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Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 11:32am

Even I have noticed this around my home. Birds are singing in the night!

Birds in light-polluted areas stay up late into the night

Birds that are active during the day sing later into the night in places with significant light pollution, according to new research.

Researchers analyzed data gathered from around the world, comparing more than 180 million bird vocalizations in a single year with global satellite imagery.

They were shocked by their findings: Under the brightest night skies, a bird's day is extended by nearly an hour. But birds staying up an hour past their normal bedtimes was an average. Actual times varied by species.

What is driving this response bybirds? We had the idea that maybe it was a species' photoreceptor sensitivity—their eyesight. And this turned out to be a key factor. Species with large eyes relative to their body size had a disproportionately stronger response to artificial light at night. They were more sensitive to light at night than species with small eyes.

Birds might have more time to forage for food and to mate, but an hour less sleep could be detrimental to their health.

Brent S. Pease et al, Light pollution prolongs avian activity, Science (2025). DOI: 10.1126/science.adv9472. www.science.org/doi/10.1126/science.adv9472

Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 8:53am

Rising temperatures linked to declining moods around the world

Rising global temperatures affect human activity in many ways. Now, a new study illuminates an important dimension of the problem: very hot days are associated with more negative moods, as shown by a large-scale look at social media postings.

Overall, the study examined 1.2 billion social media posts from 157 countries over the span of a year. The research finds that when the temperature rises above 95 degrees Fahrenheit, or 35 degrees Celsius, expressed sentiments become about 25% more negative in lower-income countries and about 8% more negative in better-off countries. Extreme heat affects people emotionally, not just physically.

This study reveals that rising temperatures don't just threaten physical health or economic productivity—they also affect how people feel, every day, all over the world. 

This work opens up a new frontier in understanding how climate stress is shaping human well-being at a planetary scale.

Unequal Impacts of Rising Temperatures on Global Human Sentiment, One Earth (2025). DOI: 10.1016/j.oneear.2025.101422. www.cell.com/one-earth/fulltex … 2590-3322(25)00248-9

Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 8:48am

To complement their findings, the researchers compared their case studies with 26 participants who had their upper limbs amputated, on average, 23.5 years beforehand. These individuals showed similar brain representations of the hand and lips to those in their three case studies, suggesting long-term evidence for the stability of hand and lip representations despite amputation.

Schone, HR et al. Stable Cortical Body Maps Before and After Arm Amputation, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02037-7

Part 2

Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 8:48am

New research shows the brain's map of the body remains unchanged after amputation

The brain holds a "map" of the body that remains unchanged even after a limb has been amputated, contrary to the prevailing view that it rearranges itself to compensate for the loss, according to new research.

The findings, published in Nature Neuroscience, have implications for the treatment of "phantom limb" pain, but also suggest that controlling robotic replacement limbs via neural interfaces may be more straightforward than previously thought.

Studies have previously shown that within an area of the brain known as the somatosensory cortex there exists a map of the body, with different regions corresponding to different body parts.

These maps are responsible for processing sensory information, such as touch, temperature and pain, as well as body position. For example, if you touch something hot with your hand, this will activate a particular region of the brain; if you stub your toe, a different region activates.

For decades now, the commonly-accepted view among neuroscientists has been that following amputation of a limb, neighboring regions rearrange and essentially take over the area previously assigned to the now missing limb. This has relied on evidence from studies carried out after amputation, without comparing activity in the brain maps beforehand.

But this has presented a conundrum. Most amputees report phantom sensations, a feeling that the limb is still in place—this can also lead to sensations such as itching or pain in the missing limb. Also, brain imaging studies where amputees have been asked to 'move' their missing fingers have shown brain patterns resembling those of able-bodied individuals.

To investigate this contradiction, researchers followed three individuals due to undergo amputation of one of their hands.

This is the first time a study has looked at the hand and face maps of individuals both before and after amputation. 

Prior to amputation, all three individuals were able to move all five digits of their hands. While lying in a functional magnetic resonance imaging (fMRI) scanner—which measures activity in the brain—the participants were asked to move their individual fingers and to purse their lips. The researchers used the brain scans to construct maps of the hand and lips for each individual. In these maps, the lips sit near to the hand.

The participants repeated the activity three months and again six months after amputation, this time asked to purse their lips and to imagine moving individual fingers. One participant was scanned again 18 months after amputation and a second participant five years after amputation.

The researchers examined the signals from the pre-amputation finger maps and compared them against the maps post-amputation. Analysis of the 'before' and 'after' images revealed a remarkable consistency: even with their hand now missing, the corresponding brain region activated in an almost identical manner.

Bearing in mind that the somatosensory cortex is responsible for interpreting what's going on within the body, it seems astonishing that it doesn't seem to know that the hand is no longer there!

As previous studies had suggested that the body map reorganizes such that neighboring regions take over, the researchers looked at the region corresponding to the lips to see if it had moved or spread. They found that it remained unchanged and had not taken over the region representing the missing hand.

