifying words.

These challenges were often most visible during primary school and closed slightly during teenage years. However, some of these learning difficulties reappear once a person reaches adulthood, as the study authors note in their paper. "These disadvantages generally increased with earlier gestational age and lower birth weight. Although some associations appeared to attenuate during adolescence, evidence of persistent disadvantages into adulthood was observed for several outcomes."

The research team believes their findings show that the impact of being born early or much smaller than average can have lifelong consequences. For some, this may mean fewer job opportunities or earning lower salaries than their peers.

Mingzheng Hu et al, Cognitive and Educational Outcomes After Preterm Birth or Low Birth Weight, JAMA Pediatrics (2026). DOI: 10.1001/jamapediatrics.2026.0533

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Comment by Dr. Krishna Kumari Challa 13 hours ago

AI's growing role in scientific peer review

Large language models can enhance scientific peer review by identifying objective errors and inconsistencies, improving draft quality, and alleviating reviewer workload. However, AI is less effective at subjective judgments, such as assessing novelty or significance. Human oversight remains essential, with transparency about AI involvement and accountability for final decisions. AI's role in science is expected to expand.

There is tremendous interest in using AI, especially language models, to support research and peer review and speed up the scientific process. A key advantage is that AI can act like a rapid, always-available critic, a sort of pre-submission review process—before scientists officially send in a paper for publication. AI can be quite good at assessing drafts for gaps and limitations, so researchers can preemptively address them. This can improve the quality of first drafts submitted for publication and reduce the back-and-forth later. And on the reviewer side, the pressure is real: As submissions grow, human reviewers are very much overburdened, which can lead to lower-quality reviews and frustration for authors.

IN their tests researchers found that  besides spotting gaps and limitations, AI can be quite good at the more objective, verifiable aspects of review. 

 AI is strongest on objective, checkable inconsistencies and technical issues and weaker on subjective judgments about the novelty or significance of the research.

The researchers say that AI should support and inform—not fully replace—human decision-making.

A human, or team of humans, must make the final editorial decisions and scientists must stand behind the work. AI can offer comments on early drafts, point out omissions, and suggest improvements in the writing and the research—but the scientists must remain accountable for incorporating and synthesizing feedback from the AI and human reviewers. 

Scientists have to be up-front about how and where AI has assisted in the research itself and in the writing and review of the papers. They should acknowledge exactly how AI was involved and what tools were used in the paper. It comes down to accountability and a clear chain of responsibility and that final decisions are still made by humans.

Following on this work, many conferences and journals are now exploring using LLMs to assist the review process.

Nitya Thakkar et al, A large-scale randomized study of large language model feedback in peer review, Nature Machine Intelligence (2026). DOI: 10.1038/s42256-026-01188-x

In one recent large-scale randomized experiment, the results of which were published in Nature Machine Intelligence, researchers provided AI assistance to human reviewers on roughly 20,000 reviews to assess AI's impact on review quality. 

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Comment by Dr. Krishna Kumari Challa 13 hours ago

Vibrations in your skull New tool for Biometric authentication

A team of researchers has developed a security system that could change how people log in to virtual and augmented reality platforms by eliminating passwords, personal identification numbers and eye scans and replacing them with something far more seamless.

A new authentication system uses unique vibration patterns from breathing and heartbeats transmitted through the skull, detected by motion sensors in XR headsets, to identify users. This software-only approach achieved over 95% accuracy in authenticating users and over 98% in rejecting unauthorized access, offering secure, continuous, and hardware-free biometric verification.

The system, a software program called VitalID, is based on the team's discovery of a new biometric: tiny vibrations generated by breathing and heartbeats that resonate through the skull in patterns unique to each person's bone structure and facial tissues.
The human body is always moving in tiny ways, even when a person is sitting still. Each breath and each heartbeat create very small vibrations inside the body. Those vibrations travel up through the neck and into the head.

