Rivalry with neighboring groups may be a key driver of male size in primates

In many primate species, males are much larger than their female counterparts, which is generally attributed to male competition for mates (sexual selection). But bigger bodies may not just be about alpha males defeating rivals. They could also come about because of competition between neighbouring social groups, according to a new study published in the journal Biology Letters.

The authors thought that the standard scientific view that a primate male's size was mostly determined by rivalry within the same group was not the full story. They wanted to see if the threat from outsiders was an even more powerful evolutionary engine. One of the reasons for this was that primate groups are not isolated. They tend to live close to other groups, meaning they must share or fight for resources.

The team searched through scientific literature and collected data on 146 different primate species. They compared male and female size against several measures of between-group competition. These included the daily encounter rate, the proportion of encounters that were antagonistic, and the home range overlap (the percentage of a group's total range that is shared with a neighbouring group).

It turns out that the mating system, which describes how males and females pair up for breeding, was not a strong predictor of size differences. Instead, it was pressure for space. The authors discovered that the more a group's territory overlaps with its neighbours, the larger the males are compared to the females. Frequent encounters with neighbouring groups also appear to promote the evolution of larger male bodies.

Their hypothesis is that the evolutionary advantage and driver of size is that it acts as a silent deterrent. Being larger helps a male defend resources and guard mates by simply being intimidating. This reduces the need for risky physical fights. Over time, evolution favors these larger males because they can successfully protect their group and territory by their physical presence alone.

"Home range overlap may select for larger males to deter rivals, defend resources or monopolize females across shared territories, potentially without frequent physical contests," wrote the research team in their paper.

Cyril C. Grueter et al, Effects of between-group competition on sexual size dimorphism in primates, Biology Letters (2026). DOI: 10.1098/rsbl.2025.0680

Natural malaria immunity:  The secret to why some people never get sick

People living in regions where malaria outbreaks are common experience repeated exposure to the disease, which gradually teaches the body how to fight back. Over time, they develop naturally acquired immunity that helps the body control the density of malaria parasites (Plasmodium falciparum) in the blood and prevent the development of clinical symptoms.

A recent study set out to pinpoint the specific parts of the malaria parasite that the immune system targets to protect the body from disease. The researchers deliberately infected 142 Kenyan adults known to be immune to malaria, then monitored their symptoms and parasite levels. They successfully identified six merozoite antigens—proteins on the surface of the malaria parasite—that were linked to natural immunity against the disease. The findings were published in Nature Communications.

 Six key proteins linked to protection: MSP1, MSP11, RAMA, MSP7, PHISTB, and PTEX150.

The team found that immunity was strongest when the body produced antibodies against more than one protein, as combinations of antibodies worked more effectively. They also observed that individuals with high levels of antibodies against four of the six proteins were the ones who showed complete protection from developing malaria symptoms during the study.

For vaccine researchers, these findings can open up promising new directions in the fight against malaria. More effective vaccines could ultimately save millions of lives, particularly among children in Africa, where the disease continues to wreak havoc every year.

Rodney Ogwang et al, Controlled human malaria infection in adults identify combinations of merozoite antigens associated with clinical immunity, Nature Communications (2026). DOI: 10.1038/s41467-026-72716-x

Losing grip on reality while using ChatGPT
Prolonged, intensive interactions with AI chatbots such as ChatGPT have been associated with the emergence of AI-induced delusions or psychosis, characterized by loss of reality, social isolation, and significant personal and psychological harm. These effects appear to be exacerbated by chatbot behaviors such as excessive flattery and emotional engagement, raising concerns about mental health risks and the need for regulatory oversight.
An unknown number of people have lost their grip on reality while communicating with chatbots, an experience tentatively being called AI-induced delusion or psychosis.
This is not a clinical diagnosis. Researchers and mental health specialists are racing to catch up to this new, little-understood phenomenon, which so far appears to particularly affect users of OpenAI's ChatGPT.

In the meantime, an online community set up by a 26-year-old Canadian has become the world's most prominent support group for these delusions, which they prefer to call "spiraling."
Questions are also being asked about whether AI companies are doing enough to protect vulnerable people.
People are literally getting brainwashed by a robot!

RESEARCH REPORTS

Loss of the X chromosome is associated with reduced chance of natural pregnancy

Chromosomes carry genetic information for biological sex, which generally assigns women two X chromosomes and men XY chromosomes. This is a basic principle of human genetics most are taught in grade school biology, but it is little known that with aging, men can lose the Y chromosome, and women can lose one of their X chromosomes.

These phenomena are known as loss of the Y chromosome (LOY) and loss of the X chromosome (LOX). LOY is associated with several diseases such as Alzheimer's disease, diabetes mellitus, and heart disease, while LOX may be linked to acute myeloid leukemia and pneumonia.
Loss of the X chromosome (LOX) in white blood cells is more prevalent in women with infertility, and a LOX cell proportion above approximately 0.9% is associated with reduced likelihood of natural pregnancy. LOX levels were not correlated with anti-Müllerian hormone (AMH), suggesting that combining LOX and AMH assessments may improve prediction of natural pregnancy potential.
The results revealed that women with infertility had a significantly higher proportion of LOX cells. Furthermore, when the proportion of LOX cells in white blood cells exceeded approximately 0.9%, the likelihood of achieving natural pregnancy decreased.
In the future, measuring LOX in individuals experiencing infertility may help determine whether natural pregnancy is possible or whether fertility treatments, such as in vitro fertilization, should be initiated at an earlier stage.

Taiki Kikuchi et al, Haematopoietic loss of the X chromosome is associated with a lower likelihood of natural conception, Reproductive BioMedicine Online (2026). DOI: 10.1016/j.rbmo.2026.105638

Osteoporosis could increase mortality risk in postmenopausal women, study suggests
Osteoporosis in postmenopausal women is associated with a 47% increased risk of mortality, particularly when femoral bone mineral density falls within the osteoporotic range (0.46–0.71 g/cm2). Lower bone mineral density serves as a prognostic biomarker for systemic health, indicating elevated mortality risk beyond fracture incidence.
Osteoporosis, which is highly prevalent in postmenopausal women, has long been associated with an increased risk of fractures. A new study suggests it may also increase a woman's overall risk of death—by as much as 47%—especially within specific ranges of bone mineral density (0.46-0.71 g/cm2 for total femur bone mineral density). Results of the study are published online in Menopause.
As the total population ages, the incidence of osteoporosis also increases. In 2022, the global prevalence of osteoporosis was 19.7%, with women exhibiting a significantly higher prevalence than men (23.1%).

One study projected that by 2030 the number of people affected by osteoporosis worldwide will reach 263 million, with 154 million of them being women. Previous research has documented that postmenopausal women experience a significantly higher mortality rate within one year after hip or vertebral fractures.

The decline of estrogen levels during the menopause transition has been linked to a number of physiologic changes across multiple systems, including bone metabolism, cardiovascular function, muscle mass, and fat distribution.

Regarding bone health, declining estrogen levels accelerate bone resorption and inhibit bone formation, leading to a rapid decrease in bone mineral density (especially in the femoral region), which in turn increases the risk of osteoporosis and fractures.
In this new study involving nearly 3,000 postmenopausal women, bone mineral density at four femoral sites was assessed using dual-energy X-ray absorptiometry.

The analysis revealed that mortality risk was significantly elevated when femoral bone mineral density reached the osteoporotic threshold or in the presence of osteoporotic fractures.

