Toronto Fire Services (TFS) is warning residents about the growing safety risks of lithium-ion batteries after several fires occurred in the city just this past day.
In a statement posted to X on Monday morning, Fire Chief & General Manager Jim Jessop said that crews had responded to three separate battery-related fires within 24 hours.
These batteries can be found in numerous household items, including smartphones, laptops, e-readers, and even some cordless vacuums, portable fans and rechargeable flashlights. They can overheat if charged for too long or not stored properly.
Halfway through 2025, TFS reported responding to 43 fires caused by lithium-ion batteries, including one in a Toronto high-rise, where a "large quantity" of lithium-ion batteries were discovered within the unit.
These batteries can also be found in e-bikes and e-scooters, which pose significant risks. In response to a 2023 fire on a Toronto subway train, the TTC has implemented a seasonal ban on e-bikes during the winter months.
Power-assisted bicycles are not permitted on TTC vehicles and property from November 15 to April 15 each year. Instead, they can be parked at or near subway station entrances, or stored in bike lockers at most subway stations.
Electric wheelchairs and other devices used by people with mobility issues, however, will continue to be allowed on the TTC as they do not pose a safety or fire risk.
The City is advising residents to use lithium-ion batteries safely by only using certified, manufacturer-approved batteries, avoiding charging them unattended, and discontinuing use if they emit a strange odour, become deformed, overheat, or leak.
A few glasses of alcohol are enough to start fragmenting the way the brain works, leading to more localized information processing and reduced brain-wide communication, a new study has discovered.
While plenty of previous research has looked at the ways booze changes the brain, little of it has considered the network-wide effects. The brain is, of course, a delicately balanced and incredibly intricate organ, and any shifts in chatter between brain regions are going to have impacts on emotions and behavior.
The researchers behind the study, led by a team from the University of Minnesota, believe that their findings could go some way to explaining why different people can feel different levels of drunkenness at the same breath-alcohol level.
"At the network level, alcohol significantly increased local efficiency and clustering coefficient, consistent with a less random and more grid-like topology," write the researchers in their published paper.
"Notably, these increases, as well as corresponding decreases in global efficiency, significantly predicted greater subjective intoxication."
The researchers recruited the help of 107 healthy participants, aged between 21 and 45. Across two sessions, they were either given a drink designed to raise their blood-alcohol level to the US limit for driving (0.08 grams per deciliter), or a placebo drink.
Local connectivity in brain regions was boosted by alcohol intake.
(Biessenberger et al., Drug Alcohol Depend., 2026)
Half an hour after imbibing, the participants went into an MRI scanner, where their brain activity was mapped. Using a variety of mathematical approaches, the researchers calculated communications between 106 different brain regions.
Overall, brain areas became more insular and less well connected to the rest of the brain, though the effect wasn't consistent over every region. It's a similar idea to traffic circling around one particular neighborhood rather than traveling city-wide.
Although the volunteers were all about as drunk as each other, some felt more intoxicated than others. The researchers found that this feeling of drunkenness was related to how disconnected their brain regions had become.
What's more, the network changes seen here – the breakdown between different brain regions – go some way to explaining how too much booze can start to cause blurred vision, difficulty walking in a straight line, and other well-known effects.
One of the regions most affected by the decreased global connectivity, for example, was the occipital lobe. It's here that the brain processes visual data fed in by our eyes, and these changes likely mean this data is less readily available to the rest of the brain.
"Our results that information transfer becomes more isolated and less integrated are consistent with alcohol's known influence on reward/aversion, inhibitory control, and stimulus valence," write the researchers.
However, this wasn't something the team tested directly; rather, the study infers it based on the computational models applied to the brain scans.
It's also worth noting that these findings only apply to brains at rest, not involved in any kind of activity, and it would also be interesting to see these impacts over longer periods.
The researchers also suggest, based on previous studies, that people with acute and chronic alcohol problems might see different changes in their brain maps when they get drunk: less of a fixed grid-like layout, less local clustering, and a more randomized and disorganized network overall.
There's lots more here for future studies to dig into as well. The researchers say future work should include broader groups of participants and look more directly at the effects of brain network disruption on people who are less physically and mentally healthy than the participants in this study.
"Given rapid changes in population demographics and increasing rates of drinking among older adults, studies of the functional neural correlates of acute alcohol use across the lifespan, in populations with heavier drinking patterns, and a broader range of negative affective symptomatology are needed," write the researchers.
Severe droughts and floods in 9th-century China may have triggered migration, weakened border defenses, and accelerated the fall of the Tang dynasty.
Credit: Shutterstock
Environmental phenomena and their consequences can disrupt social structures and destabilize political systems. An interdisciplinary research team demonstrated this through the example of the late Tang Dynasty in medieval China.
Climate driven migration is often viewed as a modern crisis, but history tells a different story. An interdisciplinary team of researchers, including scientists from the University of Basel, has shown that large-scale environmental disruption shaped societies more than a thousand years ago.
Their study examined how severe hydrological extremes such as prolonged droughts and destructive floods between 800 and 907 CE influenced political stability and everyday life in China. The findings were published in Nature Communications Earth and Environment.
Tree rings as contemporary witnesses
The period under investigation coincides with the final decades of the Tang dynasty, which ruled from 618 CE and is widely regarded as one of the most culturally and administratively advanced eras in Chinese history. During its height, the empire maintained a complex governing system and fostered remarkable achievements in art, literature, and technology.
