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Comment by Dr. Krishna Kumari Challa on Tuesday

Why do humans reject cannabolism almost everywhere?

From ancient graves to stories of survival on the frontier, signs of human flesh-eating turn stomachs, even as they raise questions. Anthropologists have uncovered bones cut up with axes and chops—like a skull from England dating back 14,700 years that had the meat scraped off its jaws. Such finds confirm that our ancestors sometimes ate each other, but now every human culture views cannibalism as a final taboo. But if eating kin saved lives, why didn't it become routine?

Cannibalism didn't happen only from hunger—it turns up in myths, religious rites and war, too. In some cultures, consuming enemies (or ancestors) was believed to transfer power or honor. The Aztecs, for example, famously depicted sacrificial cannibalism in 16th-century codices. But even in those cases, it was rare and symbolic, not a dinner plan.

A new study by a Polish-Czech team offers a compelling answer, revealing a gruesome trade-off: a few extra calories now, but a potentially deadly epidemic later. While human meat provides calories—roughly "an average meal" by caloric content—their mathematical model confirms this only pays off under extreme scarcity, such as when the bodies of the dead are readily available. However, as soon as cannibalism spreads beyond a few survivors, the hidden costs rapidly overwhelm any gains.

The problem isn't just modest energy returns; it's disease. Humans share nearly identical biochemistry, making each human plate a vector for pathogens. The model demonstrates that the risk of catching a deadly pathogen climbs exponentially with the length of the cannibalism chain, a risk even cooking can't eliminate, especially for prions like those responsible for kuru in the Fore tribes of Papua New Guinea.

The new model isolates the purely nutritional trade-off: It doesn't include social or ritual gains (like terrorizing foes or gaining status). Without those extras, cannibalism only "pays" when people are almost starving. And because infectious parasites accumulate with every generation of cannibals, a killing spree of human flesh-eating rapidly becomes a population sink.

The scientists show that eating human flesh is like signing a death warrant for disease. They cite kuru as one case—but the same logic applies to any prion: Once an organism serving as food is very similar to the eater, even a tiny dose of misfolded protein can jump the species barrier. "Pathogens have an easier task because they end up in an organism with almost identical physiology," the team explains.

In their model, groups that let cannibalism run unchecked eventually collapse under runaway epidemics. 

The long-term practice of cannibalism can lead to population collapse by causing illnesses in those who eat other people. Every cannibal who eats another cannibal just compounds the risk—a phenomenon named cannibalism order.

Can cooking help? A bit, but not much. High heat might kill many bacteria and viruses, but not prions.

 The model finds that even if people always fully roast the flesh, the inevitable prions in nervous tissue still accumulate and eventually undo the benefit. So the basic story remains: Unless almost every human meal is a rare windfall (like a corpse after a disaster), the epidemic cost of cannibalism quickly outweighs its calories.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

This study offers evidence suggesting that glucose in the blood may contribute to processes linked to accelerated brain aging. Interestingly, the researchers found that higher levels of blood glucose were also linked to an increased risk of developing seven different conditions known to affect brain function.

"Clinically, elevated plasma glucose was positively associated with seven brain disorders, including all-cause dementia, Alzheimer's disease, vascular dementia, Parkinson's disease, stroke, depression, and anxiety, and negatively associated with cognitive performance, movement function, and mental health outcomes," wrote the authors.

"Higher glucose concentrations were also associated with reduced regional brain volumes across 80 cortical, subcortical, and cerebellar regions. These findings implicate glucose metabolism as a modifiable pathway in brain aging, with implications for early intervention strategies aimed at preserving brain health across the lifespan."

Zhirong Li et al, Metabolomic signatures of brain aging: A multimodal and genetic study, Molecular Psychiatry (2026). DOI: 10.1038/s41380-026-03703-3

Part 2

Comment by Dr. Krishna Kumari Challa on Tuesday

Higher blood glucose levels linked to faster brain aging
The human brain is known to naturally change with age, shrinking in size and volume after people reach their 30s or 40s. In some cases, however, it can age faster than expected, which can increase the risk of early memory loss, cognitive decline and some brain-related disorders.
Faster brain aging has been linked to various neurological and psychiatric disorders, as well as some neurodegenerative diseases. The factors that influence the speed at which the brain ages, however, have not yet been clearly and comprehensively elucidated.

