Category: 7. Science

An important cache of 35 wooden tools, dated at an estimated 300,000 years ago, has been unearthed at the Gantangqing site in Yunnan Province, southwest China. This discovery sheds new light on the technological progress and plant subsistence behaviors of early hominins in East Asia. Preserved in oxygen-poor clay sediments on the banks of an ancient lake, the tools are the oldest wooden artifacts ever found in the region and represent a world-class archaeological find.

The tools, made of pine and other hardwoods, include digging sticks, hooks, and small pointed devices likely employed in the harvesting of underground plants such as tubers, rhizomes, and roots. The majority of them still bear signs of wear, scraping patterns, and even microscopic plant and soil residues. Micro-wear analysis shows that 32 out of 35 exhibit deliberate modification at their tips or edges, implying purposeful design and use.

“This discovery is exceptional because it preserves a moment in time when early humans were using sophisticated wooden tools to harvest underground food resources,” the lead author of the study, Professor Bo Li of the University of Wollongong (UOW), stated in a statement released by the University of Wollongong. “The tools show a level of planning and craftsmanship that challenges the notion that East Asian hominins were technologically conservative.”

Professor Li’s team used infrared-stimulated luminescence—a technique he helped pioneer—to date potassium feldspar grains, alongside electron spin resonance analysis of a mammal tooth. These methods dated the tools to between 250,000 and 361,000 years ago. The sediments in which the tools were found also contained animal fossils, antler soft hammers, stone tools, and plant remains, suggesting a complex prehistoric ecosystem and a community adept at woodworking.

Unlike European Paleolithic finds such as the hunting spears of Schöningen, Germany, the Gantangqing tools were employed primarily for the gathering of plant foods. This suggests another strategy for living: whereas European hominins hunted large mammals, their East Asian contemporaries were targeting plant-based resources, revealing high behavioral adaptability.

The research, which was published in the journal Science, was a collaborative effort by University of Wollongong scholars, Chinese Academy of Sciences researchers, researchers from the Yunnan Provincial Institute of Cultural Relics and Archaeology, and several other institutions. The results contradict the usual notions that prehistoric societies in East Asia were behind Africa and Europe in technological development—a belief previously based on discoveries in the region that had largely consisted of simple stone tools.

“The diversity and sophistication of the wooden tools also fill a significant gap in the archaeological record,” said Professor Li. They show that early humans in East Asia had highly developed cognitive skills and a deep knowledge of their environment.

In addition to shedding light on toolmaking, the discovery also provides unique insight into the diets of early humans in the area. While plant residues on the tools were too decomposed to be positively identified, other remains at the site include pine nuts, hazelnuts, kiwi fruit, aquatic tubers, and berries. The presence of such plant food items indicates that these early hominins possessed knowledge of edible flora and undertook strategic foraging trips to the lakeshore with accompanying tools.

It’s officially summer, and with that comes the first full moon of the season. July’s full moon — known as the Buck Moon or the Thunder Moon — will light up the night sky on July 10 and be at its fullest going into July 11. It’ll be bright for the whole night but will reach peak luminosity at around 4:37 a.m. local time, which is a bit late (or early) for most skygazers. 

According to Stellarium’s sky map, the moon will rise from the southeastern horizon just after sunset on Thursday and streak across the sky before setting on the southwestern horizon just before dawn. No matter where you are in the US, you’ll be able to see it virtually all night. 

Should you not be able to see the moon due to weather or some other reason, you can also soak up a great view anytime between July 9 and July 12, as the moon will be more than 95% full during those days. 

Why is it called the Buck Moon and Thunder Moon?

According to The Farmer’s Almanac, July’s full moon actually has several names, including Buck Moon, Thunder Moon, Feather Moulting Moon and Salmon Moon. These names typically come from Native American and colonial times, and were used to describe the moon for the entire month, not just when it’s full. 

White-tailed deer start growing antlers in March or April as the days start to lengthen. July marks the peak of their antler growth season, hence the name Buck Moon. Thunderstorms are also common in July, which is why it’s called the Thunder Moon. 

The other two names are less common, but July marks the time when some species of salmon begin migrating for the mating season, while ducks engage in their annual moulting around this time of year as well. 

Catch a glimpse of Mars and Venus

The moon will be joined in the sky by Mars and Venus during its trip across the sky on July 10. Mars will be visible just after sunset in the western sky before setting. You won’t have long, since it’s scheduled to dip below the horizon before midnight. If you choose to stay up late, Venus will crest the eastern horizon shortly after 2 a.m. local time and be visible until sunrise. 

