Comment

Comment by Dr. Krishna Kumari Challa 2 hours ago

From mother to offspring: Young birds show how 'forever chemicals' accumulate

PFAS (per- and polyfluoroalkyl substances) are synthetic fluorine-containing organic chemicals used in the manufacture of many household and industrial goods, as well as historically, in perfluorinated aqueous film-forming foams (AFFF) used to fight flammable liquid fires.

The highest PFAS concentrations in wildlife are typically recorded around petrochemical manufacturing facilities and near former firefighting training areas—the Williams Laverton RAAF Base has an extensive history of the use of firefighting foams.

New research has found young birds living near contaminated industrial and military sites in suburban Melbourne carry especially high concentrations of PFAS, so-called "forever chemicals."

Analysis of the samples showed that PFAS levels peaked in young, newly fledged birds after the chemicals were transferred from mothers into their eggs and through the insect-heavy diets chicks are fed when being reared
Young house sparrows near industrial and military PFAS hotspots in suburban Melbourne show elevated blood PFAS, with PFOS medians about 10-fold higher than in birds from uncontaminated sites. Concentrations peak in recently fledged chicks and decline with age, driven by maternal transfer via eggs and insect-heavy nestling diets, indicating substantial bioaccumulation and widespread environmental contamination.

PFAS concentrations generally decreased with the age of the birds: Recently fledged chicks had the highest levels, followed by older juveniles and then mature adults.

Consuming a diet where the main food source is invertebrates—including insects, spiders, snails and worms—is a key driver for PFAS exposure.
Even birds that feed mainly on grains as adults shift their diets toward animal food sources like invertebrates when they're breeding, to meet the energy demands of reproduction and rearing chicks.
Similar trends in PFAS levels with age have been reported for a wide range of species, including humans and other mammals, and this seems to be linked to transfer from mother to offspring.
The reputation of PFAS as "forever chemicals" is based on their persistence in the environment and their potential to accumulate in living organisms, where they have increasingly been associated with health risks.

Max M Gillings et al, Early Life Uptake and Elimination of Per- and Polyfluoroalkyl Substances in a Seasonally Invertivorous Bird, Environmental Science & Technology (2026). DOI: 10.1021/acs.est.6c02297

Comment by Dr. Krishna Kumari Challa 2 hours ago

The team then ran numerical simulations of crystal settling during atmospheric deceleration to determine likely entry speeds and orbital eccentricities. The results showed that olivine "settling" will most likely occur with high encounter speeds of roughly 14–17 km/s. The team says this points to eccentric orbits (around e > 0.2), and this eccentricity is more consistent with near-Earth objects than typical main-belt asteroid sources.

They say this parent body seems to be a previously unsampled, primitive, sulfide-rich carbonaceous asteroid related to a group of carbonaceous meteorites called the CM–CO–CY chondrite clan.

The study authors write, "Given that we have linked their composition to the CM-CO-CY clan of carbonaceous chondrites, it is plausible that their parent body was a primitive carbonaceous asteroid that migrated onto an Earth-crossing orbit—attaining comet-like orbital parameters. For instance, one might consider the disrupted fragments of a thermally altered but water-bearing asteroid (like the CY group) that evolved into near-Earth space."

The researchers note that this hypothetical parent body represents a "missing" meteorite type. The micrometeorite samples exist, but no meteorite like it exists in current collections. They say that future identification through asteroid missions or meteorite finds would be considered "a pivotal discovery."

Matthias Van Ginneken et al, ¹⁶ O poor cosmic spherules from near-Earth CY chondrite asteroids, Science Advances (2026). DOI: 10.1126/sciadv.aed6340

Part 3

Comment by Dr. Krishna Kumari Challa 2 hours ago

To try to learn more about their origins, the researchers examined 10 CumPo cosmic spherules from Antarctica and a more modern collection found on urban rooftops. They used electron microscopy and microprobe chemistry to analyze textures and key minerals and chemistry. They also measured oxygen isotopes with SIMS and NanoSIMS to fingerprint sources.