When they reach the skull, they cause it to vibrate slightly. Because every skull has a different shape, thickness and bone structure, the vibrations change in unique ways as they move through each person's head. Soft tissues in the face, such as muscle and fat, also influence how the vibrations travel.

As a result, each person produces a distinct vibration pattern. Motion sensors built inside virtual reality headsets can detect these tiny patterns and assess them like a fingerprint to determine who is wearing the device.
We do not need to add any device or additional hardware. It requires only software.
In testing across 52 users over a 10-month period using two popular XR headsets, the system correctly authenticated legitimate users more than 95% of the time and rejected unauthorized users more than 98% of the time.

The researchers built a filtering system that removes interference from extraneous head and body movement, allowing the headset to focus only on the tiny vibrations in the skull caused by breathing and heartbeat. They then used advanced computer models to analyze those vibration patterns.

Because the vibrations travel internally through bone and tissue, they may also be more difficult to spoof. Someone might imitate another person's breathing rhythm but cannot easily replicate the biomechanical properties of another person's skull.

The headset would continuously confirm identity in the background simply by sensing the subtle vibrations that come with being alive.

Tianfang Zhang et al, Harnessing Vital Sign Vibration Harmonics for Effortless and Inbuilt XR User Authentication, Proceedings of the 2025 ACM SIGSAC Conference on Computer and Communications Security (2025). DOI: 10.1145/3719027.3765060

Comment by Dr. Krishna Kumari Challa 14 hours ago

Antibacterial soaps and wipes can fuel antimicrobial resistance, scientists warn

An international team of scientists is warning that everyday antibacterial soaps, wipes, sprays, and other "germ-killing" products are quietly contributing to the global rise of antimicrobial resistance (AMR) while providing no added health benefit for most consumer uses.

Widespread use of antibacterial soaps, wipes, and other consumer products containing biocides such as quaternary ammonium compounds is contributing to antimicrobial resistance (AMR) without providing added health benefits for most uses. These chemicals promote bacterial resistance, including cross-resistance to antibiotics, and persist in the environment. Health authorities recommend plain soap and water for routine handwashing.
The authors summarize numerous laboratory and real-world studies showing that environmental levels of these chemicals cause resistant bacteria to survive and spread, promote cross-resistance to important antibiotics, and cause lasting genetic changes to microbes, including the exchange of resistance genes.

Over time, these shifts can allow resistant strains to dominate. This translates to the spread of antibiotic resistant genes that threaten the effectiveness of antibiotics when we really need them and can contribute to rising deaths.
Evidence shows biocides in many consumer products provide no added health benefit, but the biocides do raise concerns about AMR and toxicity.

Targeting Biocide Overuse in Consumer Products Will Strengthen Global AMR Action, Environmental Science & Technology (2026). DOI: 10.1021/acs.est.5c17673

Comment by Dr. Krishna Kumari Challa 14 hours ago

Animals are powerful landscape engineers shaping the Earth's surface, global study finds

Wild animals significantly modify Earth's surface by altering soil and sediment through activities such as burrowing and feeding. A global meta-analysis by researchers analyzed data from 64 studies covering 61 species of wild animals across freshwater and terrestrial environments
Animal activity increases soil porosity and reduces fine material, influencing erosion and landscape development. These effects are more pronounced in freshwater ecosystems (136% change) than terrestrial ones (66%), highlighting animals as key geomorphic agents.

Wild animals are not just inhabitants of the natural world. Many also act as natural landscape engineers, reshaping Earth's surface as they burrow, feed, and build shelters that move soil and sediment across ecosystems. From animals disturbing riverbeds to burrowing species redistributing soil, wildlife constantly modifies the physical structure of landscapes through everyday activities.
The research found that animals consistently increased the porosity of soils and sediments and reduced the amount of fine material present. These changes influence how water and sediment move through ecosystems and can affect processes such as erosion, river behaviour and landscape development.
The new study provides quantitative evidence of how strongly animal activity can modify geomorphic processes across ecosystems.

