While diverticula can develop in the large and small intestine, around 95 percent of patients in the Western world have diverticula in their sigmoid colon.

This part of the digestive tract works under great pressure to push feces into the rectum.

Once diverticula form, possibly from excessive pressure, they are prone to bleeding when aggravated, in a similar way to hemorrhoids, which form inside and outside the rectum and around the anus.
Diverticular bleeding is estimated to cause between 30 and 65 percent of all cases of lower gastrointestinal bleeding. It's usually painless and self-limiting, but seeing blood in the stool is a serious matter, as it may indicate other severe conditions.
Treatment depends on the severity of the episode.

https://www.sciencealert.com/most-people-develop-diverticulosis-in-...

Part 3

2.8 days to disaster: Why we are running out of time in low earth orbit

Satellite mega-constellations in low Earth orbit experience close approaches every 22 seconds, with each satellite performing frequent avoidance maneuvers. Solar storms increase atmospheric drag and can disable satellite control systems, raising collision risks. If operators lose control, a catastrophic collision could occur within 2.8 days, compared to 121 days in 2018, highlighting increased vulnerability.

Sarah Thiele et al, An Orbital House of Cards: Frequent Megaconstellation Close Conjunctions, arXiv (2025). DOI: 10.48550/arxiv.2512.09643

Physicists crack a 'Big Bang Theory' problem that could help explain dark matter
Theoretical work demonstrates that axions, hypothetical particles considered a candidate for dark matter, could be produced in fusion reactors using deuterium, tritium, and lithium. Neutron interactions with reactor walls and bremsstrahlung processes may generate axions or axion-like particles, offering a new approach to probing dark matter beyond solar-based searches.

Chaja Baruch et al, Searching for exotic scalars at fusion reactors, Journal of High Energy Physics (2025). DOI: 10.1007/jhep10(2025)215

The moon-forming event: Why it was by explosive ejection rather than a giant impact
A new model proposes that the Moon formed from explosive ejection of Earth's mantle and crust, driven by accumulated internal gravitational energy (LɅ) released at the core-mantle boundary, rather than by a giant impact. This mechanism explains the Moon's isotopic similarity to Earth and links geophysical processes, such as mantle plumes and LLVPs, to lunar formation.

Matthew R. Edwards, Explosive lunar fission above a large low-velocity province, Acta Geochimica (2025). DOI: 10.1007/s11631-025-00834-2

Scientists observe 'extraordinary' seven-arm octopus
A rare deep-sea encounter captured footage of the seven-arm octopus, Haliphron atlanticus, at 700 meters depth in Monterey Bay. This species, with females reaching up to 4 m and 75 kg, primarily inhabits the ocean's twilight zone and feeds on gelatinous animals such as jellyfish, supporting previous observations of its unusual diet.

Hoving, H.J.T. and S.H.D. Haddock. 2017. The giant deep-sea octopus Haliphron atlanticus forages on gelatinous fauna. Scientific Reports, 7: 44952. https://doi.org/10.1038/srep44952

 Natural daylight can help people with diabetes improve blood sugar levels

People with type 2 diabetes may be able to improve their blood sugar by doing something as simple as sitting by a window for a few hours each day. In a study published in Cell Metabolism, scientists showed that natural daylight helps maintain healthy glucose levels.

Daylight is known to be a mood enhancer and also beneficial for our health. However, according to the research team, most people living in Western societies typically stay indoors around 80% to 90% of the time under artificial light, which is not as bright or dynamic as sunlight. This is important because the human body operates on circadian rhythms, internal 24-hour clocks that orchestrate a range of biological processes, such as digestion and temperature regulation. These are synchronized by light, and a lack of natural light is a risk factor for type 2 diabetes.

Previous studies have shown that artificial light at night disrupts these rhythms and that daylight outdoors can improve the body's response to insulin, which helps control blood sugar levels. But no prior research examined how natural light entering a window affects people with diabetes.

To test this, researchers recruited 13 volunteers with type 2 diabetes to examine how their bodies responded to both natural window lighting and artificial indoor lighting. The participants spent two separate 4.5-day periods in a controlled office environment. In one session, they sat at a desk facing large windows from morning to late afternoon.
In the other, they were in the same room, with the windows blocked and only standard office lights. All participants ate similar meals three times a day and performed the same exercises at the same time across the two sessions. They also continued taking their medication.

The results revealed that while average glucose levels were similar across the two sessions, the participants spent significantly more time in the normal glucose range when exposed to natural daylight. The body's metabolism also changed. In daylight, the volunteers burned more fat for energy and fewer carbohydrates.

The researchers also took muscle biopsies and grew muscle cells in the lab. They found that genes involved in their internal cellular clocks were better aligned to the time of day under natural light. This suggested that sunlight was acting as a signal to keep the muscles "on time," making them better at processing nutrients.

Although this study involved only a handful of people, the results indicate that natural daylight can help reduce the sharp peaks and swings in blood sugar that often affect those with this condition. It offers a simple, natural way to support people with type 2 diabetes alongside existing treatments.

Jan-Frieder Harmsen et al, Natural daylight during office hours improves glucose control and whole-body substrate metabolism, Cell Metabolism (2025). DOI: 10.1016/j.cmet.2025.11.006

Scientists who use AI tools are publishing more papers than ever before

Science is entering a massive publishing boom, in large part due to artificial intelligence. New research published in the journal Science has revealed that scientists who use large language models (LLMs) like ChatGPT are producing significantly more papers across many fields. The technology is also helping to level the playing field for researchers whose first language isn't English.

The growing use of AI in scientific research has sparked concerns about shoddy work and machines making things up. But this new analysis also reveals that papers produced with LLMs use more complex language and cite a wider array of sources.

They found that when scientists use AI, their productivity soared. The biggest jump was in the social sciences and humanities, where output increased by 59.8%, while biology and life sciences saw a 52.9% increase. Meanwhile, in physics and math, the scientists report a 36.2% boost. "LLM adoption is associated with a large increase in researchers' scientific output," wrote the research team in their paper.

One of the most fascinating findings was the massive increase in productivity from non-English-speaking countries. Most top journals require manuscripts to be written in high-level English, which has long disadvantaged these scientists. But with AI handling some of the workload, researchers from Asia saw their output jump by as much as 89% in some cases.
However, the study authors also issued a warning regarding AI and quality. While the machines can make papers sound more professional, this can be a trap. Historically, sophisticated writing was a sign of high-quality research, but now the opposite can sometimes be true. The study found that the more complex the AI-generated writing was, the less likely the paper was to be high quality. In other words, good writing can mask weak ideas.

