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Comment by Dr. Krishna Kumari Challa 2 hours ago

Is it a boy or a girl? For alligators, it may come down to one degree

The future of the alligator species could come down to a one- or two-degree temperature difference, according to new research .
A small change on the thermometer could determine whether a gator develops as a male or female. And that could have ramifications for alligator populations as temperatures rise.

Typically, incubations at cooler temperatures (think 86 to 88 degrees Fahrenheit) and hot spells (97 degrees Fahrenheit and above) result in more female gators. Moderate temperatures (90 to 92 degrees Fahrenheit) yield more males.

But these trends largely reflect controlled experiments in laboratories in which alligator eggs are incubated under constant temperatures.

Nests in the wild don't experience constant temperatures; instead, temperatures fluctuate due to heat waves or just going from day to night.

The present study gives scientists a better understanding of real-world nest conditions.
Whenever a population is out of balance, it can impact population growth. Whenever you start to lose females, then the population can really get in trouble.
The researchers' new model closely matched previous sex outcomes at cooler temperatures. But at higher temperatures, even a change of one or two degrees made a big difference in whether alligator embryos developed as male or female.
A small difference can lead to mostly males or mostly females being produced.
That's really relevant for how the environment is going to be changing in the near future. If temperatures are biasing sex ratios, that's a big issue.
The eggs' swap back to a female outcome occurred at a lower temperature threshold than anticipated. Whereas some previous models expected the flip to happen around 97 degrees Fahrenheit, the new model suggests that sex was more likely to be female starting at 93 degrees Fahrenheit. Temperatures between the two female-producing ranges still produce mostly males.

Karin R. Ebey et al., A sex ratio by incubation temperature reaction norm for the American alligator ( Alligator mississippiensis ) based on fluctuating thermal regimes, Journal of Experimental Biology (2026). DOI: 10.1242/jeb.252972

Comment by Dr. Krishna Kumari Challa 3 hours ago

Microplastic shape can influence viral disease severity in rainbow trout
Continuous nylon microfiber exposure approximately doubled the odds of death in rainbow trout infected with infectious hematopoietic necrosis virus, while rounded nylon particles did not significantly increase mortality. These laboratory results indicate that microplastic shape can affect viral disease severity; effects in natural environments remain uncertain.

Meredith E Seeley et al., Microplastic fibers can alter viral disease severity, contingent on particle shape and exposure timing, Environmental Toxicology and Chemistry (2026). DOI: 10.1093/etojnl/vgag233

Comment by Dr. Krishna Kumari Challa 3 hours ago

Because internal clocks regulate many aspects of animal behaviour and physiology, the researchers suggest that similar time shifts could potentially have effects beyond navigation. In humans, traveling rapidly across time zones can cause jet lag, which involves a mismatch between the body's internal clock and local time and can lead to disturbed sleep, fatigue and other symptoms.

Patrick Lewin et al., Rapid longitudinal flights cause time shifts and sun compass error, Science (2026). DOI: 10.1126/science.adz2542. www.science.org/doi/10.1126/science.adz2542

Part 2

Comment by Dr. Krishna Kumari Challa 3 hours ago

Long-distance flights can throw seabirds' internal clocks out of sync, causing navigation errors
A new study has found that seabirds flying long distances across the Atlantic can experience a mismatch between their internal body clocks and local time (the same process that leads to jet lag in humans), causing them to make predictable errors when navigating by the sun. The results have been published in the journal Science.
Many animals, including birds, use the sun to find their way. But because the sun moves across the sky throughout the day, they need an accurate internal clock to interpret its position correctly.

Normally, birds reset their internal clocks using sunrise as a cue. However, when they travel rapidly east or west during the day, their internal clocks may temporarily become out of sync with local solar time. This could cause them to misjudge the sun's position and fly slightly off course.