Saturn will also be visible in the eastern sky, not far from the moon, but you’ll likely need binoculars or a telescope to see it beyond the moon’s glow.

Once the moon finishes its monthly cycle, skygazers can check out the Alpha Capricornids and Southern Delta Aquariids meteor showers, both of which are scheduled to peak during the last few days of July.

When NASA’s DART mission crashed into the asteroid Dimorphos, the first stage of the impact saw the spacecraft’s solar panels strike and pulverize two large boulders on the target, debris from which spun off in two directions. That ejection created enough momentum to give Dimorphos an extra kick on top of the direct effects of the kinetic impact, according to a new analysis of the collision.

DART, the Double Asteroid Redirection Test, slammed into the 558-foot-wide (170-meter-wide) asteroid Dimorphos on Sept. 26, 2022. The force of the impact shortened Dimorphos’ orbit around its larger asteroid companion, Didymos, by about 32 minutes. The point of the mission was to show that we could deflect hazardous asteroids if they’re ever found to be on a collision course with Earth.

Aren’t the summer days supposed to be longer and the winter days shorter?

Since when have things gone in reverse for the summertime?

Since now, maybe? Starting today?

Okay, here’s what’s going on.

Planet Earth is set to spin a bit faster on three separate days this summer, officially starting today. The result will be shorter days, but don’t panic because the change will be so small that you won’t even notice.

The change is equal to several milliseconds that will be shaved off of the 24 hours it takes for Earth to complete a full rotation.

Now to your next question: How long are several milliseconds? It’s less than the time you’d take to blink your eye.

So why is this happening?

It takes the planet 24 hours, or one day, to complete a full rotation on its axis, which equals to 86,400 seconds. But Earth’s rotation could change by a millisecond — which is .001 seconds — or two every day.

Also, the orbit of the moon can have an effect on how fast the Earth spins.

“Our planet spins quicker when the moon’s position is far to the north or south of Earth’s equator,” according to TimeandDate.com.

“Earthquakes, volcanoes, tidal forces, subterranean geology, and many other mechanisms can cause the planet’s rotation to slow down or speed up, and those micro-adjustments can trend over time,” Popular Mechanics reported.

If you can recall, the 8.9 magnitude earthquake that hit Japan back in 2011 accelerated Earth’s rotation, shortening the length of the standard 24-hour day by 1.8 microseconds (0.0018).

These small, day-to-day fluctuations in the Earth’s rotational speed started to be measured in the 1950s with atomic clocks, where any number above or below the standard 86,400 seconds is called the length of day (LOD).

If you’re wondering what the shortest day ever was, that happened on July 5, 2024, when Earth completed its full rotation 1.66 milliseconds faster than the standard 86,400 seconds.

As for when this three-day event will happen, there are three days this summer when the moon will be around its furthest distance from Earth’s equator, resulting in the slight increase in Earth’s rotational speed.

Scientists are predicting that this will happen on July 9, July 22 and Aug. 5.

Today, July 9, will be shortened by 1.30 milliseconds. On July 22, Earth loses 1.38 milliseconds of the day. And Aug. 5, the day will be shortened by 1.51 milliseconds.

Volcanic eruptions at Earth’s surface have significant consequences. Smaller ones can scare tourists on Mount Etna or disrupt air traffic.

Giant, large-scale eruptions can have more serious impacts. One such event contributed to the demise of the dinosaurs 66 million years ago. Giant volcanoes also triggered events that led to the largest mass dying on Earth, the Permian–Triassic extinction 252 million years ago).

But what fuels a giant eruption, and how does it make its way to the surface from deep within the planet?

In a new study published in Communications Earth and Environment, we show that columns of hot rock, which rise some 3,000 kilometres through Earth’s mantle and cause giant eruptions, are connected to continent-sized source regions we call BLOBS.

Hidden blobs within Earth

BLOBS are hot regions at the bottom of Earth’s mantle (between about 2,000km and 3,000km in depth) which might be composed of different material compared with the surrounding mantle rocks.

Scientists have long known about these two hot regions under the Pacific Ocean and Africa. Geologist David Evans from Yale University suggested the acronym BLOBS, which stands for Big LOwer-mantle Basal Structures.

These BLOBS have possibly existed for hundreds of millions of years. It is unclear whether they’re stationary or if they move around as part of mantle motion (called convection).

