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Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 11:49am

Over the course of three decades, about one in four people in the surveillance program suffered episodes of heart failure. The risk was more than twice as likely among patients who at some point had been hospitalized for infections, according to the latest study, published  in the Journal of the American Heart Association.

Risks were highest following bloodstream and respiratory infections, but were also significant for skin and urinary tract infections. Digestive infections were only weakly correlated with heart failure later in life.

Risks were highest following bloodstream and respiratory infections, but were also significant for skin and urinary tract infections. Digestive infections were only weakly correlated with heart failure later in life.

Heart failure can lead to cardiac arrest or damage the kidney and liver. Treatments range from medications to increase blood flow to surgeries to implant pacemakers or remove obstructions in blood vessels.

Establishing a precise cause-and-effect relationship between infections and heart failure will be difficult, because researchers can't deny preventive care to patients just to see if it increases their risks.

Rebecca L. Molinsky et al, Infection‐Related Hospitalization and Incident Heart Failure: The Atherosclerosis Risk in Communities Study, Journal of the American Heart Association (2025). DOI: 10.1161/JAHA.123.033877

Part 2

Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 11:47am

Study uncovers new link between infections and heart failure

People hospitalized for infections—almost any infections—are at substantially increased risk years later for heart failure, according to a collaborative research.

The study of more than 14,000 people over two decades doesn't establish cause and effect, but advocates said this week that it establishes a strong enough correlation that people should take heed and try to reduce their infection risks.

Heart failure, which affects millions around the world, is a weakening of the heart that prevents it from pumping sufficient blood and oxygen. Researchers were surprised to find that hospitalizations resulting from common skin and urinary tract infections increased heart failure risks, alongside respiratory infections such as influenza and blood infections such as sepsis.

That suggests that the body's response to infection is a big part of the heart failure risk, say the researchers.

There's some notion that really severe infections sort of turn on the immune system in a way where it just doesn't quite turn off, and it stays revved up, possibly for many years. 

Other possibilities include that serious infections cause genetic or biological changes that lay dormant after hospitalization but emerge later in life to cause heart failure.

Other studies have found hospitalizations increase risks of health problems later in life, so it's possible infections are driving people to as-yet unknown risks from those hospital visits, they stress.

Even without cause and effect being established, they say the results should encourage people to prevent infections through vaccines and good hygiene. People who have already been hospitalized because of infections can talk with their doctors about ways to reduce cardiac risks.

They had already discovered in 2023 that infection-related hospitalizations increased the risk for dementia later in life.

Part 1

Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 11:24am

There are many news stories about dogs attacking people badly and often there are specific breeds that are targets of this reporting (such as pit bulls). Some people claim that these dogs will bite harder than other dogs of the same size, or they have special features like 'locking jaws' that make them especially dangerous to people. This study shows that this is simply not true; dogs bred to bite things aren't structurally different than dogs that have been bred to do other things.
Similarly, breeds selected for scent work did not demonstrate significantly enhanced olfactory morphology compared to other breeds. The lone group that showed distinct skull morphology was brachycephalic breeds (e.g., bulldogs), which are characterized by their shortened snouts, but this feature is not tied to functional specialization. Instead, human aesthetic preferences have played a larger role in shaping dog morphology.
Humans have done so much breeding work to alter the visual appearance of these animals that the researchers honestly expected to see really marked groupings of some kind but they really didn't see much of that.
However, researchers found that domesticated dog breeds' morphologies differed greatly from wild canids, such as wolves and foxes, which tend to have skull shapes that align more closely with their natural functional needs. Wolves and foxes tend to possess elongated snouts relative to their cranial length, which is a typical feature of species that rely on keen senses like smell.

Undomesticated animals, particularly wolves, show skull morphologies that reflect evolutionary adaptations for hunting and scent work, which contrasts with the lack of strong morphological specialization in domesticated breeds.