To investigate whether this happens in the wild, researchers analyzed 20 years of GPS tracking data from 1,045 Manx shearwaters, covering 3,688 foraging trips.
Manx shearwaters (Puffinus puffinus) breed on islands off the western coasts of the U.K. and Ireland. They regularly travel hundreds of kilometers out to sea in search of food, sometimes reaching feeding grounds around 1,000 km (621 miles) west of their breeding colonies.

When returning to their nests, the birds can travel rapidly eastward across lines of longitude, moving into places where the sun rose earlier (just as we do when we fly into earlier time zones). As a result, their internal clocks may lag behind local solar time by up to around one hour.

The researchers found that the birds' flight directions showed systematic deviations consistent with the predicted effects of these time shifts on their sun compass. As the birds traveled eastward, they tended to deviate clockwise from their expected direction, as would be predicted if their internal clocks were running behind local time.

The team used statistical models to compare the observed deviations with those predicted from the birds' movements and the changing position of the sun. The results supported the sun-compass explanation, which also fit the data better than an alternative explanation based on changes in the Earth's magnetic field.
The researchers found that these navigational errors persisted even when the birds were flying along visible coastlines, where landmarks could help guide them. When the predicted compass error pointed toward land, the shearwaters tended to fly closer to the coast. When it pointed away from land, they tended to fly farther out to sea.

This suggests that the birds continued to rely on their sun compass even when other navigational cues were available, rather than simply following the coastline.
So billions of migratory animals look up to the sun for direction, relying on clocks silently ticking away inside them, and that errors in those clocks can cause them to take tiny shifts off course.

The navigational errors were relatively small, reaching approximately 15° in the shearwaters studied. Because these birds appear able to reassess their position and adjust their route home continuously, the additional distance travelled is likely to be modest.
However, the findings could have wider implications for animals that travel long distances without being able to correct their position continuously. For example, in birds undertaking their first migration, small compass errors could potentially accumulate, shifting their eventual destination by hundreds of kilometers.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

Night shifts during pregnancy linked to heightened risk of young child's neurodevelopmental abnormalities
Working night shifts during pregnancy is linked to a heightened risk of neurodevelopmental abnormalities detected by screening in the child by the age of 4, finds research published online in Occupational & Environmental Medicine.
But nightly prenatal sleep length during this period may modify this observed association, exploratory findings suggest.

Night shift work during pregnancy has been associated with unfavourable health outcomes for both mother and child, including neurodevelopmental issues, potentially related to body clock and sleep disturbances, note the researchers.
During the study researchers noted that compared with the children of mothers who didn't work night shifts, the children of those who discontinued night shift work were more likely to have developmental screening abnormalities, but only in the fine motor skills domain (24% higher risk).

But the children of mothers who continued night shifts during their pregnancy had higher risks of developmental abnormalities in three domains compared with children whose mothers didn't work night shifts.

These were in the domains of communication skills (29% higher risk); fine motor skills (34% higher risk); and personal–social functioning (31% higher risk).

Only the fine motor skills domain showed a significant association, regardless of whether night shifts were continued or discontinued.

"One possible explanation is that maternal inflammation associated with persistent night work may preferentially affect neural pathways involved in fine motor function," suggest the researchers.

A separate exploratory analysis showed that the observed association between night shift pattern and the child's neurodevelopmental risk differed according to how long the mothers slept.

Prenatal sleep duration of 10 or more hours was associated with an 80% heightened risk of abnormalities in any of the five domains compared with prenatal sleep length of 6–9 hours.

Long prenatal sleep duration may also reflect underlying fatigue, subclinical depression, inflammation, or anemia, rather than representing a harmful exposure in itself, suggest the researchers.
In light of the findings, it may be worth employers considering flexible work schedules for pregnant night shift workers, they say.

