Ancient DNA reveals the deadly diseases behind Napoleon’s defeat

 Scientists from the Institut Pasteur have conducted a genetic analysis of the remains of soldiers who retreated from Russia in 1812. Their work uncovered traces of two disease-causing pathogens -- those behind paratyphoid fever and relapsing fever -- which match the symptoms described in eyewitness records from that time. The findings were first shared as a preprint on bioRxiv on July 16, 2025, and later published in the journal Current Biology on October 24.

Investigating the Mystery of the 1812 Retreat

Napoleon's invasion of Russia in 1812, known as the "Patriotic War of 1812," ended in one of history's most disastrous retreats. To better understand what role disease may have played in this collapse, researchers from the Institut Pasteur's Microbial Paleogenomics Unit partnered with the Laboratory of Biocultural Anthropology at Aix Marseille University. The team analyzed the DNA of 13 French soldiers exhumed in 2002 from a burial site in Vilnius, Lithuania, uncovered during archaeological excavations led by the Aix-Marseille University group. Using next-generation sequencing technology on ancient DNA, they searched for genetic traces of infectious organisms.

The researchers detected two distinct disease agents: Salmonella enterica subsp. enterica (serovar Paratyphi C), which causes paratyphoid fever, and Borrelia recurrentis, the bacterium responsible for relapsing fever. The latter is transmitted by lice and produces alternating periods of fever and recovery. Although different, both infections can cause severe fever, exhaustion, and digestive distress. Their combined impact could have intensified the soldiers' suffering at a time when cold, hunger, and poor sanitation were already taking a heavy toll.

Genetic Evidence From Napoleonic Soldiers

Out of the 13 soldiers examined, DNA from S. enterica Paratyphi C was found in four individuals, and B. recurrentis was detected in two. This marks the first direct genetic confirmation that these pathogens were present in Napoleon's army. Their exact contribution to the enormous death toll remains uncertain, but the findings complement earlier research that identified Rickettsia prowazekii (the cause of typhus) and Bartonella quintana (responsible for trench fever), both long suspected of spreading through the ranks during the retreat.

Because only a small number of samples could be analyzed compared to the thousands of remains in Vilnius, researchers cannot yet determine how widespread these infections were. The tested soldiers represent a tiny fraction -- 13 out of more than 3,000 bodies at the site and roughly 500,000 to 600,000 troops who took part in the campaign, of whom about 300,000 died during the retreat.

Understanding the Past to Protect the Future

"Accessing the genomic data of the pathogens that circulated in historical populations helps us to understand how infectious diseases evolved, spread and disappeared over time, and to identify the social or environmental contexts that played a part in these developments. This information provides us with valuable insights to better understand and tackle infectious diseases today," explains Nicolás Rascovan, Head of the Microbial Paleogenomics Unit at the Institut Pasteur and last author of the study.

Source: ScienceDaily

Hippos once roamed frozen Germany with mammoths

 Hippos, now found only in sub-Saharan Africa, managed to survive in central Europe far longer than anyone previously believed. A new analysis of ancient bones shows that hippos lived in the Upper Rhine Graben between about 47,000 and 31,000 years ago, during the depths of the last ice age. The findings come from an international research team led by the University of Potsdam and the Reiss-Engelhorn-Museen Mannheim in collaboration with the Curt-Engelhorn-Zentrum Archäometrie, and were recently published in Current Biology.

Extinction Timeline Rewritten

Until recently, scientists thought the common hippopotamus (Hippopotamus amphibius) disappeared from central Europe roughly 115,000 years ago, when the last interglacial period ended. However, the new study -- conducted by researchers from the University of Potsdam, the Reiss-Engelhorn-Museen Mannheim, the Curt-Engelhorn-Zentrum Archäometrie Mannheim, ETH Zurich, and several international partners -- reveals that hippos actually persisted in the Upper Rhine Graben of southwestern Germany tens of thousands of years later, well into the middle of the last ice age.