After full adjustment, osteoporosis was associated with a 47% increased risk of mortality. A stronger inverse association between increased bone mineral density and mortality risk was observed within specific ranges, suggesting that bone mineral density should serve as a prognostic biomarker of systemic health.

Osteoporosis often remains a silent threat after menopause, despite its profound effect on women's lives—from loss of height, poor balance, and reduced mobility to disfigurement, pain, and even premature death.
Early screening and preventive measures, including a calcium-rich diet (preferably from food sources), regular weight-bearing exercise, and hormone therapy when appropriate, can significantly improve bone health and reduce risks not only of fractures but also cardiovascular disease, certain cancers, and dementia.

Zheng Zhang et al, Femoral bone mineral density and mortality risk in postmenopausal women: a National Health and Nutrition Examination Survey cohort study, Menopause (2026). DOI: 10.1097/gme.0000000000002787

Why Planes Fly Across The Atlantic At Night

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AI-generated fake citations are flooding scientific literature across publications, scientists warn

The citations at the end of a research paper should represent a solid foundation of existing knowledge about a particular field, a pool of peer-reviewed sources built over years of research and study. However, with the increasing use of AI and large language models in writing research papers, there's a growing chance that the citation someone clicks on may not even exist, and that the study, the source, or even the researchers themselves could be entirely fake.

In a recent study posted to the arXiv preprint server, researchers audited millions of papers and found that an estimated 146,900 hallucinated citations were present in research papers hosted on four major scientific repositories—arXiv, bioRxiv, SSRN, and PubMed Central. These numbers were for 2025 alone.

The hallucinated citations were not limited to a handful of bad apples but appeared across many papers, each containing a small number of fake references, pointing to a broader pattern of researchers using AI yet failing to fact-check the output.

Scientific research advances by building on prior discoveries, where each new finding depends on what has already been established. In this space, the rapid growth of AI use and the accompanying hallucinations show no sign of slowing down, which raises serious concerns.

Generative AI tools built on large language models are quite good at producing information that sounds plausible and realistic, yet is completely fabricated or incorrect. These models are trained on massive datasets to learn patterns, which they then use to predict the next word and generate new content.

As a result, they can sometimes produce output based on pattern prediction rather than any reliance on actual facts.

Hallucinated content isn't limited to scientific literature, as it makes its appearances in government reports, legal filings, and even news articles from renowned media publications.

Scientists have previously studied AI hallucinations, but most studies were either conducted under laboratory conditions or confined to small samples or narrow domains. The actual scale and impact of such mistakes, particularly within scientific literature, was still unclear.

The audit revealed a sharp surge in fake, non-existent citations appearing in serious scientific papers, especially from mid-2024 onward.

The study found that early-career scientists and small teams were most likely to include these fake citations, and in some cases, these same researchers saw their productivity increase by roughly three times since the advent of AI.

Part 1

Another interesting pattern appeared where hallucinated references tended to disproportionately credit already prominent and male scholars, suggesting that errors generated by LLMs may reinforce existing inequalities in scientific recognition.

The data exposed existing gaps in guardrails, such as preprint moderation, journal editors, and peer review, which could catch only a small fraction of these errors. For example, while arXiv moderation caught some issues, an estimated 78.8% of non-existent citations still passed through and appeared on the platform.
The researchers warn that hallucinations are steadily infiltrating knowledge production at scale, threatening both its reliability and equity. Without intervention, its impact could bleed from the future of scientific discovery to policy and public understanding.

Zhenyue Zhao et al, LLM hallucinations in the wild: Large-scale evidence from non-existent citations, arXiv (2026). DOI: 10.48550/arxiv.2605.07723

AI system developed to help prevent airport collisions

An AI system, World2Rules, uses neural and symbolic methods to learn explicit, interpretable safety rules from airport movement data, distinguishing normal from unsafe behaviours. It identifies and explains specific rule violations in real time, enabling earlier and clearer warnings of potential collisions. The approach is adaptable to other safety-critical domains by learning relevant rules and behaviours.

https://www.cmu.edu/news/stories/archives/2026/may/cmu-researchers-...

You can persuade AI models to accept falsehoods as truth, study shows

Large language models can be persuaded to accept and reinforce falsehoods when subjected to conversational pressure, even after initially identifying statements as false. This vulnerability, not captured by traditional evaluation methods, raises concerns about AI reliability in interactive settings, especially in critical domains such as health or law. The degree of resistance to falsehoods varies among models, and the mechanisms underlying this behaviour remain unclear.

original article.

By age 4, one side of the brain is already calling the shots on language

The brain's capacity to use and understand language expands rapidly in the first years of life, as babies start to make sense of the words they hear and eventually begin to piece together sentences of their own. The language-processing parts of the brain that make this possible continue to evolve in older children, as they expand their vocabularies and learn to use language more flexibly.

By age four, the brain's language network is already strongly lateralized to the left hemisphere, similar to adults, and this lateralization does not gradually emerge with age. The integration and responsiveness of the language network increase through adolescence, but right hemisphere involvement in language processing in developmental disorders is not due to delayed lateralization. Early brain plasticity allows the right hemisphere to compensate for left hemisphere damage despite early lateralization.

Brain researchers have captured snapshots of the developing language-processing network in brain scans of hundreds of children and adolescents. Their data, reported in Nature Communications, show that the network continues to mature, becoming better integrated and increasingly responsive until around age 16. But they also found that a key feature of the adult language network is established early on: its localization in the left side of the brain.

Ola Ozernov-Palchik et al, Precision fMRI reveals that the language network exhibits adult-like left-hemispheric lateralization by 4 years of age, Nature Communications (2026). DOI: 10.1038/s41467-026-72916-5

How chemotherapy can backfire: An immune shift tied to tumor resistance and poorer outcomes

Chemotherapy with gemcitabine can induce pyroptosis in cancer cells, leading to the release of IL-1α, which disrupts bone marrow function and skews immune cell production toward pro-tumorigenic neutrophils. This immune shift can promote tumor resistance and poorer outcomes, but blocking IL-1α or its signaling pathway restores normal immune responses and enhances chemotherapy efficacy.

Stephen QR Wong et al, Chemotherapy-induced activation of caspase-1 and IL-1α release by cancer cells remotely skews myelopoiesis to drive pro tumorigenic systemic neutrophil-dominant inflammation, Nature Communications (2026). DOI: 10.1038/s41467-026-71471-3

Severe childhood malaria linked to cognitive impairment later in life

Survivors of severe childhood malaria, including cerebral malaria and severe malarial anemia, exhibit persistent cognitive and academic impairments into adolescence, with cognition scores 3 to 7 IQ points lower than peers. Acute kidney injury and elevated uric acid during illness are associated with worse outcomes, indicating a need for improved prevention and therapeutic strategies.

Paul Bangirana et al, Long-Term Cognitive Ability and Academic Achievement After Childhood Severe Malaria, JAMA (2026). DOI: 10.1001/jama.2026.0704

WHO declares global health emergency over Ebola outbreak in Congo and Uganda
A Bundibugyo Ebola virus outbreak in Congo and Uganda has resulted in over 300 suspected cases and 88 deaths, prompting a WHO public health emergency declaration. The Bundibugyo variant lacks approved therapeutics or vaccines, complicating containment, especially amid conflict and migration. Delayed detection and limited diagnostic capacity have hindered response, raising concerns about wider regional spread.