Yet by the ninth century, that stability began to weaken. The research focuses on northern China, particularly the region surrounding the Huanghe River (Yellow River), an area central to agriculture, transportation, and political power.
To understand how the climate shifted during this critical period, scientists turned to natural archives known as climate proxies. Among the most valuable of these are tree rings. Trees record environmental conditions in their annual growth patterns. In wetter years, abundant rainfall allows trees to grow more quickly, producing wider rings. In dry years, growth slows, leaving narrower rings. The longer a tree lives, the further back this environmental record extends, offering a detailed timeline of past climate conditions.
The team relied on long-term tree ring datasets from the Yellow River basin to reconstruct historical runoff patterns. These reconstructions helped model hydroclimatic conditions, especially in the river’s upper reaches. Water flowing downstream directly affected how much was available for irrigation and farming. As the study’s first author Michael Kempf explained, “The runoff eventually reaches further downstream and influences the amount of water available, for example, for irrigating the fields.” Kempf conducted the research at the University of Basel and has since moved to the University of Cambridge.
Fatal changes in agriculture
After examining the evidence, the team determined that shifts in climate and a rise in severe weather events played a major role in the fall of the Tang dynasty in 907 CE. More frequent droughts and floods placed intense pressure on the soldiers responsible for defending the empire’s frontiers, as well as on their families. These environmental hardships weakened their ability to protect the realm from invading forces beyond its borders.
“Hydroclimatic extremes have a very direct influence on crop failure and grain storage conditions,” says Kempf. Seed shortages and increased food demand quickly pushed supply systems to their limits. A bad year, therefore, also had consequences for the future.
The situation was further exacerbated by the choice of cereal crops: people increasingly favored the cultivation of wheat and rice over millet. Kempf can only speculate about the reasons for the agricultural change. Perhaps millet was considered a less prestigious food than wheat and rice. However, these are less climate-resistant than drought-resistant millet and require more water to grow. “As long as there is enough water, this is not a problem, but during prolonged dry periods, shortages occur.” Millet cultivation could perhaps have cushioned these negative effects. As it was, however, the risk of crop failures and famines increased.
These losses could not easily be compensated for by shipments from other parts of the country. This was also because droughts and floods affected supply routes and supply corridors collapsed.
Fleeing from hunger
The malnutrition of the population may ultimately have led to the collapse of border defenses in the north of the empire. “Of course, people were weakened and therefore more vulnerable. Due to the military pressure on the outer border regions, they migrated south, where they believed they would find better conditions,” says Kempf. “This led to political destabilization and is likely to have contributed to the demise of the Tang dynasty.”
However, Kempf emphasizes: “Our results are approximations. The actual conditions at that time cannot be reconstructed with certainty. It’s a complex interplay of many different factors.”
The study concluded that sociocultural and climatic changes can lead to tipping points in the system because the balance is disrupted. This is a development that could occur more frequently in view of climate change today.
Bacteria extracted from 5,000-year-old ice in the Scărișoara Ice Cave in Romania could help us fight superbugs, new research shows – if it doesn't become one itself.
The research was led by a team from the Institute of Biology Bucharest (IBB) of the Romanian Academy, and points towards the untapped therapeutic potential – and risk – of microbes preserved in cold environments for millennia.
As bacteria continuously evolve to outsmart the best treatments we can fire at them, antibiotic resistance represents a serious challenge to public health. It's not a new phenomenon, though: This cat-and-mouse survival game has played out over millions of years.
The Scărișoara Ice Cave.
(Paun V.I.)
Extreme environments, such as the ice cave this bacteria was found in, help to push diversity in their microorganisms, and it's possible that this genetic adaptation may give us a route to improved antibiotics – or make the situation worse.
"The Psychrobacter SC65A.3 bacterial strain isolated from Scărișoara Ice Cave, despite its ancient origin, shows resistance to multiple modern antibiotics and carries over 100 resistance-related genes," says IBB microbiologist Cristina Purcarea.
"But it can also inhibit the growth of several major antibiotic-resistant 'superbugs' and showed important enzymatic activities with important biotechnological potential."
The researchers removed a 25-meter (82-foot) ice core from a section of the Scărișoara Ice Cave known as the Great Hall. After carefully isolating bacterial strains in the ice, genome sequencing was used to identify which genes were linked to survival in the cold and antimicrobial activity.
An ice core was drilled from Scărișoara Ice Cave, which contains the largest and oldest perennial block of ice.
(Itcus C.)
That analysis revealed that Psychrobacter SC65A.3 could be a blessing and a curse: sure, it could provide leads for new antibiotic drugs, but if it's allowed to reemerge and spread, it could also share its drug-resistant genes with other bacteria.
The researchers found Psychrobacter SC65A.3 was resistant to common antibiotics used to treat lung, skin, blood, and other common infections.
This bacterial strain is part of the Psychrobacter genus of bacteria, which have specifically developed to survive in the cold. While we know some species can cause infections, there are still a lot of open questions about how these microbes evolved, and how they could be used to improve modern antibiotics.
While the process of developing any new antibiotics from this bacteria won't be quick, along the way there will be other opportunities to learn about how resistance to drugs can develop and pass between species.
The team behind this study is calling for more research to be carried out into microorganisms that have been frozen in time – giving us a window into the ancient past, and hopefully also a way to improve the future.