The Upper Rhine Graben serves as a vital record of ancient climate conditions. Animal bones buried for millennia in layers of gravel and sand offer rare windows into the past. "It's amazing how well the bones have been preserved. At many skeletal remains it was possible to take samples suitable for analysis -- that is not a given after such a long time," said Dr. Ronny Friedrich, a specialist in age determination at the Curt-Engelhorn-Zentrum Archäometrie.

Genetic and Radiocarbon Clues

Researchers examined numerous hippopotamus fossils using both genetic and radiocarbon dating methods. Ancient DNA sequencing revealed that these Ice Age hippos were closely related to modern African populations and were part of the same species. Radiocarbon dating confirmed their presence during a warmer phase of the middle Weichselian glaciation, when conditions temporarily allowed the animals to survive in central Europe.

Further genome-wide analysis showed that the European hippo population had extremely low genetic diversity, suggesting it was both small and geographically isolated. Fossil evidence also revealed that these warm-adapted hippos lived alongside cold-climate animals such as mammoths and woolly rhinoceroses -- an unusual ecological mix that highlights the complexity of Ice Age environments.

Rethinking Europe's Ice Age Ecosystem

"The results demonstrate that hippos did not vanish from middle Europe at the end of the last interglacial, as previously assumed," summarizes first author Dr. Patrick Arnold. "Therefore, we should re-analyze other continental European hippo fossils traditionally attributed to the last interglacial period."

Prof. Dr. Wilfried Rosendahl, general director of the Reiss-Engelhorn-Museen Mannheim and project leader of "Eiszeitfenster Oberrheingraben" is convinced that ice age research still holds many exciting questions: "The current study provides important new insights which impressively prove that ice age was not the same everywhere, but local peculiarities taken together form a complex overall picture -- similar to a puzzle. It would now be interesting and important to further examine other heat-loving animal species, attributed so far to the last interglacial."

The research was carried out as part of the "Eiszeitfenster Oberrheingraben" project, supported by the Klaus Tschira Stiftung Heidelberg. This interdisciplinary effort aims to shed light on climate and environmental evolution in the Upper Rhine Graben and southwestern Germany over the past 400,000 years. The study focused on Ice Age bones from the Reis collection, housed at the Reiss-Engelhorn-Museen, which continue to reveal remarkable insights into Europe's dynamic prehistoric world.

Source: ScienceDaily

Exercise and omega-3s could be the secret to healthier teeth

 New research published in Scientific Reports has found that regular exercise paired with omega-3 supplementation can significantly enhance immune function and reduce the severity of chronic apical periodontitis, a type of inflammation that affects the tip of the tooth root.

Understanding Apical Periodontitis

Apical periodontitis occurs when bacteria from untreated tooth decay spread through the root canal to the apex of the tooth (the root tip), triggering inflammation in the surrounding bone. This infection can gradually destroy bone tissue in the area if left untreated.The new study is the first to show that moderate exercise combined with omega-3 supplementation can substantially improve this inflammatory condition. Together, these two factors helped control bacterial growth, minimize bone loss, balance the production of inflammatory molecules called cytokines, and stimulate fibroblasts, the cells that repair and maintain tissues.

The Connection Between Oral and Overall Health

Untreated apical periodontitis can lead to tooth loss, but its effects extend beyond the mouth. The condition is closely linked to systemic diseases such as diabetes, metabolic syndrome, arteriosclerosis, and kidney disease. Each can worsen the other, creating a harmful feedback loop between oral inflammation and general health.

"It's a condition that patients may not even know they have because of its chronic nature, but which can evolve and lead to bone destruction and tooth mobility. In addition, in specific situations, such as a drop in immunity, it can become acute, so the patient starts to feel pain, pus forms at the site, the face can become swollen," explains Rogério de Castilho, a professor at the Araçatuba School of Dentistry at São Paulo State University (FOA-UNESP) in Brazil. Castilho supervised the study and is supported by FAPESP.

