Semua Kabar

A new study to be presented at the SLEEP 2025 annual meeting found that teens who get moderate — but not excessive — catch-up sleep on weekends have fewer symptoms of anxiety.

Results show that teens who got up to two more hours of sleep on weekends than on weekdays exhibited fewer anxiety symptoms compared with those who did not sleep longer on weekends. However, longer durations of catch-up sleep on weekends were associated with slightly more internalizing symptoms.

"The results show that both sleeping less on weekends than weekdays and sleeping substantially more on weekends were associated with higher anxiety symptoms," said lead author Sojeong Kim, a doctoral candidate in the department of clinical psychology and psychology graduate advisor at the University of Oregon in Eugene. "In contrast, moderate catch-up sleep — defined as less than two hours — was associated with lower anxiety symptoms, suggesting that some weekend recovery sleep may be beneficial."

The American Academy of Sleep Medicine recommends that teenagers 13 to 18 years of age should sleep 8 to 10 hours on a regular basis to promote optimal health. However, CDC data show that only 23% of high school students get sufficient sleep on an average school night.

"Many teens try to make up for lost sleep by sleeping in on weekends," Kim said.

Consistently getting sufficient sleep is associated with better health outcomes including improved attention, behavior, learning, memory, emotional regulation, quality of life, and mental and physical health. In contrast, insufficient sleep in teenagers is associated with increased risks of problems such as depression and suicidal thoughts.

The study involved 1,877 adolescents with a mean age of 13.5 years. Sleep duration was estimated using Fitbit devices, while internalizing symptoms were assessed using the Child Behavior Checklist survey. Weekend catch-up sleep was calculated as the difference between weekend and weekday sleep duration.

Kim noted that it is important to identify the right amount of catch-up sleep that is beneficial to teens who restrict their sleep during the week.

"Too little or too much sleep variability from weekday to weekend may contribute to the symptoms someone is trying to combat, like physical or mental fatigue and feelings of anxiety," she said.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Wednesday, June 11, during SLEEP 2025 in Seattle. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

Abstract Title: The Sweet Spot of Weekend Catch-Up Sleep: A Protective Factor Against Depressive Symptoms?

Materialsprovided byAmerican Academy of Sleep Medicine.Note: Content may be edited for style and length.

The forerunners of dinosaurs and crocodiles in the Triassic period were able to migrate across areas of the ancient world deemed completely inhospitable to life, new research suggests.

In a paper published inNature Ecology and Evolutionon June 11, researchers from the University of Birmingham and University of Bristol have used a new method of geographical analysis to infer how these ancestral reptiles, known as archosauromorphs, dispersed following one of the most impactful climate events the Earth has ever seen, the end-Permian mass extinction.

The first archosauromorphs, some resembling modern reptiles and many times smaller than familiar dinosaurs, were previously believed to only survive in certain parts of the globe due to extreme heat across the tropics, viewed by many paleontologists as a dead zone, in the earliest Triassic.

By developing a new modelling technique based on landscape reconstructions and evolutionary trees, the team of researchers have been able to discover clues about how these reptiles moved around the world during the Triassic period, following the mass extinction where more than half of land-based animals and 81% of marine life died.

The archosauromorphs that survived the extinction event rose to prominence in Earth's ecosystems in the Triassic, leading to the evolution of dinosaurs. The team now suggest that their later success was in part due to their ability to migrate up to 10,000 miles across the tropical dead zone to access new ecosystems.

Dr Joseph Flannery-Sutherland from the University of Birmingham and corresponding author of the study said:

"Amid the worst climatic event in Earth's history, where more species died than at any period since, life still survived. We know that archosauromorphs as a group managed to come out of this event and over the Triassic period became one of the main players in shaping life thereafter.

"Gaps in their fossil record have increasingly begun to tell us something about what we weren't seeing when it comes to these reptiles. Using our modelling system, we have been able to build a picture of what was happening to the archosauromorphs in these gaps and how they dispersed across the ancient world. This is what led us to call our method TARDIS, as we were looking at terrains and routes directed in space-time.

"Our results suggest that these reptiles were much hardier to the extreme climate of the Pangaean tropical dead zone, able to endure these hellish conditions to reach the other side of the world. It's likely that this ability to survive the inhospitable tropics may have conferred an advantage that saw them thrive in the Triassic world."

"The evolution of life has been controlled at times by the environment," says Professor Michael Benton from the University of Bristol, senior author of the study, "but it is difficult to integrate our limited and uncertain knowledge about the ancient landscape with our limited and uncertain knowledge about the ecology of extinct organisms. But by combining the fossils with reconstructed maps of the ancient world, in the context of evolutionary trees, we provide a way of overcoming these challenges."

Materialsprovided byUniversity of Birmingham.Note: Content may be edited for style and length.