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WHO keeps evaluation of hantavirus as 'low risk'

The global public health risk from the hantavirus outbreak linked to the cruise ship remains low, according to current assessments. Additional cases may occur among those exposed before containment, but onward transmission risk is expected to decrease after disembarkation and control measures.

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PCOS been given a new name?
Polycystic ovary syndrome (PCOS) has been renamed polyendocrine metabolic ovarian syndrome (PMOS) to better reflect its complex, multisystem nature involving hormonal, metabolic, and ovarian dysfunction. The new name aims to improve recognition of associated risks such as diabetes, cardiovascular disease, and mental health issues, and to promote more comprehensive, multidisciplinary care. Diagnostic criteria remain unchanged.

https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(26)00717-8/fulltext

If AI can translate instantly, why learn another language?
AI translation provides rapid, accessible communication but cannot replicate the cognitive, cultural, and emotional benefits of learning a language. Multilingual experience is linked to enhanced visuospatial working memory, especially in older adults, and may contribute to cognitive resilience and delayed onset of neurodegenerative diseases. Language learning fosters deeper cultural understanding and personal expression, which AI tools cannot fully substitute.

original article.

Consistency check casts doubt on evolving dark energy

Cosmologists have long struggled to determine whether the universe's accelerating expansion is being driven by a simple cosmological constant, or whether dark energy's influence is evolving over time. In a new analysis published in Physical Review D, physicists have identified a subtle impact on the inference of the nature of dark energy, due to a tiny mismatch between a fundamental cosmological distance relation and two key datasets used to measure the properties of dark energy.

The result casts fresh doubt on the robustness of the recent claims that dark energy could be evolving over time—perhaps bringing us a step closer to solving one of cosmology's most enduring challenges.

Through their analysis, the duo found that both the supernova and DESI datasets are broadly consistent with the cosmic distance duality relation—but with a small mismatch. Crucially, this minor discrepancy correlates with a shift in the dark energy equation of state parameters away from the values expected for a simple cosmological constant. The results show that even a marginally significant mismatch can have meaningful consequences for the link between the dark energy equation of state and possible systematic errors in measuring the shape of the universe's expansion history.

Samsuzzaman Afroz et al, Hint toward an inconsistency between BAO and supernovae datasets: The evidence of redshift evolving dark energy from DESI DR2 is absent, Physical Review D (2026). DOI: 10.1103/k59d-l795. On arXiv: DOI: 10.48550/arxiv.2504.16868

Swarms of tiny light-controlled robots could revolutionize wound care

Having a swarm of microbots moving across your body may sound like the stuff of a horror movie, but it could actually be the future of targeted drug delivery and advanced wound healing. Scientists have developed a way to use blue and red light as a remote control to assemble and disperse swarms of biohybrid microrobots that could one day transform how we treat injuries.
The microrobots come in two parts. The first is a living green microalga called Chlamydomonas reinhardtii (CR), which uses two tail-like structures (flagella) to swim through aquatic environments and respond to light.

The second part consists of nanoparticles made of a biodegradable plastic called PLGA. These act like tiny backpacks that can be loaded with medicine and are given a positive charge so they can attach to the algae, which has a negative charge.

In nature, CR algae are highly sensitive to light and use their flagella to swim toward or away from it to survive. Their behaviour changes depending on the colour of the light they encounter.
Taking advantage of this, the researchers developed a system where they used light to guide millions of cells to split apart, merge together, and change shape on command, creating a variety of patterns like a gear and a star.

Such reversible swarming behavior is realized by combining the wavelength-dependent assembly ability of CR and its inherent phototactic properties with light exposures through a series of different mask openings that define the desired swarm geometry.
To demonstrate how this innovation could work in a medical setting, scientists tested it on a simulated wound on an artificial skin model.
They used an AI program to automatically scan the shape of the injury and project the exact patterns of light needed to guide the microrobots. These tiny medical helpers successfully carried and released drug-loaded particles to the target area.

Víctor de la Asunción-Nadal et al, Light-switchable swarming of biohybrid microrobots, Science Advances (2026). DOI: 10.1126/sciadv.aed0994

A de-extinction company has hatched live chicks from an artificial eggshell

A biotech company that aims to resurrect lost creatures said this week it has hatched live chicks in an artificial environment—a development that was met with mixed reviews from scientists and critics of its de-extinction mission.

Twenty-six baby chickens—ranging from a few days to several months old—were born from a 3D printed lattice structure that mimics an eggshell, according to Colossal Biosciences.

Colossal previously announced it had genetically engineered living animals to resemble extinct species, including mice with long hair like the woolly mammoth and wolf pups that take after dire wolves.

Independent scientists say the technology, while impressive, lacks some components to be truly considered an artificial egg. And they said the idea of reviving extinct beasts is likely impossible.

To hatch the chicks, Colossal scientists poured fertilized eggs into the artificial system and placed them in an incubator. They also added calcium, which is normally absorbed from the eggshell, and imaged the embryos' development and growth in real-time.

Scientists say Colossal has designed an artificial eggshell with a membrane that allows the right amount of oxygen to get in, just like a real egg. But other components of an egg—like temporary organs that form to nourish and stabilize the growing chick and remove waste—weren't included.

That's not an artificial egg because they have poured in all the other parts that make it an egg. It's an artificial eggshell.

Source: News Agencies

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Scientists solved 200-year-old puzzle of how tobacco plants make nicotine

Scientists have uncovered how tobacco plants naturally make nicotine, solving a mystery that has puzzled researchers for nearly two centuries. The discovery, published in Nature Communications, could lead to safer production of medicines and vaccines using tobacco plants, without the unwanted nicotine.

The biosynthetic pathway for nicotine in tobacco plants has been elucidated, identifying the missing genes and enzymes, including NaGR and NicGS, responsible for assembling nicotine from two metabolic precursors. Nicotine biosynthesis involves an initial attachment to a glucose molecule, which is removed in the final step, explaining previous difficulties in tracing the process. This knowledge enables the potential removal or modification of nicotine in tobacco used for pharmaceutical production.
Scientists have now discovered the missing genes and enzyme that tobacco plants need to make nicotine, and recreated the process in the lab and inside living plants, proving how it works.

Benjamin T. W. Schwabe et al, Nicotine biosynthesis is completed by cryptic activating glucosylation, Nature Communications (2026). DOI: 10.1038/s41467-026-72705-0

Urban life makes animals bolder, more aggressive across 133 species, analysis finds

A global analysis has found that urban animals are bolder and more aggressive, exploratory and active than their rural counterparts.

Urban animals across 133 species exhibit increased boldness, aggression, exploration, and activity compared to rural counterparts, with effects most pronounced in birds. These behavioural shifts may elevate risks of human-wildlife conflict and zoonotic disease transmission. Data are limited for non-avian taxa, highlighting the need for broader research and consideration of animal behaviour in urban planning.

Global meta-analysis reveals urban-associated behavioral differences among wild populations, Journal of Animal Ecology (2026). DOI: 10.1111/1365-2656.70269

Human cells can exchange genomic DNA that alters cell behavior
Large fragments of genomic DNA can transfer directly between human cells via nanotubes, become incorporated into recipient cell genomes, and remain biologically active, altering cell behaviour. The DNA can persist and change how the recipient cell functions. This process occurs between different cell types and challenges the view that human cell genomes evolve independently, with potential implications for understanding genome evolution and disease mechanisms such as cancer.
A study conducted by researchers shows DNA damage and errors in cell division can cause pieces of genomic DNA to escape from the nucleus and move into nearby cells through nanotubes—thin, tubelike structures that briefly form when some cells come into contact.

