Comment

Comment by Dr. Krishna Kumari Challa on September 25, 2025 at 12:02pm

AI-generated voices now indistinguishable from real human voices

Many people still think of AI-generated speech as sounding "fake" or unconvincing and easily told apart from human voices. But new research shows that AI voice technology has now reached a stage where it can create "voice clones" or deepfakes which sound just as realistic as human recordings.

The study compared real human voices with two different types of synthetic voices, generated using state-of-the-art AI voice synthesis tools. Some were "cloned" from voice recordings of real humans, intended to mimic them, and others were generated from a large voice model and did not have a specific human counterpart.

Participants were asked to evaluate which voices sounded most realistic, and which sounded most dominant or trustworthy. Researchers also looked at whether AI-generated voices had become "hyperreal," given that some studies have shown that AI-generated images of faces are now judged to be human more often than images of real human faces.

While the study did not find a "hyperrealism effect" from the AI voices, it did find that voice clones can sound as real as human voices, making it difficult for listeners to distinguish between them. Both types of AI-generated voices were evaluated as more dominant than human voices, and some were also perceived as more trustworthy.

Voice clones sound realistic but not (yet) hyperrealistic, PLOS One (2025). DOI: 10.1371/journal.pone/0332692

Comment by Dr. Krishna Kumari Challa on September 25, 2025 at 11:17am

Only then does the process lurch back into motion: The egg cell finally divides, and the chromosome pairs that were connected by crossovers are finally separated to deliver a single set of chromosomes to the mature egg. Maintaining the crossover connections over many years is a major challenge for immature egg cells.
If chromosome pairs aren't connected by at least one crossover, they can lose contact with each other, like two people separated in a jostling crowd. This causes them to segregate incorrectly when the cell finally divides, producing egg cells with extra or missing chromosomes. This can cause infertility, miscarriage or genetic conditions such as Down syndrome, in which a child is born with an extra copy of chromosome 21, leading to cognitive impairment, heart defects, hearing loss and other problems.
Researchers have identified dozens of proteins that bind and process these junctions. They used a technique called "real-time genetics" to investigate the function of those proteins.
With this method, they made cells degrade one or more specific proteins within the junction-associated structures. They could then analyze the DNA from these cells, to see whether the junctions were resolved and if they formed crossovers. In this way, they built up a picture in which a network of proteins function together to ensure that crossovers are formed.
They identified key proteins such as cohesin that prevent an enzyme called the STR complex (or Bloom complex in humans) from inappropriately dismantling the junctions before they can form crossovers.

They protect the double Holliday junction. That is a key discovery.
Failure to protect double-Holliday junctions may be linked to fertility problems in humans.

Shangming Tang et al, Protecting double Holliday junctions ensures crossing over during meiosis, Nature (2025). DOI: 10.1038/s41586-025-09555-1

Part 2

Comment by Dr. Krishna Kumari Challa on September 25, 2025 at 11:14am

Molecular discovery reveals how chromosomes are passed from one generation to the next

When a woman becomes pregnant, the outcome of that pregnancy depends on many things—including a crucial event that happened while she was still growing inside her own mother's womb. It depends on the quality of the egg cells that were already forming inside her fetal ovaries. The DNA-containing chromosomes in those cells must be cut, spliced and sorted perfectly. In males, the same process produces sperm in the testes but occurs only after puberty.

If that goes wrong, then you end up with the wrong number of chromosomes in the eggs or sperm. This can result in infertility, miscarriage or the birth of children with genetic diseases.

In a paper published Sept. 24 in the journal Nature,  researchers report a major new discovery about a process that helps safeguard against these mistakes. They have pieced together the choreography of proteins that connect matching chromosome pairs—ensuring that they are sorted correctly as egg and sperm cells develop and divide.

These discoveries required methods to watch the molecular events of chromosome recombination unfold with unprecedented detail. This involved genetic engineering in budding yeast—a model organism that has been used for decades to discover how fundamental cellular processes work.

Humans have 46 chromosomes in each of our cells, made up of 23 pairs of matching, "homologous" chromosomes, with one of each pair inherited from each parent. Early in the process of making sperm or eggs, those chromosome pairs line up, and the parental chromosomes break and rejoin to each other. These chromosome exchanges, called "crossovers," serve two important functions.

First, they help ensure that each chromosome that is passed on to the offspring contains a unique mixture of genes from both parents. Crossovers also keep the chromosomes connected in matching pairs. These connections guide the distribution of chromosomes when cells divide to produce eggs and sperm. Maintaining crossover connections is especially crucial in females.