The clear message from the study authors is that we can no longer judge a paper by how smart the language appears. "As traditional heuristics break down, editors and reviewers may increasingly rely on status markers such as author pedigree and institutional affiliation as signals of quality, ironically counteracting the democratizing effects of LLMs on scientific production."

To safeguard scientific integrity, the researchers propose several measures, including that institutions implement deeper checks and even specialized "AI-based reviewer agents" to help distinguish between human writing and machine-generated writing.

 Keigo Kusumegi et al, Scientific production in the era of large language models, Science (2025). DOI: 10.1126/science.adw3000

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How chirality goes from the molecular level to the cellular one

Researchers have discovered how right-handed molecules in our cells can give rise to cells that are not symmetrical about their central axes. This discovery is a key step toward determining why most of our organs lack left–right symmetry.

It's conceivable that if some molecules that make up our cells were twisted in the opposite direction, our hearts would be on the right side of our bodies rather than on the left.

That's because the difference between the left and right sides of our organs may originate from the "handedness," or chirality, of cells, which in turn comes from the chirality of molecules in cells.

However, the link between the chirality of molecules and cellular chirality is largely unknown. Many molecules in cells are chiral, including DNA and some amino acids and proteins, but it's not clear which ones convey their chirality to cells.

 By studying the chiral behaviours of individual cells, researchers have found that the cells' scaffolding, or cytoskeleton, gives rise to the cell's chirality. The findings are published in the journal eLife.

When single cells were placed on a substrate, their nuclei and surrounding cytoplasm rotated in a clockwise direction when viewed from above. This rotational motion is driven by the concentric pattern of the actomyosin filaments that make up the cytoskeleton.

This finding implies that the cell nucleus can rotate even when there is no chiral orientation of the cytoskeleton on a cellular level.
To confirm whether this mechanism was driving the rotation, the team created a 3D theoretical model of a cell and evaluated the effect of the molecular chirality of actin and myosin on it. The results revealed that the molecular scale torque generated by individual components of the cytoskeleton can generate rotation, even when cell-level chiral structures were absent.

These results help fill in a critical link in the chain from molecules to organs and bodies, the researchers say.

 Takaki Yamamoto et al, Epithelial cell chirality emerges through the dynamic concentric pattern of actomyosin cytoskeleton, eLife (2025). DOI: 10.7554/elife.102296

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

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

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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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.

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

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

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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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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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

Gut bacteria may play role in bipolar depression by directly influencing brain connectivity

Bipolar disorder (BD) is a psychiatric disorder characterized by extreme mood changes. Individuals diagnosed with BD typically alternate between periods of high energy, euphoria, irritability and/or impulsivity (i.e., manic episodes) and others marked by feelings of sadness, low energy, and hopelessness (i.e., depression).

While there are now several medications that can help patients to manage the disorder and stabilize their mood, many of these drugs have side effects and dosages often need to be periodically adjusted. Recent studies suggest that the bacteria and microorganisms living in the digestive system, also known as gut microbiota, play a key role in mental health and might also contribute to some symptoms of BD.

Researchers  recently carried out a study investigating the possible connection between gut microbiota and the depressive episodes experienced by people diagnosed with BD. Their findings, published in Molecular Psychiatry, suggest that the microorganisms in the digestive system can directly influence connections between specific brain regions known to be affected by BD depression.

Adequate evidence has shown that gut microbial dysbiosis is an emerging disease phenotype of BD and is closely related to clinical symptoms of this intractable disease, wrote the researchers in their paper.

To explore the link between gut microbiota and BD depression, the researchers collected gut bacteria from individuals diagnosed with BD who were going through a depressive phase. They then transplanted these bacteria into the digestive system of healthy mice.

They found that bipolar depression-like mice presented with a decrease in the density of dendrite spines in medial prefrontal neurons, and translation post-synapse as a key contributor to the changes in synaptic plasticity.

In addition, analysis of synaptic connectivity in the mPFC revealed that compared to control mice, fewer connections were observed between ventral tegmental area and mPFC glutamate neurons and dopamine response was decreased in BD mice.

Notably, the researchers found that after they received the microbiota taken from individuals who were experiencing BD depression, the mice also started exhibiting depression-like behaviors. In addition, neurons in two brain regions known to be implicated in mood regulation, namely the ventral tegmental area (VTA) and the medial prefrontal cortex (mPFC), appeared to be less connected with each other.

The team also observed disruptions in the production of proteins and reduced dopamine signaling. Dopamine signaling (i.e., the release of dopamine) is essential for maintaining motivation and emotional regulation.

The results of this study confirm that microorganisms and bacteria in the gut can influence the connections between neurons in different brain regions. These altered connections could in turn have an impact on motivation, mood regulation and the processing of emotions.

Part1

The team's findings will need to be validated in humans before they can be reliably translated into psychiatric and medical insight. In the future, however, they could potentially help to identify promising pathways for the treatment of depression in patients diagnosed with BD, which are designed to alter their gut microbiota.

Anying Tang et al, Gut microbiota modulates synaptic plasticity, connectivity, and dopamine transmission in the VTA-mPFC pathway in bipolar depression, Molecular Psychiatry (2025). DOI: 10.1038/s41380-025-03398-y.

Part 2

Brain chemistry can reactivate or suppress dormant HIV

Human immunodeficiency virus (HIV) infections are still fairly common and an estimated 40 million people worldwide are currently living with this condition. The HIV virus attacks the body's immune system and thus makes those who contract it more vulnerable to a wide range of infections.

While there is still no known cure for HIV, there are now various treatment options that allow affected patients to live long and healthy lives. When treated with antiretroviral therapy (ART), the virus is known to remain in a latent state, essentially 'hiding' inside cells and forming a reservoir of dormant virus. If the medication is stopped, however, the virus can be re-awoken, causing severe immune deficiencies again.

Researchers have recently been investigating how the brain, particularly tiny molecules and protein-carrying packages released by cells, influence the persistence of HIV. In a new paper, published in Molecular Psychiatry, they presented new findings that shed new light on molecular mechanisms that can either re-ignite or suppress latent HIV.

In their experiments the researchers found that ECs collected from the brains of SIV-infected but untreated macaques strongly re-activated latent virus reservoirs increasing the activity of viral genes, the production of proteins and causing the virus to spread between cells. Interestingly, however, particles extracted from the brains of infected macaques who were treated with cannabinoids were found to suppress the re-activation of the virus.