Once inside a recipient cell, transferred DNA can enter the nucleus and become incorporated into the cell's genome. Researchers found that transferred DNA persisted through multiple rounds of cell division, remained biologically active, and conferred new traits to recipient cells.
Using advanced live-cell microscopy, the team observed DNA moving from one cell to another. In one experiment, pieces of the Y chromosome transferred from male cells into female cells. The transferred DNA carried male-specific genes that became active in the female cells, indicating the transferred DNA remained functional after entering the recipient cell.
Researchers also observed DNA transfer between different types of human cells.

Elizabeth G. Maurais et al, Genome instability triggers intercellular DNA transfer between human cells, Cell (2026). DOI: 10.1016/j.cell.2026.04.041

A mop, a broom and a calmer mind. Why some find mental health benefits in everyday tasks

It can be tempting to dismiss housework as drudgery, so dreaded or anxiety-inducing that it's best delegated to others if at all possible.
But experts from Zen monks to psychologists say there are mental health benefits to be found in such manual chores as sweeping, mopping and clearing away clutter. These tasks can encourage mindfulness or permit the mind to wander, all while producing a concrete sense of achievement in accomplishing the basic tasks of daily life.

As one famous Zen saying goes:

"Before enlightenment, chop wood, carry water. After enlightenment, chop wood, carry water."
Zen apprentices, or "unsui" monks, spend much of their time cleaning and tidying.

The monks sweep dust to remove worldly desires. They scrub dirt to free themselves of attachments!
A clinical psychologist based in Greenwich, Connecticut, agrees and confirms that the process of cleaning can be calming and almost meditative.
There is a link between mental health and the act of cleaning!
Repetitive, physical activities like cleaning can be regulating for the nervous system because they're predictable, structured and give a clear sense of completion. That gives people a feeling of control and grounding.
Plus, you can immediately see the result of what you've done, which can be satisfying in a way that many cognitive or emotional tasks aren't.

In a clean space, even if the person who cleaned it is not there, you can feel their consideration and awareness. This awareness creates a sense of peace and safety, similar to why sacred spaces feel different from the busy streets.

Source: News agencies

A key science publishing platform is cracking down on AI slop

AI-generated text is on the rise everywhere. A study released last week suggests half of new articles published online are now "primarily AI-generated."
Science is not immune to this trend. Last month, the journal Organization Science published a study of how the rise of AI has affected submissions and peer reviews since the release of ChatGPT in 2022. Reporting a dramatic rise in submitted papers and a drop in quality, the authors conclude that "the current state of AI tools, amplified by existing publish-or-perish incentives, appears to be pushing the system toward an equilibrium of more rather than better research."
A common problem in AI-generated research writing is hallucinated citations: references to other research that does not exist.

The traditional safeguard against poor quality in scholarly publishing is peer review: another expert in the subject at hand reads the research paper and interrogates the work behind it before it can be published.

However, the peer review system was already struggling before AI. Pressured researchers often have little time or incentive to do the unpaid work of peer review.

And on arXiv, which publishes preprints—articles which have most often not been peer-reviewed—even this system is not available. Last year, flooded with AI-generated submissions, the site stopped accepting certain types of article.

A study published in January (itself a preprint) estimated around 1 in 8 papers in biomedical science now contain AI-generated text.

Most researchers would agree that AI-generated text is not a problem in itself. The problem is the lower-quality work that AI can make easy to produce.
Part 1

The pre-print website arXiv has announced that researchers who put their names to papers which included errors clearly generated by artificial intelligence (AI) will face a year-long ban and ongoing restrictions.

arXiv has implemented a year-long ban for authors submitting papers with clear, unchecked AI-generated errors, responding to a surge in low-quality, AI-generated research. While AI-generated text itself is not inherently problematic, its ease of use has led to increased submission volume and decreased quality, including issues like hallucinated citations. Critics argue that blanket penalties may be disproportionate, especially in large collaborations, and suggest that AI tools could instead be leveraged to enhance quality control and peer review processes.
The move is a response to a growing influx of AI-generated papers faced by scholarly journals as well as sites such as arXiv, which serve as unofficial platforms for research publication ahead of peer review.

However, not everyone agrees that arXiv's response to the problem is appropriate—and the solution to the flood of AI slop research may involve more AI, not less.

The arXiv announcement doesn't come out against AI use, but rather says, "If a submission contains incontrovertible evidence that the authors did not check the results of LLM generation, this means we can't trust anything in the paper."

This may be true as far as it goes. But the penalty—a year-long ban for all authors listed on a paper—may be out of keeping with current research practices.

In the past, research was often carried out by people working alone or in groups of two or three. In these circumstances, it seems reasonable to expect each author to take responsibility for the whole.

But research is now more collaborative than ever before. Many papers have four or five authors, and in a growing number of extreme cases papers may be credited to groups of hundreds of scientists working together, each working on their own specialty and trusting their colleagues to be doing the same.

In a case where one author of dozens or hundreds included an AI-hallucinated reference in their part of the paper, banning the lot seems harsh.

And there are no equivalent sanctions for publishing other problematic material. There's no ban for pushing fringe or discredited theories, or using poor quality evidence and illogical arguments, for example.
The rise of AI produces problems for publishers and quality assurance. And the idea of some kind of sanctions for reckless use of AI, such as included hallucinated references, is a good one.

original article.

Part 2

Extreme Heat May Be Raising the Risk of Gestational Diabetes

Gestational diabetes mellitus (GDM), a condition in which hormones produced by the placenta make the body less responsive to insulin, which leads to an inability to control blood sugar levels during pregnancy. When GDM goes unmanaged, it can increase the risk of complications such as preterm birth, preeclampsia, and stillbirth
Studies from around the world suggest prolonged heat exposure during pregnancy can disrupt blood sugar regulation, increasing the risk of gestational diabetes.
A growing body of research shows that climate change-driven extreme heat may be increasing the risk of GDM. Studies from around the world are also pointing to critical windows of vulnerability, suggesting that rising temperatures may be shaping maternal health in overlooked ways. Emerging evidence suggests GDM may be shaped not just by biology, but by the environment too.
Recent studies suggest that prolonged heat exposure during pregnancy can carry an increased risk of developing GDM.
Some studies suggest that the timing of heat exposure during pregnancy also matters. In eastern China, an analysis of over 3,000 pregnancies revealed that when temperatures climbed above 25°C, the risk of GDM increased most sharply between the 13th and 18th weeks of pregnancy, with a clear peak around week 16.6 Wider gaps between daytime and night time temperatures further raised the risk.

Researchers have observed similar patterns in larger populations. In southern California, they analyzed almost 396,000 health records over more than a decade. Extreme heat between the 11th and 16th weeks of pregnancy was associated with a higher GDM risk, while extreme low temperatures between the 20th and 24th weeks also increased the risk. The team found that these effects varied by location, with local factors such as greenness, tree cover, built surfaces, and land temperature either amplifying or reducing the risk.