"To advance a comprehensive understanding of microbial life in cold environments, integrated research should focus on mapping their taxonomic and functional diversity, uncovering the mechanisms of cold adaptation, evaluating their roles in biogeochemical cycles and climate feedback processes, and exploring novel microbial taxa and functions with potential applications in biotechnology and medicine," write the researchers in their published paper.
The researchers talk about the possibility of frozen environments acting as reservoirs of resistance genes. As climate change turns frozen environments into unfrozen ones, we're already seeing thousands of tonnes of dormant microbes making a return to a world very different from the one they're familiar with.
That means the race is on to find ways to use these bacteria to fight infections and disease before they can cause any harm.
It's thought that antibiotic resistance contributes to more than a million deaths worldwide every year, and although the trend is heading in the wrong direction, there are still signs of encouraging progress too.
"If melting ice releases these microbes, these genes could spread to modern bacteria, adding to the global challenge of antibiotic resistance," says Purcarea.
"On the other hand, they produce unique enzymes and antimicrobial compounds that could inspire new antibiotics, industrial enzymes, and other biotechnological innovations."
Genomic evidence has revealed that hunter-gatherer communities in parts of present-day Belgium and the Netherlands persisted for thousands of years longer than elsewhere in Europe, even after farming spread across the continent.
Credit: Shutterstock
Ancient DNA shows that hunter-gatherers in northwestern Europe endured for millennia, with women driving a gradual cultural shift toward farming.
Researchers at the University of Huddersfield have analyzed ancient DNA to show that hunter-gatherer communities in one region of Europe endured for thousands of years longer than elsewhere on the continent. Their findings also highlight the central role women played during this extended transition.
The project formed part of a broader international collaboration of geneticists and archaeologists led by David Reich at Harvard University. The results have been published in the journal Nature.
At Huddersfield, the research was conducted by doctoral researcher Alessandro Fichera and postdoctoral fellow Dr. Francesca Gandini, working under the supervision of Dr. Maria Pala, Professor Martin B. Richards, and Dr. Ceiridwen Edwards from the Archaeogenetics Research Group in the School of Applied Sciences.
Funding came through a Doctoral Scholarship awarded by the Leverhulme Trust to Professor Richards and Dr. Pala. The team also worked closely with paleoecologist Professor John Stewart at Bournemouth University and archaeologists from the Université de Liège in Belgium, who were responsible for excavating and curating the ancient human remains used in the study. Ancient DNA redraws Europe’s prehistory
To reconstruct this chapter of Europe’s past, the researchers sequenced complete human genomes from individuals who lived between 8500 and 1700 BCE in a region that today includes Belgium, Germany, and the Netherlands.
Map indicating hunter-gatherer ancestry proportions across Europe 4500–2500 BCE.
Credit: University of Huddersfield
This period marked a transformative era in European prehistory, defined by sweeping population movements and cultural change. Long before modern borders existed, communities traveled widely across the continent. As new groups arrived, they mixed with local populations, reshaping the genetic landscape and introducing new languages, traditions, and lifeways that would leave a lasting imprint on modern European ancestry.
Dr. Maria Pala, Senior Lecturer in Molecular Biology, Department of Physical and Life Sciences, School of Applied Sciences.
Credit: University of Huddersfield
The impact of these changes was so profound and expansive that virtually all modern-day European populations carry evidence of three ancestral components: a hunter-gatherer component, a Neolithic component brought by the first farmers from the Near East, and a third component associated with pastoralists from Russia.
Farming arrived without genetic turnover
This latest research reveals that the arrival of farming in the area in question, around ~4500 BCE, did not result in anything like the major shift in genetic composition that took place across the rest of Europe. Instead, it involved the uneven acquisition of farming-related practices by local hunter-gatherer communities with only minimal genetic input from the incoming farmers.
Strikingly, genomic data from the study suggest that this farmer influx was mostly from women marrying into the local hunter-gatherer communities, bringing with them their know-how as well as their genes. This pattern was limited to the riverine wetlands and coastal areas across the region. The wealth of natural resources seems to have allowed the local people to selectively embrace some aspects of farming while also preserving many hunter-gatherer practices, and therefore genes.
The high levels of hunter-gatherer ancestry persisted across the region (modern-day Belgium and the Netherlands) until the end of the Neolithic, around 2500 BCE, when new people spread across Europe. The new incomers this time arrived and mixed fully with local communities, so that the genomic trajectory of the area finally realigned with the neighboring regions.
The ancient DNA lab at the University of Huddersfield.
Credit: University of Huddersfield
Women drove knowledge transfer
Professor Stewart commented: “We expected a clear change between the older hunter-gatherer populations and the newer agriculturalists, but apparently in the lowlands and along the rivers of the Netherlands and Belgium, the change was less immediate. It’s like a Waterworld where time stood still.”
Dr. Pala said, “Ancient DNA studies often bring to light unexpected pages of our past. We might anticipate finding the unexpected when analyzing samples from unexplored or peripheral regions of the globe. But here we are looking at the heartland of Europe, making these results even more striking. It’s a testament to the power of ancient DNA studies that findings like these can still surprise us.”
She added: “This study has also brought to light the crucial role played by women in the transmission of knowledge from the incoming farming communities to the local hunter-gatherers. Thanks to ancient DNA studies, we can not only uncover the past but also give voice to the invaluable but often overlooked role played by women in shaping human evolution.”
Artist's impression of a Falcon 9 upper stage with payload in 2015.
(SpaceX)
Space junk returning to the Earth is introducing metal pollution to the pristine upper atmosphere as it burns up on re-entry, a new study has found.