The team found many similarities between the two collections and defined them as a new subset of sulfur-rich cumulate olivine cosmic spherules, which they call "SCumPo." The subset is strongly tied to the oxygen-16-poor Group 4 signature. The group shares a set of features that imply extremely reducing conditions during atmospheric entry. This includes an uncommon near-absence of magnetite, frequent iron-nickel-sulfur droplets, consistently low nickel in olivine crystals, and unusually sulfur-rich glass.

Some spots within a single spherule showed both oxygen-16-poor and oxygen-16-rich signatures, implying the original dust was likely a mixture of at least two components because this does not happen naturally.

The study authors explain, "We interpret this as strong evidence that the SCumPo precursors were composite materials containing at least two different components: one component carrying a 16O-rich signature (relatively low δ18O and negative Δ17O, typical of carbonaceous chondrite anhydrous phases) and another carrying a 16O-poor signature (high δ18O and positive Δ17O not matched to known meteorites but akin to Group 4 fine-grained material)."
Part 2

Comment by Dr. Krishna Kumari Challa 2 hours ago

Much of Earth's 'space dust' may come from unidentified near-Earth asteroids

Like a shelf in an old house, the Earth collects a lot of dust from its surroundings. This "space dust" is mostly made up of micrometeorites that survive atmospheric entry and provides researchers with a cheap and easy way to obtain samples to study our cosmic neighbors. However, it can be difficult to determine which objects certain samples originated from if their parent bodies aren't already in available catalogs. A recent study, published in Science Advances, describes a new subset of space dust with such mysterious origins and how researchers are tracking down potential sources.

Some micrometeorites, called cosmic spherules, melt upon entry, resulting in a spherical shape. These cosmic spherules lose their original mineral structure during entry heating, making their parent bodies hard to identify. In some cases, oxygen isotopes act like a chemical fingerprint, helping researchers determine where this dust came from. Yet about 10% of cosmic spherules have unusually small oxygen-16 isotope signatures that don't match any previously identified meteorite group. Researchers refer to these as the "Group 4" cosmic spherules.

The team involved in the new study says orbital parameters could also prove useful for source identification. They write, "In one particular case, however, the mineralogical and textural properties of a subset of cosmic spherules do provide information on the orbital parameters of their precursors, including eccentricity and encounter velocity. This subset is termed CumPo after its characteristic cumulate olivine porphyritic texture, characterized by clustered olivine phenocrysts that increase in size from one side of the spherule to the other."

The features associated with CumPo spherules suggest unusual orbital parameters that may point to atypical parent bodies, according to the researchers. In particular, prior research on these textures suggested some spherules may have experienced unusually high entry speeds, which can hint at the orbital eccentricity of the parent body.
Part 1

Comment by Dr. Krishna Kumari Challa 2 hours ago

Approaching sounds can warp your perception of time

Everyone's perception of time is unique. It is a subjective experience shaped by factors such as age, emotions, memory and environmental contexts. And it may also be influenced by background noise, as scientists have demonstrated in a paper published in the journal Scientific Reports.
Previous research has shown that approaching noise can stretch our perception of time. But in this paper, researchers discovered that even when people were concentrating on a different sound, moving sounds in the background still changed their sense of time.
Their experiment revealed that people who listened to the approaching background sound overestimated the length of the tones by about 15%. "We discovered that an approaching background sound significantly accelerated the perceived time when compared to a receding sound," the study authors wrote in their paper.

Participants in the receding background noise group underestimated the time by about 6%. Those in the scrambled noise group produced intermediate results. The differences between this group and the others were not statistically significant.

So what does all this mean? This study showed for the first time that background moving sounds modulate time estimation.

The researchers framed the results in an evolutionary context. They said that an overestimation of time when an object is approaching means that our brains are put into a state of alertness to either avoid or catch something. An underestimation of time when a sound is moving away from us occurs because a retreating object is less likely to be perceived as a threat, and therefore it requires less attention.