As the evidence builds around the link between heat and GDM, scientists are also identifying the biological mechanisms behind this association.
High temperatures may make the body less responsive to insulin, which can lead to insulin resistance.”8 This makes it difficult for the body to move sugar out of the bloodstream and into cells, causing blood sugar levels to rise. In hot conditions, the body also sends more blood toward the skin to release heat. This can affect how the body regulates glucose, though the exact mechanisms are still being studied.

Some effects may be indirect. During extreme heat, people tend to stay indoors, which can reduce their vitamin D levels. Vitamin D supports the body’s response to insulin, helping cells take up glucose from the bloodstream and regulate blood sugar levels. Heat exposure can also stress the body, triggering low-grade inflammation, which can interfere with how the body responds to insulin.
Epidemiological studies have also linked higher temperatures to increased rates of prediabetes, diabetes, and insulin resistance.
Part 1

1. Plows JF, et al. The pathophysiology of gestational diabetes mellitus. Int J Mol Sci. 2018;19(11):3342.
2. Sweeting A, et al. Epidemiology and management of gestational diabetes.Lancet. 2024;404(10448):336-348.
3. Mohan V, et al. Prevalence of gestational diabetes mellitus in India: The ICMR-INDI.... Indian J Med Res. 2025.
4. Chakraborty A, Yadav S. Prevalence and determinants of gestational diabetes mellitus among .... BMC Women’s Health. 2024;24(1):147.
5. Granés L, et al. Cumulative daily exposure to high temperature increases gestational.... Nat Health. 2026.
6. Zhang J, et al. The effect of ambient temperature in pregnancy on the risk of gesta.... Int J Biometeorol. 2026;70(64).
7. Part 2

• Teyton A, et al. Examining the relationship between extreme temperature, microclimat.... Environ Epidemiol. 2023;7(3):e252.
• Ratter-Rieck JM, et al. Diabetes and climate change: current evidence and implications for .... Diabetologia. 2023;66:1003-1015.
• Argano C, et al. The role of vitamin D and its molecular bases in insulin resistance.... Int J Mol Sci. 2023;24(20):15485.
• Hanssen MJW, et al. Short-term cold acclimation improves insulin sensitivity in patient... Nat Med. 2015;21:863-865.
• Booth GL, et al. Influence of environmental temperature on risk of gestational diabetes. CMAJ. 2017;189(19):E682-E689.
• Mbepera SM, et al. Heat stress induces oxidative stress and predisposes rats to gestat.... J Biol Life Sci. 2023;14(2):90-102.
• Horcas-Martín M, et al. Polyhydramnios at term in gestational diabetes: Should we be concer... Children. 2025;12(7):920.
• Part 3

The direction of a magnet could shape the building blocks of life

In a new discovery, researchers have found that something in the direction of a magnetic field can influence how molecules of life behave at the most fundamental level and how early chemical processes linked to life may have unfolded.

The study, published in Chem  shows that tiny differences between atoms (different isotopes) can lead to measurable changes in molecular behaviour when combined with an invisible quantum property known as electron spin. Separation of the different isotopes can be achieved by magnetic surfaces.

At the center of the story is L-methionine, an amino acid, a basic building block of life. Like other biological molecules, methionine has a specific "handedness," meaning it exists in a form that is not identical to its mirror image. This property, called chirality, is a mystery: why did nature choose one "hand" over the other? Now, the team's findings suggest that magnetism and the spin of electrons may have played a role.

The answer lies in a subtle quantum property: electron and nuclear spin. Particles behave a bit like tiny spinning tops, and their "spin direction" can influence how they interact with materials, especially when those materials are magnetic.
Chiral molecules like methionine are known to interact with electron spin in a special way, a phenomenon called chiral-induced spin selectivity (CISS). This means that the molecule's shape can "filter" electrons based on their spin.

What this new research shows is that this same effect can extend to isotopes atoms that differ only slightly in mass and nuclear spin. In other words, spin and magnetism can influence not just how molecules react, but which versions of those molecules are favoured.

Part 1

Understanding how spin, magnetism, and molecular structure interact could open new doors in:

Isotope separation technologies
Advanced materials design
Analytical chemistry
And even quantum biology, an emerging field exploring how quantum effects influence living systems
In the end, the study reveals something both simple and profound: even at the smallest scales, direction matters.

A magnet pointing north or south can change how molecules move, interact, and separate. And those tiny differences may hold clues to the very origins of life.

Ofek Vardi et al, Spin-dependent isotopic fractionation of L-methionine, Chem (2026). DOI: 10.1016/j.chempr.2026.102993

Part 2

When Mendel's rules don't apply: Mouse study reveals hidden epigenetic inheritance

The well-studied rules of genetic inheritance—known as Mendel's Laws—cover how genetic materials known as alleles sort themselves, are dominant or recessive, and in what ways they get passed down to new generations. Alleles are variations in genes that lead to a specific trait or disease state. In mammals, one allele is inherited from each parent, and either of those alleles can be dominant or recessive.
The rules state, for example, that alleles in offspring are inherited from each parent, and the traits of dominant alleles prevail over recessive ones, which are silenced.
Analysis of three generations of mice revealed that approximately 7% of DNA methylation patterns are inherited in ways that violate Mendel's laws, including novel forms of epigenetic inheritance such as paramutation and emergent methylation not present in either parent. These findings indicate that non-Mendelian epigenetic inheritance is more frequent and diverse than previously recognized, potentially enabling rapid trait variation in response to environmental factors.

Scientists have long known that the DNA code in genes is not the only way to pass genetic traits from parents to offspring. "Epigenetic" marks—chemical modifications to DNA that don't change the DNA code itself—can also be passed down.
Now, a new study using mice reveals that some of those marks—about 7% of them—can be inherited in ways that break the century-long understanding of the rules of inheritance explored and recorded by Gregor Mendel's work with pea plants. The study also reveals new, unexpected examples of inheritance patterns that defy Mendel's law—such as a naturally occurring paramutation, seen previously in plants and flies, and not in mammals.
Non-Mendelian patterns of inheriting epigenetics could be a faster way to acquire diverse or new traits than alterations in the genomic sequence itself, especially in response to environmental pressures.
Several previous studies have already shown that some patterns of epigenetic inheritance, such as genomic imprinting, can break the guiding principles established by the Austrian-born friar. The new study also found examples of genomic imprinting, but also other types of non-Mendelian patterns of epigenetic inheritance that surprised the scientists.

In examples of genomic imprinting, an allele in either parent can be labeled as coming from sperm or an egg and silenced by methylation. Such imprinted alleles are passed down to offspring and are silenced not because they are recessive but based on which parent contributes the imprinted allele. The new research found imprinting examples in five additional genes.

In addition to the new examples of genetic imprinting, results of the current study suggest that epigenetic patterns of inheritance that defy Mendel's rules may be more frequent than described in other studies. In addition, the research team found epigenetic patterns passed down to offspring that were not present in either parent.
Part 1

In their experiments, the researchers found 522 instances—about 7% of epigenetic inheritance patterns—in which methylation was inherited on non-sex chromosomes in a variety of ways that broke Mendel's laws.

Some 54 of those instances represented rare or "emergent" types of epigenetic inheritance not present in either parent. For example, a cross between two mice with no methylation on the same allele, which should have resulted in a mouse that inherited no methylation on the allele, could instead result in a mouse with methylation on both alleles. "The methylation seemingly appeared out of nowhere" .
The scientists also found another rare type of inheritance called paramutation in a gene called Capn11, which encodes a calcium-dependent gene that regulates normal sperm development. Alterations in the human version of the gene cause infertility and problems with sperm.