Published today in the journal Communications Earth & Environment, the study was led by Robin Wing from the Leibniz Institute of Atmospheric Physics in Germany.
Using highly sensitive lasers, he and his team of international researchers observed a plume of lithium pollution, tracking it back to the uncontrolled re-entry of a discarded SpaceX Falcon 9 rocket upper stage.
This is the first observational evidence that re-entering space debris leaves a detectable, human-caused chemical fingerprint in the upper atmosphere. This was also the first time a pollutant plume from a specific space junk re-entry event has been monitored from the ground.
With many more satellite launches planned for the future, this event won't be the last. It highlights the urgent need for governments and the space industry to tackle this problem before it gets out of hand.
A part of the atmosphere we barely understand
The region that comprises the upper stratosphere, mesosphere, and lower thermosphere (around 80 to 120 kilometres above Earth) is one of the least studied parts of the Earth system. It's too high for balloons, too low for satellites, and too harsh for aircraft.
Yet this region is crucial for radio and GPS communications, upper atmospheric weather patterns, and stratospheric ozone.
The upper atmosphere is largely unpolluted by humans. But the new space age is injecting growing quantities of metals and other pollutants from satellites, rocket bodies, and space debris.
The impact this will have on the stratospheric ozone layer, which is crucial to protecting life on Earth from harmful ultraviolet radiation, is as yet unquantified. But early findings are cause for concern.
For example, research from 2024 suggests aluminium and chlorine emissions related to rocket launches and re-entries may slow the ozone layer's recovery.
Soot from rocket launches is also likely to cause warming in the upper atmosphere.
Finding lithium with lasers
For the new study, the researchers used a highly sensitive laser-based sensor to detect the fluorescence of trace metals in the mesosphere and lower thermosphere. This is not an off-the-shelf and readily available observation system, but it could be.
Space debris from satellites is contributing to metal layers in our atmosphere left by meteors.
(Wing et al. Commun Earth Environ, 2026)
On 20 February 2025, they captured a clear, sudden enhancement in lithium ions from lithium batteries and human-made metal casings used in satellites. These are quite distinct from natural meteor material.
Using atmospheric trajectory modelling, they traced the timing and altitude of the lithium plume directly to the re-entry path of a discarded Falcon 9 rocket stage as it burnt up through the lower thermosphere into the mesosphere over the Atlantic Ocean, west of Ireland.
Lasers in operation at the Leibniz Institute of Atmospheric Physics.
(Danny Gohlke)
A rapidly escalating problem
The number of satellites in orbit has exploded from a few thousand a couple of years ago to roughly 14,000 right now, driven largely by megaconstellations.
There are many more satellites planned. In fact, SpaceX has applied to launch a megaconstellation of up to one million satellites to power data centres in space. Every one of these satellites will eventually re-enter the atmosphere. So too will the rockets that launch them.
Current estimates suggest that by 2030, several tonnes of spacecraft material will burn up in the upper atmosphere every single day.
So far, there is no regulatory framework for these emissions, few monitoring options, and limited scientific understanding of the likely impacts.
The new lithium detection demonstrates that pollutants from re-entry are measurable and can be traced back to individual re-entry events. This is an important step when it comes to holding companies involved in space accountable.
International regulatory bodies need to be set up to liaise with governments and scientists to establish monitoring networks and instruments to track changes to our atmosphere from this emerging threat.
As the space industry skyrockets, our efforts to understand, monitor, and regulate upper-atmospheric emissions must keep pace.
(Villaescusa et al., Archaeol. Anthropol. Sci., 2026)
A new investigation of ancient horned animal skulls found in Spain's Des-Cubierta Cave deepens the mystery of when and why Neanderthals put them there.
According to multiple lines of evidence, the skulls weren't all placed there at the same time but were likely carried into a narrow gallery repeatedly over a prolonged period during the late Middle Paleolithic, between around 70,000 and 50,000 years ago.
Excavation of the cave began in 2009, and one of the rock layers caught archaeologists' attention for a large assemblage of Mousterian stone tools, a culture primarily associated with Neanderthals in Europe.
But it wasn't just tools; there was also an unusual assemblage of animal remains, overwhelmingly composed of skulls.
Researchers cataloged the top parts of the skulls of at least 35 individual animals, including 28 bovines, five deer, and two rhinoceroses. Most of the rest of the skeletons, such as jawbones, limbs, and even cheekbones, are absent.
The deliberate accumulation of animal crania is pretty rare in the archaeological record. A team led by archaeologist Lucía Villaescusa of the University of Alcalá in Spain wanted to know if the site itself could yield any clues about the way these skulls were placed.
They studied multiple lines of evidence, including the spatial distribution of geological debris and archaeological artifacts in the deposit; reassembly of the fragmented bones; and the level of preservation of the bones.
Their results showed that rockfall first introduced a cone of debris into the gallery. It was after this rockfall that Neanderthals began to bring in animal skulls, placing them in the cave during separate phases of activity.
The timeframe of this activity is unclear, but the separation between deposits makes it clear that it was not a one-and-done instance of skull collection.
As with so many ancient human and Neanderthal activities, it's likely we'll never know why the Neanderthals of Des-Cubierta had a repeated tradition of putting crania in a cave, but the repeated pattern suggests a structured practice that offers a rare glimpse into the possible symbolic lives of our ancient relatives.
