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Comment by Dr. Krishna Kumari Challa 5 hours ago

In modern animals, larger eggs typically contain more yolk, providing all the nutrients an embryo needs to develop independently, without parental feeding after hatching.

This strongly suggests that Lystrosaurus did not produce milk for its young, unlike modern mammals. Large eggs also offer another crucial advantage: they are more resistant to drying out. In the harsh, drought-prone environment following the extinction, this would have been a critical survival trait.

The findings further suggest that Lystrosaurus hatchlings were likely precocial, born at an advanced stage of development. These young animals would have been capable of feeding themselves, escaping predators, and reaching reproductive maturity quickly.

In other words, Lystrosaurus succeeded by living fast and reproducing early.
In a world on the brink, this strategy proved unstoppable. This discovery not only provides the first direct evidence of egg-laying in mammal ancestors but also offers a powerful explanation for how Lystrosaurus came to dominate post-extinction ecosystems.

PLOS One (2026). DOI: 10.1371/journal.pone.0345016

Part 2

Comment by Dr. Krishna Kumari Challa 5 hours ago

Mammal ancestors laid eggs

A remarkable new discovery is shedding light on one of the greatest survival stories in Earth's history, and answering a decades-old scientific mystery. Lystrosaurus, a hardy, plant-eating mammal ancestor, rose to prominence in the wake of the End-Permian Mass Extinction some 252 million years ago, the most devastating extinction event our planet has ever experienced.

While countless species vanished, Lystrosaurus not only survived but thrived in a world marked by extreme environmental instability, intense heat, and prolonged droughts.

Now, groundbreaking research published in PLOS ONE reveals a discovery that transforms our understanding of this iconic survivor. An international research team has identified, for the first time, an egg containing an embryo of Lystrosaurus, dating back approximately 250 million years.

This extraordinary fossil represents the first-ever egg discovered from a mammal ancestor, finally answering a long-standing question: Did the ancestors of mammals lay eggs?

The answer is yes!

The researchers suggest these eggs were likely soft-shelled, explaining why they have remained elusive for so long. Unlike the hard, mineralized eggs of dinosaurs, which fossilize readily, soft-shelled eggs rarely preserve, making this find exceptionally rare. But the implications go far beyond reproduction.

The study reveals that Lystrosaurus laid relatively large eggs for its body size.

Part 1

Comment by Dr. Krishna Kumari Challa 6 hours ago

"Ghost Murmur"

Comment by Dr. Krishna Kumari Challa yesterday

Can drugs skip the blood-brain barrier?
Researchers have skipped the blood-brain barrier altogether by injecting drug-loaded nanoparticles into the space between skull bone layers. Immune cells then ferried these nanoparticles into the brain. In a randomized study of 20 stroke patients, clinical outcomes were better in the group where treatment was also injected through the skull, compared to the standard of care. The ability to skip the blood-brain barrier in its entirety could be massively useful for treating many brain-based disorders, but there’s a lot more work in store, writes medicinal chemist Derek Lowe.

https://www.sciencedirect.com/science/article/pii/S0092867425014217...

Comment by Dr. Krishna Kumari Challa yesterday

Loss of microbiota alters the profile of cells that protect the intestinal wall, experiments reveal

Research by scientists has made significant progress in understanding the relationship between gut microbiota and intestinal cells. The study, published in the journal Gut Microbes, showed how microbiota and the compounds it produces, such as butyrate, influence the functioning of cells that line the large intestine. This intestinal layer is in close contact with bacteria and produces mucus that contributes to its barrier function, helping to prevent bacteria from entering the body.
Loss of gut microbiota increases the abundance of a dual-function intestinal epithelial cell capable of both mucus secretion and nutrient absorption, a process regulated by microbiota-derived butyrate and its receptor GPR109A. This cell population expands in conditions of dysbiosis or aging, indicating adaptive epithelial plasticity and altered barrier function.
Among the findings is a description of the dual function of a cell that was previously thought to be exclusively mucus-secreting. The researchers discovered that the cell also absorbs nutrients and that its abundance in the epithelium is regulated by signals from the gut microbiota. The number of these cells increases when the gut microbiota is reduced.