Part 1

Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 8:34am

Novel cement lets buildings cool themselves

When temperatures get too hot to handle, most of us crank up the air conditioning to keep cool. It does the job, but it's expensive and uses a significant amount of energy. But now an innovation by scientists could help us cut our reliance on AC. They've developed a new type of cement that allows buildings to stay cool on their own. Their research is published in the journal Science Advances.

Typically, cement absorbs infrared radiation from the sun and stores it as heat, which increases the temperature inside a building. To address this, a research team modified the building material's formula. They created a cement that reflects light and emits heat instead of absorbing it, using tiny reflective crystals of a mineral called ettringite on its surface.

The scientists developed the material from the ground up, starting with its basic chemical recipe. They ground tiny pellets made from minerals like limestone and gypsum into a fine dust and mixed it with water. The mixture was then poured into a silicon mold covered in holes that created depressions in the cement's surface where the ettringite crystals could grow. The result was a supercool cement that acts like a mirror and a radiator, bouncing away sunlight and emitting heat.

Once the cement was created, it was put to the test on a rooftop at Purdue University. Under a strong midday sun, the cement's surface was 5.4 degrees Celsius cooler than the surrounding air. The material also underwent rigorous mechanical, environmental, and optical durability testing.

Additionally, the team used machine learning to analyze its potential environmental benefits, which revealed that it could potentially lead to a net-negative carbon footprint over a 70-year period.

This breakthrough holds the potential to turn the heavy cement industry into a negative-carbon emission system, where supercool cement could play a key role in driving an energy-efficient, carbon-free future for the construction industry.

Buildings currently account for about 40% of global energy use and 36% of carbon emissions. If the supercool cement is successfully scaled up for commercial use, its benefits could be significant. As well as helping to cool the planet, it could dramatically cut energy bills by reducing our reliance on air conditioning. And by keeping buildings and the surrounding air cooler, this novel cement could also create a more pleasant and healthier urban environment.

Guo Lu et al, Scalable metasurface-enhanced supercool cement, Science Advances (2025). DOI: 10.1126/sciadv.adv2820

Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 8:23am

One longstanding puzzle that researchers are particularly excited about is cosmic inflation, a period of extremely rapid expansion in the early universe. Inflation was initially proposed to explain why the universe looks the way it does today, stretching out an initially small patch, so that the universe looks similar across a vast expanse.
If you don't have inflation, a lot of things fall apart. But while inflation helps explain the state of the universe today, nobody has been able to explain how or why the baby universe had this sudden short-lived growth spurt.

The trouble is, to probe this using Einstein's equations, cosmologists have to assume that the universe was homogeneous and isotropic in the first place—something which inflation was meant to explain. If you instead assume it started out in another state, then you don't have the symmetry to write down your equations easily.
But numerical relativity could help us get around this problem—allowing radically different starting conditions. It isn't a simple puzzle to solve, though, as there's an infinite number of ways spacetime could have been before inflation. Researchers are therefore hoping to use numerical relativity to test the predictions coming from more fundamental theories that generate inflation, such as string theory.
There are other exciting prospects, too. Physicists could use numerical relativity to try to work out what kind of gravitational waves could be generated by hypothetical objects called cosmic strings—long, thin "scars" in spacetime–potentially helping to confirm their existence. They might also be able to predict signatures, or "bruises," on the sky from our universe colliding with neighboring universes (if they even exist), which could help us verify the multiverse theory.
Excitingly, numerical relativity could also help reveal whether there was a universe before the Big Bang. Perhaps the cosmos is cyclic and goes through "bounces" from old universes into new ones—experiencing repeated rebirths, big bangs and big crunches. That's a very hard problem to solve analytically.

"Bouncing universes are an excellent example, because they reach strong gravity where you can't rely on your symmetries. Several groups are already working on them—it used to be that nobody was."
Numerical relativity simulations are so complex that they require supercomputers to run. As the technology of these machines improves, we might expect significant improvement in our understanding of the universe.
Cosmologists who are interested in solving some of the questions they cannot solve, can use numerical relativity, the researchers say.

Josu C. Aurrekoetxea et al, Cosmology using numerical relativity, Living Reviews in Relativity (2025). DOI: 10.1007/s41114-025-00058-z

Part 2

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Comment by Dr. Krishna Kumari Challa on August 22, 2025 at 8:18am

What happened before the Big Bang? Computational method may provide answers

We're often told it is "unscientific" or "meaningless" to ask what happened before the Big Bang. But a new paper by astrophysicists and cosmologists published in Living Reviews in Relativity, proposes a way forward: using complex computer simulations to numerically (rather than exactly) solve Einstein's equations for gravity in extreme situations.