"The integration of geological, spatial, and taphonomic data demonstrates that the accumulation of large herbivore crania was not a single depositional event, but rather the result of repeated episodes embedded within a long-term process of gallery use," the researchers write.
"This sustained and reiterated behaviour highlights the structured and transmitted nature of this practice, adding a significant piece to the broader discussion on the complexity and symbolic potential of Neanderthal cultural expressions."
Men tend to lose the Y chromosome from their cells as they age. But because the Y bears few genes other than for male determination, it was thought this loss would not affect health.
But evidence has mounted over the past few years that when people who have a Y chromosome lose it, the loss is associated with serious diseases throughout the body, contributing to a shorter lifespan.
Loss of the Y in older men
New techniques to detect Y chromosome genes show frequent loss of the Y in tissues of older men. The increase with age is clear: 40% of 60-year-old men show loss of Y, but 57% of 90-year-olds. Environmental factors such as smoking and exposure to carcinogens also play a role.
Loss of Y occurs only in some cells, and their descendants never get it back. This creates a mosaic of cells with and without a Y in the body. Y-less cells grow faster than normal cells in culture, suggesting they may have an advantage in the body – and in tumours.
The Y chromosome is particularly prone to mistakes during cell division – it can be left behind in a little bag of membrane that gets lost. So we would expect that tissues with rapidly dividing cells would suffer more from loss of Y.
Why should loss of the gene-poor Y matter?
The human Y is an odd little chromosome, bearing only 51 protein-coding genes (not counting multiple copies), compared with the thousands on other chromosomes. It plays crucial roles in sex determination and sperm function, but was not thought to do much else.
Is the Y chromosome vanishing in men? Read our story on the scientific debate.
(Dmitry Bayer/Getty Images)
The Y chromosome is frequently lost when cells are cultured in the lab. It is the only chromosome that can be lost without killing the cell. This suggests no specific functions encoded by Y genes are necessary for cellular growth and function.
Indeed, males of some marsupial species jettison the Y chromosome early in their development, and evolution seems to be rapidly dispensing with it. In mammals, the Y has been degrading for 150 million years and has already been lost and replaced in some rodents.
So the loss of Y in body tissue late in life should surely not be a drama.
Association of loss of Y with health problems
Despite its apparent uselessness to most cells in the body, evidence is accumulating that loss of Y is associated with severe health conditions, including cardiovascular and neurodegenerative diseases and cancer.
Loss of Y frequency in kidney cells is associated with kidney disease.
Several studies now show a relationship between loss of Y and cardiac disease. For instance, a very large German study found men over 60 with high frequencies of loss of Y had an increased risk of heart attacks.
Loss of Y has also been linked to death from COVID, which might explain the sex difference in mortality. A tenfold higher frequency of loss of Y has been found in Alzheimer's disease patients.
Several studies have documented associations of loss of Y with various cancers in men. It is also associated with a poorer outcome for those who do have cancer. Loss of Y is common in cancer cells themselves, among other chromosome anomalies.
Does loss of Y cause disease and mortality in older men?
Figuring out what causes the links between loss of Y and health problems is difficult. They might occur because health problems cause loss of Y, or perhaps a third factor might cause both.
Even strong associations can't prove causation. The association with kidney or heart disease could result from rapid cell division during organ repair, for instance.
Cancer associations might reflect a genetic predisposition for genome instability. Indeed, whole genome association studies show loss of Y frequency is about one-third genetic, involving 150 identified genes largely involved in cell cycle regulation and cancer susceptibility.
However, one mouse study points to a direct effect. Researchers transplanted Y-deficient blood cells into irradiated mice, which then displayed increased frequencies of age-related pathologies including poorer cardiac function and subsequent heart failure.
Similarly, loss of Y from cancer cells seems to affect cell growth and malignancy directly, possibly driving eye melanoma, which is more frequent in men.
Role of the Y in body cells
The clinical effects of loss of Y suggest the Y chromosome has important functions in body cells. But given how few genes it hosts, how?
The male-determining SRY gene found on the Y is expressed widely in the body. But the only effect ascribed to its activity in the brain is complicity in causing Parkinson's disease. And four genes essential for making sperm are active only in the testis.
But among the other 46 genes on the Y, several are widely expressed and have essential functions in gene activity and regulation. Several are known cancer suppressors.
These genes all have copies on the X chromosome, so both males and females have two copies. It may be that the absence of a second copy in Y-less cells causes some kind of dysregulation.
As well as these protein-coding genes, the Y contains many non-coding genes. These are transcribed into RNA molecules, but never translated into proteins. At least some of these non-coding genes seem to control the function of other genes.
This might explain why the Y chromosome can affect the activity of genes on many other chromosomes. Loss of Y affects expression of some genes in the cells that make blood cells, as well as others that regulate immune function. It may also indirectly affect differentiation of blood cell types and heart function.
The DNA of the human Y was only fully sequenced a couple of years ago – so in time we may track down how particular genes cause these negative health effects.
Researchers have demonstrated that the brain’s connection patterns can predict the function of each region across a wide range of cognitive tasks. This discovery strengthens the idea that how the brain is wired determines how it works.
Credit: SciTechDaily.com
The brain’s wiring forms a unique fingerprint that reveals how we think, remember, and make decisions.
A new study offers the strongest evidence so far that the way different parts of the brain are wired together can reveal what each region is designed to do. By analyzing large-scale brain data, researchers found that connection patterns themselves hold clues about specialized functions across the brain.
