Comment

Comment by Dr. Krishna Kumari Challa 9 hours ago

Whale, dolphin strandings show widespread disease, trauma
Analysis of 272 cetacean strandings in the Pacific Islands from 2006 to 2024 found that over 65% involved disease or human-caused trauma. Disease accounted for 62% of cases, with infectious agents like morbillivirus and brucella affecting multiple species. Human-related trauma, including vessel strikes and debris ingestion, contributed to 29% of strandings.

From land-borne pathogens to high-speed vessel strikes, Pacific whales and dolphins are caught in a "perfect storm" where human-caused trauma and infectious diseases were found in more than 65% of investigated strandings.

A study spanning nearly two decades by  researchers provides insights into the threats whales and dolphins face in the Pacific Islands.

Based on 272 stranding investigations of 20 cetacean species between 2006 and 2024, the study provides foundational data to better manage and conserve Hawaiʻi's whales and dolphins. The findings are published in the journal Diseases of Aquatic Organisms.

Over 18 years, scientists examined more than three-quarters of the stranded whales and dolphins to understand why they died. Most cases (62%) were linked to diseases, and about half of those animals were in poor body condition due to long-term illness.
Infectious agents proved to be a significant threat, affecting 11 different species, including striped dolphins and Longman's beaked whales. Two of the most concerning pathogens were morbillivirus and brucella, which can cause serious brain and lung problems in marine mammals.

Toxoplasmosis—a parasite that infects warm-blooded animals and spreads through cat feces across the environment—was responsible for the deaths of two spinner dolphins and one bottlenose dolphin.

The study revealed that 29% of all strandings were linked to anthropogenic (human-caused) trauma. Vessel strikes were a significant risk, resulting in fatal vertebral and skull fractures for seven individuals, including two pygmy sperm whales, two humpback whale calves, a goose-beaked whale, a spinner dolphin and a striped dolphin.

Interactions with marine debris and fisheries were confirmed as fatal in multiple cases, including a sperm whale that died from plastic and fishery debris blocking its stomach and a bottlenose dolphin that died after a fishhook tore into it.

Kristi West et al, Pacific Islands cetaceans: a review of strandings from 2006-2024, Diseases of Aquatic Organisms (2025). DOI: 10.3354/dao03877

Comment by Dr. Krishna Kumari Challa 9 hours ago

Comment by Dr. Krishna Kumari Challa 9 hours ago

Some mammals can hit pause on a pregnancy—understanding how that happens could help us treat cancer
Embryonic diapause allows some mammals to pause development by activating a molecular brake that suppresses differentiation pathways, maintaining stem cell pluripotency during metabolic stress. This mechanism involves the displacement of Capicua, enabling genes that inhibit the MAP kinase pathway. The findings suggest similar dormancy programs may underlie long-term survival in immune, stem, and cancer cells.

Tuo Zhang et al, Transcriptional derepression of negative regulators of MAP kinase supports maintenance of diapause ES cells in the pluripotent state, Genes & Development (2025). DOI: 10.1101/gad.353143.125

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Comment by Dr. Krishna Kumari Challa 10 hours ago

The postcanine dental crown area analysis of the Dmanisi hominin fossils... supports the hypothesis of distinct species coexisting temporally at the site (Homo caucasi and Homo georgicus). This possibility challenges the prevailing model of Homo erectus migration out of Africa..." commented the researchers in their paper.

While the research lends weight to the idea that two species left Africa at roughly the same time, more specimens may be needed before a consensus is reached.

Victor Nery et al, Testing the taxonomy of Dmanisi hominin fossils through dental crown area, PLOS One (2025). DOI: 10.1371/journal.pone.0336484

Part 2

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Comment by Dr. Krishna Kumari Challa 10 hours ago

Two ancient human species came out of Africa together, not one, suggests new study

The textbook version of the "Out of Africa" hypothesis holds that the first human species to leave the continent around 1.8 million years ago was Homo erectus. But in recent years, a debate has emerged suggesting it wasn't a single species, but several. New research published in the journal PLOS One now hopes to settle the matter once and for all.