Paramutation occurs when methylation in one allele leads to methylation in another allele. The paramutation was located in an area of the gene associated with a repetitive element of a type known to be influenced by environmental exposure. It's almost like the methylation is transferred to another allele. Epigenetic influences on the genome have been tied to environmental pressures such as environmental stress, trauma and diet.

This work may convince scientists to integrate both genomics and epigenomics more often for a complete understanding of how traits that produce disease and healthy states are inherited.

Adam Davidovich et al, Non-Mendelian inheritance of DNA methylation patterns in mice, Nature Genetics (2026). DOI: 10.1038/s41588-026-02604-z

Part 2

Rewiring early life: What extremely preterm birth teaches us about the brain

Extremely preterm birth (before 28 weeks of gestation) places infants into the world at one of the most extraordinary moments in human development. The brain at this stage is not simply growing; it is folding, organizing, and laying down the networks that will eventually support language, memory, attention, and learning. It is doing all of this in the dark, in the warmth, protected. When birth happens this early, all conditions change in an instant.
Extremely preterm birth disrupts typical brain development, leading to widespread structural differences such as thinner cortex, reduced folding, and altered sulcal depth, especially in regions linked to language, memory, and attention. Cognitive difficulties are associated with altered connectivity and repositioned network hubs, but many preterm children show neural resilience and typical cognitive outcomes, highlighting both risk and protective factors. Early identification of at-risk children may enable timely interventions to support cognitive development.
Modern neonatal medicine has achieved something remarkable: More of these children survive than ever before.
The third trimester is, in many ways, one of the brain's most ambitious phases. Its surface expands rapidly and folds into the ridges and grooves familiar from anatomy textbooks. But those folds are not cosmetic. They reflect an underlying organization of neural networks, the scaffolding of future thought.

When an extremely preterm infant enters the world, that scaffolding is still being built. The brain is suddenly exposed to an environment it was never designed to encounter at this stage. The noise, light, and necessary interventions—none of this is what the developing brain expects. Development continues, but on an altered course. At the same time, the infant is deprived of natural stimuli such as kicking the walls of the mother's womb and hearing the mother's voice.
Researchers found what happens in these conditions to the developing brain.
The structural differences they found were not confined to one region. Children born extremely preterm showed a thinner cortex, less folding, and shallower sulci (i.e., the grooves between brain folds) compared with their term-born peers. These differences were most evident in temporal and cingulate regions; areas closely related to language, memory, attention, and cognitive control.
Part 1

arXiv clamps down on AI citations
The preprint repository arXiv has announced a one-year posting ban for researchers whose submissions are found to contain references hallucinated by artificial intelligence. Even after this penalty period, affected researchers can’t post to arXiv unless their manuscript has already been accepted at a “reputable peer-reviewed venue”, according to computer scientist Thomas Dietterich, chair of arXiv’s computer science section. Some researchers have praised the server for taking a stand; others suggest it doesn’t go far enough to tackle ‘AI slop’ in preprints.

https://www.linkedin.com/posts/vk2lndx_arxiv-just-declared-war-on-a...

https://www.linkedin.com/feed/update/urn:li:activity:74618939739688...

80% of Earth's Rivers Are Quickly Losing Oxygen, Study Reveals

Oxygen levels have decreased in almost 80 percent of rivers worldwide, and they're going to continue losing this precious resource unless we make some serious changes.

Satellite and climate data collected between 1985 and 2023 reveal that over 16,000 rivers across the world have been losing their dissolved oxygen.

On average, these rivers have been losing 0.045 milligrams of oxygen per liter each decade.

Without enough dissolved oxygen essential to sustain life underwater, rivers – and the communities that rely on their water and resources – are under serious threat.

By the end of the century, assuming carbon dioxide emissions continue to rise at similar rates (as opposed to some of the worst-case scenarios), rivers across most of South America, India, the Arctic, and the Eastern United States are expected to lose around 10 percent of their dissolved oxygen.

The most severe shifts so far have occurred in tropical rivers, such as the Ganges in India and the Amazon River in South America. The Ganges River in particular is losing oxygen 20 times faster than the global average.

Scientists didn't see this coming. Previously, they assumed that high-latitude rivers would experience the worst deoxygenation because these regions are climate change hotspots.
But tropical rivers had a disadvantage from the start: Since their waters were already warmer, they already had lower levels of dissolved oxygen. This means they're already closer to reaching hypoxia (insufficient oxygen to sustain most life).

Dissolved oxygen is very different from the oxygen atoms that pair with a hydrogen to form water. Dissolved oxygen is what aquatic life needs to 'breathe': that goes for animals, plants, plankton, bacteria, and anything else living underwater.

But the bonds that keep oxygen gas dissolved in water are relatively weak. Just a slight shift in temperature is enough to rip them apart, allowing the oxygen to escape.

https://www.science.org/doi/10.1126/sciadv.aef3132

Part 2

Astronomers have discovered the tiniest odd radio circle

Astronomers have identified a possible new member of one of astronomy's strangest classes of objects: Odd radio circles (ORCs), enormous ring-like structures visible only at radio wavelengths. The newly discovered source, J1248+4826, appears to be the most compact ORC candidate identified so far, with a ring only about 30,000 parsecs across. The paper was posted to the arXiv preprint server on May 6.

First reported in 2021, odd radio circles are faint ring-shaped radio emissions that are not detected at other wavelengths. They typically have a massive early-type galaxy with hundreds of billions of solar masses at their center, existing somewhere when the universe was roughly 8–11 billion years old. They span hundreds of kiloparsecs across.

Where they come from is still an open question. Leading ideas include remnants of magnetized plasma ejected roughly a billion years ago by a supermassive black hole, a past starburst episode, merging galaxy groups, or large-scale active galactic nuclei-driven outflows.

This newly discovered one  is a radio ring surrounded by a faint diffuse envelope, located very close to a galaxy group as seen when the universe was 11.2 billion years old.

The team's analysis revealed that the ring's radius is about 9 arcseconds, which corresponds to only 30 kiloparsecs physically. This is well below the previously reported radii of the ring-structure of ORCs, which range from 44 to 365 kiloparsecs. The surrounding diffuse envelope, extending to roughly 100 kiloparsecs, is more in line with the other members of the population.

Despite its compact size, the structure shares many of the same radio properties as previously known ORCs. However, unlike other ORCs that have their host galaxy at their center, this structure's host galaxy was found not at the center but at the edge.

M. Polletta et al, A Compact Radio Ring with a Diffuse Envelope in LOFAR: Odd Radio Circle or Distinct Phenomenon?, arXiv (2026). DOI: 10.48550/arxiv.2605.05174

Quantum supremacy just ran into an unexpected rival: An ordinary laptop armed with new math

Using a conventional computer and cutting-edge mathematical tools and code, physicists have cracked a daunting quantum physics problem previously claimed to be solvable only by quantum computers.

The technique is so ground-breaking in its efficiency that the researchers were even able to use a personal laptop to solve the problem.

By enabling scientists to squeeze extra problem-solving power from classical computers, the breakthrough methodology is opening new avenues for research on quantum dynamics and may be useful as a protocol for solving problems about finding the optimal solution amid an abundance of feasible ones.