Earlier work had linked connectivity to individual abilities such as perception or social behavior. This new research expands that view, examining how connectivity relates to many mental functions across the entire brain. Lead author Kelly Hiersche, a doctoral student in psychology at The Ohio State University, described the approach as providing a “bird’s eye view” of how brain structure supports a wide range of cognitive abilities.
“We found evidence suggesting that connectivity is a fundamental organizational principle governing brain function, which has implications for understanding what happens when things go wrong in the brain,” Hiersche said.
The Brain’s Unique Connectivity Fingerprints
The researchers report that each brain region carries its own distinctive “connectivity fingerprint.” These fingerprints reflect how a region is linked to other parts of the brain and correspond to the mental tasks it performs.
“Just like how everyone’s fingerprint is unique, we find that different brain regions have uniquely identifying connectivity fingerprints based on what mental function they perform,” said co-author Zeynep Saygin, associate professor of psychology at Ohio State.
Senior author David Osher, assistant professor of psychology at Ohio State, explained that scientists can use these fingerprints to predict what a region does. “Our findings help us understand the connectivity pattern that makes a language area unique, for example, and what makes it different from adjacent areas in the brain,” Osher said.
The results were published in the journal Network Neuroscience.
Combining MRI Brain Scans and Cognitive Maps
To conduct the study, the team used data from the Human Connectome Project, which includes MRI scans from 1,018 participants. These scans capture how brain regions are connected.
The researchers also relied on NeuroQuery, an online meta-analysis tool that generates brain maps for specific cognitive processes. NeuroQuery estimates how the brain activates across 33 mental functions, including speech, decision-making, listening to music, and face perception. Hiersche and her colleagues then developed computational models that linked the connectivity data from MRI scans with the activity patterns identified by NeuroQuery.
Connectivity Predicts Brain Activity
The findings revealed a strong and reliable relationship between connectivity patterns and brain activation across nearly all regions and cognitive domains. Specific wiring patterns could predict whether a region would be active—or inactive—during different tasks, from recognizing a face to having a conversation or making a choice.
“It supports a broadly held hypothesis among neuroscientists, that brain connectivity determines brain function, but this has not been explicitly shown until now, and not across such a large breadth of cognitive domains,” Osher said.
Stronger Links in Higher Level Skills
Although the connection between wiring and function appeared throughout the brain, the tightest relationships were found in areas responsible for higher-level abilities such as executive function and memory. These regions showed stronger connectivity function alignment than areas involved in sensory processing or social skills, Hiersche said.
“These higher-level skills take many years to develop in people, much longer than sensory or social skills,” she said.
“It may be that as you continually use these regions of the brain for them to develop, it results in this very tight link between connectivity and function for these higher-order skills.”
A Baseline for Understanding Brain Disorders
Because the study examined the whole brain at once, it provides a reference point for how healthy young adult brains are typically organized, Hiersche said.
Researchers can now compare this baseline to brain data from people with neurological or psychiatric conditions to better understand how connectivity and function differ in those cases.
“Knowing that connectivity is a general organizational principle of brain function across the entire brain provides a foundation for future work in this area.”
The waters off Western Australia are becoming dramatically less salty and the cause traces back to climate-driven shifts in global winds. Scientists warn that this quiet transformation could ripple through ocean circulation and marine life worldwide.
Credit: SciTechDaily.com
A vast region of the Southern Indian Ocean is freshening at an unprecedented pace.
Ocean water is not just “wet.” Its saltiness helps determine how seawater stacks up in layers, how currents move heat around the planet, and how easily nutrients can reach the sunlit surface where much of marine life begins. That is why scientists are paying close attention to a startling shift now unfolding off Western Australia: the Southern Indian Ocean there is freshening fast.
According to a study published in Nature Climate Change, researchers from the University of Colorado Boulder report that rising global temperatures over the past 60 years have altered major wind patterns and ocean currents. These shifts are funneling increasing amounts of freshwater into the Southern Indian Ocean. The researchers warn that this trend could reshape how the ocean and atmosphere interact, interfere with large circulation systems that regulate climate worldwide, and place added stress on marine ecosystems.
“We’re seeing a large-scale shift of how freshwater moves through the ocean,” said Weiqing Han, professor in the Department of Atmospheric and Oceanic Sciences. “It’s happening in a region that plays a key role in global ocean circulation.” The Indo-Pacific Freshwater Pool
Much of the incoming freshwater can be traced back to a huge tropical region where surface waters are naturally diluted by frequent rain. This zone, stretching from the eastern Indian Ocean across to the western Pacific in the Northern Hemisphere tropics, stays relatively fresh because rainfall is high while evaporation is comparatively low. Scientists often call it the Indo Pacific freshwater pool.
That pool is not isolated. It connects to the thermohaline circulation, a global current system sometimes described as a conveyor belt because it moves heat, salt, and freshwater between ocean basins. Warm surface waters from the Indo Pacific feed into pathways that ultimately influence conditions in the Atlantic. In the North Atlantic, that transported water cools, becomes denser, sinks, and then returns southward at depth before eventually flowing back toward the Indian and Pacific Oceans. Small shifts in salinity can matter here because salt helps set seawater density, and density helps power the sinking and spreading that keep the system moving.
The waters off Australia’s southwest have typically been dry at the surface, with evaporation outpacing rainfall. That pattern has historically favored higher salinity. But long-term observations show that the balance is changing.