Exercise and Supplements Show Measurable Impact

"In rats, physical exercise alone brought about a systemic improvement, regulating the local immune response. In addition, when combined with supplementation, it further reduced the destructive condition caused by endodontic pathology," explains Ana Paula Fernandes Ribeiro, the first author of the study, carried out during her doctorate at FOA-UNESP.

To explore these effects, researchers induced apical periodontitis in 30 rats and divided them into three groups. One group received no treatment, the second completed a 30-day swimming routine, and the third both swam and received omega-3 supplements, a fatty acid known for reducing inflammation in chronic diseases.

The swimming-only group showed improved outcomes compared to the untreated animals, but the group that both exercised and took omega-3 supplements demonstrated the greatest improvement in immune regulation and infection control.

Lower Inflammation, Stronger Bone

Detailed immune testing showed that rats receiving both interventions had the lowest levels of the inflammatory cytokines interleukin 17 (IL-17) and tumor necrosis factor alpha (TNF-α). Those that exercised without supplementation also had reduced levels compared to untreated rats, but the combination proved most effective.

Researchers also observed fewer osteoclasts -- cells that break down bone -- in the exercise and supplement groups, indicating less bone loss. Micro CT scans confirmed these findings: animals that swam had less loss of alveolar bone (the bone that supports teeth) than the control group, and the omega-3 group showed the greatest bone preservation overall.

Implications for Human Health

According to the authors, these results add to growing evidence that exercise and omega-3 fatty acids benefit not only systemic immunity but also oral health.

"To know if the same would be true for humans, we'd need a clinical study with a significant number of patients. However, in addition to the many proven benefits of physical exercise and omega-3 consumption, this is yet another important piece of evidence," Jacinto says.

The work was supported by FAPESP through Scientific Initiation grants awarded to Michely de Lima Rodrigues (20/13089-3 and 22/04884-0), another co-author of the study.

Source: ScienceDaily

Dinosaurs were thriving when the asteroid struck

 For much of the past century, scientists thought dinosaurs were already in decline long before the asteroid impact that ended their reign 66 million years ago. However, a new study published in Science by researchers from Baylor University, New Mexico State University, The Smithsonian Institution, and several international partners challenges that long-standing belief.

The findings reveal that dinosaurs were not fading away at all -- they were thriving.

A final flourish in the San Juan Basin

In northwestern New Mexico, layers of ancient rock hold clues to a lively, previously overlooked chapter of Earth's history. Within the Naashoibito Member of the Kirtland Formation, scientists found evidence of rich dinosaur ecosystems that continued to flourish until just before the asteroid struck.High-precision dating determined that fossils from these rocks are between 66.4 and 66 million years old, placing them right at the boundary between the Cretaceous and Paleogene periods, when the global extinction event occurred.

"The Naashoibito dinosaurs lived at the same time as the famous Hell Creek species in Montana and the Dakotas," said Daniel Peppe, Ph.D., associate professor of geosciences at Baylor University. "They were not in decline -- these were vibrant, diverse communities."

Dinosaurs in their prime

The fossil evidence from New Mexico tells a strikingly different story from what many had assumed. Instead of dwindling, dinosaurs across North America were thriving in distinct regional communities. By analyzing ecological and geographic patterns, researchers found that dinosaur populations in western North America were divided into separate "bioprovinces" shaped primarily by regional temperature differences rather than by mountains or rivers.

"What our new research shows is that dinosaurs are not on their way out going into the mass extinction," said first author Andrew Flynn, Ph.D. '20, assistant professor of geological sciences at New Mexico State University. "They're doing great, they're thriving and that the asteroid impact seems to knock them out. This counters a long-held idea that there was this long-term decline in dinosaur diversity leading up to the mass extinction making them more prone to extinction."

Life after impact

The asteroid impact brought the age of dinosaurs to an abrupt end, but the ecosystems they left behind became the foundation for a new evolutionary chapter. Within just 300,000 years, mammals began rapidly diversifying, developing new diets, sizes, and ecological roles.