The problem at hand involves simulating a quantum system composed of hundreds of interacting "qubits"—the quantum computing equivalent of the bits used in classical computers—arranged in square, cubic, or diamond lattices. While bits can have values of 0 or 1, qubits can exist in a superposition of multiple values, making it challenging for traditional computers to simulate their dynamics.

The research team  achieved their breakthrough by developing and implementing new tools based on tensor networks. The tensor networks made the problem feasible for classical computers. The team ran many of their simulations using relatively modest computational resources.

Despite using only modest computational hardware, the researchers demonstrated that their simulations yielded state-of-the-art accuracies. The simulations converged on solutions that matched theoretical predictions and provided accurate results when applied to smaller test problems. The results also agreed with those reported by the quantum computing researchers—but with no quantum computer required.

Joseph Tindall et al, Dynamics of disordered quantum systems with two- and three-dimensional tensor networks, Science (2026). DOI: 10.1126/science.adx2728. www.science.org/doi/10.1126/science.adx2728

Common food preservatives linked to high blood pressure and heart disease

Food preservatives are used in hundreds of thousands of industrially processed foods. Experimental studies suggest that some preservative food additives may be harmful to cardiovascular health.

Eating foods that contain common preservative food additives may increase the risks of high blood pressure and cardiovascular disease, according to research published in the European Heart Journal.

Researchers carried out detailed analyses of the ingredients of all the food and drink, including any preservatives. They also tracked the volunteers' health for an average of seven to eight years to see if they develop high blood pressure or any cardiovascular disease.

Researcher found that 99.5% of the volunteers had consumed at least one food preservative within the first two years of taking part.

Overall, they found that people who ate the largest amounts of "non-antioxidant" preservatives had a 29% higher risk of hypertension, compared to those who ate the least, and a 16% higher risk of cardiovascular disease, including heart attack, stroke, and angina. People who ate the most antioxidant preservatives had a 22% higher risk of hypertension.

Non-antioxidant preservatives are designed to stop harmful microbes, such as mold and bacteria, from growing, whereas antioxidant preservatives are designed to stop oxidation which means the food will not turn brown or become rancid.

Researchers also looked at 17 of the most commonly eaten preservatives and found that eight of these were specifically linked to high blood pressure. These were: potassium sorbate (E202), potassium metabisulphite (E224), sodium nitrite (E250), ascorbic acid (E300), sodium ascorbate (E301), sodium erythorbate (E316), citric acid (E330) and extracts of rosemary (E392). Ascorbic acid (E300) was also specifically linked to cardiovascular disease.

The findings are based on highly detailed data, and the researchers have taken account of other factors that can increase or lower the risk of cardiovascular disease. Experimental research in the literature consistently suggested that preservatives may cause oxidative stress in the body or affect the way the pancreas works.

These results suggest we need a re-evaluation of the risks and benefits of these food additives by the authorities in charge for better consumer protection.

These findings support existing recommendations to favour non-processed and minimally processed foods, and avoid unnecessary additives.

Preservative food additives, hypertension, and cardiovascular diseases: the NutriNet-Santé study, European Heart Journal (2026). DOI: 10.1093/eurheartj/ehag308

Extraterrestrial life may be slipping past space missions, astrobiologists warn

Current astrobiological detection methods risk false-negative results, potentially missing existing extraterrestrial life due to preservation issues, detection limitations, and insufficiently targeted research strategies. Overlooking such evidence may deprioritize promising environments and lead to premature resource exploitation, risking irreversible loss of undiscovered life. Improved strategies integrating laboratory, modeling, fieldwork, and AI-driven pattern recognition are needed to minimize these risks.

False negatives in the search for extraterrestrial life, Nature Astronomy (2026). DOI: 10.1038/s41550-026-02863-0

How does gold keep its glitter? Researchers uncover why it resists tarnish

Gold has been prized for thousands of years for its enduring shine, but researchers have discovered that gold's resistance to tarnishing depends on more than its chemistry.

In a new study published in Physical Review Letters, researchers found that atoms on certain gold surfaces naturally rearrange themselves into protective patterns that dramatically suppress reactions with oxygen.

The discovery helps explain why gold jewelry and other gold objects can remain untarnished for centuries—and could also point the way toward designing more effective gold-based catalysts for industrial and energy-related applications.

Using computer simulations that predict how atoms and electrons behave, the researchers studied how oxygen molecules interact with two common gold surface structures. They found that without this atomic rearrangement, oxygen molecules could break apart and react with gold much more easily.

Instead, the rearranged surfaces suppress oxygen reactions by a factor of a billion to a trillion, essentially creating a protective atomic-scale barrier that helps gold stay shiny indefinitely.

The findings offer a new explanation for one of gold's best-known properties while also opening the door to potential advances in catalysis.

Anonymous, Role of reconstruction in the inertness of gold towards oxygen, Physical Review Letters (2026). DOI: 10.1103/g3bc-t1qv

Decades after Chernobyl disaster, this radioactive landscape has become one of wildlife's most unlikely strongholds
Today (May 22nd) we are celebrating the International Day for Biological Diversity 2026

The Chernobyl Exclusion Zone and adjacent protected areas, with minimal human activity, exhibit the highest mammal diversity and occupancy rates, including rare and endangered species. Large, strictly protected zones provide superior refuge for wildlife compared to smaller parks or unprotected areas, highlighting the significant positive impact of reduced human disturbance on biodiversity.

There are nearly 8 million species on our planet, yet around 15,000 of them are now threatened with extinction. Even more alarming is the speed at which this is happening. Species today are disappearing at a rate estimated to be 1,000 to 10,000 times higher than the natural extinction rate—in other words, the pace at which species would have vanished if humans weren't here.

It is well documented that human activities and changes in land use for agriculture, industrialization, and urbanization have destroyed several habitats, leading to a decline in biodiversity. Establishing protected areas is a sound way to protect vulnerable species and preserve biodiversity. Compared to unprotected regions, these special zones experience far less human disturbance, reducing stressors such as hunting, habitat loss, and human-animal interactions, allowing ecosystems to recover and thrive.
Some areas are deliberate PAs, while others are devoid of human establishments due to natural or man-made disasters such as the CEZ.

The researchers in this study explored a vast area of about 60,000 km² in northern Ukraine to see how different levels of PAs—CEZs, nature reserves, national parks, and areas with no legal protection—affected where large animals live. They set up 174 motion-sensing camera traps to capture images of wildlife residents in the area and analyzed the images using mathematical tools such as Bayesian occupancy models to estimate occupancy and detection probabilities.

The results revealed that the CEZ and its nearby natural reserve have transformed into an excellent refuge for endangered and shy wildlife. The number and variety of animals in the region were much higher than in smaller parks, owing to the region's strict human-entry rules.

Svitlana Kudrenko et al, The Chornobyl Exclusion Zone as a wildlife refuge: restricted human access shaped mammal recolonization, Proceedings of the Royal Society B: Biological Sciences (2026). DOI: 10.1098/rspb.2025.3151

Wildlife is watching us, too—and changing behaviour in response

Analysis of GPS-tracked movements of 37 bird and mammal species across the U.S., combined with mobile phone and satellite data, shows that over 65% of species alter their behaviour in response to human presence, with effects varying by species and habitat context. Some animals reduced their range to avoid humans, while others expanded it or exploited human-associated resources. These findings indicate that both habitat alteration and direct human presence influence wildlife, suggesting conservation strategies should address not only habitat loss but also the timing and intensity of human activity.

