The aging brain depends on a microscopic border that works every second to keep danger out and support the nerve cells inside. When that barrier begins to fail, memory, mood, and thinking may suffer. Andrew A. Pieper, MD, PhD, and colleagues have now traced part of that breakdown to a single protein that appears to help keep the brain’s protective walls intact.

The research, led by the Pieper Laboratory and published in Proceedings of the National Academy of Sciences, was conducted by a research group from University Hospitals, Case Western Reserve University and the Louis Stokes Cleveland VA Medical Center.

The focus is the blood-brain barrier (BBB), a protective structure made from tightly packed endothelial cells that line the brain’s blood vessels. Endothelial cells act like a living seal between the bloodstream and the brain. Maintaining that seal takes energy, but it allows the barrier to block harmful substances and pathogens, clear some waste produced during normal brain activity, and adjust blood flow toward whichever brain regions are working hardest.

Scientists have known for years that these blood-brain barrier functions weaken in the aging brain. However, whether that decline could directly drive cognitive problems, and what molecular change might be setting the process in motion, had remained uncertain. Without that missing cause, designing targeted treatments has been difficult.

NASA’s Perseverance rover has completed the equivalent of a full marathon on Mars, reaching 26.2 miles (42.195 kilometers) after five years and four months of driving across the Red Planet.

The milestone came on the 1,890th Martian day, or sol, of the mission. Perseverance reached the distance considerably faster than NASA’s Opportunity rover, which required 11 years and two months to cover the same ground.

A Tiny Rover Seen From Mars Orbit
One day before Perseverance crossed the marathon mark, NASA captured the rover from high above the Martian surface. In the image, taken on June 13, 2026, the robotic explorer appears as a tiny green speck against the surrounding terrain.

The view came from NASA’s Mars Reconnaissance Orbiter (MRO), which photographed the area using its High-Resolution Imaging Science Experiment, better known as the HiRISE camera. Faint lines extending across the landscape reveal the tracks left by Perseverance during its journey.

At the time, the rover was traveling through a region west of Jezero Crater that mission scientists have named “Arbot.”

Tropical forests draw down and store large quantities of CO₂ from the atmosphere. The Amazon rainforest in South America, for example, stores approximately 123 billion tons of carbon—more than is stored in any other terrestrial ecosystem in the world. But these forests are facing a critical challenge.

Research from 2023, which was carried out by me and more than 100 colleagues, found that tropical forests in South America are vulnerable to climate extremes. We determined that during an El Niño event, the warm phase of a natural fluctuation in Earth's climate system, South American tropical forests may fail to act as a carbon sink.

This finding becomes even more alarming when we consider the increasing frequency and intensity of El Niño events. There have been twice as many "very strong" El Niños in the past 60 years as there were in the 60 years before that. And the U.S. National Oceanic and Atmospheric Administration has recently confirmed that such an El Niño is currently underway.

Tropical forests absorb CO₂ through the process of photosynthesis and convert it into biomass. However, the balance between photosynthesis and respiration is delicate and depends on two factors: temperature and water availability.

In hotter and drier conditions, plants close the pores of their leaves to avoid water loss. But closing them effectively cuts off a plant's fuel supply because it is through these pores that they absorb CO₂. This starves plants of the carbon needed for photosynthesis and growth.

During El Niño years, which are characterized by high-temperature anomalies, prolonged climate stress leads to reduced forest growth and increased tree mortality. The effects of this are felt for decades as carbon is released back into the atmosphere when the dead trees decompose.

For years, weight loss has been framed as a simple test of discipline: consume fewer calories and exercise more. Modern research, however, shows that body weight is regulated by powerful biological systems that cannot be reduced to willpower alone.

To understand why losing weight can be so difficult, it helps to look back hundreds of thousands of years. Many of the biological responses that frustrate weight loss today helped our ancestors survive when food was scarce and unpredictable.

For early humans, stored body fat provided essential protection against starvation, although carrying too much could hinder movement. Over generations, the body developed sophisticated brain-based defenses to protect its energy reserves. In modern environments where calorie-dense food is widely available and physical activity is often optional, those survival mechanisms can work against efforts to lose weight.