The same temperature-related patterns that once defined dinosaur ecosystems continued into the Paleocene epoch, guiding how life recovered after the disaster.

"The surviving mammals still retain the same north and south bio provinces," Flynn said. "Mammals in the north and the south are very different from each other, which is different than other mass extinctions where it seems to be much more uniform."

Why this discovery matters

This discovery offers more than just a look into the distant past. It underscores both the resilience and fragility of life on Earth. Conducted on public lands managed by the U.S. Bureau of Land Management, the research highlights how protected landscapes can unlock vital insights into how ecosystems respond to global upheaval.

By refining the timeline of the dinosaurs' final days, the study reveals that their extinction was not a slow decline but an abrupt, catastrophic end to a flourishing era of life -- cut short by chance from beyond the sky.

About the authors

In addition to Peppe and Flynn, the research team included scientists from Baylor University, New Mexico State University, the Smithsonian Institution, the University of Edinburgh, University College London and multiple U.S. and international institutions.

• Stephen L. Brusatte, Ph.D., The University of Edinburgh
• Alfio Alessandro Chiarenza, Ph.D., Royal Society Newton International Fellow, University College London
• Jorge Garcia-Giron, Ph.D., University of Leon
• Adam J. Davis, Ph.D., WSP USA Inc.
• C. Will Fenley, Ph.D., Valle Exploration
• Caitlin E. Leslie, Ph.D., ExxonMobil
• Ross Secord, Ph.D., University of Nebraska-Lincoln
• Sarah Shelley, Ph.D., Carnegie Museum of Natural History
• Anne Weil, Ph.D., Oklahoma State University
• Matthew T. Heizler, Ph.D., New Mexico Institute of Mining and Technology
• Thomas E. Williamson, Ph.D., New Mexico Museum of Natural History and Science.

Source: Science Daily

MIT physicists just found a way to see inside atoms

 Physicists at MIT have introduced a technique to study the interior of an atom's nucleus by relying on the atom's own electrons as "messengers" inside a molecule.

In research published on October 23 in Science, the team precisely measured the energy of electrons orbiting a radium atom that was chemically bound to a fluoride atom, forming radium monofluoride. By using the molecular environment as a microscopic stand-in for a particle collider, they confined the radium atom's electrons and increased the likelihood that some would briefly pass through the nucleus.Traditional experiments that investigate nuclear interiors depend on kilometer-scale accelerators that speed up electron beams to smash into and fragment nuclei. The new molecule-centered approach provides a compact, table-top way to directly probe the inside of a nucleus.

Table-Top Method Detects Nuclear "Messages"

Working with radium monofluoride, the researchers tracked the energies of the radium atom's electrons as they moved within the molecule. They observed a small shift in energy and concluded that some electrons must have briefly entered the nucleus and interacted with what lies inside. As those electrons left, they retained the energy change, effectively carrying a nuclear "message" that reveals features of the nucleus's interior.

The method opens a path to measuring the nuclear "magnetic distribution." Inside a nucleus, each proton and neutron behaves like a tiny magnet, and their orientations depend on how these particles are arranged. The team plans to use the technique to map this property in radium for the first time, a step that could inform one of cosmology's central puzzles: why the universe contains far more matter than antimatter.

"Our results lay the groundwork for subsequent studies aiming to measure violations of fundamental symmetries at the nuclear level," says study co-author Ronald Fernando Garcia Ruiz, who is the Thomas A. Franck Associate Professor of Physics at MIT. "This could provide answers to some of the most pressing questions in modern physics."

MIT co-authors include Shane Wilkins, Silviu-Marian Udrescu, and Alex Brinson, together with collaborators from several institutions, including the Collinear Resonance Ionization Spectroscopy Experiment (CRIS) at CERN in Switzerland, where the experiments took place.