Read more:
Volcanoes, diamonds, and blobs: a billion-year history of Earth’s interior shows it’s more mobile than we thought

Mantle plumes were the implicit link in previous studies relating BLOBS to giant volcanic eruptions. Their shape is a bit like a lollipop: the “stick” is the plume tail and the “candy” is the plume head.

Mantle plumes rise very slowly through the mantle because they transport hot solid rock, not melt or lava. At lower pressures in the uppermost 200km of Earth’s mantle, the solid rock melts, leading to eruptions.

A long-sought relationship

In our new study, we simulated mantle convection from 1 billion years ago and found that mantle plumes rise from moving BLOBS and can sometimes be gently tilted.

Giant volcanic eruptions can be identified by the volume of volcanic rocks preserved at Earth’s surface. The ocean floor preserves detailed fingerprints of mantle plumes for the past 120 million years or so (there is not much seafloor older than that).

Oceanic plateaus, such as the Ontong Java-Manihiki-Hikurangi plateau currently in the southwest Pacific Ocean, are linked to plume heads. In contrast, series of volcanoes such as the Hawaii-Emperor seamount chain and the Lord Howe seamount chain are linked to plume tails.

We used statistics to show that the locations of past giant volcanic eruptions are significantly related to the mantle plumes predicted by our models. This is encouraging, as it suggests that the simulations predict mantle plumes in places and at times generally consistent with the geologic record.

Are BLOBS fixed or mobile?

We showed that the considered eruption locations fall either onto or close to the moving BLOBS predicted by our models. Eruption locations slightly outside moving BLOBS could be explained by plume tilting.

We represented fixed BLOBS with 3D images of Earth’s interior, created using seismic waves from distant earthquakes (a technique called seismic tomography). One out of the four seismic tomographic models that we considered matched the locations of past giant volcanic eruptions, implying that the fixed BLOBS scenario cannot be ruled out for geologically recent times – the past 300 million years.

One of the next steps for this research is to explore the chemical nature of BLOBS and plume conduits. We can do so with simulations that track the evolution of their composition.

Our results suggest the deep Earth is dynamic. BLOBS, which are some 2,000km below Earth’s surface, move hundreds of kilometres over time, and are connected to Earth’s surface by mantle plumes that create giant eruptions.

To take a step back and keep things in perspective: while deep Earth motions are significant over tens of millions of years, they are generally in the order of 1 centimetre per year. This means BLOBS shift at roughly the rate at which human hair grows.

Read more:
Where should we look for new metals that are critical for green energy technology? Volcanoes may point the way

Astronomers have recently added a new member to the small club of confirmed interstellar objects. The icy wanderer, known as 3I/Atlas, was officially recognized this week by the International Astronomical Union’s Minor Planet Center (MPC).

Observations showed it is racing through the solar system on a hyperbolic path – one that will carry it back into interstellar space after a brief celestial cameo.

A fuzzy comet with incredible speed

Early images of 3I/Atlas revealed the hazy glow typical of a comet. “It looks kind of fuzzy,” said Peter Veres, an astronomer at the MPC who helped confirm the object’s status. “It seems that there is some gas around it, and I think one or two telescopes reported a very short tail.”

That fuzzy halo is created as sunlight warms the comet’s surface, releasing dust and gas that trail behind it. Current estimates suggest the nucleus spans six to 12 miles (10 to 20 kilometers).

Because icy bodies reflect sunlight efficiently, the true size may prove smaller if the surface is especially bright.

What is certain is the object’s speed. Preliminary calculations put its velocity at more than 60 km per second (roughly 135,000 mph). At that speed, solar gravity cannot capture it, confirming its extrasolar origin.

Spotting an interstellar traveler

The discovery began on Tuesday when a telescope in Chile, operated as part of the NASA-funded ATLAS survey, recorded an unfamiliar, rapidly moving speck.

Within hours, professional and amateur observers worldwide had combed archival data, tracing its motion back to at least June 14.

The collected positions fit a hyperbolic orbit – unmistakable evidence the object is diving in from beyond the Sun’s gravitational reach.

Richard Moissl, head of planetary defense at the European Space Agency, emphasized that 3I/Atlas poses no danger.

“It will fly deep through the solar system, passing just inside the orbit of Mars,” he said, adding that the flyby comes nowhere near a collision with Earth or the Red Planet.

Calculations show the interstellar comet will reach perihelion, its closest point to the Sun, on 29 October, then fade as it speeds back into the darkness over the next few years.