As chromosomes pair up in developing egg or sperm cells, matching DNA strands are exchanged and twined together over a short distance to form a structure called a "double Holliday junction." DNA strands of this structure are then cut to join the chromosomes forming a crossover.

In males, developing immature sperm cells then immediately divide and distribute chromosomes to the sperm. In contrast, egg cells developing in the fetal ovary arrest their development after crossovers have formed. The immature egg cells can remain in suspended animation for decades after birth, until they are activated to undergo ovulation.

Part 1

Comment by Dr. Krishna Kumari Challa on September 25, 2025 at 9:24am

Study finds microplastics in all beverages tested, raising exposure estimates

Microplastics have found their way deep inside our bones, brains, and even babies. A UK study found that 100% of all 155 hot and cold beverage samples tested contained synthetic plastic particles.

MPs are tiny pieces of plastic ranging in size from 1 μm to 5 mm, which are widespread across aquatic, terrestrial, and even airborne environments. They have become a growing health concern for living beings across species due to their ability to accumulate and carry toxic chemicals through the food webs.

Humans come into contact with MPs every day through food, water, consumer goods, and even air.

The researchers tested different products from popular UK brands, including coffee, tea, juices, energy drinks, soft drinks, and even tap and bottled water, and not a single beverage was free of microplastics (MPs). Surprisingly, the more expensive tea bag brand showed a higher concentration of MPs, compared to the cheaper ones.

Traces of plastics, including polypropylene, polystyrene, polyethylene terephthalate, and polyethylene—commonly used for food packaging and disposable containers—were found in the fluids. The daily average exposure through beverages was found to be 1.65 MPs/kg body weight per day.

The findings are published in Science of the Total Environment.

This can be true to all countries in the world.

 Muneera Al-Mansoori et al, Synthetic microplastics in hot and cold beverages from the UK market: Comprehensive assessment of human exposure via total beverage intake, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.180188

Comment by Dr. Krishna Kumari Challa on September 25, 2025 at 9:17am

The Ganges River is drying at an unprecedented rate, new study finds

The Ganges River is in crisis. This lifeline for around 600 million people in India and neighboring countries is experiencing its worst drying period in 1,300 years. Using a combination of historical data, paleoclimate records and hydrological models, researchers discovered that human activity is the main cause. They also found that the current drying is more severe than any recorded drought in the river's history.

In their study, published in the Proceedings of the National Academy of Sciences, researchers first reconstructed the river's flow for the last 1,300 years (700 to 2012 C.E.) by analyzing tree rings from the Monsoon Asia Drought Atlas (MADA) dataset. Then they used powerful computer programs to combine this tree-ring data with modern records to create a timeline of the river's flow. To ensure its accuracy, they double-checked it against documented historical droughts and famines.

The scientists found that the recent drying of the Ganges River from 1991 to 2020 is 76% worse than the previous worst recorded drought, which occurred during the 16th century. Not only is the river drier overall, but droughts are now more frequent and last longer. The main reason, according to the researchers, is human activity. While some natural climate patterns are at play, the primary driver is the weakening of the summer monsoon.

This weakening is linked to human-driven factors such as the warming of the Indian Ocean and air pollution from anthropogenic aerosols. These are liquid droplets and fine solid particles that come from factories, vehicles and power plants, among other sources and can suppress rainfall. The scientists also found that most climate models failed to spot the severe drying trend.

How to avoid this?

The researchers suggest two main courses of action. Given the mismatch between climate models and what they actually found, they are calling for better modeling to account for the regional impacts of human activity.

And because the Ganges is a vital source of water for drinking, agricultural production, industrial use and wildlife, the team also recommends implementing new adaptive water management strategies to mitigate potential water scarcity.

Dipesh Singh Chuphal et al, Recent drying of the Ganga River is unprecedented in the last 1,300 years, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2424613122

Comment by Dr. Krishna Kumari Challa on September 24, 2025 at 9:52am

Scientists show how to grow more nutritious rice that uses less fertilizer

The cultivation of rice—the staple grain for more than 3.5 billion people around the world—comes with extremely high environmental, climate and economic costs.

This may be about to change, thanks to new research. 

Scientists have shown that nanoscale applications of the element selenium can decrease the amount of fertilizer necessary for rice cultivation while sustaining yields, boosting nutrition, enhancing the soil's microbial diversity and cutting greenhouse gas emissions. 

In a new paper published in the Proceedings of the National Academy of Sciences, they demonstrate for the first time that such nanoscale applications work in real-world conditions.

They used an aerial drone to lightly spray rice growing in a paddy with the suspension of nanoscale selenium. That direct contact means that the rice plant is far more efficient at absorbing the selenium than it would be if we applied it to the soil.