The abundance of this cell is regulated by the production of butyrate—a compound resulting from the fermentation of dietary fiber—and its receptor, GPR109A. The more butyrate produced, the fewer of these cells there are.

This study paves the way for a better understanding of the role of microbiota and its metabolites in conditions such as inflammatory bowel disease and in developing treatments. Furthermore, the study demonstrates how the integrity of the intestinal wall can change, particularly in older individuals.
When the microbiota is reduced, the large intestine—which under normal conditions prioritizes mucus production—begins to express characteristics linked to nutrient absorption typically associated with the small intestine. We still don't know why this happens, but this change may be related to the expansion of dual-function cells and represent an adaptive response to the decrease in bacteria in this portion of the intestine, say the researchers.

Matheus de T. Moroti et al, Historical shifts, geographic biases, and biological constraints shape mammal species discovery, Journal of Systematics and Evolution (2026). DOI: 10.1111/jse.70040

Comment by Dr. Krishna Kumari Challa yesterday

City animals act in the same brazen ways around the world

Urban animals worldwide exhibit similar bold, opportunistic behaviours, such as food-stealing and reduced fear of humans, due to shared city environments and selective pressures favouring these traits. This behavioural homogenization is accompanied by a loss of behavioural and genetic diversity, reducing species' resilience to environmental change and complicating conservation efforts. The trend also increases potential for human-wildlife conflict and loss of unique, socially learned behaviours.

original article.

Comment by Dr. Krishna Kumari Challa yesterday

Human-altered mountains drive most fatal landslides worldwide, analysis finds

A new study reveals that most fatal landslides occur in human-transformed environments. Conducted by an international team of researchers, the study provides a global overview of how human pressure modulates landslide occurrences. The paper is published in the journal Science Advances.

The most important finding of the study is that land-use-land-cover change has a substantially greater influence on landslide fatalities than physical factors such as topography and precipitation, especially in low- and lower-middle-income nations.

Landslides are among the most destructive hazards, typically killing over 4,500 people and causing $20 billion in damage annually. The starting point for this research was a critical global question: Why are landslides deadlier in certain regions than others with comparable terrain and climate?

As populations exposed to hazards in mountain areas have doubled since 1975, it's important to understand that human alterations to the land surface—such as clear-cutting, agricultural transition, and road construction—are drastically destabilizing hill slopes. This study highlights how increasing human-made pressure on nature exacerbates the vulnerability of socioeconomically disadvantaged people.

The researchers focused on mountainous landmasses across 46 countries, categorized by national income levels. They addressed a massive dataset comprising approximately 60 years of land-use-land-cover changes and 45 years of population dynamics. The team introduced a new metric, the total land-use-land-cover change, to quantify overall human alterations, integrating this with topography, precipitation, and exposure models.

The findings are striking: While high-income nations altered only 7% of their mountainscapes, low-income countries changed 50% of the mountain land cover of their countries. Such changes could include deforestation, and expansion of farmland and infrastructure.

In countries like Haiti, Sri Lanka, and El Salvador, this land-use-land-cover change correlates with a surge in fatal landslides and death tolls. However, this correlation weakens in wealthy nations such as Switzerland, Japan, and Italy, which experience fewer fatalities despite landslide-prone topography and climates.

Economically disadvantaged countries often also face substantial population pressures, unlike wealthier nations. These pressures lead to the rapid clearing of fragile mountainous areas for farming, informal housing, and basic infrastructure needs, the researchers say.

The authors of the study thus clearly demonstrate that minimal human intervention in land use in mountainous regions reduces the risk of fatal landslides.