How interstellar comets differ

Unlike comets bound to the Sun, interstellar objects are born around distant stars. Jonathan McDowell of the Harvard–Smithsonian Center for Astrophysics explained the likely origin scenario.

“We think that probably these little ice balls get formed associated with star systems. And then as another star passes by, tugs on the ice ball, frees it out. It goes rogue, wanders through the galaxy, and now this one is just passing us,” he said.

In 2017, astronomers found the first known example, 1I/ʻOumuamua, whose odd shape and tumbling motion sparked contentious debate – including speculation it might be alien technology.

Two years later came 2I/Borisov, a more conventional comet with clear gas jets. 3I/Atlas now becomes the largest and fastest of the trio, offering scientists a fresh specimen to study.

Observations of a fast-moving comet

The MPC initially labeled the body A11pl3Z, but the “3I” prefix signifies its confirmed interstellar status. As data pours in, researchers aim to refine its orbit, rotation rate, and composition.

Scientists are particularly eager to learn whether its chemistry differs from solar system comets, which would provide clues about its natal environment.

Despite enthusiasm, a spacecraft intercept is beyond reach, since there is not enough time to plan, launch, and meet with an object moving this quickly and appearing on such short notice.

Ground-based and space-based telescopes will therefore carry the observational load, capturing spectra and high-resolution imagery while the interstellar comet remains within range.

Interstellar objects may be common

Mark Norris, an astronomer at the University of Central Lancashire, pointed out an intriguing statistic: modeling work suggests up to 10,000 interstellar objects could be drifting inside the solar system at any given moment – most of them too small or faint to detect.

The newly built Vera C. Rubin Observatory in Chile, scheduled to begin its wide-field survey soon, is expected to uncover many more. Such a flood of discoveries would transform the study of planetary system formation.

Each passerby carries a chemical and physical record of processes that occurred around alien suns. They deliver natural “samples” at no cost other than the telescopic time required to study them.

Fly-by science in action

Scientists will watch 3I/Atlas brighten through the northern autumn, hoping for unobstructed views of its coma chemistry.

Spectrographs on large telescopes may reveal ratios of carbon monoxide, carbon dioxide, and water vapor – benchmarks that help distinguish comets formed under different conditions.

Photometric monitoring can nail down its spin. Careful astrometry will improve the orbit and may even hint at non-gravitational forces from asymmetric outgassing.

Improving planetary defense capabilities

Beyond pure science, each interstellar detection enhances planetary defense capabilities.

Rapidly identifying an object’s orbit and assessing any hazard is a rehearsal for future surprises – though, happily, none of the known interstellar visitors have posed a threat.

For now, astronomers relish the serendipity. A cosmic snowball born around an unknown star has swung through humanity’s celestial neighborhood, offering a fleeting chance to study matter forged in a far-off corner of the galaxy.

With upgraded surveys on the horizon, the odds of such encounters – and the insights they carry – are only set to increase.

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For the first time in human history, three objects from outside the solar system: 1I/‘Oumuamua, 2I/Borisov and 3I/ATLAS, were discovered in space over the past decade. Where did these interstellar objects originate and how old are they?

Most stars in the Milky-Way galaxy reside in a disk. Young stars are made out of gas in a thin cold disk that rotates around the Galactic center. These constitute the thin disk of stars with a scale-height (disk thickness as measured from its mid-plane) of about a thousand light-years. Older stars formed in this gas disk billions of years earlier. During their lifespan, they were scattered by gravitational perturbations from passing star clusters, infalling dwarf galaxies or spiral arms in the disk. As a result, they currently populate a thicker disk with a scale-height that increases with stellar age and extends up to a few thousand light-years. The Sun was born 4.6 billion years ago in the last third of cosmic history. It represents a young adult, intermediate between the oldest stars from 13.7 billion years ago and the youngest stars which are less than a billion years in age.

To find out where the three interstellar objects came from, I asked my excellent student Shokhruz Kakharov, to follow their trajectories back in time in the gravitational field of the Milky-Way galaxy. Our results were submitted for publication in a new paper, available here.

We initiated the trajectories based on the measured velocities of the three interstellar objects relative to the so-called Local Standard of Rest (LSR). This is the Milky-Way frame of reference that averages over the random motions of the stars in the vicinity of the Sun. Since the scale-height of stars in the Milky-Way disk increases with age, we used the vertical excursion of each interstellar object from the disk mid-plane to constrain the likely age of these interstellar objects.