Your breath is one of a kind. A study published June 12 in the Cell Press journalCurrent Biologydemonstrated that scientists can identify individuals based solely on their breathing patterns with 96.8% accuracy. These nasal respiratory "fingerprints" also offer insights into physical and mental health.

The research stemmed from the lab's interest in olfaction, or the sense of smell. In mammals, the brain processes odor information during inhalation. This link between the brain and breathing led researchers to wonder: since every brain is unique, wouldn't each person's breathing pattern reflect that?

To test the idea, the team developed a lightweight wearable device that tracks nasal airflow continuously for 24 hours using soft tubes placed under the nostrils. Most breathing tests last just one to 20 minutes, focusing on evaluating lung function or diagnosing disease. But those brief snapshots aren't enough to capture subtle patterns.

"You would think that breathing has been measured and analyzed in every way," says author Noam Sobel of the Weizmann Institute of Science, Israel. "Yet we stumbled upon a completely new way to look at respiration. We consider this as a brain readout."

Sobel's team fitted 100 healthy young adults with the device and asked them to go about their daily lives. Using the collected data, the team identified individuals using only their breathing patterns with high accuracy. This high-level accuracy remained consistent across multiple retests conducted over a two-year period, rivaling the precision of some voice recognition technologies.

"I thought it would be really hard to identify someone because everyone is doing different things, like running, studying, or resting," says author Timna Soroka of the Weizmann Institute of Science. "But it turns out their breathing patterns were remarkably distinct."

Moreover, the study found that these respiratory fingerprints correlated with a person's body mass index, sleep-wake cycle, levels of depression and anxiety, and even behavioral traits. For example, participants who scored relatively higher on anxiety questionnaires had shorter inhales and more variability in the pauses between breaths during sleep. Soroka noted that none of the participants met clinical diagnostic criteria for mental or behavioral conditions. The results suggest that long-term nasal airflow monitoring may serve as a window into physical and emotional well-being.

"We intuitively assume that how depressed or anxious you are changes the way you breathe," says Sobel. "But it might be the other way around. Perhaps the way you breathe makes you anxious or depressed. If that's true, we might be able to change the way you breathe to change those conditions."

The current device still faces real-world challenges. A tube that runs under the nose is often associated with illness and may deter adoption. The device also doesn't account for mouth breathing and can slip out of place when sleeping. The team aims to design a more discreet and comfortable version for everyday use.

Soroka and Sobel are already investigating whether people can mimic healthy breathing patterns to improve their mental and emotional states. "We definitely want to go beyond diagnostics to treatment, and we are cautiously optimistic," says Sobel.

Materialsprovided byCell Press.Note: Content may be edited for style and length.

In a compelling Genomic Press Interview published today in Brain Medicine, Sophia Shi, PhD, unveils her pioneering research that fundamentally changes our understanding of brain aging and opens revolutionary therapeutic pathways for Alzheimer's disease and related neurodegenerative conditions.

Uncovering the Brain's Hidden Shield

Dr. Shi's groundbreaking work focuses on the glycocalyx, a complex "forest" of sugar molecules coating blood-brain barrier endothelial cells. Her research, recently published in Nature, demonstrates that this protective layer deteriorates dramatically with age, leading to blood-brain barrier dysfunction and neuroinflammation, key drivers of cognitive decline and neurodegenerative diseases.

"The glycocalyx acts like a protective shield for the brain's blood vessels," Dr. Shi explains. "When we restored these critical sugar molecules in aged mice, we saw remarkable improvements in both barrier integrity and cognitive function." This discovery represents the first time scientists have successfully reversed age-related blood-brain barrier dysfunction through glycocalyx restoration.

From Puzzles to Proteins: A Scientific Journey

Dr. Shi's path to this breakthrough began with childhood fascinations with puzzles and pattern recognition, skills that would later prove invaluable in decoding the complex language of glycosylation. Working under the mentorship of Nobel laureate Carolyn Bertozzi and renowned neurobiologist Tony Wyss-Coray at Stanford, she bridged two distinct fields, glycobiology and neuroscience, to tackle questions others had overlooked.

Her interdisciplinary approach faced significant challenges. How do you study molecules so structurally complex that they've resisted traditional analysis methods? What techniques can capture the dynamic nature of glycosylation in living brain tissue? Dr. Shi's innovative solutions to these problems exemplify the power of cross-disciplinary thinking in modern biomedical research.

Recognition and Research Excellence

The impact of Dr. Shi's work extends far beyond the laboratory. Her research garnered the prestigious David S. Miller Young Scientist Award at the Cerebral Vascular Biology Conference, recognizing her as one of the field's most promising young investigators. Perhaps more remarkably, she is launching her independent laboratory at Harvard's prestigious Rowland Institute directly from doctoral training — a rare achievement that speaks to the transformative potential of her discoveries.