"Cannabinoids have been shown to inhibit neuroinflammation," said the authors of the research paper. They showed that cannabinoids exert similar anti-inflammatory effects via EVs and in the current study on ECs, we report that ECs isolated from brains (basal ganglia) of rhesus monkeys have this anti-inflammatory effect and that cannabinoids modulate the cargos of the ECs, with resultant effects on latent HIV reservoirs.

Overall, the findings gathered by these researchers suggest that the brain's chemistry, particularly ECs, do play a key role in the reactivation or suppression of dormant HIV. In the future, their work could pave the way for the development of new drugs and therapeutic interventions aimed at better managing, or perhaps even curing, HIV infections.

Wasifa Naushad et al, Extracellular condensates (ECs) are endogenous modulators of HIV transcription and latency reactivation, Molecular Psychiatry (2025). DOI: 10.1038/s41380-025-03354-w.

The global fish trade is spreading 'forever chemicals' around the world

Eating fish may well be good for you, but it carries a hidden risk of exposure to so-called "forever chemicals." A new study published in the journal Science has revealed that the global seafood trade is acting as a massive delivery system for per- and polyfluoroalkyl substances (PFAS), industrial pollutants that persist in the environment for decades.

These forever chemicals are used in many products, from nonstick cookware and cosmetics to food packaging and firefighting foams. They are extremely resistant to breaking down in the environment and have been linked to a variety of serious illnesses such as cancer and liver disease.

PFAS can travel long distances around the planet in the air and through water. Once they wash into the ocean, they are absorbed by tiny organisms at the bottom of the food chain, such as plankton and algae. Because these chemicals do not break down, they accumulate in their bodies, and when small fish eat them, the toxic substances pass up the food chain. Large predatory fish, the kind that end up on our dinner plates, eat these smaller marine creatures, and as a result, the chemical concentrations build up in their tissues and organs.

In their paper, the researchers set out to map how these chemicals move once they are inside the fish. They built a computer model covering 212 different species to track how toxins accumulate up the food chain and then validated this with lab tests on fish from numerous countries. Then the team combined this data with global trade records to see how the fish and PFAS travel from one country to another.

One of the most significant findings was that the international fish trade acts like a global conveyor belt, redistributing PFAS from contaminated regions to consumers thousands of miles away.
Before this study, it was generally assumed that forever chemicals were a local problem. If your country's rivers and seas were clean, then so were the fish. However, a nation with clean water can still be exposed to high levels of PFAS through the seafood it imports from other parts of the world. For example, researchers found that Italians buy only 11% of their fish from Sweden, yet this accounts for more than 35% of their PFAS exposure.

Given that this problem doesn't respect borders, researchers argue that a unified global strategy is needed to protect public health.

Wenhui Qiu et al, Risks of per- and polyfluoroalkyl substance exposure through marine fish consumption, Science (2025). DOI: 10.1126/science.adr0351

Jennifer Sun et al, Reevaluating PFAS exposure risks from marine fish, Science (2025). DOI: 10.1126/science.aed7431

Raindrops form 'sandballs' as they roll downhill, contributing more to erosion than previously thought

We know that the initial splash of raindrops on soil contributes to erosion, but a new study, published in the Proceedings of the National Academy of Sciences, finds that the journey of the raindrop downhill might have an even bigger impact on erosion than the initial splash.

Researchers observed natural raindrops hitting the surface of a hillside and noticed that they collected particles of sand as they rolled downhill. This spurred the researchers to document the event with a camera and then take the idea to the lab.

In the lab, they constructed a 1.2 meter long bed covered with dry silicate sand and tilted at an angle of 30°. The lab conditions enabled the team to properly document the phenomenon by recording the evolution of the raindrops' shapes as they rolled and take precise measurements of the relevant parameters. They found that each raindrop formed what they refer to as "sandballs" and that they took on differing shapes, depending on the conditions, and that the sandballs can move up to 10 times more soil than the initial splash alone.

"In the initial rolling stage, drops rapidly increase their speed and sediment entrainment rate. Under increasing centrifugal force, the rolling drops undergo a metamorphosis: Their rounded shape destabilizes, as both liquid and entrained grains drift away from the core to create sandballs," the study authors write in their paper.

The researchers found that the sandy raindrops formed two distinct shapes: a peanut shape and a doughnut shape. Peanuts occurred at comparably lower velocities and maintained their grains at the surface of the drop. They only gather grains up to a certain point and then usually plateau.

"Once their mass plateaus, peanuts continue to increase their angular velocity as they roll; this sometimes causes a shift in their mode of motion, triggering an additional phase of mass accumulation. Other times, peanuts break, tumble slower or settle. If peanuts survive to the end of the slope and roll onto a flat surface, they immediately fall apart," the study authors explain.

Instead of only gathering grains at the surface, doughnut-shaped drops absorb sand grains into their interior volume, making them more dense and opaque in appearance. The researchers call the emergence of these kinds of drops "unexpected."

The team found that these drops destabilize into the doughnut shape from axisymmetric radial stretching. These shapes only occur at very high spin rates in pure-liquid drops, but occurred at slightly lower rates in the lab experiments due to the water-glycerol mixture used in the lab-based drops.

Part 1

The study authors write, "Fully developed doughnuts continue to speed up (above 1 m/s), until a point where they sometimes break apart in an apparent fracture process. This breakage occurs when the tensile force driven by the centrifugal sandball stretching overcomes the strength of capillary bonds, producing child sandballs that carve their own track as they tumble down the slope."

Studying the shapes that raindrops take on as they tumble down dry dirt hills might seem frivolous, but these dynamics have real implications for soil erosion models, which are used for predicting soil loss from rain. These models help with conservation planning, land management, and environmental assessment by estimating erosion rates, identifying more vulnerable areas, designing control measures and evaluating land health in agriculture. 

Bertil Trottet et al, Sandball genesis from raindrops, Proceedings of the National Academy of Sciences (2025). DOI: 10.1073/pnas.2519392122

Part 2

New species are being discovered faster than ever before, study suggests

According to a new  study published in Science Advances, scientists are discovering species quicker than ever before, with more than 16,000 new species discovered each year. The trend shows no sign of slowing, and the team behind the new paper predicts that the biodiversity among certain groups, such as plants, fungi, arachnids, fishes and amphibians is richer than scientists originally thought.

Researchers  analyzed the taxonomic histories of roughly 2 million species, spanning all groups of living organisms. Between 2015 and 2020—the most recent period with comprehensive data—researchers documented an average of more than 16,000 new species each year, including more than 10,000 animals (dominated by arthropods and insects), 2,500 plants and 2,000 fungi.

and the  good news is that this rate of new species discovery far outpaces the rate of species extinctions, which researchers calculated to about 10 per year.