Interestingly, foxes' skull shapes overlap significantly with some domestic dogs, particularly terrier breeds, which were historically bred for pest control, suggesting functional similarities in skull structure for small prey pursuit.

While these results run counter to the popular notion that purpose-bred dogs are better at biting or scenting than those not bred for that purpose, they suggest that observable behavior traits are associated with performance, rather than morphological traits.
Recent research suggests that many breed-associated behaviors are partially heritable. This has important implications for how dogs are bred and selected for specific tasks in areas such as law enforcement and search and rescue—behavioral traits and individual trainability may be more important determinants of performance.

Nicholas Hebdon et al, Dog skull shape challenges assumptions of performance specialization from selective breeding, Science Advances (2025). DOI: 10.1126/sciadv.adq9590

Part 2

Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 11:15am

Myth busting: Purpose-bred dogs are not better at biting or scenting than those not bred for that purpose

Since their domestication millennia ago, dogs have been man's best friend, and aside from friendship, centuries of selective breeding have tailored them for tasks like herding, hunting and guarding—or so we thought.

Now, the results of a new study challenge the prevailing belief that some breeds are inherently superior at specific tasks, based on their skull morphology.

The study published in Science Advances on January 29, used advanced 3D reconstruction techniques to analyze 117 skulls from 40 domestic dog breeds and 18 wild canid species.

The researchers found substantial overlap in skull shapes across breeds and functional categories, but no clear evidence that breeds selected for bite work or scent work have developed distinct morphological traits that enhance these abilities. This suggests that humans have been breeding dogs primarily for preferred visible traits, and that other factors like individual personality affect dogs' performance of tasks.

In the past 200 years, humans have created hundreds of dog breeds that look really different and are pretty specialized at some tasks like herding, protecting, and detecting odors. We have assumed that these dogs look different because they are 'structurally' specialized at these tasks, but this new study shows that, at least for their skulls, they 'are not' specialized for tasks that involve the skull, such as biting tasks and scent work.

The study examined dog breeds commonly used for tasks like bite work and scent work, such as those in law enforcement and military programs, where dogs are trained for patrol and detection. Researchers used advanced methods, including 3D skull analysis, to compare breeds across various functional groups.

The results showed that domesticated dog breeds exhibit exceptional diversity in their skull shapes, but have high overlap among the parts of the skulls that correspond with functional tasks.

This indicates that specific breeds are not as morphologically specialized for such tasks as previously thought. For instance, bite-force measurements did not show any significant differences between breeds purpose-bred for bite work and those not.

Part 1

Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 11:04am

BioSonics spectroscopy can 'listen' to the sounds made by individual viruses

A team of chemists and microbiologists has found that an all-optical method can be used to detect natural vibrational frequencies made by individual viruses as a way to identify them. In their study published in Proceedings of the National Academy of Sciences, the group found a way to bounce light off viruses and detect the resulting patterns of vibrations, which could be easily identified.

Light can be used to identify nanoparticle-scale objects. Prior research has shown that firing beams of light at such objects can cause them to vibrate slightly. The vibration patterns that emerge are unique for different targets. Thus, the technique can be used to identify nanoscale objects even among other similarly scaled objects.

The researchers wondered if the same technique could be used with biological agents like viruses and bacteria, so they conducted experiments that involved firing extremely tiny amounts of light at both kinds of microorganisms at such a small scale that they were able to watch the impact of single photons.

Eventually, they shifted their focus to viruses only and found that with the appropriate parameter settings, they could detect the vibrations emitted by the virus using a technique that they call BioSonics spectroscopy. The sound was not just too faint to hear with the human ear, but too high, at a frequency 1 million times higher than humans can hear.

After testing multiple viruses, the research team found that each of them vibrated in their own unique ways, distinct from one another and from all the other molecules they tested. That meant that BioSonics could be used as a sensor of sorts, enabling devices that could, for example, scan a room, detect viruses in the air and identify them.