Seçkin Fidan, Wealth and land cover change govern landslide fatalities on world's mountains, Science Advances (2026). DOI: 10.1126/sciadv.aec2739. www.science.org/doi/10.1126/sciadv.aec2739

Comment by Dr. Krishna Kumari Challa yesterday

Some common IBS treatments are linked to a higher risk of death, say study

IBS is a chronic gastrointestinal condition.  There is no cure, but dietary modifications, behavioural therapy, and medications can help manage symptoms.

A large, long-term study led by Cedars-Sinai Health Sciences University investigators suggests that some medications commonly prescribed to treat irritable bowel syndrome (IBS)—including antidepressants—may be associated with a small but measurable increase in the risk of death. The findings, published in Communications Medicine, are based on nearly two decades' worth of electronic health records from more than 650,000 U.S. adults with IBS, making it the largest real-world study to examine the long-term safety of IBS treatments.

The study does not establish that these medications directly cause death; rather, the observed associations may reflect higher rates of adverse outcomes, such as cardiovascular events, falls, and stroke, which were more frequent among exposed patients.

Researchers emphasized that while the increase in risk is significant and may sound concerning, the overall risk to any individual patient is small.

"IBS patients should not panic, but they do need to understand and weigh the small but meaningful risks when considering long-term treatments," the researchers  stress.

Association of pharmacotherapy with all-cause mortality among patients with irritable bowel syndrome, Communications Medicine (2026). DOI: 10.1038/s43856-026-01498-6

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Comment by Dr. Krishna Kumari Challa yesterday

The atlas revealed a previously unknown maternal cell type located where fetal placental cells first enter the uterus. These cells appear to regulate how deeply placental cells invade uterine tissue, a process that is essential for establishing blood flow to the fetus.

The researchers found that these cells carry a cannabinoid receptor. Exposure to cannabinoid molecules caused them to further restrict placental cell invasion.

Population studies have linked cannabis use during pregnancy to poorer outcomes. This cell type may help explain the biological basis of that association.
To understand how complications arise, the team integrated genetic data from more than 10,000 patients. They mapped genetic risk signals for conditions including preterm birth, preeclampsia, and miscarriage onto regulatory regions of DNA that control gene activity. This approach allowed the researchers to identify the specific cell types and states most strongly associated with each condition.
The team then focused on preeclampsia, a potentially life-threatening disorder marked by sudden high blood pressure. They found that the most affected cell types are involved in remodeling the mother's uterine blood vessels, a process required to supply adequate blood to the placenta.

The findings suggest that preeclampsia may result from disrupted communication between maternal and fetal cells that normally coordinate this process.

Having established a detailed map of healthy pregnancies, the researchers plan to study complicated pregnancies to identify potential targets for treatment.

Single-cell spatiotemporal dissection of the human maternal–fetal interface, Nature (2026). DOI: 10.1038/s41586-026-10316-x. www.nature.com/articles/s41586-026-10316-x

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Cell-by-cell analysis offers clues to pregnancy risks

The biological connection between a pregnant woman and her developing baby has been mapped in unprecedented detail by  scientists, revealing new cell types and insights into conditions such as preeclampsia, preterm birth, and miscarriage.

Using advanced single-cell and spatial tools, the researchers analyzed about 200,000 individual cells and compared them with nearly 1 million cells in their original positions within the uterine and placental tissue. This enabled them to identify different cell types, track how they develop, and see how they are linked to pregnancy complications.

This work gives us a much clearer picture of this critical region than ever before.

The maternal-fetal interface is a temporary but essential structure composed of uterine and placental cells that forms about a week after fertilization and lasts throughout pregnancy. It supports fetal growth while maintaining the mother's health. Its complexity has long limited scientists' ability to study how healthy pregnancies develop and why complications arise.

By examining this tissue cell by cell across pregnancy, we can begin to understand both normal development and what may go wrong, say the researchers. 

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