Selenium stimulates the plant's photosynthesis, which increased by more than 40%. Increased photosynthesis means the plant absorbs more CO₂, which it then turns into carbohydrates. Those carbohydrates flow down into the plant's roots, which causes them to grow.

Bigger, healthier roots release a host of organic compounds that cultivate beneficial microbes in the soil, and it's these microbes that then work symbiotically with the rice roots to pull more nitrogen and ammonium out of the soil and into the plant, increasing its NUE from 30 to 48.3%, decreasing the amount of nitrous oxide and ammonia release to the atmosphere by 18.8–45.6%.

With more nutrients coming in, the rice itself produces a higher yield, with a more nutritious grain: levels of protein, certain critical amino acids, and selenium also jumped.

On top of all of this, they  found that their nano-selenium applications allowed farmers to reduce their nitrogen applications by 30%. Since rice cultivation accounts for 15–20% of the global nitrogen use, this new technique holds real promise for helping to meet the triple threat of growing population, climate change, and the rising economic and environmental costs of agriculture.

Wang, Zhenyu et al, Nanotechnology-driven coordination of shoot–root systems enhances rice nitrogen use efficiency, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2508456122

Comment by Dr. Krishna Kumari Challa on September 24, 2025 at 9:26am

Popular keto diet linked to glucose intolerance and fatty liver in mice

Avocado toast with fried cheese as the bread and zucchini noodles in butter-bacon sauce are among the many recipe ideas fueling social media's beloved high-fat, low-carbohydrate ketogenic, or keto diet. However, scientists have found that while keto can lead to limited weight gain and even weight loss, it does so at the cost of metabolic issues like glucose intolerance.

scientists divided mice into four dietary groups: ketogenic diet (KD, 90% fat), a high-fat diet (HFD, 60% fat), low-fat (LFD), and low-fat moderate protein (LFMP), with varying levels of carbohydrates and proteins.

The mice were allowed to eat freely for up to 36 weeks in males and 44 weeks in females. Test results showed that while the KD supported weight control, it also raised blood cholesterol levels and led to fatty liver in males.

The diet is named "ketogenic" because it sends the body into ketosis—a metabolic state where the body burns fat as the primary fuel instead of the usual carbohydrates, and, as a result, produces molecules called ketone bodies. The diet isn't a new food trend, it has been around for nearly 100 years and is well-established for treating drug-resistant epilepsy in children, by reducing seizures in many cases. The exact way a KD helps control seizures is still unclear, but several ideas have been proposed. Some studies have suggested that KD can stabilize blood glucose (BG), which is beneficial to brain metabolism and neurotransmitter activity, while others highlight the anticonvulsant effects of ketone bodies themselves.

For this study, the researchers included both male and female mice and carried out regular check-ins to assess the long-term effects of KD on health parameters, including body composition, organ health, and blood profile.

They found that KD protected against excessive weight gain compared to the conventional high-fat diet, but gained more weight than low-fat diets. Long-term KD caused severe hyperlipidemia, meaning there were very high levels of fat in the blood.

KD-fed mice developed severe glucose intolerance because the diet caused a severe impairment in insulin secretion from the pancreas. While female mice on KD seemed fine, the male ones showed signs of liver dysfunction and fatty liver.

The findings made it quite evident that long-term KD can trigger several metabolic disturbances, raising caution against its widespread use as a health-promoting diet.

 Molly R. Gallop et al, A long-term ketogenic diet causes hyperlipidemia, liver dysfunction, and glucose intolerance from impaired insulin secretion in mice, Science Advances (2025). DOI: 10.1126/sciadv.adx2752

Comment by Dr. Krishna Kumari Challa on September 24, 2025 at 9:21am

The hunted, not the hunters: AI reveals early humans were prey for leopards

A new study may be about to rewrite a part of our early human history. It has long been thought that Homo habilis, often considered the first true human species, was the one to turn the tables on the predator–prey relationship. However, a recent analysis of previous archaeological finds suggests that they were possibly more hunted than hunters and not the dominant species we once believed them to be.

To investigate this, researchers used artificial intelligence and computer vision to analyze tiny tooth marks on two H. habilis fossils. These ancient remains come from Olduvai Gorge in Tanzania and date back almost 2 million years.  

The researchers trained the AI models on a library of 1,496 images of tooth marks made by modern carnivores, including leopards, lions, crocodiles, wolves and hyenas. Once it was trained, they presented the AI with photos of the fossil tooth marks.

As the scientists detail in their paper, published in the Annals of the New York Academy of Sciences, the AI compared these marks to what it had learned and concluded, with more than 90% probability, that leopards made the tooth marks. A key reason for this was that the triangular shape of the tooth pits on the bones matched those in the leopard reference samples.