These thousands of newly found species each year are not just microscopic organisms, but include insects, plants, fungi and even hundreds of new vertebrates.

The team also analyzed the rates of new species appearing over time to project how many species will be discovered and described in the future. For example, they projected that there might be as many as 115,000 fish species and 41,000 amphibian species, even though there are only about 42,000 fish and 9,000 amphibian species described now. They also projected that the final number of plant species might be over a half million.

Discovering new species is important because these species can't be protected until they're scientifically described. 

Additionally, the discovery of new species contributes to finding new natural products for human benefit.

Spider and snake venoms and many plants and fungi also contain natural products with potential medicinal applications, including treatments for pain and cancer.

Beyond medicine, many species have adaptations that can inspire human inventions, such as materials mimicking the "super-clinging" feet that allow geckos to climb up vertical surfaces. Scientists are still just scratching the surface of what these species can do for humanity.

Xin Li et al, The past and future of known biodiversity: Rates, patterns, and projections of new species over time, Science Advances (2025). DOI: 10.1126/sciadv.adz3071

Fathers' microplastics exposure tied to their children's metabolic problems

Paternal exposure to microplastics in mice leads to metabolic dysfunction in offspring, with female progeny showing increased susceptibility to diabetes and altered gene expression linked to inflammation. These effects are associated with changes in sperm small noncoding RNAs, indicating a mechanism for transgenerational impact of environmental pollutants.

A new study has shown for the first time that a father's exposure to microplastics (MPs) can trigger metabolic dysfunctions in his offspring. The research, conducted using mouse models, highlights a previously unknown pathway through which environmental pollutants impact the health of future generations.

While MPs have already been detected in human reproductive systems, the study, published in the Journal of the Endocrine Society, is the first to bridge the gap between paternal exposure to MPs and the long-term health of the next generation (the "F1 offspring").

MPs are tiny plastic particles (less than 5 millimeters) resulting from the breakdown of consumer products and industrial waste. Metabolic disorders refer to a cluster of conditions—including increased blood pressure, high blood sugar, and excess body fat—that increase the risk of heart disease and diabetes.

Key findings and sex-specific effects The research team found that female offspring of male mice exposed to MPs were significantly more susceptible to metabolic disorders than offspring of unexposed fathers, despite all offspring being fed the same high-fat diet.

"The exact reasons for this sex-specific effect are still unclear", say the researchers. They observed upregulation of pro-inflammatory and pro-diabetic genes in their livers—genes previously linked to diabetes. These changes were not seen in male offspring.
The research team found that while male offspring did not develop diabetes, they showed a slight yet significant decrease in fat mass. Female offspring showed decreased muscle mass alongside increased diabetes.

Seung Hyun Park et al, Paternal microplastic exposure alters sperm small non-coding RNAs and affects offspring metabolic health in mice, Journal of the Endocrine Society (2025). DOI: 10.1210/jendso/bvaf214

Why mangoes fall before they're ripe—and how science is helping them hang on

 Why your mango tree drops fruit before it's ripe? Each season, mango growers across the world watch helplessly as millions of mangoes fall to the ground too early.

These mangoes never ripen properly, never reach consumers, and represent a major loss—both economically and environmentally.
Premature fruit drop is a major contributor to low mango yields, with as little as 0.1% of fruits reaching maturity. This costs growers millions and wastes valuable resources.
As climate stress intensifies, understanding why fruit is lost before harvest has global significance. It affects everything from food security to farm profitability.

Its sensitivity to environmental stress makes it vulnerable in a less predictable and more extreme climate. Drought, heat waves, and even leaf loss can influence a natural process that leads to fruit drop.

Just like humans, plants rely on hormones to keep things growing and functioning smoothly.

These chemical messengers help regulate everything from flowering to fruit development.

But when plants experience stress, hormone levels shift. The plant starts reallocating resources to survive. Dropping fruit is often one of the first sacrifices.

One key resource that plants reallocate is carbohydrates. Developing fruit requires a steady supply of sugars, but under stress—such as leaf damage or water scarcity—the tree may struggle to produce or transport enough.

This can trigger fruit drop, as the plant prioritizes survival over reproduction.

Stress not only disrupts carbohydrate supply but also interferes with the hormonal balance in mango trees. This triggers what we call a molecular "quit signal": a message from the plant to let go of its fruit.

This signal is a part of a complex network of gene activity and hormonal cues that help the tree decide when to shed fruit.

Researchers are studying the molecular pathways behind this signal by analyzing gene signals from mango pedicel tissue—the stem that connects the fruit to the tree.

This tissue acts like a control center, managing the flow of nutrients and signals between the tree and the developing fruit. It's where the tree and fruit stay in touch, especially during stress.

By analyzing which genes are turned on or off, we can pinpoint the molecular signals involved in fruit drop, particularly those related to hormones.

This helps us move from just observing fruit drop to developing tools to control it.

One promising solution is the use of plant growth regulators, which are synthetic versions of plant hormones.

These can be applied to mango trees to help stabilize hormone levels during stressful conditions.

It's a bit like giving the tree a hormonal pep talk, encouraging it to hold onto fruit even when times are tough.

Applying plant growth regulators during flowering, before fruit has fully emerged, was more effective than applying them later in the season.

This early intervention helped reinforce the hormonal signals that support fruit retention. Initial trials have increased tree yield by up to 17%.

Even small-scale growers might one day use targeted treatments to help their trees hold on to fruit longer.

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For consumers, reducing fruit drop means better access to fresh, affordable produce. For growers, it's about staying viable in an increasingly unpredictable climate. And for policymakers, it's about preparing the horticultural industry for the challenges ahead.

Importantly, fruit drop isn't unique to mangoes. Apples, citrus, and avocados also suffer losses due to hormonal imbalances triggered by environmental stress.

Better understanding the molecular mechanisms controlling fruit drop in mango, could benefit a wide range of fruit crops globally as the climate changes.

This article is republished from THE CONVERSATION under a Creative Commons license. Read the original article.

Part 2

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Why do reindeer eyes change colour?

Get this right: 

Over 50% of Heart Attacks in Younger Women Aren't From Clogged Arteries

Traditionally, most heart attacks have been blamed on clogged arteries causing atherothrombosis – where blood clots block flow to the heart.
But research suggests we may be underestimating the role of other causes, particularly in younger adults.

Scientists from the Mayo Clinic in the US analyzed 1,474 heart attack events in people aged 65 or younger, recorded between 2003 and 2018 in Olmsted County, Minnesota. By carefully reviewing medical records and imaging, they identified a primary cause behind each case.

Strikingly, more than half of heart attacks in women were found to have non-atherothrombotic causes.