Maternal night shift patterns during pregnancy and offspring's development at 4 years of age: the Japan Environment and Children's Study, Occupational and Environmental Medicine (2026). DOI: 10.1136/oemed-2026-111018

Comment by Dr. Krishna Kumari Challa yesterday

Comets probably didn't seed life on Earth after all, new study suggests
The theory that comets delivered the molecular building blocks for life on Earth is a long-standing one, since comets are known to carry many of these molecules. However, a new study challenges this idea.

Researchers found the cometary delivery of these building blocks would be—at best—a 'one-off fluke,' and not the steady rain of prebiotic molecules that had been theorized.

Using computer modelling, the researchers determined that comets travel too fast and at too sharp an angle to Earth's atmosphere for the fragile organic molecules to survive: they would almost certainly vaporize on impact with the surface. However, the researchers also found that another planet in our system—Mars—could be a slightly more promising candidate for cometary delivery of prebiotic molecules, although this is still highly unlikely. The results are published in the journal Scientific Reports.

Cometary impacts an unlikely pathway towards the origins of life on Earth, Scientific Reports (2026). DOI: 10.1038/s41598-026-74214-y

Comment by Dr. Krishna Kumari Challa on Wednesday

Scientists reveal hidden world of living cells in human milk

Human milk is a complex biological system containing many different types of living cells.

Advanced nanoscale imaging technology has revealed the diversity of living cells in human milk and uncovered new insights into how these cells are structured, what they contain and how they use nutrients.
Researchers examined major cell populations found in human milk, including milk-producing cells, known as lactocytes, and different types of immune cells such as neutrophils, macrophages and dendritic cells.
Nanoscale imaging, isotope tracing and single-cell analysis identified distinct metabolic profiles in human milk cells. Macrophages incorporated glucose into lipid droplets, lactocytes showed active protein production and energy metabolism, and neutrophils contained high sulfur and iron levels.

Qiongxiang Lin et al., Multimodal Nanoscale Imaging Reveals Cellular and Metabolic Complexity of Human Breast Milk, ACS Nano (2026). DOI: 10.1021/acsnano.6c12691

Comment by Dr. Krishna Kumari Challa on Wednesday

The researchers conducted a health risk assessment based on toxicological parameters. In general, the expected intake of microplastics and plasticizers based on average daily tea consumption is negligible. However, the study authors do exhibit some concern about the concentration of BPA found in the tea brewed with plastic bags.

Some studies suggest BPA disrupts hormone levels, but it is somewhat unclear what levels may be safe and suggested limits vary. While the amount of BPA was only 4.55%–21.70% of the EFSA daily intake benchmark, the team notes that this accounts for only a part of the total daily intake and the benchmark may be exceeded with higher tea intake or with BPA from other sources.

The study authors write, "Our study found that BPA intake could reach 21.7% of the EFSA TDI value, a finding that serves as a critical warning, particularly for vulnerable groups such as pregnant women and children."
The research team suggests limiting consumption of microplastics, BPA and other plastic-related chemicals when possible. Avoiding plastic tea bags is a relatively simple way to do this.

Necla Pehlivan et al., Microplastic release from plastic tea bags versus bulk tea and migration of bisphenol A and plasticizer esters, npj Science of Food (2026). DOI: 10.1038/s41538-026-01175-x

Part 2

Comment by Dr. Krishna Kumari Challa on Wednesday

Plastic tea bags are releasing BPA, plasticizers and up to 2,500 microplastic particles into your cup of tea

Microplastics are now impossible to avoid. They have made their way into everything from agricultural soils to freshwater systems. So, it is unsurprising that they end up in most foods and drinks. However, some methods of packaging or serving these items can increase microplastic exposure even more. One such example is the plastic tea bag. While many tea bags are still made of a cellulose material, some brands use a plastic mesh, despite the well-established fact that plastics can break down in hot water.
Studies have reported particle release from tea bags, along with the migration of other plastic-related chemicals, such as phthalate esters (PAEs) and bisphenol A (BPA), which are added during production for increased flexibility, durability and thermal resistance. One study even reported that a single plastic tea bag releases billions of microplastic pieces at normal brewing temperatures.