Researchers recently analyzed available neuroimaging, genomic and biological data to better understand the contribution of metabolic processes (i.e., the chemical reactions that transform food into energy) to brain aging. Their findings, published in Molecular Psychiatry, suggest that higher levels of glucose in the blood are associated with accelerated brain aging.
To explore the biological underpinnings of brain aging, the researchers analyzed data from the UK Biobank, a large biomedical database that contains health-related, genetic and imaging data collected from thousands of people living in the U.K. By analyzing these people's brain scans, they derived measurable brain features, such as the size of specific brain regions, tissue characteristics and structural changes.

Subsequently, they trained machine learning algorithms to predict the age of people based on the brain features they identified. They found that a specific statistical method, known as a least absolute shrinkage and selection operator (LASSO) regression model, was best at predicting the age of people's brains, with an average error rate of 3.26 years.

Using the best-performing LASSO model, the researchers calculated a value called BAG for thousands of people included in the UK Biobank database. This is essentially a value indicating whether a person's predicted brain age is higher or lower than their actual age, and by how many years.
They then analyzed metabolomics data derived from the same people's blood samples. This allowed them to identify nine molecules in the blood that appeared to be significantly associated with BAG values.
Notably, glucose appeared to have the strongest association with BAG values. Specifically, higher blood glucose levels were linked to brains that showed more signs of aging in imaging scans and thus appeared older than their actual age.
Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

There are two ways galaxies typically lose gas like this: tidal interaction or merger, where gravity from another galaxy pulls gas away, and ram-pressure stripping, which occurs when the galaxy plows through a hot, dense gas medium and that resistance physically strips gas off it.

The team rules out a merger because the only candidate for a merging companion—a bright knot embedded in the tail—is too low-mass to gravitationally rip away that much gas.

Instead, several clues point to ram-pressure stripping. The stripped gas moves smoothly and continuously, rather than as a torn-off fragment. It's calm and diffuse, and despite holding onto a massive gas supply, the galaxy's star formation remains surprisingly low—unlike the starburst expected from a merger. The tail also happens to point toward the center of the cluster, consistent with gas trailing behind a galaxy as it moves through hot intracluster gas.

"Together with the tail alignment and the independently detected hot ICM in SPT2349−56, these observations therefore favor ram-pressure stripping over tidal interaction as the main mechanism shaping C26," the team writes in the paper.

This kind of dramatic stripping is what creates "jellyfish galaxies" that flaunt tentacle-like tails of gas. But it's normally assumed this needs a mature, well-developed cluster with a hot, dense intracluster medium to work efficiently. SPT2349−56 is still a young cluster in the process of forming, very early in the universe's history.
Ram-pressure stripping effectively starves the galaxy of fuel. Without gas, star formation eventually shuts down in a process called "quenching." The team suggests that C26 may be caught mid-transformation, where a massive, still-star-forming galaxy has already lost most of its gas and is on its way to becoming a dead, non-star-forming galaxy.

"C26 may capture an intermediate stage between these two regimes, in which most of the cold-gas reservoir has already been removed by the external environment, while the stellar head is not yet fully quenched," they explain.

As a result, this connects to a broader puzzle in astronomy about why astronomers find quiet, mature-looking galaxies surprisingly early in cosmic history. Interestingly, other galaxies in this same cluster core also show signs of being gas-poor, suggesting this stripping process might be actively reshaping the whole protocluster, not just C26.

Dazhi Zhou et al, An extreme ram-pressure stripping event in a protocluster at redshift 4.3, arXiv (2026). DOI: 10.48550/arxiv.2606.18229

Part 2

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Comment by Dr. Krishna Kumari Challa on Tuesday

Astronomers may have caught an early galaxy in the process of dying

Astronomers have spotted many "red and dead" galaxies in the early universe. These are massive systems that stopped forming stars surprisingly early in cosmic history. Now, they may have found evidence of one in the act of becoming dead: a massive galaxy being stripped of its star-forming gas just 1.4 billion years after the Big Bang. The clues behind why it lost its star-forming material are detailed in a paper posted to the arXiv preprint server on June 16.

SPT2349–56 is an emerging galaxy cluster, or "protocluster," containing about 30 star-forming galaxies within a region 100 kiloparsecs wide. Among its members, C26 is particularly interesting because of its unusual shape. It has a head and a tail like a comet. It also has a dense, bright region called the "knot," embedded within the tail. It was first detected in ALMA images.