"The implications of this are major, since it shows that H. habilis was still more of a prey than a predator," wrote the researchers in their paper. "It also shows that the trophic position of some of the earliest representatives of the genus Homo was not different from those of other australopithecines."

Although the research was limited to just two individuals, the scientists contend that if H. habilis had become a powerful species that could compete with carnivores, their bones would more likely have been scavenged by bone-crushing animals, such as hyenas, after they died from other causes.

The fact that the bites were from a flesh-eating predator means the leopards were actively hunting them. This suggests that the transition to a dominant position in the food chain came later in human evolution, according to the research team.

Marina Vegara‐Riquelme et al, Early humans and the balance of power: Homo habilis as prey, Annals of the New York Academy of Sciences (2025). DOI: 10.1111/nyas.15321

Comment by Dr. Krishna Kumari Challa on September 24, 2025 at 7:21am

UK Biobank analysis finds higher dementia incidence with frailty

Researchers report evidence that physical frailty is associated with dementia and that genetic background, brain structure, and immunometabolic function may mediate this link.

Dementia causes loss of cognitive abilities and daily functioning, and reached an estimated 57 million cases worldwide in 2021 with projections indicating a rise to 153 million by 2050. Treatments remain limited in effectiveness, creating a need for early identification of risk factors.

Previous studies have noted associations between frailty and elevated risk of incident dementia. Frailty is characterized by decreased physical function and a reduced ability to overcome stressors. Genetic susceptibility might influence the frailty-dementia relationship, and immunometabolic processes and brain structure are implicated, though mechanisms remain unclear.

In the study, "Association of Frailty With Dementia and the Mediating Role of Brain Structure and Immunometabolic Signatures," published in Neurology, researchers conducted a prospective cohort investigation to elucidate the link between physical frailty and dementia, assess causality, and explore biologic mechanisms.

UK Biobank contributed data from 489,573 participants without dementia at enrollment between 2006 and 2010, with a median follow-up of 13.58 years during which 8,900 dementia cases were documented. Brain MRI was available for a subset.

Physical frailty was defined by five criteria: weight loss, exhaustion, physical inactivity, slow walking speed, and low grip strength. Components were summed to a 0–5 score and categorized as nonfrail, prefrail, or frail. Biomarker panels included peripheral blood cell counts, biochemical measures, and metabolomic markers with correction for multiple testing.

Risk climbed with frailty status, with prefrailty associated with higher hazard versus nonfrailty (HR 1.50, 95% CI 1.44–1.57) and frailty associated with a larger increase (HR 2.82, 95% CI 2.61–3.04). Joint analyses placed the greatest hazards where frailty met genetic susceptibility, including HR 3.87 (95% CI 3.30–4.55) for high polygenic risk with frailty and HR 8.45 (95% CI 7.51–9.51) for APOE-e4 gene carriers with frailty.

Neuroimaging and biomarker findings linked frailty severity with image-derived brain measures and immunometabolic markers. Mendelian randomization supported a potential causal effect of physical frailty on dementia (OR 1.79, 95% CI 1.03–3.12), with reverse analysis reporting a null association (OR 1.00, 95% CI 0.98–1.01).

Authors conclude that the findings support a causal association between physical frailty and dementia, suggesting frailty may serve as a correlative early marker of vulnerability.

Xiangying Suo et al, Association of Frailty With Dementia and the Mediating Role of Brain Structure and Immunometabolic Signatures, Neurology (2025). DOI: 10.1212/wnl.0000000000214199

Comment by Dr. Krishna Kumari Challa on September 23, 2025 at 10:20am

And in trials where the target never crossed the middle of the field of view, these handoff dynamics were not apparent in the measurements.

The study shows that the brain is not simply tracking objects in one hemisphere and then just picking them up anew when they enter the field of view of the other hemisphere.

"These results suggest there are active mechanisms that transfer information between cerebral hemispheres," the authors wrote. "The brain seems to anticipate the transfer and acknowledge its completion."

But they also note based on other studies that the system of interhemispheric coordination can sometimes appear to break down in certain neurological conditions including schizophrenia, autism, depression, dyslexia and multiple sclerosis. The new study may lend insight into the specific dynamics needed for it to succeed.

Matthew B. Broschard et al, Evidence for an active handoff between hemispheres during target tracking, The Journal of Neuroscience (2025). DOI: 10.1523/jneurosci.0841-25.2025

Part 3

• ‹ Previous
• 1
• …
• 28
• 29
• 30
• 31
• 32
• …
• 1145
• Next ›
• Page