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Comment by Dr. Krishna Kumari Challa 13 hours ago

Why Were Dinosaurs So Big?

Metabolic adaptations, air sac-filled bones, and evolutionary pressure likely contributed to dinosaurs’ gigantism.

Scientists have found evidence that the long-necked and long-tailed sauropods had a comparatively slower metabolism relative to today’s large mammals, which indicates that they likely didn’t have to eat as much. (1)

And when sauropods did eat, they likely swallowed most of their food whole: Sauropods’ teeth had very little wear, unlike those of other herbivorous species, such as the duck-billed dinosaurs, and even mammals. (2,3)They could ‘vacuum up’ a lot of food without having to spend a lot of time chewing.

Some sauropod bones were also filled with air sacs, which could make even larger body sizes mechanically feasible.  (4)This adaptive anatomical feature is found in many birds, dinosaurs’ closest living relatives, and it helps reduce their body weight and promote flight.

Sources: 

1. Baumgart SL, et al. The living dinosaur: accomplishments and challenges of reconstructi.... Biol Lett. 2025;21(5):20250126.

2. Whitlock JA. Inferences of diplodocoid (Sauropoda: Dinosauria) feeding behavior .... PLoS One. 2011;6(4):e18304.

3. Fiorillo AR. Dental micro wear patterns of the sauropod dinosaurs camarasaurus a.... Hist Biol. 1998;13(1):1-16.

4. Wedel MJ. Evidence for bird-like air sacs in saurischian dinosaurs. J Exp Zool A Ecol Genet Physiol. 2009;311(8):611-628.

5. https://www.the-scientist.com/why-were-dinosaurs-so-big-73254?utm_c...

Comment by Dr. Krishna Kumari Challa 13 hours ago

Exercise intensity could be impacting your gut

While exercise is great for both your mental and physical health, new research from Edith Cowan University (ECU) has found that exercise intensity could result in changes to the internal gut biome.

Researchers undertook research into the impact of high and low training loads on athletes, in the hope of assisting athletes to improve their overall health, well-being and performance by better understanding the gut microbiome.

It appears that athletes have a different gut microbiota when compared with the general population. This includes greater total short chain fatty acid concentrations, alpha diversity, an increased abundance of some bacteria and a lower abundance of others.

 while the differing microbiome between athletes and the public could likely be due to the differences in their dietary intake , fitness markers, which include oxygen uptake, have also been correlated.

Published in the Journal of the International Society of Sports Nutrition, this research uncovered that training load had an influence on gut health markers in athletes, with differences detected in short-chain fatty acid concentrations and the abundance of specific bacteria.

 One of the potential reasons for the change in the gut could be the higher levels of blood lactate which results from higher intensity training. The lactate produced in muscle is transported to the gut to be metabolized, which could potentially result in increased bacteria in the gut.

The changes found in the gut biome when comparing high training loads to low training loads, were also related to diet.

Another observation made during the research was the significant slowing of gut transit times in athletes during low training loads. That slowing of transit time during the low training load appears to also be impacting the gut microbiome for an athlete.

The gut may play a role in lactate metabolism and regulating pH levels, both of which could impact performance and overall athlete health, say the researchers. 

B. Charlesson et al, Training load influences gut microbiome of highly trained rowing athletes, Journal of the International Society of Sports Nutrition (2025). DOI: 10.1080/15502783.2025.2507952

Comment by Dr. Krishna Kumari Challa 13 hours ago

Positive emotional bias could be an early sign of cognitive decline in aging populations

As people age, they display a bias in recognizing emotions as positive—to the point of improperly labeling neutral or negative emotions as positive.

Some researchers theorize this bias is an adaptive mechanism to support mental and emotional wellness, but new evidence suggests it may be a sign of cognitive decline.

In a JNeurosci paper, researchers advance understanding of what this positive emotional bias that elders exhibit signifies about their brains' health.

A large pool of participants (665) viewed faces in an emotion recognition task. Age-related positivity bias correlated with poorer cognitive performance in two assessments, but not necessarily emotional decline as measured by examining nonclinical depressive symptoms.

The researchers also observed structural changes in brain areas associated with emotional processing and changes in how these areas communicate to another brain region involved in social decisions. Thus, positivity bias from aging impacts the brain in observable ways that could be leveraged clinically to detect early rising signs of age-related neurodegeneration and cognitive decline.

Researchers are now  exploring how these findings relate to older adults with early cognitive decline, particularly those showing signs of apathy, which is often another early sign of dementia.