Ruth Y. Oliver et al, Interacting effects of human presence and landscape modification on birds and mammals, Science (2026). DOI: 10.1126/science.adq3396. www.science.org/doi/10.1126/science.adq3396

Why some antibiotics fail in the body—pH conditions can dramatically change how bacteria respond

When researchers test whether an antibiotic will work, they usually do so in a controlled laboratory environment. But when an infection happens inside the human body, things aren't so clean and tidy. New research found that even a slight change in acidity may dramatically shift how bacteria respond to treatment.
The study is centered around Klebsiella pneumoniae, a major cause of deadly infections and one of the world's most antibiotic-resistant pathogens.

Klebsiella pneumoniae exhibits up to 64-fold increased resistance to beta-lactam antibiotics under mildly acidic conditions (pH 5), due to the expression of alternative cell wall synthesis proteins (PBP2PARA, PBP3PARA, and PBP1b). Silencing these proteins reduces resistance, indicating their critical role in antibiotic survival at low pH. These findings highlight the need to assess antibiotic efficacy under physiologically relevant conditions.
Researchers set out to learn what happens to antibiotic resistance when K. pneumoniae grows in mildly acidic conditions like those found in parts of the human body during an active infection. What they found was that when grown at a pH of 5, the bacterium became up to 64 times more resistant to beta-lactam antibiotics, the most widely prescribed treatment for infections.

These beta-lactams work by shutting down the cell wall-building proteins in the bacterium known as PBPs. Without these, the bacterium can't properly construct its cell wall or divide, and it eventually dies. However, in addition to these PBPs made at neutral pH, it appears that K. pneumoniae has a reserve team ready to step up when conditions get acidic.
K. pneumoniae has a backup set of cell wall-building proteins that come online as the cell enters, in this case, an acidic environment.
PBP2PARA and PBP3PARA are duplicate copies of essential cell wall synthesis genes, and when conditions turn acidic, these alternate versions of cell building and division proteins are expressed.

This was surprising, given that past research on pathogen resistance had been done on a model organism, E. coli, which does not have a backup team of proteins. "This sets up a lot of implications for reevaluating and rethinking how we're assessing antibiotic resistance in pathogens.
Additionally, they identified another duplicate cell wall synthesis protein, PBP1b, whose activity appeared to be important for stress response during growth at low pH. These results suggest that these duplicate proteins may be important for helping the bacterium survive against antibiotic treatments under acidic conditions.
To confirm this, researchers silenced these proteins and they found that when these proteins weren't made, the cell lost much of its antibiotic resistance. PBP1b and PBP3PARA make the most impact on resistance, so their presence is most critical to the cell at low pH.

In the face of antibiotic resistance, these findings offer a warning and a potential path forward.

Sarah Beagle et al, Acid-dependent beta-lactam resistance in Klebsiella pneumoniae is mediated by paralogous class B PBPs and the class A PBP, PBP1b, mBio (2026). DOI: 10.1128/mbio.00092-26

Overpopulation can impair fertility. A new study explains why

Scientists have reported it for decades: overpopulation can impair reproduction. Crowded chickens lay fewer eggs. Crowded mice have smaller broods. In humans, several studies have associated increased population density with reduced fertility.

External factors, such as resource scarcity and social influences, undoubtedly play a role. But researchers have long suspected that intrinsic, biological mechanisms may also be at play as an evolutionary tool to keep populations in check.

New research, published this month in the journal Nature Communications, identifies one key mechanism. It found that overcrowded animals secrete a chemical messenger that can damage eggs, impair embryos and cause genetic mutations in offspring for generations to come.
Overcrowding in animals triggers secretion of a cysteine protease enzyme (CPR-4/Cathepsin B), which damages DNA in germ cells, increases genetic mutations, reduces fertility, and causes developmental defects in offspring. These mutations can be inherited across generations. Silencing the enzyme prevents these effects, indicating its central role in crowding-induced reproductive impairment. Implications for humans remain to be determined.

Bin Yu et al, Cathepsin B protease mediates high population density-induced mutagenesis to drive genome evolution and competitive growth, Nature Communications (2026). DOI: 10.1038/s41467-026-72521-6

Why energy fades with age: Missing membrane lipid may destabilize mitochondria

Why do cells age—and why do we lose our energy and vitality as we get older? This question is one of the central challenges of modern biomedicine. The focus is particularly on mitochondria—tiny cellular organelles long known as the cell's powerhouses but now understood as dynamic control centers that not only produce energy, but also coordinate cellular communication, adaptation, and many of the processes essential for life.
They supply us with the energy that our body needs for movement, growth, and repair processes. But as we age, these powerhouses begin to slow down. It has long been known that their function declines with age.
Age-related decline in cellular energy is linked to reduced phosphatidylcholine synthesis, leading to destabilized mitochondrial membranes and impaired mitochondrial network function. Supplementation with phosphatidylcholine or its precursor choline restores mitochondrial structure and energy production in aged cells, indicating that aspects of mitochondrial and systemic aging are modifiable through targeted metabolic interventions.
For a long time, it was assumed that genetic damage within the mitochondria themselves was primarily responsible. A study now published in Nature Communications by an international research team.
provides a surprising answer to this question: A key factor appears to be the imbalance in the structure of the mitochondrial network, which is caused by the absence of a major lipid in the membrane composition.

The focus is on phosphatidylcholine—a fundamental lipid that is a major component of biological membranes. It ensures that membranes remain flexible and can dynamically reorganize themselves. Precisely this property is crucial for so-called "mitochondrial fusion"—a process in which individual mitochondria merge into networks. These networks are necessary for cells to distribute key molecules—such as cellular energy equivalents, metabolic products, DNA, and signaling molecules—and facilitate their exchange, thereby preventing imbalances and replacing damaged components.

The study shows that the body's production of phosphatidylcholine declines with age, leading to increased fragmentation and dysfunction of mitochondrial membranes. When genes involved in phosphatidylcholine synthesis were deactivated in young worms, their mitochondria in the cells quickly began to look "aged."

The researchers were particularly fascinated by how closely these changes resembled the mitochondria typically observed in chronologically old organisms. Even more striking was the observation that the mitochondria regained a more youthful structure within just two days when the worms were fed phosphatidylcholine or its precursor, choline.

The most important finding of the study, however, lies in the reversibility of aging-associated failures: through a targeted increase in phosphatidylcholine levels—for example, via diet.

Tetiana Poliezhaieva et al, Aging-associated decline of phosphatidylcholine synthesis is a malleable trigger of natural mitochondrial aging, Nature Communications (2026). DOI: 10.1038/s41467-026-71508-7

part 2

Calcium and vitamin D supplements offer little to no meaningful benefit on fracture, fall prevention, review concludes

Calcium, vitamin D, or combined supplements offer little to no clinically meaningful benefit for fracture and fall prevention in most older people, finds an in-depth review of the latest evidence published by The BMJ.
Calcium, vitamin D, or combined supplementation provides little to no clinically meaningful benefit for preventing fractures or falls in most older adults, based on moderate to high certainty evidence from 69 randomized controlled trials. These findings suggest routine supplementation is not supported for fracture or fall prevention, and recommendations should be re-evaluated.

Calcium, vitamin D, or combined supplementation to prevent fractures and falls: systematic review and meta-analysis, The BMJ (2026). DOI: 10.1136/bmj-2025-088050