In this new study, using observations from the Hubble Space Telescope and the James Webb Space Telescope, researchers studied this galaxy's head, tail and knot to estimate its mass and star-forming properties.
Part 1

Interestingly, the tail seems to house a younger stellar population, as it is detected in UV light. The stellar head has a mass of around 22 billion solar masses, and the tail, including the knot, has a mass of around 6 billion solar masses.

The specific star-formation rate of the head is lower than expected for a typical star-forming galaxy, whereas the tail and knot are consistent with expectations.

Calculating the amount of cold gas in the galaxy available for the formation of new stars, the team found that while tens of billions of solar masses of gas are present, more than half of it is not even inside the galaxy. This displaced gas has been pulled out into the long tail trailing behind it, and it appears diffuse and calm—not really dense and turbulent gas suitable for star formation.

Comment by Dr. Krishna Kumari Challa on July 4, 2026 at 9:40am

“A society that loses science loses the future.”

Comment by Dr. Krishna Kumari Challa on July 4, 2026 at 9:27am

Many students listen to music to focus and stay motivated while they study—but it doesn't always help
Music’s impact on studying depends on task demands, music type, and individual differences. Many students report music enhances motivation, mood, and engagement, but lyrics and complex or loud music often disrupt language-heavy or challenging tasks. More motivated and confident students are likelier to study with music. Strategic, task-dependent use—often instrumental or as a delayed reward—is recommended.

original article.

Comment by Dr. Krishna Kumari Challa on July 4, 2026 at 9:16am

You can dream while you're awake. The boundary between wakefulness and sleep is a lot blurrier than you'd think
Wake–sleep transitions show overlapping mental states: memories, sensory-related thoughts, deliberate reflections, and dream-like imagery all occur during wakefulness, N1, and N2 sleep. EEG-based analyses and machine learning identify consistent brain signatures for each state, indicating similar neural mechanisms can generate dream-like or reflective experiences regardless of vigilance level.

original article.

Comment by Dr. Krishna Kumari Challa on July 4, 2026 at 9:10am

Songs play a greater role than plumage color in limiting bird hybridization, study suggests

Across bird species, greater divergence in song strongly correlates with reduced hybridization, even in overlapping geographic ranges, indicating songs are primary prezygotic barriers. Male plumage coloration shows little association with hybridization, whereas divergent female plumage modestly reduces hybridization. These patterns clarify mechanisms of reproductive isolation in birds.

Vicente García-Navas et al, Song but not colour divergence constrains hybridization in birds, Biology Letters (2026). DOI: 10.1098/rsbl.2026.0237.

Comment by Dr. Krishna Kumari Challa on July 4, 2026 at 9:05am

Rescue mission launches to save NASA telescope that's falling back to Earth

A three-armed spacecraft rocketed into orbit Friday, this week, to rescue a NASA telescope that's in danger of crashing back to Earth.
Northrop Grumman launched Katalyst Space Technologies' Link spacecraft from the Marshall Islands in the Pacific. The Pegasus rocket blasted off from the belly of a modified airplane, putting Link on course to reach and capture NASA's Swift Observatory in about a month.

Launched in 2004, Swift is sinking faster than ever because of recent solar storms. NASA is paying $30 million for Katalyst to capture the telescope and boost its orbit so it can continue tracking some of the biggest explosions in the universe, like gamma ray bursts and exploding stars.

If all goes well, Swift could be back scanning the cosmos by September. Observations are currently on hold to preserve the telescope's orbit as long as possible.

NASA's Hubble Space Telescope could be a candidate for a similar salvage operation in a few years. It's also slipping in altitude because of increased atmospheric drag caused by the sun's outbursts.

The 1.6-ton (1.4-metric ton) Swift currently is circling 224 miles (360 kilometers) above Earth. Katalyst aims to raise the telescope's altitude by 150 miles (240 kilometers), back to where it all began. Link's thrusters will fire to boost Swift slowly, so there's no heavy jostling.

Katalyst threw the mission together in just nine months. NASA insisted on a rush job because the telescope will be too low to recover by the fall. Without a boost, it's predicted to plunge to its demise in October.

Bad weather and technical issues caused a series of last-minute launch delays.

"This is a high-risk, high-reward mission," Katalyst Space CEO Ghonhee Lee said ahead of liftoff. "The biggest danger was always we don't launch anything and we let Swift burn up in the atmosphere. So we were always trying to avoid that risk, and our team has done that."

Source: NASA

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