 Age-Related Positivity Bias in Emotion Recognition is Linked to Lower Cognitive Performance and Altered Amygdala–Orbitofrontal Connectivity, JNeurosci (2025). DOI: 10.1523/JNEUROSCI.0386-25.2025

Comment by Dr. Krishna Kumari Challa on Tuesday

Kidney fibrosis linked to molecule made by gut bacteria

A molecule made by bacteria in the gut can hitch a ride to the kidneys, where it sets off a chain reaction of inflammation, scarring and fibrosis—a serious complication of diabetes and a leading cause of kidney failure—according to a new study from researchers .

After finding high levels of corisin—a small peptide produced by Staphylococcus bacteria in the gut—in the blood of patients with diabetic kidney fibrosis, the researchers used computer simulations and tissue and mouse experiments to track how corisin affects the kidneys, how it gets there from the gut, and a possible method of countering it with antibody treatment.

These  new findings suggest corisin is indeed a hidden culprit behind progressive kidney damage in diabetes, and that blocking it could offer a new way to protect kidney health in patients.

Taro Yasuma et al, Microbiota-derived corisin accelerates kidney fibrosis by promoting cellular aging, Nature Communications (2025). DOI: 10.1038/s41467-025-61847-2

Comment by Dr. Krishna Kumari Challa on Tuesday

Cells from the spleen found to play a surprising role after heart attack

After a person survives a heart attack, the heart has a brief window of time in which it can heal if the right circumstances exist. But most of the time, scar tissue forms in the areas that lacked oxygen during the heart attack. This scar tissue impairs heart function, which can worsen into heart failure, reducing quality of life and increasing the risk of early death.

A new study has identified a surprising role for the spleen—a small organ near the ribs that filters blood and fights infections—in helping the heart heal after a heart attack.

The research, published in Circulation, demonstrated in mice that specific immune cells called marginal metallophilic macrophages, which originate in the spleen, travel from the spleen to the heart and support a healing response after a heart attack.

Using mouse models, single-cell RNA sequencing and other advanced techniques, the researchers established that these specialized macrophages from the spleen help clear damaging immune cells, suppress inflammation and activate genes that help repair the injured cardiac tissue following a heart attack.

To assess whether the same thing occurs in humans, the researchers measured levels of marginal metallophilic macrophages in blood samples collected from people upon their hospital admission due to a heart attack. The researchers compared these levels with those of cardiac patients who had coronary artery disease but had not recently had a heart attack. The researchers  found that levels of the specialized macrophages were higher in patients who had just had a heart attack.

The researchers also demonstrated that they could boost the numbers of these specialized immune cells in mice with an experimental drug, and that doing so improved the healing and anti-inflammatory effects. This medical intervention is not yet in clinical trials, but it suggests a possible future cardiac immunotherapy targeting the spleen to prevent heart failure in patients who survive a heart attack.

 Mohamed Ameen Ismahil et al, Splenic CD169⁺Tim4⁺ Marginal Metallophilic Macrophages Are Essential for Wound Healing After Myocardial Infarction, Circulation (2025). DOI: 10.1161/CIRCULATIONAHA.124.071772

Comment by Dr. Krishna Kumari Challa on Tuesday

This human type, which the researchers called "Nesher Ramla Homo" (after the archaeological site near the Nesher Ramla factory where it was found), encountered Homo sapiens groups that began leaving Africa about 200,000 years ago, and according to the current study's findings, interbred with them.

The child from the Skhul Cave is the earliest fossil evidence in the world of the social and biological ties forged between these two populations over thousands of years. The local Neanderthals eventually disappeared when they were absorbed into the Homo sapiens population, much like the later European Neanderthals.

The researchers reached these conclusions after conducting a series of advanced tests on the fossil.
The fossil they studied is the earliest known physical evidence of mating between Neanderthals and Homo sapiens.
The current study reveals that at least some of the fossils from the Skhul Cave are the result of continuous genetic infiltration from the local—and older—Neanderthal population into the Homo sapiens population.

Bastien Bouvier et al, A new analysis of the neurocranium and mandible of the Skhūl I child: Taxonomic conclusions and cultural implications, L'Anthropologie (2025). DOI: 10.1016/j.anthro.2025.103385

Part 2

Comment by Dr. Krishna Kumari Challa on Tuesday

Earliest evidence discovered of interbreeding between Homo sapiens and Neanderthals

An international study by researchers provides the first scientific evidence that Neanderthals and Homo sapiens had biological and social relations, and even interbred for the first time, in the Land of Israel.