Han’s team estimates that the area covered by salty seawater in this Southern Indian Ocean region has shrunk by about 30% over the past 60 years. They describe it as the fastest freshening seen anywhere in the Southern Hemisphere.
“This freshening is equivalent to adding about 60% of Lake Tahoe’s worth of freshwater to the region every year,” said first author Gengxin Chen, visiting scholar in the Department of Atmospheric and Oceanic Sciences and senior scientist at the Chinese Academy of Sciences’ South China Sea Institute of Oceanology. “To put that into perspective, the amount of freshwater flowing into this ocean area is enough to supply the entire U.S. population with drinking water for more than 380 years,” he said. Climate-Driven Wind Shifts
The researchers found that the growing influx of freshwater cannot be explained by local rainfall. By analyzing observational records alongside computer simulations, they concluded that global warming is reshaping surface wind patterns across the Indian and tropical Pacific Oceans. These altered winds are steering ocean currents in ways that transport more freshwater from the Indo-Pacific freshwater pool into the Southern Indian Ocean.
As salt levels drop, seawater becomes less dense. Fresher water tends to remain above saltier, heavier water, increasing the separation between surface and deep layers. This enhanced layering limits vertical mixing, the process that normally allows surface water to sink and deeper water to rise, distributing heat and nutrients throughout the ocean.
Previous studies have suggested that climate change could slow part of the thermohaline circulation, as melting from the Greenland Ice Sheet and Arctic sea ice adds freshwater to the North Atlantic, disrupting the salinity balance needed for the conveyor belt to keep moving. The expansion of the freshwater pool could further influence this system by transporting fresher water into the Atlantic.
Weaker vertical mixing could also harm marine life. When nutrient-rich water from the depths does not reach the sunlit surface, organisms in upper layers have fewer resources to survive. At the same time, reduced mixing traps excess heat near the surface, raising temperatures further for species already coping with warming oceans.
“Salinity changes could affect plankton and sea grass. These are the foundation of the marine food web. Changes in them could have far-reaching impact on the biodiversity in our oceans,” Chen said.
Deep inside the Greenland ice sheet, radar images have revealed strange, plume-like structures distorting the layering deposited over eons.
Now, more than a decade after their discovery, scientists think they have figured out what causes these structures, and it's a real hum-dinger. According to modeling, the plumes are a striking match for convection: the roiling upward transport of heat more commonly linked to the fiery, molten rock churning beneath Earth's crust.
"Finding that thermal convection can happen within an ice sheet goes slightly against our intuition and expectations. Ice is at least a million times softer than the Earth's mantle, though, so the physics just work out," says glaciologist Robert Law of the University of Bergen in Norway.
"It's like an exciting freak of nature."
Example plume structures from northern Greenland, mapped from radar surveys.
(Law et al., The Cryosphere, 2026)
The Greenland ice sheet, which covers 80 percent of the island, is one of our planet's biggest reservoirs of frozen water, and is forecast to play a major role in rising sea levels as it melts into the ocean. Understanding the physics inside it is vital for predicting how the ice sheet will change over time.
This is why scientists use ice-penetrating radar. Radio waves pass through the ice and reflect back differently as they encounter internal layers – snow that fell long ago and was compacted into ice as more snow piled on top. Each of these layers has its own characteristics – slightly different acidity levels, for example, and variations in dust, ash, and chemical content.
In a 2014 paper, scientists described strange structures these radar images had revealed deep inside the ice in northern Greenland. These large, upward-buckling features were unrelated to the topography of the bedrock below, presenting a puzzle researchers have been trying to solve ever since.
https://www.youtube.com/watch?v=-JdzA6fC91s&t=1s
Previous efforts suggested that mechanisms such as glacial meltwater freezing onto the underside of the ice sheet, or migrating slippery spots, may be responsible for the structures. One idea that had not been tested, however, was that thermal convection may take place within ice sheets.
To test the idea, Law and his colleagues turned to computer modeling. They built a simplified digital slice of the Greenland ice sheet and asked a simple question: If the base of the ice is warmed from below, could convection form structures that match what radar sees?
They used a geodynamics modeling package normally used to simulate convection in Earth's mantle to model a slab of ice 2.5 kilometers (1.6 miles) thick. They tweaked variables such as snowfall rate, ice thickness, how soft the ice is, and how fast the ice moves on the surface.
Under the right conditions, the model began producing plume-like upwellings – rising columns of ice that folded the overlying layers into shapes strikingly similar to those seen in radar images.
In the model, plumes only formed when the ice near the base was warmer and significantly softer than standard assumptions allow, suggesting that if convection is responsible, the real ice at the base of northern Greenland's ice sheet may also be softer than previously thought.
Meanwhile, the heat required to produce these convection upwellings in the model was consistent with the heat continuously flowing from Earth, generated by the radioactive decay of elements within the crust and by residual heat from Earth's formation as it gradually cools over billions of years.
This effect is tiny, but over time, and under a giant slab of insulating material, it could build up enough to warm and soften the ice above it.
"We typically think of ice as a solid material, so the discovery that parts of the Greenland ice sheet actually undergo thermal convection, resembling a boiling pot of pasta, is as wild as it is fascinating," says climatologist Andreas Born of the University of Bergen.
Now, that doesn't mean the ice is slushy. It's still solid ice, flowing only on timescales of thousands of years. It also doesn't necessarily mean that it will melt faster. Further investigation into the physics of ice, and the effects of convection on the evolution of the ice sheet, is required to determine what this means for the future.