Atherothrombosis accounted for 75 percent of heart attacks in men, which wasn't surprising. But in women, it was behind 47 percent – less than half. That has major implications for the prevention and treatment of heart attacks.

This research shines a spotlight on heart attack causes that have historically been under-recognized, particularly in women. In women, 34 percent of all heart attack events were attributed to supply/demand mismatch secondary myocardial infarctions (SSDMs) – defined as an imbalance of oxygen supply and demand caused by other stressors on the body, such as anemia or an infection.

Among the other factors significantly contributing to heart attacks were spontaneous coronary artery dissections (SCADs), where tears in artery walls collect blood, and embolisms (blood clots traveling from other areas of the body).

Causes of Myocardial Infarction in Younger Patients: Troponin-Eleva...

Why the human brain matures slower than its primate relatives

The human brain is a fascinating and complex organ that supports numerous sophisticated behaviors and abilities that are observed in no other animal species. For centuries, scientists have been trying to understand what is so unique about the human brain and how it develops over the human lifespan.

Researchers have recently set out to study both the human and macaque brain, comparing their development over time using various genetic and molecular analysis tools. Their paper, published in Nature Neuroscience, highlights some key differences between the two species, with the human pre-frontal cortex (PFC) developing slower than the macaque PFC.

The researchers collected several samples of brain tissue that was surgically removed from the PFC of macaques and humans at different stages after birth. The human subjects were children with epilepsy who were undergoing surgical procedures as part of their treatment plan.

The researchers analyzed the expression of genes in single cells taken from the tissues they collected, as well as chromatin accessibility (i.e., how open DNA is within individual cells). They also mapped the expression of genes across the entire brain tissues, using a technique known as spatial transcriptomics, and looked at the types of cells that were present.

"Integrative analyses outlined species-specific dynamic trajectories of different cell types, highlighting key windows and gene regulatory networks for processes such as synaptogenesis, synaptic pruning and gliogenesis," wrote the authors in their paper.

The researchers' analyses revealed that the human PFC takes longer to develop than that of macaques. They also observed that glial progenitors (i.e., stem-like cells that later divide and develop into specific types of glial cells) proliferate more in humans.
"We identified regulatory correlates of the prolonged development of human PFC relative to macaques," wrote the researchers. "Glial progenitors showed higher proliferation capability in humans compared to macaques, associated with distinct gene expression profiles. Furthermore, we uncovered cell types and lineages most susceptible to neurodevelopmental and neuropsychiatric disorders, focusing on transcription factors with human-specific expression features."

Part 1

they gathered new valuable observations that could explain in greater detail known differences between the brain functions of humans and other primates. Notably, the researchers also identified transcription factors that modulate the development of the human brain but not of macaques, while also pinpointing types of cells in human tissues that are known to be affected in the brains of patients with specific disorders.

Jiyao Zhang et al, Single-cell spatiotemporal transcriptomic and chromatin accessibility profiling in developing postnatal human and macaque prefrontal cortex, Nature Neuroscience (2025). DOI: 10.1038/s41593-025-02150-7

Part 2

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"Our discoveries shed light on human-specific regulatory programs extending postnatal cortical maturation through coordinated neuronal and glial development, with implications for cognition and neurodevelopmental disorders," wrote the team.

How do I make clear ice at home? A food scientist shares easy tips

Clear ice forms when water freezes in a single direction, pushing air and impurities to one end, unlike typical home freezing that traps them throughout the cube and causes cloudiness. Using an insulated container to promote directional freezing produces clear ice, while water quality or boiling alone does not prevent cloudiness. Clear ice is denser, melts slower, and resists imparting flavors.

Clear ice is actually made from regular water—what's different is the freezing process.

With a little help from science, you can make clear ice at home, and it's not even that tricky. However, there are quite a few hacks on the internet that won't work. Let's dive into the physics and chemistry involved.

Why ice goes cloudy

Homemade ice is often cloudy because it has a myriad of tiny bubbles and other impurities. In a typical ice cube tray, as freezing begins and ice starts to form inward from all directions, it traps whatever is floating in the water: mostly air bubbles, dissolved minerals and gases.

These get pushed toward the center of the ice as freezing progresses and end up caught in the middle of the cube with nowhere else to go.

That's why when making ice the usual way—just pouring water into a vessel and putting in the freezer—it will always end up looking somewhat cloudy. Light scatters as it hits the finished ice cube, colliding with the concentrated core of trapped gases and minerals. This creates the cloudy appearance.

The point of clear ice

As well as looking nice, clear ice is denser and melts slower because it doesn't have those bubbles and impurities. This also means that it dilutes drinks more slowly than regular, cloudy ice.

Because it doesn't have impurities, the clear ice should also be free from any inadvertent flavors that could contaminate your drink.

Additionally, because it's less likely to crumble, clear ice can be easily cut and formed into different shapes to further dress up your cocktail.

If you've tried looking up how to make clear ice before, you've likely seen several suggestions. These include using distilled, boiled or filtered water, and a process called directional freezing. Here's the science on what works and what doesn't.

Myths about clear ice that don't work

You might think that to get clear ice, you simply need to start out with really clean water. However, a recent study found this isn't the case.

Using boiling water: Starting out with boiling water does mean the water will have less dissolved gases in it, but boiling doesn't remove all impurities. It also doesn't control the freezing process, so the ice will still become cloudy.

Using distilled water: While distilling water removes more impurities than boiling, distilled water still freezes from the outside in, concentrating any remaining impurities or air bubbles in the center, again resulting in cloudy ice.

Using filtered or tap water: Filtering the water or using tap water also doesn't stop the impurities from concentrating during the conventional freezing process.

What actually works

As it turns out, it's not the water quality that guarantees clear ice. It's all about how you freeze it. The main technique for successfully making clear ice is called "directional freezing."

Directional freezing is simply the process of forcing water to freeze in a single direction instead of from all sides at once, like it does in a regular ice cube tray.

This way, the impurities and air will be forced to the opposite side from where the freezing starts, leaving the ice clear except for a small cloudy section.

In practice, this means insulating the sides of the ice container so that the water freezes in one direction, typically from the top down. This is because heat transfer and phase transition from liquid to solid happens faster through the exposed top than the insulated sides.

Part 2

How to make clear ice at home

The simplest way to have a go at directional freezing at home is to use an insulated container—you can use a really small cooler (that is, an "esky"), an insulated mug or even a commercially available insulated ice cube tray designed for making clear ice at home.

Fill the insulated container with water and place it in the freezer, then check on it periodically.