The researchers also demonstrated the Vierordt effect, a well-known phenomenon that explains how our memory biases our estimation of time. Participants consistently guessed that the shortest tones (1 second) were longer than they were, while the longest tones (6 seconds) were guessed to be shorter.

Achille Pasqualotto et al, Approaching background sounds extend the duration of foreground auditory stimuli, Scientific Reports (2026). DOI: 10.1038/s41598-026-58785-4

Comment by Dr. Krishna Kumari Challa 3 hours ago

Neuroscientists observe electrical signals in the soma and dendrites of living mice

The human brain contains billions of neurons, specialized nerve cells that communicate with each other via electrical and chemical signals. Every neuron is made up of its body (i.e., soma), where most cellular processes occur; a long projection called an axon that sends signals to other neurons; and tree-like branches called dendrites, which receive and process incoming information.

Originally, dendrites were viewed as "passive" components that merely collect incoming signals and do not process information. More recently, however, studies have gathered evidence suggesting that they play a more active role in the transformation of incoming signals and the brain's plasticity (i.e., its ability to alter its structure, connections and activity patterns in response to experiences).

Specifically, neuroscientists discovered that when a neuron receives signals from other cells, dendrites integrate them and influence whether the neuron will produce a rapid electrical impulse called an action potential. After they are initiated, action potentials can also propagate backward from a neuron's soma into dendrites, a phenomenon known as back-propagating action potentials (bAPs).

So far, observing these fast electrical events across intricate dendritic networks inside the brains of living animals has proved challenging. In a new Nature Neuroscience paper, researchers introduced an approach that allowed them to monitor these events in living mice, yielding new insights into how brain cells integrate incoming information.

The researchers found that under the conditions they examined, voltage signals were coordinated across dendritic branches, instead of each branch behaving as an independent electrical unit. In addition, they suggest specific patterns of earlier neuron activity led to the filtering or alteration of bAPs, the electrical signals traveling back from the soma into dendrites.

"We propose that this dendritic filtering of bAPs may have a critical role in the regulation of bursting and in activity-dependent plasticity," wrote the authors in their paper.

J. David Wong-Campos et al, Voltage dynamics of cortical dendrites in vivo, Nature Neuroscience (2026). DOI: 10.1038/s41593-026-02339-4.

Comment by Dr. Krishna Kumari Challa 23 hours ago

Study reveals how the uterine microbiome may impact pregnancy success
Women with unsuccessful ART had a more diverse, less   Lactobacillus‑dominated endometrial microbiome and higher expression of endometrial receptivity genes than women who conceived. Butyrate produced by endometrial bacteria upregulated receptivity markers but also induced inflammation and impaired epithelial barrier function, indicating that microbiome–immune balance, not receptivity markers alone, is critical for implantation success.

Researchers have uncovered new evidence that the communities of bacteria living in the uterus may play an important role in determining whether pregnancy is successful following assisted reproductive technologies (ART) such as IVF. Among the key findings was one notable surprise, which suggests the biological signals that have long been used to govern the timing of embryo transfer may be misleading.

The study examined women with unexplained infertility who underwent ART and found that those who did not become pregnant had a different endometrial microbiome (the collection of microbes associated with the lining of the uterus) than women who achieved pregnancy. In particular, women with unsuccessful treatment outcomes had a more diverse microbiome, with fewer beneficial Lactobacillus bacteria and higher levels of other bacterial species.

Unexpectedly, the researchers also discovered that women who did not become pregnant showed higher levels of gene expression for several genes that are commonly used as markers of endometrial receptivity, which is the state in which the uterus is considered ready to receive an embryo. These markers are widely studied in fertility medicine and are sometimes used to help identify the optimal timing for embryo transfer, meaning the new result calls into question how effective this forecasting method is likely to be.
Lactobacillus‑dominated endometrial microbiome and higher expression of endometrial receptivity genes than women who conceived. Butyrate produced by endometrial bacteria upregulated receptivity markers but also induced inflammation and impaired epithelial barrier function, indicating that microbiome–immune balance, not receptivity markers alone, is critical for implantation success.