The team argues that numerical relativity should be applied increasingly in cosmology to probe some of the universe's biggest questions–including what happened before the Big Bang, whether we live in a multiverse, if our universe has collided with a neighboring cosmos, or whether our universe cycled through a series of bangs and crunches.

Einstein's equations of general relativity describe gravity and the motion of cosmic objects. But wind the clock back far enough and you'll typically encounter a singularity—a state of infinite density and temperature—where the laws of physics collapse.

Cosmologists simply cannot solve Einstein's equations in such extreme environments—their normal simplifying assumptions no longer hold. And the same impasse applies to objects involving singularities or extreme gravity, such as black holes.

One issue might be what cosmologists take for granted. They normally assume that the universe is "isotropic" and "homogeneous"—looking the same in every direction to every observer. This is a very good approximation for the universe we see around us, and one that makes it possible to easily solve Einstein's equations in most cosmic scenarios. But is this a good approximation for the universe during the Big Bang?

Numerical relativity allows you to explore those questions. 

Numerical relativity was first suggested in the 1960s and 1970s to try to work out what kinds of gravitational waves (ripples in the fabric of spacetime) would be emitted if black holes collided and merged. This is an extreme scenario for which it is impossible to solve Einstein's equations with paper and pen alone—sophisticated computer code and numerical approximations are required.

Its development received renewed focus when the LIGO experiment was proposed in the 80s, although the problem was only solved in this way in 2005, raising hopes that the method could also be successfully applied to other puzzles.

Part 1

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 11:59am

Breast tumors tunnel into fat cells to fuel up

Scientists caught cancer cells in the act of breaking into fat cells and releasing their fat. The energy heist seems to be critical for the growth of deadly breast cancer. The study appears in Nature Communications.

When triple-negative breast cancer grows, the fat cells around it seem to shrink. Researchers have discovered that the cells of these tumors, which are among the deadliest types of breast cancer, build molecular tunnels, called gap junctions, into nearby fat cells. The tumor cells then send instructions that trigger the fat cells to release stores of energy that could feed the cancer.

Blocking the gap junctions stopped tumors from growing.

The findings have immediate clinical implications. Although no one is yet testing drugs that block gap junctions for breast cancer, there are ongoing clinical trials using these drugs for brain cancer.

Nature Communications (2025). DOI: 10.1038/s41467-025-62486-3

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 11:52am

What happens in the brain when it learns something new

Memories of significant learning experiences—like the first time a driver gets a speeding ticket—are sharp, compared to the recollection of everyday events—like what someone ate for dinner two weeks ago. That's because the human brain is primed to learn from helpful associations.

Researchers have identified specific neural connections that are especially sensitive to this process of learning about causality. The discovery, while seemingly intuitive, could have widespread implications for understanding how humans learn and inform new ways to address learning challenges.

What's happening inside the brain when experiencing something for the first time—and how it decides if it's meaningful—is the subject of new research which focuses on how memory and learning shape the brain. The study is published in the journal Cell Reports.

 Researchers looked at how the connection between two different types of neurons—cells that transmit information to different parts of the brain—changes in response to new learning experiences. They found that the strength of the connection only changed if an experience was meaningful. These neurons are located in the sensory cortex, a part of the brain that other animals—like cows and dogs—have as well. That means that this finding could have a wider significance and help researchers understand how a broad range of animals learn.

Researchers found this change in the brain if something was useful to learn. If there was nothing to learn, there was no change.

This means that somehow the brain can distinguish whether there is a useful association to make, or there is nothing to learn.

The research shows that the brain is primed to learn new important things and that our brains are very sensitive to things that make sense.

 Eunsol Park et al, Somatostatin neurons detect stimulus-reward contingencies to reduce neocortical inhibition during learning, Cell Reports (2025). DOI: 10.1016/j.celrep.2025.115606

Comment by Dr. Krishna Kumari Challa on August 21, 2025 at 11:41am

Cancer-associated nerve injury can lead to chronic inflammation and immunotherapy resistance

Cancer cells can break down the protective covers around nerves, causing nerve injury that triggers chronic inflammation, leading to immune exhaustion and eventual resistance to immunotherapy, according to new research .

Tumors can sometimes infiltrate the space around nerves and nervous system fibers that are in close proximity, a process known as perineural invasion, which leads to poor prognosis and treatment escalation in various cancer types. 

The study, published today in Nature, underscores the importance of investigating interactions between cancer and the nervous system—a field known as cancer neuroscience. The results suggest that targeting the signaling pathways involved can reverse this inflammation and improve treatment responses.

These findings uncover novel mechanisms by which the immune system and nerves within the tumor microenvironment interact, revealing actionable targets that could transform the way we approach resistance to immunotherapy in patients with cancer.

 Baruch, E.N. et al, Cancer-induced nerve injury promotes resistance to anti-PD-1 therapy, Nature (2025). DOI: 10.1038/s41586-025-09370-8 www.nature.com/articles/s41586-025-09370-8

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