They also note that the technology could reveal individual virus activity, opening the door to better understanding them. It could be used, for example, to watch as individual viruses assemble themselves, a phenomenon that is still not well understood.

Yaqing Zhang et al, Nanoscopic acoustic vibrational dynamics of a single virus captured by ultrafast spectroscopy, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2420428122

Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 9:52am

Gut microbes may mediate the link between drinking sugary beverages and diabetes risk

It is well known that consuming sugary drinks increases the risk of diabetes, but the mechanism behind this relationship is unclear. Now, in a paper appearing in Cell Metabolism, researchers show that metabolites produced by gut microbes might play a role.

In a long-term cohort of US Hispanic/Latino adults, the researchers identified differences in the gut microbiota and blood metabolites of individuals with a high intake of sugar-sweetened beverages. The altered metabolite profile seen in sugary beverage drinkers was associated with a higher risk of developing diabetes in the subsequent 10 years. Since some of these metabolites are produced by gut microbes, this suggests that the microbiome might mediate the association between sugary beverages and diabetes.

This study suggests a potential mechanism to explain why sugar-sweetened beverages are bad for your metabolism. 

Previous studies in Europe and China have shown that sugar-sweetened beverages alter gut microbiome composition, but this is the first study to investigate whether this microbial change impacts host metabolism and diabetes risk.

The researchers found that high sugary beverage intake—defined as two or more sugary beverages per day—was associated with changes in the abundance of nine species of bacteria. Four of these species are known to produce short-chain fatty acids—molecules that are produced when bacteria digest fiber and that are known to positively impact glucose metabolism. In general, bacterial species that were positively associated with sugary beverage intake correlated with worse metabolic traits. Interestingly, these bacteria were not associated with sugar ingested from non-beverage sources. 

The researchers also found associations between sugary beverage consumption and 56 serum metabolites, including several metabolites that are produced by gut microbiota or are derivatives of gut-microbiota-produced metabolites.

These sugar-associated metabolites were associated with worse metabolic traits, including higher levels of fasting blood glucose and insulin, higher BMIs and waist-to-hip ratios, and lower levels of high-density lipoprotein cholesterol ("good" cholesterol). Notably, individuals with higher levels of these metabolites had a higher likelihood of developing diabetes in the 10 years following their initial visit.

They found that several microbiota-related metabolites are associated with the risk of diabetes. In other words, these metabolites may predict future diabetes.

These results have to be validated in other populations too for a final conclusion. 

 Sugar-sweetened beverage intake, gut microbiota, circulating metabolites, and diabetes risk in Hispanic Community Health Study/Study of Latinos, Cell Metabolism (2025). DOI: 10.1016/j.cmet.2024.12.004. www.cell.com/cell-metabolism/f … 1550-4131(24)00486-8

Comment by Dr. Krishna Kumari Challa on February 1, 2025 at 8:42am

Ear muscle we thought humans didn't use—except for wiggling our ears—activates during focused listening

If you can wiggle your ears, you can use muscles that helped our distant ancestors listen closely. These auricular muscles helped change the shape of the pinna, or the shell of the ear, funneling sound to the eardrums.

There are three large muscles which connect the auricle to the skull and scalp and are important for ear wiggling. These muscles, particularly the superior auricular muscle, exhibit increased activity during effortful listening tasks. This suggests that these muscles are engaged not merely as a reflex but potentially as part of an attentional effort mechanism, especially in challenging auditory environments.

It's difficult to test how hard someone is listening without self-reported measures. But electromyography, which measures electrical activity in a muscle, can help identify activity in the auricular muscles linked to listening closely.

Similar research has already shown that the largest muscles, posterior and superior auricular muscles, react during attentive listening. Because they pull the ears up and back, they are considered likely to have been involved in moving the pinna to capture sounds.

The exact reason these became vestigial is difficult to tell, as our ancestors lost this ability about 25 million years ago. One possible explanation could be that the evolutionary pressure to move the ears ceased because we became much more proficient with our visual and vocal systems.