Matter-Antimatter Imbalance and Radium's Role

According to current understanding, the early universe should have contained nearly equal amounts of matter and antimatter. Yet nearly everything we can detect today is matter built from protons and neutrons inside atomic nuclei.This observation conflicts with expectations from the Standard Model, suggesting that additional sources of fundamental symmetry violation are needed to account for the scarcity of antimatter. Such effects could appear within the nuclei of certain atoms, including radium.

Unlike most nuclei, which are close to spherical, radium's nucleus has an asymmetric, pear-like shape. Theorists predict that this geometry can amplify signals of symmetry violation enough to make them potentially observable.

"The radium nucleus is predicted to be an amplifier of this symmetry breaking, because its nucleus is asymmetric in charge and mass, which is quite unusual," says Garcia Ruiz, whose group has focused on developing methods to probe radium nuclei for signs of fundamental symmetry violation.

Building Ultra-Sensitive Molecular Experiments Peering inside a radium nucleus to test fundamental symmetries is extremely challenging.

"Radium is naturally radioactive, with a short lifetime and we can currently only produce radium monofluoride molecules in tiny quantities," says study lead author Shane Wilkins, a former postdoc at MIT. "We therefore need incredibly sensitive techniques to be able measure them."

The team recognized that embedding a radium atom in a molecule could confine and magnify the behavior of its electrons.

"When you put this radioactive atom inside of a molecule, the internal electric field that its electrons experience is orders of magnitude larger compared to the fields we can produce and apply in a lab," explains Silviu-Marian Udrescu PhD '24, a study co-author. "In a way, the molecule acts like a giant particle collider and gives us a better chance to probe the radium's nucleus."

Energy Shift Reveals Electron-Nucleus Encounters

The researchers created radium monofluoride by pairing radium atoms with fluoride atoms. In this molecule, the radium electrons are effectively squeezed, which increases the chance that they will interact with and briefly enter the radium nucleus.

Source: ScienceDaily

Life expectancy gains have slowed sharply

 A new international analysis led by a University of Wisconsin-Madison professor reveals that the remarkable gains in life expectancy seen across wealthy nations during the early 20th century have slowed dramatically. The findings indicate that no generation born after 1939 is expected to reach an average age of 100.

Researchers Track a Century of Longevity Data

The study, published in the Proceedings of the National Academy of Sciences, was conducted by Héctor Pifarré i Arolas of the La Follette School of Public Affairs, José Andrade of the Max Planck Institute for Demographic Research, and Carlo Giovanni Camarda of the Institut national d'études démographiques. Drawing from the Human Mortality Database, the researchers examined data from 23 high-income, low-mortality countries using six independent methods to forecast mortality trends.According to Pifarré i Arolas, "The unprecedented increase in life expectancy we achieved in the first half of the 20th century appears to be a phenomenon we are unlikely to achieve again in the foreseeable future. In the absence of any major breakthroughs that significantly extend human life, life expectancy would still not match the rapid increases seen in the early 20th century even if adult survival improved twice as fast as we predict."

A Century of Uneven Gains

Between 1900 and 1938, life expectancy in wealthy nations rose by roughly five and a half months per generation. Someone born in 1900 could expect to live an average of 62 years, while a person born in 1938 could expect to reach about 80 years -- a dramatic improvement over just a few decades.

For generations born between 1939 and 2000, however, progress slowed to around two and a half to three and a half months per generation, depending on the statistical model used. Mortality forecasting models -- analytical tools that predict future lifespans using past and present mortality data -- allowed the researchers to project multiple possible futures for human longevity.

"We forecast that those born in 1980 will not live to be 100 on average, and none of the cohorts in our study will reach this milestone. This decline is largely due to the fact that past surges in longevity were driven by remarkable improvements in survival at very young ages," according to corresponding author Andrade.

In the early 20th century, rapid declines in infant mortality -- brought about by medical innovation, improved sanitation, and higher living standards -- significantly boosted average life expectancy. Today, infant and child mortality rates in high-income countries are already extremely low, meaning future gains must come from improved survival at older ages. The study concludes that such advances are unlikely to match the explosive pace of progress achieved a century ago.