Once all the impurities and air bubbles are concentrated in a single cloudy area at the bottom, you can either pour away this water before it's fully frozen through, or let the block freeze solid and then cut off the cloudy portion with a large serrated knife, then cut the ice into cubes for your drinks.

If using a commercial clear ice tray, it will likely come with instructions on how to get rid of the cloudy portion so you can enjoy the sparkling clear ice.

How do I make clear ice at home? A food scientist shares easy tips

Author: Paulomi (Polly) Burey

The gut bacteria that put the brakes on weight gain in mice

The gut bacterium Turicibacter reduces weight gain and improves metabolic health in mice on a high-fat diet by producing fatty molecules that lower ceramide levels. Obese individuals tend to have less Turicibacter, suggesting a potential role in human weight regulation. Turicibacter’s effects depend on dietary fat, indicating a feedback loop between diet and gut microbiota.

The gut microbiome is intimately linked to human health and weight. Differences in the gut microbiome—the bacteria and fungi in the gut—are associated with obesity and weight gain, raising the possibility that changing the microbiome could improve health. But any given person's gut contains hundreds of different microbial species, making it difficult to tell which species could help.

Now, new research has identified a specific type of gut bacteria, called Turicibacter, that improves metabolic health and reduces weight gain in mice on a high-fat diet.

People with obesity tend to have less Turicibacter, suggesting that the microbe may promote healthy weight in humans as well. The results could lead to new ways to control weight by adjusting gut bacteria.

The results are published in Cell Metabolism.

The researchers found that a rod-shaped bacterium called Turicibacter could single-handedly reduce blood sugar, levels of fat in the blood, and weight gain for mice on a high-fat diet.

Turicibacter appears to promote metabolic health by producing fatty molecules that are absorbed by the small intestine. When the researchers added purified Turibactor fats to a high-fat diet, they had the same weight-controlling effects as Turicibacter itself.

They don't yet know which fatty molecules are the important part—the bacterium produces thousands of different fats, in what Klag describes as a "lipid soup"—but they hope to narrow down on the most important molecules in future work for potential therapeutic use.

Turicibacter appears to improve metabolic health by affecting how the host produces a fatty molecule called ceramides, the researchers found.

 The fats produced by Turicibacter are able to keep ceramide levels low, even for mice on a high-fat diet.

Turicibacter levels are themselves affected by how much fat the host eats, the researchers discovered. The bacterium won't grow if there's too much fat in its environment, so mice fed a high-fat diet will lose Turicibacter from their gut microbiome unless their diet is regularly supplemented with the microbe.

The results point to a complex feedback loop, in which a fatty diet inhibits Turicibacter and fats produced by Turicibacter improve how the host responds to dietary fats.

Kendra Klag et al, Dietary fat disrupts a commensal-host lipid network that promotes metabolic health, Cell Metabolism (2025). DOI: 10.1016/j.cmet.2025.10.007

With every extinction, we lose not just a species but a treasure trove of knowledge

Extinction results in the irreversible loss of unique scientific knowledge, cultural traditions, and spiritual connections associated with each species. Current extinction rates, driven mainly by human activities, far exceed natural background levels, threatening up to 1 million species this century. These losses diminish biodiversity, erode cultural and spiritual heritage, and reduce opportunities for future discoveries.

Study shows tooth loss, not low-protein intake, drives memory decline in aging mice
Tooth loss in aging mice leads to significant memory decline and increased markers of brain cell death, independent of dietary protein intake. Reduced chewing, rather than low-protein diet, promotes inflammation and neuronal loss in hippocampal regions critical for memory, highlighting a direct link between oral health and cognitive function.

Tooth loss doesn't just make eating harder, it may also make thinking more challenging. A new study shows that aging mice missing their molars experience measurable cognitive decline, even when their nutrition remains perfectly intact.

The study examined whether tooth loss itself, independent of nutritional deficiency such as a low-protein diet, can cause cognitive decline in male mice.

To explore how chewing ability and nutrition jointly influence the brain, the research team used aging-prone male mice and assigned them to one of four conditions: a normal-protein diet with no tooth extraction, a low-protein diet with no extraction, molar extraction with a normal-protein diet, and molar extraction with a low-protein diet.

After six months, the mice underwent behavioral tests and detailed analyses of their brain tissue for markers of inflammation, neuronal loss, and cell death–related gene expression.

The results were striking: mice that lost their molars showed significant memory decline even though they received the same diet as the control groups.

This suggests that reduced masticatory stimulation, not dietary protein intake, contributes to cognitive deterioration. It is surprising that a peripheral event in the mouth can so profoundly affect the central nervous system.

Brain tissue analysis supported these behavioral findings. The results showed no interaction effect between tooth loss and low-protein diet on the levels of the Bax/Bcl-2 mRNA ratio, a marker representing cell death versus survival.

Instead, tooth loss alone significantly increased this ratio, indicating a shift toward pro-apoptotic, or cell death–promoting, activity in the brain. Losing teeth caused inflammation and cell loss in the CA1 and dentate gyrus regions of the hippocampus—areas essential for memory formation and storage.

Meanwhile, the effects of a low-protein diet were limited to the CA3 region, which plays a role in pattern completion. These findings suggest that a reduction in chewing induces pro–cell death pathways in the brain.

This study adds to growing evidence that oral health is deeply connected to brain health, and that protecting one's chewing ability may be a simple but powerful strategy for preserving cognitive function later in life.

Rie Hatakeyama et al, Tooth loss induces cognitive decline independent of low-protein diet intake in male mice, Archives of Oral Biology (2025). DOI: 10.1016/j.archoralbio.2025.106421

New sprayable powder forms instant gel barrier to stop severe bleeding in seconds

A sprayable powder hemostatic agent rapidly forms a hydrogel barrier within one second upon contact with blood, effectively stopping severe bleeding, including from deep or irregular wounds. Composed of biocompatible natural materials, it demonstrates high absorption (725%), strong adhesion (>40 kPa), low hemolysis (<3%), high cell viability (>99%), and antibacterial properties (99.9%).

Youngju Son et al, An Ionic Gelation Powder for Ultrafast Hemostasis and Accelerated Wound Healing, Advanced Functional Materials (2025). DOI: 10.1002/adfm.202523910

'Don't use them': Tanning beds triple skin cancer risk, study finds

Tanning bed use is associated with nearly a threefold increase in melanoma risk, with users developing more DNA mutations in skin cells, particularly melanocytes. Melanomas in tanning bed users often appear on body areas usually shielded from sunlight. Over 80% of common melanomas are linked to ultraviolet radiation, including that from tanning beds.

