Comment

Comment by Dr. Krishna Kumari Challa on Thursday

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 on Thursday

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 on Thursday

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 on Thursday

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 on Thursday

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. 

Part 1

Comment by Dr. Krishna Kumari Challa on Thursday

AI uncovers hidden immune defenses inside bacteria

Researchers have discovered thousands of new proteins that protect bacteria from virus attacks using an AI system called DefensePredictor. What would usually take months of lab work can now be narrowed down to promising candidates in minutes.

Bacteria are under constant attack from viruses called bacteriophages. One of their most powerful defenses is CRISPR-Cas, a system that cuts up viral DNA to stop an infection and is now a valuable biotechnology tool for precisely editing genes in a lab.

Traditional methods of finding these defenses are long and laborious, equivalent to looking for a needle in a haystack. They involve searching for nearby known defensive genes and manually testing thousands of DNA fragments. But now, AI can take the strain.

To develop their machine learning tool, the scientists trained it on 17,000 different bacterial genomes, as they describe in a paper published in the journal Science. Because genes contain instructions for making proteins, the system identifies the proteins encoded in each genome and analyzes them using a protein language model called ESM2. It can distinguish between a normal protein and a defensive one by examining specific characteristics, such as gene length, nearby genes and patterns in the DNA sequences surrounding each gene.

To further refine DefensePredictor, the team trained it on 15,000 proteins already known to fight viruses and 186,000 normal proteins that perform everyday tasks. By comparing these two groups, the AI learned to rapidly distinguish defensive proteins from non-defensive ones.

Next came the system's big test. DefensePredictor scanned 69 diverse E. coli strains and identified 624 protein clusters as defensive. This included more than 100 that had no previously known connection to bacterial immune systems. The researchers then cloned 94 of these predicted systems into E. coli cells and exposed them to 24 different phages. Nearly 45% protected the bacteria from infection.

The results demonstrate that DefensePredictor is a powerful tool for discovering new prokaryotic immune systems

The researchers have released DefensePredictor as a resource for the global scientific community and will continue to refine it as new data arrives.

Peter C. DeWeirdt et al, DefensePredictor: A machine learning model to discover prokaryotic immune systems, Science (2026). DOI: 10.1126/science.adv7924

Comment by Dr. Krishna Kumari Challa on April 8, 2026 at 1:06pm

In the 19th century—after colonialism spread the disease—rinderpest culled about 90% of plow oxen in Ethiopia. Rinderpest itself has no effect on human health, but the resulting famine killed one-third of Ethiopia's population.
"Without cattle to plow fields and fertilize crops with dung, the once-fertile Ethiopian lands became a graveyard
Attempts to develop a vaccine, which began as early as the 18th century, provided some protection, but not a full cure. It wasn't until the middle of the 20th century that the first effective vaccines were introduced. Shortly after, the U.N. Food and Agriculture Organization began a worldwide campaign to inoculate animals, shipping vaccines and brokering meetings between countries to discuss collaborative vaccination campaigns.

Soon, the number of global rinderpest infections fell precipitously, but occasional outbreaks continued.
Complete eradication remained out of reach until a technological breakthrough—along with what Mariner and other researchers have called "social innovations"—made it possible.

Most vaccines require refrigeration, and the rinderpest vaccine was no exception. But in many places where the disease was common—rural areas with cattle ranching—refrigerated shipping was expensive and complex.

It was extremely challenging to keep the vaccine cold while traveling to isolated areas then.
It required refrigeration facilities, ice machines, cold boxes, and fleets of vehicles. They needed an easier way to deliver the vaccine.
In the 1980s, researchers earned grant funding to experiment with ways to make a vaccine that did not require refrigeration. His team worked for two years and eventually developed a method to freeze-dry the vaccine. As a result, it could stay effective at temperatures as high as 98 degrees Fahrenheit and could last 30 days without refrigeration.

That innovation made it possible to deliver vaccines to a wider array of far-flung places, but it didn't necessarily make it easier.
So, the scientists engaged in a more targeted and strategic approach and went directly to those remote areas. Researchers helped train people in these communities to provide the vaccine and relied on their knowledge to decide how and when to distribute it. These efforts increased vaccination in herds that had been missed during previous campaigns. Locals then monitored for signs of disease after vaccination occurred.
The successful eradication, then, relied on both science and collaboration, and a tool called participatory epidemiology, which incorporates both researchers and stakeholders.