One of the anomalies of 1I/`Oumuamua was that it started nearly at rest in the Galactic LSR frame of reference before entering the Solar system. As a result, integrating 1I/‘Oumuamua’s past trajectory suggests that it originated near the mid-plane of the thin Galactic disk of stars, with a likely age that is younger than 1–2 Gyr. Simply put, 1I/`Oumuamua is a kid in our cosmic block.

However, we have found that the excursion of the comet 2I/Borisov is similar to that of the Sun, suggesting a similar age. Simply put, 2I/Borisov is a young adult in our cosmic block.

Finally, the interstellar object 3I/ATLAS exhibits a larger vertical excursion when its trajectory is integrated back in time, suggesting that it originated from an older population in the thick Galactic disk, compared to 1I/’Oumuamua or 2I/Borisov. Simply put, 3I/ATLAS is among the elders in our cosmic block.

Our constraints apply to the full age of these interstellar objects, because they respond — just like the underlying population of stars — to gravitational perturbations that pump up their scale-height over time.

Our constraints on the ages of the various interstellar objects represent upper limits because the velocity dispersion of the interstellar objects includes both the velocity dispersion of their parent stars and the dispersion in their characteristic ejection speed away from their birth system.

How quickly did it take these objects to migrate from the opposite side of the Milky-Way disk relative to the Sun? For 1I/`Oumuamua, the time is about a billion years; for 2I/Borisov, it is 1.7 billion years, and for 3I/ATLAS, it is 0.8 billion years. Through their orbit around the Milky-Way, all three objects travel a few thousand light-years closer to the Galactic center than the Sun does.

In summary, 1I/`Oumuamua is anomalous relative to 2I/Borisov and 3I/ATLAS, not only because it is much younger than they are, but also because it had an extreme disk-like shape, it exhibited a non-gravitational acceleration and it did not show any evidence for cometary activity like 2I/Borisov or 3I/ATLAS.

Thomas Kuhn’s book, titled “The Structure of Scientific Revolutions,” argues that science operates within paradigms encompassing comprehensive worldviews that define legitimate problems, methodologies, and solutions within the scientific community. These paradigms shape not only what questions scientists ask, but also what they can perceive as meaningful data. Contemporary astronomy operates under an implicit paradigm that systematically excludes non-naturalistic explanations of interstellar objects, creating a disciplinary worldview where all interstellar objects are assumed to result from natural processes. Astronomers interpret anomalous objects like 1I/`Oumuamua as puzzles that must be solved within this natural framework, not as potential evidence requiring paradigmatic revision. Future data from the new Rubin Observatory will test whether objects like 1I/`Oumuamua, constitute messengers from afar that convey our next scientific revolution.

ABOUT THE AUTHOR

Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.

An international study led by researchers at the University of Colorado Anschutz Medical Campus has identified a promising strategy to enhance the safety of nanomedicines, advanced therapies often used in cancer and vaccine treatments, by using drugs already approved by the FDA for unrelated conditions.

The study was published today in Science Advances.

Their research suggests that repurposing existing medications can reduce harmful immune responses associated with nanoparticles. These ultra-small particles are designed to deliver treatments with precision but, in some cases, the immune system can react adversely.

Nanoparticles are powerful tools in medicine, but the body often recognizes them as threats. We found that certain existing drugs used for immune-related conditions can help mitigate these reactions.”

Dmitri Simberg, PhD, co-director and professor at the Colorado Center for Nanomedicine and Nanosafety at the Skaggs School of Pharmacy and Pharmaceutical Sciences at CU Anschutz and lead author of the study

When introduced into the body for therapy or imaging, nanoparticles can trigger inflammation and other immune-related side effects. This occurs when the immune system, particularly the complement system, a group of blood proteins responsible for detecting potential threats, mistakenly targets helpful nanoparticles.

“This system is crucial for fighting infections, but it can become overactive in response to nanomedicine,” Simberg explained.

These overreactions may cause symptoms such as skin rashes, respiratory distress, cardiovascular problems or serious anaphylactic reactions. To address this, the team tested immune-modulating compounds that inhibit complement activation, aiming to reduce immune attacks on nanoparticles without broadly weakening the immune system.

Among the drugs tested in blood samples, iptacopan, currently approved to treat certain rare blood, nerve, and kidney disorders, was notably effective in blocking complement activity and minimizing adverse effects.

“We were impressed by how well iptacopan performed in preclinical animal models and some human samples,” said Simberg. “It not only reduced immune responses but also prevented more severe symptoms.”