The body treats weight loss as danger
When body weight falls, the brain may interpret the change as a threat. Hunger signals increase, cravings become stronger, and the body reduces the amount of energy it burns. These responses evolved to conserve fuel when food supplies changed, but easy access to inexpensive, calorie-dense foods and increasingly sedentary lifestyles can turn those once useful adaptations into obstacles.

The brain remembers a heavier body
As we found in our recent research, our brains also have powerful mechanisms for defending body weight – and can sort of “remember” what that weight used to be. For our ancient ancestors, this meant that if weight was lost in hard times, their bodies would be able to “get back” to their usual weight during better times.

But for us modern humans, it means that our brains and bodies remember any excess weight gain as though our survival and lives depend upon it. So in effect, once the body has been heavier, the brain comes to treat that higher weight as the new normal – a level it feels compelled to defend.

The fact that our bodies have this capacity to “remember” our previous heavier weight helps to explain why so many people regain weight after dieting. But as the science shows, this weight regain is not due to a lack of discipline; rather, our biology is doing exactly what it evolved to do: defend against weight loss.

A smartwatch can tell us the level of oxygen in our blood, when our sleep is restless or the number of steps we take in a day. Now imagine that kind of tracking ability for plants. By the time farmers see curling leaves or stunted growth in their fields, their crops may already have spent days under stress.

A new innovation in plant "wearable" sensors aims to catch those distress signals earlier—before the plant visibly suffers, allowing farmers to respond and help their crops thrive.

In a recent study, researchers created tiny tattoo-like sensors that adhere to leaf surfaces and a stretchable band that wraps around stems. Together, they track two vital signs of plant life—the temperature and humidity beneath the leaf's surface, and whether the stem is still growing. Even more striking, the system runs without an external battery, scavenging power from moisture evaporating from the plant itself.

The work is published in the journal ACS Applied Materials & Interfaces.

"The larger promise is not merely that one plant can wear one sensor," said Sameer Sonkusale, professor of electrical and computer engineering at Tufts and senior researcher on the project.

"It is that fields could one day contain networks of plant-level monitors, each reporting early signs of thirst, salt stress, disease or nutrient imbalance. Satellites and drones already give farmers a bird's-eye view. Plant wearables could provide something more intimate: the plant's-eye view."

Current methods for monitoring crops use satellite imagery and drones to get visible, infrared and microwave data that map greenness, uneven growth, temperature, pest damage, soil moisture and other big-picture measurements of crop stress. Soil sensors can measure moisture, temperature, pH and some nutrient levels. And weather stations provide information on air temperature, humidity, rainfall, wind and sun exposure.

While those measurements are useful, they focus on conditions that may affect the crops in the future or on an assessment of damage already done. "The leaf sensor is more of an early warning system showing how the plant is responding in the moment, before visible signs appear," said Nafize Hossain, a graduate student who led the research in the Sonkusale lab.

The sensors can also be extended to track other important indicators of plant health, such as levels of important nutrients and plant hormones that are early signals of root, leaf, stem and fruit growth, as well as responses to pathogens.

Cambridge researchers have found that many widely used sweeteners can directly slow or alter the growth of bacteria found in the human gut. The strongest effect appeared when isosteviol, a sweetener used in foods and beverages, was combined with the antidepressant duloxetine.

In laboratory experiments, that combination sharply reduced two important bacterial species associated with digestive health and blood sugar regulation. It also produced changes that could influence inflammation and immune activity.

The researchers caution that the findings come from controlled laboratory tests, not studies involving people. More work will be needed to determine whether the same interactions occur inside the human body and whether they have meaningful health consequences.

Sweeteners May Not Be Biologically Inactive
Sweeteners are found in a wide range of everyday products, including soft drinks, candy, desserts, snacks, cereals, and some medications. They are often promoted as alternatives that provide sweetness with less sugar or fewer calories.

However, growing evidence has linked the consumption of some sweeteners with conditions including type 2 diabetes, obesity, and cancer. These associations do not necessarily prove that sweeteners directly cause those diseases, but they have raised questions about how the compounds behave inside the body.

One possible link is the gut microbiome, the enormous community of bacteria and other microorganisms living throughout the digestive tract. These microbes help break down food, produce useful compounds, support the intestinal barrier, and communicate with the immune system.