The elimination of rinderpest has had an enormous impact on the lives of people and their animals.

https://now.tufts.edu/2019/07/18/world-without-rinderpest

Part 2

Comment by Dr. Krishna Kumari Challa on April 8, 2026 at 1:06pm

15 years after the eradication of rinderpest, lessons still ring true

Permanently wiping out a disease is tricky business. Polio, measles, mumps—all have effective vaccines, yet they persist in certain pockets around the world. To date, the World Health Organization considers just two viruses as successfully eradicated: smallpox and rinderpest.

Rinderpest, a highly contagious cattle disease, was officially eradicated in 2011, marking it as one of only two viruses eliminated globally. Success was achieved through a combination of technological advances, such as a heat-stable vaccine, and community-based strategies, including participatory epidemiology and targeted vaccination in remote areas. These approaches remain vital for controlling current and future animal diseases.
Rinderpest, a German word meaning "cattle plague," can be traced back as early as the Roman Empire. In the centuries when the virus was active, it ran through herds from Europe into Asia and Africa. When the disease struck, it often killed the entire herd.

The disease was so economically devastating that it's recognized as the cause of several historic famines. In the 18th century, rinderpest killed 200 million cows in Europe.

Part 1

Comment by Dr. Krishna Kumari Challa on April 8, 2026 at 12:51pm

How microbes survive in the plastisphere
Microbes inhabiting the plastisphere—biofilms on ocean plastic—possess larger genomes with more functional gene copies than marine plankton, enabling enhanced nutrient uptake, carbon utilization, UV protection, and alternative energy use. These adaptations support survival in nutrient-poor, high-UV environments and may create eutrophic niches, potentially impacting ocean ecosystem health.

Stefan Lips et al, Metagenomic analyses of the plastisphere reveals a common functional potential across oceans, Environmental Pollution (2026). DOI: 10.1016/j.envpol.2026.127830

Comment by Dr. Krishna Kumari Challa on April 8, 2026 at 12:48pm

Virus from seafood is linked to a persistent eye disease in humans
A virus that typically infects marine animals, such as shrimp and fish, has jumped to humans and is causing chronic eye disease in some people, according to a study published in the journal Nature Microbiology. In recent years, the number of people in China with a condition called persistent ocular hypertension viral anterior uveitis (POH-VAU) has been increasing with no clear explanation as to why. Symptoms include extremely elevated eye pressure and inflammation.
Researchers suspected that covert mortality nodavirus (CMNV) might be the cause since patients with the condition consistently tested negative for common eye viruses such as herpes or shingles. And earlier investigations had identified unknown virus particles in the eye tissue of a few patients that looked similar in shape and size to CMNV.

To investigate further, scientists in China recruited 70 people diagnosed with the condition between January 2022 and April 2025.

The team examined patient tissue removed during eye surgery with electron microscopes and saw similar virus particles about 25 nanometers in size. No CMNV-like particles were found in the control group of healthy volunteers. To confirm the virus's identity, they used a special gold-labeled antibody that only binds to CMNV. Sequencing its genetic material revealed a 98.96% match to the version found in aquatic animals.

"This study reveals that an aquatic animal virus is associated with an emerging human disease," wrote the scientists in their paper.
The researchers interviewed the patients about their lives, and nearly three-quarters were either handling raw seafood without gloves or were eating raw aquatic animals. "Frequent unprotected processing of aquatic animals and consumption of raw aquatic animals were commonly reported exposure events," added the team.

To confirm that the virus was actually causing the disease rather than merely being present, the team conducted cell culture studies and infected mice with the virus. These rodents developed the characteristic symptoms of the condition seen in human patients, such as elevated intraocular pressure.
This is the first study to show that a virus originating from aquatic animals can be associated with a specific eye disease in humans. And it may not just be a problem in China.

As part of their study, the researchers conducted a global survey to see how far the viruses had spread. CMNV was found in 49 species, including crabs and mollusks, across Asia, Africa, Europe, Antarctica and the Americas.

Shuang Liu et al, An emerging human eye disease is associated with aquatic virus zoonotic infection, Nature Microbiology (2026). DOI: 10.1038/s41564-026-02266-x

Fabian H. Leendertz et al, Aquatic virus transmission to humans, Nature Microbiology (2026). DOI: 10.1038/s41564-026-02306-6

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