Implications for Policy, Healthcare, and Planning

Although forecasts can never be fully certain, the authors emphasize that their results provide essential insights for policymakers preparing for the future. Unexpected developments such as new pandemics, medical breakthroughs, or major societal shifts could alter these trends, but current evidence suggests a long-term slowdown.

This slowdown has consequences that go beyond national statistics. While the study focuses on populations rather than individuals, slower life expectancy growth may influence how people approach saving, retirement, and long-term care. As Pifarré i Arolas and his colleagues suggest, both governments and individuals may need to adjust their expectations and plans for the decades ahead.

Source: ScienceDaily

Scientists reveal Alaska could get up to two minutes’ warning before the next big quake

 For a wide variety of earthquake scenarios in Alaska, an earthquake early warning (EEW) system could provide at least 10 seconds of warning time for hazardous shaking, according to a new report.

Increasing the density and improving the spacing of seismic stations around the state could add 5 to 15 seconds to these estimated warning times, write Alexander Fozkos and Michael West at the University of Alaska Fairbanks. Alaska experiences tens of thousands of earthquakes each year, and has been the site some of the world's largest and most destructive seismic events.

The study's findings published in the Bulletin of the Seismological Society of America could help lay the groundwork for the expansion of the U.S. ShakeAlert earthquake early warning system, which now covers California, Oregon and Washington State.

"There were a lot of studies before EEW was widely available on the West Coast, where people were looking at different scenarios," said Fozkos. "So we wanted a similar kind of science up here with numbers that are Alaska specific."

For earthquakes along well-known faults in southcentral and southeast coastal Alaska, Fozkos and West estimated potential warning times of 10 to 120 seconds for magnitude 8.3 scenarios.

For magnitude 7.3 earthquake scenarios in crustal faults in interior and southcentral Alaska, the researchers estimated potential warning times ranging from 0 to 44 seconds.

And for a set of magnitude 7.8 earthquake scenarios along the dip of the subducting slab beneath Alaska, estimated warning times ranged from 0 to 73 seconds.

"I was expecting decent warning times along the coast and for most of the subduction zone events," said Fozkos, because there is dense seismic station coverage in these areas. "I was not expecting decent warning times for the shallow crustal events, so that was the biggest surprise to me."

The scenarios used in the study vary in earthquake magnitude, depth, location and fault style -- all of which impacted warning times. The researchers' models estimated how many seconds after an earthquake's origin the quake could be detected, how many seconds after origin time an alert could be available, and minimum and maximum warning times at a location.

Warning times were defined as the time difference between the time of the alert and the time that peak ground motion from an earthquake arrived at a location. This definition differs from a more common definition used in EEW systems, which ties warning time to the arrival of the initial S-wave or shear wave of an earthquake.

The researchers wanted to use peak ground motion instead, to create a warning time measurement that might be more relevant to people as they respond to an earthquake. The initial S-wave may not always cause significant ground motion, and strong shaking can arrive tens of seconds after the initial S-wave in large earthquakes, they explain.

The study doesn't analyze "the time it takes to disseminate the alert -- the time it actually takes to send the alert from a radio tower or from a satellite to somebody's phone and then for them to take out their phone and react to it," Fozkos noted.

The potential lag time in transmitting data and sharing an alert with the public "could be a big challenge for Alaska, but I don't think it's going to be insurmountable," he added.

The harsh Alaskan winters and wilderness locations of some seismic stations could also be challenging for an early warning system, if stations go down and can't be repaired quickly. "I think there is definitely a need for adding stations to cover redundancy for remote stations," Fozkos said.

Ocean-bottom seismometers (OBS) and more earthquake detection via distributed acoustic sensing or DAS would also be welcome additions to a warning system, he added. "Coupled with the fact that some of our biggest earthquakes are going to be offshore, tsunamigenic threats, I think OBS and DAS are probably big targets for the future."

sources-science daily