The debate centers on the Dmanisi fossils, five skulls found in the Republic of Georgia between 1999 and 2005, which belong to some of the oldest humans ever found outside Africa. The problem is that they don't look alike. Some are larger than others, particularly Skull 5, which has a tiny braincase but a massive, protruding face. Some researchers explain this as a difference in sexes within the same species, while others argue that it represents two distinct species living together.

To provide much-needed clarity, researchers studied the teeth of three Dmanisi specimens. The reason is that, generally, skulls are not always the best species identifiers because bone is fragile and can be warped and crushed. Dentition is far more useful because enamel is the hardest biological substance produced by humans, and everything from the shape and size of individual teeth can be used to identify a species.

The team focused on the surface area (dental crown) of the back teeth (premolars and molars) of the Dmanisi specimens that had sufficient dental remains for analysis. They compared these to a database of 122 other fossil specimens, including Australopithecus and several other Homo species. Then, using a statistical sorting tool, they analyzed 583 teeth to create a biological map and determine whether the Dmanisi fossils belonged to a single family or to other branches of our family tree.

The map revealed that these ancient remains were not from a single group. Skull 5, with its large jaw, was grouped with Australopiths, a more primitive ape-like ancestor. The other two specimens were more human-like. Because of this, the study authors support using the names Homo georgicus for Skull 5 and Homo caucasi for the human-like group.
To ensure the differences weren't just between males and females, the team compared the fossils with those of great apes. In some animals, like gorillas, males are much larger than females but still have the same basic teeth. The differences between the Dmanisi teeth were so great that male-female differences within the same group couldn't explain them.
Part 1

Comment by Dr. Krishna Kumari Challa 10 hours ago

Scientists chart over 140,000 DNA loops to map human chromosomes in the nucleus
Over 140,000 DNA looping interactions were mapped in human embryonic stem cells and fibroblasts, providing a detailed 3D organization of chromosomes within the nucleus. Computational models now predict genome folding from DNA sequence alone, clarifying how chromatin loops influence gene regulation and how genetic variations may alter genome structure and function.

Job Dekker et al, An integrated view of the structure and function of the human 4D nucleome, Nature (2025). DOI: 10.1038/s41586-025-09890-3

Elzo de Wit, Systematic maps reveal how human chromosomes are organized, Nature (2025). DOI: 10.1038/d41586-025-03808-9

Comment by Dr. Krishna Kumari Challa 10 hours ago

People are getting their news from AI—and it's altering their views

Large language models increasingly shape public opinion by generating news content and summaries, often introducing subtle communication bias by emphasizing certain viewpoints while minimizing others, even when information is accurate. This bias stems from model design, training data, and market concentration. Current regulations focus on harmful outputs but are less effective against nuanced framing biases, highlighting the need for greater competition, transparency, and user involvement.

 Read the original article.

Comment by Dr. Krishna Kumari Challa 10 hours ago

Biodegradable electronics can break down into harmful microplastics
Some materials used in biodegradable electronics, such as PEDOT:PSS, can persist for years and degrade into microplastics, raising environmental concerns. In contrast, polymers like cellulose and silk fibroin degrade more safely. The environmental impact of both material choice and manufacturing processes is significant, highlighting the need for sustainable, circular approaches in electronics production.

Sofia Sandhu et al, End-of-Life usefulness of degradation by products from transient electronics, npj Flexible Electronics (2025). DOI: 10.1038/s41528-025-00411-w

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Comment by Dr. Krishna Kumari Challa 10 hours ago

More eyes on the skies can help planes reduce climate-warming contrails

Aviation's climate impact is partly due to contrails—condensation that a plane streaks across the sky when it flies through icy and humid layers of the atmosphere. Contrails trap heat that radiates from the planet's surface, and while the magnitude of this impact is uncertain, several studies suggest contrails may be responsible for about half of aviation's climate impact.
Geostationary satellites detect only about 20% of contrails visible to low-Earth-orbiting satellites, primarily missing smaller, younger contrails. Combining data from geostationary, low-Earth-orbit, and ground-based observations can provide a more complete understanding of contrail formation and evolution, supporting more effective contrail avoidance strategies to mitigate aviation's climate impact.