Scientists now found that the two auricular muscles reacted differently to the different conditions. The posterior auricular muscles reacted to changes in direction, while the superior auricular muscles reacted to the difficulty level of the task.

Electromyographic Correlates of Effortful Listening in the Vestigial Auriculomotor System, Frontiers in Neuroscience (2025). DOI: 10.3389/fnins.2024.1462507

Comment by Dr. Krishna Kumari Challa on January 31, 2025 at 3:16pm

Asteroid find upends story of life’s origin
Fragments collected from the asteroid Bennu contain the building blocks for life — all five nucleobases that form DNA and RNA and 14 of the 20 amino acids needed to make known proteins. But there’s a twist: on Earth, amino acids in living organisms tend to have a ‘left-handed’ structure. Those on Bennu, however, contain nearly equal amounts of these structures and their ‘right-handed’, mirror-image forms. This calls into question a hypothesis favoured by many scientists that asteroids similar to this one might have seeded life on Earth.

https://www.nature.com/articles/s41550-024-02472-9?utm_source=Live+...

https://www.nature.com/articles/d41586-025-00264-3?utm_source=Live+...

Comment by Dr. Krishna Kumari Challa on January 31, 2025 at 2:40pm

Amniotic fluid's protective properties: Study uncovers its role in blood clotting

Researchers have made new discoveries about amniotic fluid, a substance historically not well understood in medical research due to the difficulty in obtaining it during pregnancy, especially across gestation.

Amniotic fluid is the vital fluid that surrounds and protects a fetus during pregnancy. In addition to providing much-needed cushion and protection for the fetus, it also aids in development of vital organs—especially the lungs, digestive tract and skin—and stabilizes the temperature inside the womb.

The new study, published in the journal Research and Practice in Thrombosis and Haemostasis, found that the addition of amniotic fluid to plasma—the liquid portion of blood—improves the blood's ability to thicken and clot, which is a critical and likely a protective function throughout pregnancy and during delivery for both the birthing parent and the baby.

Researchers analyzed the properties of amniotic fluid obtained by amniocentesis, a prenatal test that involves sampling a small amount of amniotic fluid to examine the health of the pregnancy, from both human and non-human primates at gestational-age matched timepoints. The findings showed that amniotic fluid increases blood clotting through key fatty acids and proteins that change each trimester and help regulate coagulation.

 Chih Jen Yang et al, Characterization of the procoagulant phenotype of amniotic fluid across gestation in rhesus macaques and humans, Research and Practice in Thrombosis and Haemostasis (2025). DOI: 10.1016/j.rpth.2024.102676

Comment by Dr. Krishna Kumari Challa on January 31, 2025 at 2:31pm

 India doubled its tiger population in a decade and credits conservation efforts

India doubled its tiger population in a little over a decade by protecting the big cats from poaching and habitat loss, ensuring they have enough prey, reducing human-wildlife conflict, and increasing communities' living standards near tiger areas, a study published this week found.

The number of tigers grew from an estimated 1,706 tigers in 2010 to around 3,682 in 2022, according to estimates by the National Tiger Conservation Authority, making India home to roughly 75% of the global tiger population. The study found that some local communities near tiger habitats have also benefited from the increase in tigers because of the foot traffic and revenues brought in by ecotourism.

The study in the journal Science says India's success "offers important lessons for tiger-range countries" that conservation efforts can benefit both biodiversity and nearby communities.

Wildlife conservationists and ecologists welcomed the study but said that tigers and other wildlife in India would benefit if source data were made available to a larger group of scientists. The study was based on data collected by Indian government-supported institutions.

Also there are several species, including the great Indian bustard and caracal which are all on the edge. "And there is really not enough focus on that."

 Yadvendradev V. Jhala et al, Tiger recovery amid people and poverty, Science (2025). DOI: 10.1126/science.adk4827

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