Z. Khan et al, Signatures of Wild Animal Life in Earth's Landscapes, Journal of Geophysical Research: Earth Surface (2026). DOI: 10.1029/2025jf008351

Comment by Dr. Krishna Kumari Challa 14 hours ago

Scientists capture atoms in motion

Researchers have captured the exact atomic movements that write data to next-generation memory devices, which could pave the way for smaller, faster and more energy-efficient electronics.

Using advanced electron microscopy the research team captured atomic-scale movements inside promising memory materials, known as fluorite-type ferroelectrics, that could overcome current limits to how small and efficient memory devices can become.
Everyday technologies, such as smartphones, medical devices, wearable electronics and contactless IC cards used in public transport, store data as billions of digital 1s and 0s. In these materials, the physical position of an atom acts like a "switch"—and moving an atom just a fraction of a nanometer is what flips a data bit from a 0 to a 1.

This research shows exactly how that physical movement happens in real time. Until now, scientists couldn't directly see how this switching actually happened, in fractions of a second.

They discovered that switching doesn't happen in a single step, but through previously unseen intermediate atomic structures, and that the process can be controlled by changing the material's composition.

Kousuke Ooe et al, Direct observation of cation-dependent polarisation switching dynamics in fluorite ferroelectrics, Nature Communications (2026). DOI: 10.1038/s41467-026-70593-y

Comment by Dr. Krishna Kumari Challa 14 hours ago

Why Does the Middle East Have the Largest Oil Reserves?

Comment by Dr. Krishna Kumari Challa 14 hours ago

 Evacuating in 90 seconds? New simulations show the safest cabin layout

In case of an emergency, the  Aviation Administration requires aircraft to be able to evacuate within 90 seconds. However, as the median age of the global population increases, the growing number of elderly airline passengers poses new challenges during emergency situations.

In AIP Advances, an international collaboration of researchers simulated 27 different evacuation scenarios in the case of a dual-engine fire in an Airbus A320, one of the most common narrow-body aircraft in the world. They compared three different cabin layouts with three different ratios of passengers over the age of 60 and three different distributions of those passengers.

While a dual-engine fire scenario is statistically rare, it falls under the broader category of dual-engine failures and critical emergencies in aviation.

In seeking the most efficient combination of factors, the researchers created full-scale computer-aided design models of the A320 cabin and used Pathfinder—the industry-standard software for evacuation modelling—to simulate passengers' behaviour. They found the proportion and location of elderly passengers have the largest effect on evacuation time.

The fastest option—a layout that accommodates a total of 152 passengers with two rows of first-class seats at the front, and 30 elderly passengers evenly distributed throughout the cabin—still required 141 seconds for all the passengers to reach the ground, much longer than the AA mandates.

Previous studies have shown that cognitive decline in elderly populations can affect situational awareness and delay decision making, and that reduced dexterity can be exacerbated during high-stress situations.
The researchers hope that incorporating this information into their findings—for example, by offering additional safety briefings to elderly passengers—will help further accelerate the deboarding process.

Children, infants, and pregnant women also introduce unique physical capabilities and behaviours that add another vital layer to evacuation modelling, which the group plans to investigate in their future work.

Effect of elderly passenger distribution on A320 aircraft evacuation under dual-engine fire scenarios, AIP Advances (2026). DOI: 10.1063/5.0310405

Comment by Dr. Krishna Kumari Challa yesterday

The four types of dementia most people don't know exist
Dementia encompasses over 100 types, with Alzheimer's disease accounting for about 60% of cases. Less common forms include posterior cortical atrophy, Creutzfeldt-Jakob disease, FTD-MND, and progressive supranuclear palsy, each presenting distinct symptoms beyond memory loss, such as visual, motor, or behavioral changes. Early recognition of these subtypes is crucial for appropriate care.

original article.

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