Pilots could conceivably reduce their planes' climate impact by avoiding contrail-prone regions, similarly to making altitude adjustments to avoid turbulence. But to do so requires knowing where in the sky contrails are likely to form.

To make these predictions, scientists are studying images of contrails that have formed in the past. Images taken by geostationary satellites are one of the main tools scientists use to develop contrail identification and avoidance systems.

But a new study shows there are limits to what geostationary satellites can see.

Researchers analyzed contrail images taken with geostationary satellites, and compared them with images of the same areas taken by low-Earth-orbiting (LEO) satellites. LEO satellites orbit Earth at lower altitudes and therefore can capture more detail. However, since LEO satellites only snap an image as they fly by, they capture images of the same area far less frequently than geostationary (GEO) satellites, which continuously image the same region of Earth every few minutes.

The researchers found that geostationary satellites miss about 80% of the contrails that appear in LEO imagery. Geostationary satellites mainly see larger contrails that have had time to grow and spread across the atmosphere. The many more contrails that LEO satellites can pick up are often shorter and thinner. These finer threads likely formed immediately from a plane's engines and are still too small or otherwise not distinct enough for geostationary satellites to discern. The study highlights the need for a multiobservational approach in developing contrail identification and avoidance systems. The researchers emphasize that both GEO and LEO satellite images have their strengths and limitations.

Observations from both sources, as well as images taken from the ground, could provide a more complete picture of contrails and how they evolve.

With more 'eyes' on the sky, we could start to see what a contrail's life looks like, the researchers conclude.

 Marlene V. Euchenhofer et al, Contrail Observation Limitations Using Geostationary Satellites, Geophysical Research Letters (2025). DOI: 10.1029/2025gl118386

Comment by Dr. Krishna Kumari Challa 11 hours ago

PFAS concentrations can double with every step up the food chain
PFAS concentrations increase twofold on average with each step up the food chain, resulting in significantly higher levels in top predators and humans. Analysis of 119 global food webs shows substantial variation among PFAS compounds, with some newer alternatives magnifying even more than legacy chemicals. These findings highlight the need for compound-specific regulation and further research into health impacts.

The authors examined 119 aquatic and terrestrial food webs across the globe, finding that top predators such as large fish, seabirds, and marine mammals can accumulate PFAS concentrations exponentially larger than the environments in which they're found. The study is published in the journal Nature Communications.

PFAS concentrations double, on average, with each step up the food chain.

Known as "forever chemicals," PFAS are from a family of more than 12,000 man-made compounds.
These chemicals are prized for their heat resistance and water-repelling properties, and are used in cleaning products, food packaging, non-stick pans, clothing, and fire-fighting equipment.

Since being discovered by the American chemical company DuPont in the 1930s, PFAS are now detectable in the bloodstream of almost every human being on the planet.

Unlike other chemicals, PFAS never break down, meaning that throughout the world right now, they're building up in environments, plants, and animals on land and in the ocean.

For humans, sitting as we do at the top of the food chain, this means our diets can be an important pathway for PFAS exposure.

Given what we know about PFAS toxicity from other studies, these extreme accumulation rates in top predators suggest serious health risks. This creates a cascading ecological risk: Apex predators face disproportionately high exposure even in relatively low-contaminated environments.

Some compounds—including chemicals marketed as safer alternatives to existing products—showed even higher magnification than the chemicals they were designed to replace.

 Lorenzo Ricolfi et al, Unravelling the magnitude and drivers of PFAS trophic magnification: a meta-analysis, Nature Communications (2025). DOI: 10.1038/s41467-025-65746-4

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