Now, a new study, published in npj Science of Food, has analyzed plastic tea bags from four different brands to break down their average microplastic release, the types of microplastics they contain and the PAE and BPA content in the average cup. The study compares tea brewed with plastic tea bags to bagless bulk tea.
Researchers involved in the new study screened four bagged-tea brands with plastic tea bags. The plastic bags were brewed for three minutes at approximately 95°C (203 degrees Fahrenheit). Bulk leaves underwent direct chemical digestion rather than an equivalent brewing experiment. The researchers used microscopy to count suspected particles, infrared spectroscopy to identify a subset and chromatography to measure chemicals in bagged-tea infusions. Health risks were then modelled.
The plastic-bag brands produced averages of between 555 and 2,498 microplastic particles per cup under the tested brewing conditions, with some brands producing significantly more than others. The methods used only identified particles greater than 100 micrometers, so these concentrations don't include smaller particles that may be present. The particles from these bags were all identified as polyamide fibers, consistent with the bag material.

BPA and plasticizer compounds were also found in all four bagged-tea infusions. The team says that the modeled BPA intake from the bags reached between 4.55% and 21.70% of the European Food Safety Authority (EFSA) daily intake benchmark for BPA.

The bulk tea leaves contained between 146 and 1,178 particles per kilogram. This converts to approximately 0.3–2.4 particles per 2-gram (0.07-ounce) serving of tea leaves. The comparison is not direct, since the bulk tea was not brewed, but the results still point to a far lower concentration of microplastics in the bulk tea. In contrast to the tea bags, the polymer distribution of bulk tea consisted of a mixture of polymer types.

The study authors write, "The primary drivers for this mixed polymer profile are the use of plastic sacks and bundles (PE/PP) in agricultural activities, combined with the deposition of atmospheric dust, which typically contains PET and PA fibers. Furthermore, during industrial processing, tea leaves maintain intensive contact with plastic-laden equipment, including loading machinery, conveyor belts and rolling (twisting) stations. This mechanical interaction facilitates MP transfer or plasticizers from the machinery to the leaf surface.

"During the withering stage, leaves are exposed to ambient air for extended periods, making the gravitational settling of airborne MPs (microplastics) a significant contributory factor to the overall pollutant load."
Part 1

Comment by Dr. Krishna Kumari Challa on October 24, 2026 at 7:09am

Furthermore, rather than simply allowing tumors to escape the cell-killing effects of chemotherapeutic drugs, IAPs enabled surviving tumor cells to enter a highly unusual zombie-like state called "premature senescence" that converts cells into coordinators of wound healing that can orchestrate a beneficial immune response and help tumors bounce back from chemotherapy.

Senescent cells are nondividing zombie-like cells that undergo dramatic changes within a few days of exposure to chemotherapy, including becoming almost 10 times bigger than a normal cell and ramping up genes associated with wound healing. These changes endow them with a greatly increased ability to secrete inflammatory mediators, which attracts cells of the immune system. The accumulation of senescent cells in tissues as we age is also thought to contribute to the inflammatory processes associated with aging, as well as a decline in the normal function of many tissues.

The scientists also found that senescent cells formed in response to chemotherapy are highly dependent on IAPs for their continued survival. Accordingly, compounds that neutralized IAPs (called IAP antagonists) selectively eliminated senescent cells by reactivating the death receptor self-destruct program within these cells.
These new findings suggest ways in which we may be able to lower the defenses of tumours by neutralizing IAPs after the delivery of chemotherapeutic drugs, which should block their entry to senescence and kill more cells of the tumour.

Gokhan Gunay et al., Death receptors regulate entry to therapy-induced senescence and orchestrate addiction to IAPs, Science Advances (2026). DOI: 10.1126/sciadv.aed4541. www.science.org/doi/10.1126/sciadv.aed4541

Part 2

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