Pedram Gerami et al, Molecular effects of indoor tanning, Science Advances (2025). DOI: 10.1126/sciadv.ady4878. www.science.org/doi/10.1126/sciadv.ady4878

Clouds are vital to life—but many are becoming wispy ghosts. Here's how to see the changes above us
Cloud cover, especially highly reflective clouds near the equator, is steadily declining by 1.5–3% per decade, reducing Earth's ability to reflect solar radiation and increasing heat retention. This shift alters rainfall patterns and climate stability, with the loss often unnoticed. Clouds play a crucial role in moderating temperature and sustaining life, making their decline a significant concern.

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skies that feel hollowed out, clouds that look like they have lost their conviction. I think of them as ghost clouds. Not quite absent, but not fully there. These wispy formations drift unmoored from the systems that once gave them coherence. Too thin to reflect sunlight, too fragmented to produce rain, too sluggish to stir up wind, they give the illusion of a cloud without its function.

Clouds are vital to life – but many are becoming wispy ghosts. Here...

Traffic Has a Curious Effect on The Atmosphere's Electric Field, Study Shows

Detailed measurements collected in metropolitan Tel Aviv, Israel, have revealed how the ebb and flow of traffic throughout the week affects the electric field generated by Earth's atmosphere.

A number of specific pollutants were tracked, including gases and particles from car exhaust and tire wear, and additional compounds formed in chemical reactions with gases in the atmosphere.

The atmospheric electric field is the result of natural differences in charge between the surface and upper atmosphere, powered largely by the swirl of currents that form in thunderstorms.

A number of factors influence this planetary circuit, including fluctuations in local weather and air pollution. 

The data showed that traffic pollution in Tel Aviv has an immediate impact on the atmospheric electric field in the region, with both NOx gases and vehicle congestion peaking at the same times (the rush hours at the start and end of the working day).

There was also an association between PM2.5 particles and the electric field, though this was delayed by around two-and-a-half hours. The researchers put this down to different particle size, chemical composition, and lifetime in the atmosphere.

The team reports a noticeable weekend effect as well, with significant drops in traffic pollution corresponding with a weakening of the electrical field. That's further confirmation that the two are indeed linked.

What they observed is a direct physical link between emission peaks and electrical variability.

Nitrogen oxides reduce atmospheric conductivity very quickly, so the electric field responds almost instantaneously during traffic rush hours.

The reason behind the effect is ions: the charged particles in the air. Pollutants can capture these ions, reducing the conductivity of the atmospheric electric field, which then triggers a compensatory effect where the electric field gets stronger.

These changes aren't dangerous, and nor is the electric field itself .

Effects of urban air pollution on the fair-weather electric field i...

Ancient African bedrock reveals the violent beginnings of life on our blue planet

Ancient bedrock from the Makhonjwa Mountains reveals that early Earth featured extensive oceans, intense volcanic activity, and a hostile atmosphere rich in methane and CO2 but lacking oxygen. Life began as anaerobic microbes near undersea vents, thriving despite frequent volcanic eruptions, earthquakes, and asteroid impacts. Plate tectonics and a stable climate enabled Earth to remain habitable and blue.

The Oldest Rocks on Earth | Columbia University Press

Ancient African bedrock reveals the violent beginnings of life on o...

Evidence of upright walking found in 7-million-year-old Sahelanthropus fossils

Analysis of Sahelanthropus tchadensis fossils using 3D methods identified features unique to bipedal hominins, including a femoral tubercle, femoral antetorsion, and gluteal muscle attachments. These findings indicate that this seven-million-year-old species was adapted for upright walking, making it the earliest known bipedal hominin.

The analysis revealed three features that point to bipedalism in Sahelanthropus:

The presence of a femoral tubercle, which provides attachment for the iliofemoral ligament linking the pelvis to the femur and has so far been identified only in hominins

A natural twist, specifically within the range of hominins, in the femur—or femoral antetorsion—that helps legs to point forward, thereby aiding walking.

The presence, drawn from the 3D analysis, of gluteal, or butt, muscles similar to those in early hominins that keep hips stable and aid in standing, walking, and running.

Scott Williams, Earliest evidence of hominin bipedalism in Sahelanthropus tchadensis, Science Advances (2026). DOI: 10.1126/sciadv.adv0130. www.science.org/doi/10.1126/sciadv.adv0130

Two white-blooded fish, two paths: Icefish and noodlefish independently lose red blood cell function

Both Antarctic icefish and Asian noodlefish independently evolved to lack hemoglobin and red blood cells, resulting in white blood. Icefish survive in cold, oxygen-rich waters by dissolving oxygen directly in their blood, while noodlefish, living in warmer waters, lost myoglobin and have nonfunctional hemoglobin genes, likely aided by their short, juvenile-like life span. These findings highlight distinct evolutionary paths to similar physiological outcomes.

 Yu-Long Li et al, Independent evolutionary deterioration of the oxygen-transport system in Asian noodlefishes and Antarctic icefishes, Current Biology (2025). DOI: 10.1016/j.cub.2025.05.050

Bacteria reveal second 'shutdown mode' for surviving antibiotic treatment
Bacteria can survive antibiotic treatment through two distinct growth-arrest states: a regulated, protective dormancy and a disrupted, dysregulated arrest marked by impaired membrane stability. This duality explains conflicting observations of antibiotic persistence and suggests that targeting each state differently could improve treatment effectiveness and reduce infection relapse.

A new study reveals that bacteria can survive antibiotic treatment through two fundamentally different "shutdown modes," not just the classic idea of dormancy. The paper is published in the journal Science Advances.

The researchers show that some cells enter a regulated, protective growth arrest, a controlled dormant state that shields them from antibiotics, while others survive in a disrupted, dysregulated growth arrest, a malfunctioning state marked by vulnerabilities, especially impaired cell membrane stability. This distinction is important because antibiotic persistence is a major cause of treatment failure and relapsing infections even when bacteria are not genetically resistant, and it has remained scientifically confusing for years, with studies reporting conflicting results.

By demonstrating that persistence can come from two distinct biological states, the work helps explain those contradictions and provides a practical path forward: different persister types may require different treatment strategies, making it possible to design more effective therapies that prevent infections from coming back.

For years, persistence has largely been blamed on bacteria that shut down and lie dormant, essentially going into a kind of sleep that protects them from antibiotics designed to target active growth. But new research reveals that this explanation tells only part of the story.

The study shows that high survival under antibiotics can originate from two fundamentally different growth-arrest states, and they are not just variations of the same "sleeping" behavior. One is a controlled, regulated shutdown, the classic dormancy model. The other is something entirely different: a disrupted, dysregulated arrest, where bacteria survive not by protective calm but by entering a malfunctioning state with distinct vulnerabilities.