Researchers investigated butyrate, a molecule produced by certain bacteria found in the endometrium. Using lab models that mimic the conditions of embryo implantation, the researchers showed for the first time that butyrate can directly increase the expression of receptivity markers.

However, butyrate also promoted inflammation and weakened the barrier function of endometrial cells. These changes could thus interfere with successful implantation.
Together, the studies suggest that pregnancy success depends on a delicate balance between the immune environment of the uterus and the composition of its microbiome, and that timing the point of embryo transfer to maximize the chance of successful implantation is not as easy as might have been assumed.

F Giangrazi et al, Contribution of endometrial microbiome to inflammation-mediated infertility in women undergoing ART, Human Reproduction (2026). DOI: 10.1093/humrep/deaf252

Comment by Dr. Krishna Kumari Challa 23 hours ago

Learning languages could net you a younger brain, study says

Thinking about taking a Spanish or French class? There's a hidden benefit to picking up another language—their brain might age more slowly, a new study says.
People who speak additional languages have brains that appear 6 to 13 years younger than those of people who speak only one language, researchers reported at the Federation of European Neuroscience Societies Forum in Barcelona, Spain.

In simple terms, people who spoke more languages tended to have brains that looked younger than expected for their chronological age
Multilingual individuals showed brain connectivity patterns corresponding to brains 6–13 years “younger” than monolinguals. Greater number of languages, higher proficiency, and earlier acquisition were each associated with more delayed brain aging. Benefits appeared across ages, suggesting cumulative, gradient effects of language learning on brain aging markers.

 Federation of European Neuroscience Societies Forum

Comment by Dr. Krishna Kumari Challa yesterday

Speaking another language could slow aging in the brain

People who speak more than one language seem to have younger brains, according to research presented at the Federation of European Neuroscience Societies (FENS) Forum 2026. Our brains are made up of billions of nerve cells that need to communicate with one another. As we age, connectivity in our brains tends to deteriorate and, as a result, our memory and the speed of our thinking also decline.
The new research found that the more languages people speak, the younger their brains appear. Learning an extra language at a younger age and becoming highly fluent in another language also seem to slow brain aging.

The researchers recently published a study showing that in countries where people typically speak more than one language, people seem to age more slowly. In the new study, the researchers carried out a detailed analysis of a group of people from the Basque region of Spain who spoke between one and four different languages, including combinations of Spanish, Basque, French and English.
Multilingual adults showed reduced brain age relative to chronological age, estimated via magnetoencephalography-based connectivity and an AI-derived brain aging clock. Speaking two, three, or four languages was associated with brains appearing ~6, ~7, and ~13 years younger, respectively. Earlier acquisition and higher proficiency further correlated with delayed brain aging, independent of age, sex, and education.

In simple terms, people who spoke more languages tended to have brains that looked younger than expected for their chronological age. The effect was not only related to the number of languages spoken. Higher language proficiency and earlier acquisition of a second language were also associated with more delayed brain aging.

This suggests that multilingual experience matters as a gradient: It is not simply about being bilingual or not, but about the depth and duration of language experience.

fens2026.abstractserver.com/pr … s/presentations/5474

Comment by Dr. Krishna Kumari Challa yesterday

Uterine aging linked to poorer pregnancy outcomes after 49 despite donor eggs
Women ≥49 years using donor oocytes show reduced clinical pregnancy and live birth rates and increased miscarriage compared with women 35–40, despite similar endometrial thickness. A decline in trilaminar endometrial pattern with age supports an independent uterine aging effect. Donor eggs mitigate but do not fully offset reproductive aging, especially beyond 49 years.

Beatrice Crestani et al, Advanced maternal age independently affects live birth and increases miscarriage risk in donor oocyte cycles, Human Reproduction (2026).

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