Despite the widespread use of sweeteners, relatively few studies have examined whether they interact directly with individual gut bacteria.

Professor Kiran Patil from the Medical Research Council (MRC) Toxicology Unit at the University of Cambridge said: “Most of what we know about the potential impact of sweeteners on our health comes from animal research or from population studies. While these studies have indicated involvement of the microbiome in mediating the effect of sweeteners, it’s difficult to know how sweeteners act in the body – is it through direct interactions with our gut bacteria?”

“Answering this is further complicated by the fact that we rarely ever take sweeteners by themselves – we take them with drinks, in snacks, or even in medication to mask bitterness,” added Dr. Sonja Blasche, a lead author of the study, also the MRC Toxicology Unit.

The Submillimeter Array (SMA), an 8-telescope radio interferometer located near the summit of Maunakea in Hawaii, reached an important milestone early this year. On January 26th, 2026, scientists from the Harvard & Smithsonian Center for Astrophysics (CfA) demonstrated this new alert system's ability to rapidly respond to astronomical phenomena identified by space telescopes. Within minutes of a gamma-ray burst (GRB) being identified, the SMA made the first observations of such an event at millimeter and submillimeter wavelengths.

This followed an automated alert from NASA's Neil Gehrels Swift Observatory, which detected a flash of gamma rays from a source located about 1.8 billion light-years from Earth. Within 90 seconds of detection, the system alerted the on-duty operator. Within 13 minutes, the telescopes were on target while a separate automated analysis generated images of the explosion in near real time. The entire process happened almost entirely without human intervention, demonstrating the alert system's ability to narrow the gap for millimeter/submilliter observations of transient events.

GRBs are the most powerful outbursts in the Universe, rapid but extremely energetic events that are produced by relativistic jets - streams of charged particles traveling at close to the speed of light. These jets are produced when massive stars collapse (a supernova) or when compact objects, such as neutron stars, merge (a kilonova). They are followed by an afterglow that X-ray and optical telescopes have been able to track within minutes or even seconds of an event.

Unfortunately, millimeter-wave telescopes have traditionally lagged in this respect.

Addressing this is of great importance to astronomers, since it would yield valuable data on what accompanies GRBs. As they indicate in their paper, which appeared in The Astrophysical Journal Letters, the interaction of relativistic jets with their environment produces a forward shock (FS) propagating in the local medium, and a reverse shock (RS) propagating back into the ejecta. Since the FS emission is sensitive only to the explosion energy, RS radiation remains key to studying the jet's composition, magnetization, and other properties.

In the classic guessing game “20 Questions,” imagine asking “animal, vegetable, or mineral?” to help narrow down the answer.

For the ancient sea worm Perinereis cultrifera (which is still around to this day), the answer is surprisingly complicated. This species and other predatory bristle worms have powerful jaws made from structural proteins combined with ions. They use these jaws to bite, crush, and consume food.

The jaws are so unusual in both composition and performance that some scientists have proposed a new name for materials like them: bio-metals. Their study is becoming an emerging area of biophysics.

What Makes a Material a Bio-Metal?
The term “bio-metal” describes more than a biological material that simply resembles metal. Scientific literature has previously used phrases such as “metallike biomaterials” or “biomaterials with metallike properties” for natural substances that approach metals in strength or electrical conductivity.

Bio-metals, however, are defined through a broader combination of characteristics. These include hardness, the way the material responds to strain, and its internal structure of proteins and ions.

Researchers from TU Wien (Vienna University of Technology) and the University of Vienna examined the metal-like behavior of the worm’s jaws in an effort to more clearly define this proposed category. Their findings were published in Biophysics Reviews, by AIP Publishing.

The shrinking of computer chips has exposed a stubborn problem: even when a semiconductor can carry electricity efficiently, getting that electricity into the material can waste power and slow the device down.

Researchers in South Korea have now demonstrated a possible way around this obstacle. Their design allows electrical current to move smoothly from a conductive region into a semiconducting region without crossing the conventional junction between two separate materials. The team also directly mapped the movement of charges at the nanometer scale, providing experimental evidence that the new interface does not disrupt the current.