"Greenland and its nature is truly special. The ice sheet there is over one thousand years old, and it's the only ice sheet on Earth to have a culture and permanent population at its margins," Law says.
"The more we learn about the hidden processes inside the ice, the better prepared we'll be for the changes coming to coastlines around the world."
Researchers have identified a period of sluggish magnetic field flipping for planet Earth, some 40 million years ago – raising big questions about how long these reversals actually take, and how we might be affected by the next one.
Magnetic field flips are thought to happen fairly regularly, as far as geological timescales go. There have been some 540 reversals across the last 170 million years, and it seems they've been happening for billions of years.
But something was different 40 million years ago. One transition around this time took 18,000 years, and another took at least 70,000 years, the international team of researchers found, which is far longer than the typical timespan of 10,000 years or so that scientists think is the norm.
"This finding unveiled an extraordinarily prolonged reversal process, challenging conventional understanding and leaving us genuinely astonished," writes lead author and paleomagnetist Yuhji Yamamoto from Kochi University in Japan.
"The variability in reversal duration revealed by this study reflects the intrinsic dynamical properties of the Earth's geodynamo, and it provides empirical evidence that geomagnetic reversals can last significantly longer than the widely assumed 10,000-year duration."
The team analyzed a sediment core extracted from a location off the coast of Newfoundland in the North Atlantic. The magnetic signals inside these cores, locked to tiny crystals, reveal the direction of Earth's magnetic field over vast time periods.
Yuhji Yamamoto studying a drilling core.
(Peter Lippert)
In this case, the researchers looked closely at a specific layer measuring 8 meters (a little over 26 feet) top to bottom, representing part of the Eocene era. There was a clear shift in polarity, but across an unexpectedly large section of the sediment core.
Two magnetic field flips were discovered, one lasting around 18,000 years, and another lasting 70,000 years. Computer modeling suggested events like these could potentially stretch across 130,000 years in some cases – though that's never been seen in the geological record.
https://www.youtube.com/watch?v=IgouMVdqLDI&t=5s
These magnetic field flips are driven by shifts in Earth's liquid iron and nickel outer core, around 2,200 kilometers (1,367 miles) thick. While this outer core is always in flux, it occasionally becomes unstable enough that the magnetic poles change position.
The planet doesn't tip over, but magnetic north becomes magnetic south, and vice versa – your compass would eventually point in the opposite direction, after tens of thousands of years of being incredibly confused.
Not only did these newly identified flips take a long time, but they were messier and more variable than the researchers expected. There were multiple 'rebounds' where the magnetic field seemed unsure about which direction to travel in, matching findings from our planet's most recent flip – the Brunhes-Matuyama reversal.
"The occurrence of multiple rebounds is not unprecedented: this behaviour is also reported for the Brunhes-Matuyama reversal," write the researchers in their published paper.
"We suggest that it may be more common and that polarity reversals are inherently complex, if not somewhat chaotic, events."
The Brunhes-Matuyama reversal, which happened around 775,000 years ago, backs up the new findings. A study from 2019 found that the flip took 22,000 years to complete – so drawn-out reversals may be the rule, rather than the exception.
When the next one happens, we need to be ready. One of the consequences of a magnetic field reversal is that our planet gets far less protection from the radiation and geomagnetic activity beaming down from space.
If that exposure is going to last tens of thousands of years longer than previously thought, we need to know about it. It has the potential to disrupt everything from animal species to climate systems – though more research will be needed to know the precise effects.
"It's basically saying we are exposing higher latitudes in particular, but also the entire planet, to greater rates and greater durations of this cosmic radiation," says paleomagnetist Peter Lippert from the University of Utah.
"Therefore, it's logical to expect that there would be higher rates of genetic mutation. There could be atmospheric erosion."
Paleontologist Paul Sereno with the reconstructed Spinosaurus mirabilis skull. (Keith Ladzinski/University of Chicago)
A new Spinosaurus species has been unearthed from the Saharan desert, and its skull bears a magnificent crest never seen before on this kind of dinosaur.
Paleontologists have named it Spinosaurus mirabilis, meaning 'wonderful spine lizard'. We heartily agree.
Paleoartist rendering of Spinosaurus mirabilis eating a coelacanth.
(Dani Navarro)
The discovery reveals more than just the dinosaur's beauty, however. Spinosaurus have mostly been found in coastal deposits, while this new specimen hails from deep inland in Niger, hundreds of kilometers from any ocean.
Even the paleontology team, led by Paul Sereno of the University of Chicago, was caught off guard.
"This find was so sudden and amazing, it was really emotional for our team," Sereno says.
"I'll forever cherish the moment in camp when we crowded around a laptop to look at the new species for the first time… One member of our team generated 3D digital models of the bones we found to assemble the skull – on solar power in the middle of the Sahara. That's when the significance of the discovery really registered."
With its spiky, interlocking teeth reminiscent of modern crocodiles, and its proximity to long-necked dinosaurs buried in nearby river sediments, Sereno and team think this Spinosaurus might have led a semi-aquatic lifestyle amidst a forested habitat.
"I envision this dinosaur as a kind of 'hell heron' that had no problem wading on its sturdy legs into two meters of water but probably spent most of its time stalking shallower traps for the many large fish of the day," Sereno says.
The scimitar-shaped crest sure is handsome, but exactly what purpose it served remains a mystery. The team suspect it was once sheathed in keratin – perhaps brightly colored, like a toucan's bill – to create a kind of visual display.