Part 1

Two 'survival modes' and why they matter
The researchers identified two archetypes of growth arrest that can both lead to persistence, but for very different reasons:

Regulated growth arrest: a protected dormant state. In this mode, bacteria intentionally slow down and enter a stable, defended condition. These cells are harder to kill because many antibiotics rely on bacterial growth to be effective.

Disrupted growth arrest: survival through breakdown. In the second mode, bacteria enter a dysregulated and disrupted state. This is not a planned shutdown, but a loss of normal cellular control. These bacteria show a broad impairment in membrane homeostasis, a core function needed to maintain the integrity of the cell. That weakness could become a key treatment target.
Antibiotic persistence plays a role in recurring infections across a wide range of settings, from chronic urinary tract infections to infections tied to medical implants. Yet despite intense research, scientists have struggled to agree on a single mechanism explaining why persister cells survive. Different experiments have produced conflicting results about what persisters look like and how they behave.

This study offers an explanation: researchers may have been observing different types of growth-arrested bacteria without recognizing they were distinct.

By separating persistence into two different physiological states, the findings suggest a future where treatments could be tailored, targeting dormant persisters one way, and disrupted persisters another.
How the researchers saw what others missed
The team combined mathematical modeling with several high-resolution experimental tools, including:

Transcriptomics, to measure how bacterial gene expression shifts under stress
Microcalorimetry, to track metabolic changes through tiny heat signals
Microfluidics, allowing scientists to observe single bacterial cells under controlled conditions
Together, these approaches revealed clear biological signatures distinguishing regulated growth arrest from disrupted growth arrest, along with the specific vulnerabilities of the disrupted state.

Adi Rotem et al, Differentiation between regulated and disrupted growth-arrests allows tailoring of effective treatments for antibiotic persistence, Science Advances (2026). DOI: 10.1126/sciadv.adt6577. www.science.org/doi/10.1126/sciadv.adt6577

Part 2

Tumor bacteria linked to immunotherapy resistance in head and neck cancer

Researchers have discovered that bacteria inside cancerous tumors may be key to understanding why immunotherapy works for some patients but not others.
Elevated bacterial levels within head and neck squamous cell carcinoma tumors suppress immune responses and contribute to resistance against immunotherapy. These bacteria attract neutrophils, which can inhibit the immune activity required for effective treatment. Reducing tumor bacteria with antibiotics may enhance immunotherapy efficacy, suggesting new avenues for patient selection and targeted interventions.

These studies shift the focus of immunotherapy resistance research beyond tumor genetics to unexpected factors like the tumor microbiome.

By identifying bacteria as a key barrier to treatment, we're opening the door to new strategies for patient selection and targeted antibiotic therapies, potentially improving outcomes for those who don't benefit from immunotherapy, the researchers say.

The research confirmed that patients with high tumor bacteria levels had poorer outcomes with immunotherapy compared to standard chemoradiotherapy.

Together, the two studies showed that elevated bacteria levels in tumors attract neutrophils, white blood cells that fight infection. While neutrophils are essential for combating bacterial infections, in cancer they can suppress the immune system needed for immunotherapy to work effectively.

These findings lay the foundation for future research on why bacteria are attracted to tumors and how to modify them to improve treatment.

1. Tumor ecosystem and microbiome features associated with efficacy and resistance to avelumab plus chemoradiotherapy in head and neck cancer, Nature Cancer (2025). DOI: 10.1038/s43018-025-01068-0

2. Nature Cancer (2025). www.nature.com/articles/s43018-025-01067-1

Assisted reproductive technology associated with higher risk of childhood atopic diseases

Researchers  report higher risks of atopic disease among children conceived via assisted reproductive technology compared to those conceived naturally.

Assisted reproductive technology use has increased, with estimates placing assisted reproductive technology at 1% to 4% of births, especially in high-income societies, alongside wider use of embryo transfer.

Atopic disease covers three conditions; asthma, allergic rhinitis, and atopic dermatitis. Atopic diseases are believed to be influenced by genetic factors and environmental triggers, with developmental origins of health and disease theory proposing that fetal-stage factors can program changes in organ and tissue structure and function.

In the study, "Atopic Disease Development in Offspring Conceived via Assisted Reproductive Technology," published in JAMA Network Open, researchers conducted a retrospective, population-based cohort analysis to investigate whether conception via assisted reproductive technology was associated with atopic disease development in offspring.

Data came from a pool of 23.5 million people in Taiwan through Taiwan's National Health Insurance Research Database, Assisted Reproduction Database, and the Maternal and Child Health Database.

Assisted reproductive technology included procedures such as in vitro fertilization and embryo transfer, intracytoplasmic sperm injection, gamete intrafallopian transfer, zygote intrafallopian transfer, and tubal embryo transfer.

Part 1

Cohort groups included 13,957 children conceived via assisted reproductive technology and 55,828 children conceived naturally after 1:4 matching by maternal age, neonatal sex, and birth month.

Asthma, allergic rhinitis, and atopic dermatitis were analyzed and reported individually, allowing a child to receive one, two, or all three diagnoses during follow-up. Mean follow-up for asthma measured 7.99 years in the assisted reproductive technology group and 8.41 years in the control group, with allergic rhinitis at 5.79 and 6.34 years, and atopic dermatitis at 7.34 and 7.62 years.
Intracytoplasmic sperm injection use showed no statistically significant differences in risk estimates across the three outcomes. Adjusted hazard ratios measured 1.04 for asthma, 0.99 for allergic rhinitis, and 1.04 for atopic dermatitis.

Fresh embryo transfer carried a higher allergic rhinitis risk than frozen embryo transfer, with an adjusted hazard ratio of 1.12. Asthma showed no statistically significant difference between fresh and frozen embryo transfer, with an adjusted hazard ratio of 0.96, and atopic dermatitis showed no statistically significant difference, with an adjusted hazard ratio of 1.01.

Interaction testing showed no statistically significant interaction between intracytoplasmic sperm injection and embryo type for asthma, allergic rhinitis, or atopic dermatitis.
Researchers conclude that children conceived via assisted reproductive technology had a higher risk of developing asthma, allergic rhinitis, or atopic dermatitis than children conceived naturally. Findings supported an association between assisted reproductive technology conception and later atopic disease development across the outcomes evaluated.

Yao-Chi Hsieh et al, Atopic Disease Development in Offspring Conceived via Assisted Reproductive Technology, JAMA Network Open (2025). DOI: 10.1001/jamanetworkopen.2025.51690

Part 2