The advance could support the development of smaller and more energy-efficient electronics, including AI processors, low-power devices, and future logic chips.

Why Contact Resistance Holds Back Smaller Chips
Modern transistors depend on metal electrodes to deliver electricity into a semiconductor. However, the boundary where those materials meet can resist the movement of electrical charges. This contact resistance consumes energy, produces heat, and limits how much performance engineers can gain by making transistors smaller.

The problem is particularly important for two-dimensional semiconductors. These materials can be only one or a few atomic layers thick, making them attractive for electronics that may eventually need to operate at dimensions beyond the practical limits of conventional silicon. Yet their extreme thinness also makes it difficult to create efficient electrical contacts without damaging or altering the semiconductor.

Bacteria can defend themselves against antibiotics with the help of an enzyme released by dying cells, according to a study. This discovery helps scientists understand bacterial survival mechanisms and improve the effectiveness of antibiotics.

The team demonstrated that Escherichia coli (E. coli) bacteria can produce an enzyme that chemically breaks down the antibiotic, rendering it ineffective.

Because the enzyme is released particularly by dying bacteria, the researchers refer to this as "altruistic cell death," which ensures the survival of the population as a whole. These findings help explain bacteria's collective survival mechanisms, which, in turn, could contribute to improving the effectiveness of existing and future antibiotics.

The project was prompted by a discovery by the study's first author who demonstrated that although bacterial cultures initially die off when exposed to the antibiotic, they eventually recover and continue to grow unhindered.

The team investigated two strains of E. coli bacteria—pathogens responsible for urinary tract infections, among other conditions, as well as septicemia and hospital-acquired infections—and their response to beta-lactams, the most widely used class of antibiotics worldwide. The bacteria produce the enzyme beta-lactamase, which chemically breaks down the antibiotic.

As soon as the antibiotic's concentration fell below a threshold level as a result of enzymatic activity, the bacterial cultures began to recover. "Therefore, the death of some of the bacteria contributes significantly to the long-term survival of the population as a whole, which can be interpreted as an example of altruistic collective behavior," Krug says.

There is something quietly reassuring about a scientific mystery that gets solved not by a dramatic new discovery, but by simply looking again, more carefully, at something we thought we already understood. That’s exactly what has happened with the Sun, and the missing element at the heart of it is silver.

For years, there’s been a nagging problem. The Sun and the meteorites in our Solar System formed from the same swirling cloud of gas and dust, 4.6 billion years ago, which means they should, in theory, contain the same proportions of heavy elements. Meteorites are essentially untouched time capsules from that era, so they can be used as a trusted benchmark. And yet, whenever astronomers measured how much silver the Sun contained, the number always came up short compared to the meteorites but not by a small margin. The Sun appeared to be missing a substantial amount of silver that, by all rights, it should have had.

Now, thanks to new work led by Sema Caliskan at Uppsala University, that mismatch has finally been resolved. The Sun, it turns out, was never missing its silver at all, we simply weren't measuring it properly.

To understand how, it helps to know how astronomers work out what a star is made of in the first place. Starlight carries the fingerprints of every element within it. As sunlight passes through the outer layers of the Sun, atoms of each element absorb tiny amounts of light at very specific wavelengths, leaving faint dark lines in the spectrum. By studying the pattern and strength of those lines, astronomers can work out exactly which elements are present, and in what quantities.

The trouble is, converting that pattern into an accurate number depends entirely on how well you model the Sun's atmosphere in the first place, and previous models were, in hindsight, oversimplified. Caliskan and her colleagues built a far more realistic model, one that accounts for the genuinely turbulent, dynamic nature of the Sun's outer layers, combined with more precise atomic physics describing exactly how silver atoms interact with light and their surroundings. Crucially, the new model also accounts for the fact that light itself affects the very atoms producing those tell tale absorption lines, something earlier, simpler calculations had overlooked entirely.

Researchers have discovered that children's brains can contain cells with their mother's DNA and that these cells can persist for decades.

The findings, which were posted to the preprint database bioRxiv June 10 but have not been peer-reviewed yet, are part of a growing body of work showing that a mother and fetus exchange cells during pregnancy — a phenomenon known as "microchimerism." Previously, scientists had found that a mother's brain harbors cells with her children's DNA.