The researchers also noted considerable variability in how individuals respond to nanoparticle-based treatments, often depending on specific ingredients used. This highlights the importance of personalized approaches to nanomedicine.

“We still need to understand which patients are at higher risk of allergic or inflammatory reactions, in order to apply immune modulating drugs during nanomedicine treatment,” Simberg added.

Simberg said the findings open the door to broader and safer applications of nanomedicine for diseases such as cancer, infections and genetic conditions.

“If we can manage the body’s response more effectively, we can improve access to these life-saving therapies for a wider group of patients,” said Simberg.

The collaborative study involved scientists from both the University of Colorado Anschutz Medical Campus, Cardiff University, and Newcastle University in the United Kingdom.

A collaboration between researchers from the University of Notre Dame, Harvard Medical School/Massachusetts General Hospital, and Boston University, have developed a new method to determine the amount of physical force (called solid stress) a brain tumor places on surrounding brain tissue. Published in the journal Clinical Cancer Research, the new method, using samples of a resected brain tumor, could eventually be used to determine the tumor type and inform post-surgical care.

“During brain tumor removal surgery, neurosurgeons take a slice of the tumor, put it on a slide and send it to a pathologist in real-time to confirm what type of tumor it is. Tumors that originally arise in the brain, like glioblastoma, are prescribed different treatments than tumors that metastasize to the brain from other organs like lung or breast, so these differences inform post-surgical care,” said co-first author Meenal Datta, PhD, an assistant professor of aerospace and mechanical engineering at Notre Dame. “By adding a two-minute step to a surgeon’s procedure, we were able to distinguish between a glioblastoma tumor versus a metastatic tumor based on mechanical force alone.”

Solid stress, unlike fluid pressure, is a mechanical force generated by tumor expansion and transmitted through solid tissue. It has been shown in previous animal studies to promote invasion, restrict blood flow, and impair treatment efficacy.

In earlier work, the same team had shown that tumors that apply solid stress to the brain can lead to more severe neurological dysfunction than tumors that infiltrate and destroy tissue. Retrospective estimates of solid stress, inferred from MRI-based growth patterns, correlated with worse neurological scores in patients. This new research was the first to attempt to provide direct, real-time measurements of solid stress.

For this research, the investigators enrolled 30 patients undergoing brain tumor resection. Prior to tumor removal, they performed intraoperative measurements of the brain surface through the craniotomy site using neuronavigation technology. This system provided a real-time, three-dimensional view of the brain, allowing the team to collect data on brain deformation caused by tumor pressure. Using these measurements and finite element modeling, they calculated tumor-induced solid stress and also estimated the percentage of brain tissue displaced or lost by the tumor.

In some cases, up to 10% of a patient’s brain volume was estimated to be replaced by the tumor. Metastatic or more nodular tumors that displaced brain tissue also exerted higher solid stress. In contrast, glioblastomas, which tend to infiltrate tissue, showed lower solid stress but greater brain tissue replacement.

To validate their method beyond their small cohort of patients, the team also tested mouse models of glioblastoma, ependymoma, and breast cancer metastasis to the brain. In the metastatic model, they observed that changes in solid stress occurred earlier than reductions in tumor size following chemotherapy. “In this model, we showed that mechanical force is a more sensitive readout of chemotherapy response than tumor size,” said Datta. “Mechanics are sort of disease-agnostic in that they can matter regardless of what tumor you are looking at.”

The researchers believe that this new approach allows for personalized assessment of both tumor behavior and disease burden. By providing insight into whether a tumor is displacing or replacing brain tissue, clinicians may better anticipate symptoms, choose therapies, and plan postoperative care.

“We present in this study a quantitative approach to intraoperatively measure solid stress in patients that can be readily adopted into standard clinical workflows,” the researchers wrote.

One limitation their work, the researchers noted, was determining the contribution of fluid pressure to tissue deformation, which they noted cannot be fully separated from solid stress. In their mouse models, the researchers were able to minimize this factor by halting blood flow prior to measurements, a technique not feasible in human subjects. In addition, current imaging tools still aren’t fully able to distinguish between fluid-filled and cancer-infiltrated edematous areas, which complicates tumor characterization.

Future studies aim to incorporate more recent imaging advances and refine fluid-versus-solid stress analysis. The team also plans prospective clinical trials to analyze how their measurements, and the actions taken based on them, influence clinical outcomes.