The research team found a combination of Neanderthal and Homo sapiens traits in the skeleton of a five-year-old child discovered about 90 years ago in the Skhul Cave on Mount Carmel. The fossil, estimated to be about 140,000 years old, is the earliest human fossil in the world to display morphological features of both of these human groups, which until recently were considered two separate species.

Genetic studies over the past decade have shown that these two groups exchanged genes.

Even today, 40,000 years after the last Neanderthals disappeared, part of our genome—2% to 6%—is of Neanderthal origin. But these gene exchanges took place much later, between 60,000 to 40,000 years ago.

In the new study, the researchers were dealing with a human fossil that is 140,000 years old. They  show that the child's skull, which in its overall shape resembles that of Homo sapiens—especially in the curvature of the skull vault—has an intracranial blood supply system, a lower jaw, and an inner ear structure typical of Neanderthals.

For years, Neanderthals were thought to be a group that evolved in Europe, migrating to the Land of Israel only about 70,000 years ago, following the advance of European glaciers.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

Scientists discover rare freshened water beneath the seafloor

How did freshened water end up beneath the New England Shelf miles offshore?

Researchers are attempting to answer the question by studying samples collected from three sites off the coast of Nantucket. Sampling of this offshore freshened groundwater to the extent that they can make comprehensive geochemical assessments of its history, including its age, is unprecedented in scientific ocean drilling.

The salinity levels of sediments below the seafloor are typically close to those in the overlying ocean, yet offshore New England, the subseafloor contains an unusually large reservoir of freshened water.

The sheer freshness of the water, which was close to drinking water limits, was a surprise.

The cores will be archived and made accessible for further scientific research for the scientific community after a one-year moratorium period. All expedition data will be open access and resulting outcomes will be published.

https://www.uri.edu/news/2025/05/gso-professor-joins-expedition-to-...

Comment by Dr. Krishna Kumari Challa on Saturday

Scientists Have Just Created The Most Synthetic Life Form Ever

Scientists have created a bacteria with a genetic code more streamlined – and more meddled with – than any other life on Earth. This bacteria, a synthetic Escherichia coli called Syn57, has been engineered to build its body using just 57 of the 64 'codons' that have served all known organisms for billions of years. The recipe for life is written in a language that uses 64 different codons, each composed of a triplet of nucleotides. It's the long sentences of 'three-letter' codons that make up our DNA and RNA. They provide our cells with the essential instructions to translate ordinary matter into the building blocks of life, amino acids, which are threaded in sequence to form proteins. When a cell is building proteins, it 'reads' the codon sequence, written using those 64 nucleotide triplets, to know which amino acids to add next, and when to stop.By engineering the entire genome from scratch, the researchers set out to eliminate four of the six codons associated with the amino acid serine, two of the four alanine codons, and one 'stop' codon. Where these redundant codons appeared in the bacteria's genome, the researchers substituted them with synonymous codons that give the same instructions. This required more than 101,000 changes to the genetic code. These were planned out on the computer first, in 100-kilobyte fragments, and then came the arduous work of assembling the gene. To make sure they weren't inserting fundamentally harmful changes into the microbes, the team tested small fragments of the synthetic genome in living bacteria bit by bit, eventually stitching it all together to form the final, entirely synthetic strain.

https://www.science.org/doi/10.1126/science.ady4368

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Comment by Dr. Krishna Kumari Challa on Saturday

Croatian Freediver Shatters Record For Longest-Held Breath
This year, on June 14, Croatian freediver Vitomir Maričić set a world record when he held his breath for 29 minutes and 3 seconds.

That’s longer than a bottlenose dolphin, and 5 minutes longer than the previous Guinness World Record holder.
Nearly half an hour without air is mind boggling. That's roughly twice as long as a bottlenose dolphin is thought to hold its breath.
With each breath, a seal can replace 90 percent of the air in its lungs – but our species can only replace 20 percent. To keep up, we need more breaths to fill our lungs with fresh air.

To get as much oxygen into his body as it could possibly carry, Maričić inhaled pure oxygen for 10 minutes before the attempt.
This increased the oxygen dissolved in his blood plasma, which is a crucial reservoir for the body's tissues.

On an Instagram reel, Maričić explains that he started his record-breaking attempt with nearly five times more oxygen in his body than usual. Without that, he never could have lasted so long.

https://www.sciencealert.com/croatian-freediver-shatters-record-for...

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