The findings are important for several reasons, said Amy Boddy, co-director of the Microchimerism, Human Health and Evolution Project at the University of California, Santa Barbara, who was not involved in the study. Past work mostly found evidence of maternal microchimerism in infancy, and in blood samples, she told Live Science in an email. "What's exciting here is that it's tissue, not blood; it's real human data, not an animal model; and the methods are cutting-edge."

More broadly, the work reinforces the idea that microchimerism is "a normal process of mammalian biology," Boddy said.

Hunting down maternal cells in the brain
Before this study, there was sparse evidence for maternal microchimeric cells in brains, mostly because it is hard for researchers to get samples of human brain tissue and DNA from both parents and their children.

To overcome this challenge, a team led by Sami Kanaan, a staff scientist at the Fred Hutchinson Cancer Center in Seattle, analyzed brain tissue that had been surgically removed from dozens of children with severe epilepsy as part of their treatment. The patients ranged in age from 28 days to 19 years at the time of their surgery, and their mothers provided DNA samples through cheek swabs.

Kanaan's team used a tool called quantitative PCR to identify and count maternal cells hiding among millions of cells in the children's brains.

"Guardrails" built by the EU to govern AI fall short in both ambition and execution and have become too heavy to absorb rapid changes in technology, a new study in Big Data & Society warns.

The rules took years of negotiations and political effort and are difficult to change but not to remove, making them a "rigidity trap in action."

Recent changes have amounted to a "partial retreat" before the EU AI Act has been fully implemented, experts have said. The European Union's 2024 AI Act, supposed to take effect this year, has already been replaced with the 2026 AI Simplification Act.

The study says the EU's regulatory framework fails to fulfill the European Commission's stated goals of promoting trustworthy, human-centric and rights-respecting AI.

In contrast, in the U.S.—more by accident than design—there are "regulatory leashes" that can be pulled in response to need, and these are more binding and enforceable than the EU guardrails. Rules are more concrete and easier to enforce.

The study, by Alison Harcourt of the University of Exeter, Claudio M. Radaelli of the European University Institute and Philipp Trein of the University of Lausanne, says the EU's efforts to anticipate AI risks and impose comprehensive rules made adaptive regulation hard to develop. This has made the AI Act hard to enforce and limited its capacity to protect human rights and public values.

The United States intervenes legislatively when specific risks are clearly present or on a sector-by-sector basis. The study says this approach is more enforceable than the EU AI Act, and the state-by-state and sector-by-sector evolution of rules provides more space for learning from experience.

Silicon chips have driven the computing revolution for more than 50 years. Now, researchers are finding new ways to use them in biology, including monitoring large groups of neurons, sequencing DNA, and even manufacturing DNA itself.

A Harvard-led research team has developed a silicon chip that can synthesize 64 different DNA sequences at the same time. The work, published in Nature Electronics, replaces the solvent-heavy chemistry commonly used in custom DNA production with a water-based enzymatic method.

Rather than controlling DNA synthesis with conventional laboratory equipment, the chip uses precisely regulated electric currents to activate chemical reactions at individual locations across its surface. The research was led by Donhee Ham, the John A. and Elizabeth S. Armstrong Professor of Engineering and Applied Sciences at the John A. Paulson School of Engineering and Applied Sciences (SEAS).

A Chip That Writes DNA in Water
Synthetic DNA plays a central role in many areas of modern science and medicine, including diagnostics, genome engineering, and cancer research.

Most synthetic DNA is currently produced through phosphoramidite chemistry. This well-established process can create millions of sequences in parallel, but it relies on hazardous organic solvents and is usually carried out in large, centralized facilities.

Enzymatic DNA synthesis offers a gentler alternative. It takes place in water and more closely resembles the way living cells naturally assemble DNA. In the future, this approach could make DNA-writing devices smaller, safer, and easier to use.

Until now, however, enzymatic methods have lagged far behind conventional chemistry in the number of DNA sequences they can produce simultaneously. Previous systems had created no more than about a dozen sequences at once.

The Harvard team raised that number to 64 distinct sequences, with each one reaching a length of up to 39 nucleotides. The result establishes a new benchmark for parallel enzymatic DNA synthesis.