"Post-translational modifications like glycosylation have been understudied for too long," Dr. Shi notes. "These modifications can completely transform protein function, yet we're only beginning to understand their role in brain health and disease." Her work positions glycoscience at the forefront of neurodegeneration research, challenging long-held assumptions about therapeutic targets.

Therapeutic Implications and Future Directions

The therapeutic implications of Dr. Shi's findings are profound. By identifying specific mucin-type O-glycans as critical for blood-brain barrier integrity, her research provides concrete molecular targets for drug development. This precision approach could lead to treatments that address the root causes of neurodegeneration rather than merely managing symptoms.

Intriguing questions emerge from this work: Can glycocalyx restoration prevent or slow Alzheimer's disease progression in humans? How early in the aging process do these protective molecules begin to deteriorate? What environmental or genetic factors influence glycocalyx health throughout the lifespan? These questions will drive the next phase of Dr. Shi's research program at Harvard.

Building an Inclusive Scientific Future

Beyond her scientific contributions, Dr. Shi is committed to fostering diversity in science. "It's easy to feel isolated or like you don't belong in science, especially without early exposure or role models," she reflects. Her dedication to mentoring and creating inclusive research environments promises to amplify her impact by inspiring the next generation of interdisciplinary scientists.

The interview reveals how personal experiences shape scientific pursuits. Dr. Shi's appreciation for hiking and trail running mirrors her approach to research: seeking new perspectives from challenging vantage points. This blend of rigorous science with human experience characterizes the new generation of biomedical researchers.Implications for Brain Medicine

Dr. Shi's discoveries raise fundamental questions about how we approach brain aging and disease. If glycocalyx deterioration is a common pathway in multiple neurodegenerative conditions, could targeting these molecules provide a unified therapeutic strategy? How might lifestyle factors influence glycocalyx health? These considerations could reshape preventive medicine approaches for brain health.

The transition from viewing the blood-brain barrier as a simple wall to understanding it as a dynamic, sugar-coated interface represents a paradigm shift in neuroscience. This new perspective demands innovative research approaches and may explain why previous therapeutic strategies targeting the barrier have shown limited success.

Dr. Sophia Shi's Genomic Press interview is part of a larger series called Innovators & Ideas that highlights the people behind today's most influential scientific breakthroughs. Each interview in the series offers a blend of cutting-edge research and personal reflections, providing readers with a comprehensive view of the scientists shaping the future. By combining a focus on professional achievements with personal insights, this interview style invites a richer narrative that both engages and educates readers. This format provides an ideal starting point for profiles that explore the scientist's impact on the field, while also touching on broader human themes.

Materialsprovided byGenomic Press.Note: Content may be edited for style and length.

Despite global reductions in mercury emissions, mercury concentrations in Arctic wildlife continue to rise. A new study published inNature Communicationsby researchers from Aarhus University and the University of Copenhagen reveals that ocean currents may be transporting legacy mercury pollution to the Arctic — posing a long-term threat to ecosystems and human health.

"We've monitored mercury in Arctic animals for over 40 years. Despite declining global emissions since the 1970s, we see no corresponding decrease in Arctic concentrations — on the contrary," says Professor Rune Dietz from Aarhus University.

Mercury released into the atmosphere from sources like coal combustion and gold mining can remain airborne for about a year. However, once it enters the ocean, it can persist for over 300 years. This means that even with current emission reductions, the Arctic may continue to experience elevated mercury levels for centuries.

Mercury's Fingerprint in Arctic Wildlife The researchers analyzed over 700 environmental samples — including tissues from polar bears, seals, fish, and peat — from across Greenland collected over the past 40 years. By examining the composition of six common mercury isotopes, they identified distinct regional differences that align with ocean current patterns.

"These isotope signatures act like fingerprints, revealing the sources and transport pathways of mercury," explains Senior Researcher Jens Søndergaard from Aarhus University.

For example, central West Greenland is influenced by Atlantic inflow via the Irminger Current, while other regions are dominated by Arctic Ocean currents.

Implications for Global Mercury Regulation

Mercury is a potent neurotoxin. In Arctic top predators like polar bears and toothed whales, concentrations are now 20-30 times higher than before industrialization. This poses serious health risks not only to wildlife but also to Indigenous communities that rely on marine mammals for food.

"Mercury affects the immune system, reproduction, and possibly sensory functions in animals, which can impact their survival," says Professor Christian Sonne from Aarhus University.

The findings have significant implications for the UN's Minamata Convention on Mercury, which aims to reduce global mercury pollution. The study offers a potential explanation for why mercury levels in Arctic biota remain high despite falling atmospheric emissions.

"Transport of mercury from major sources like China to Greenland via ocean currents can take up to 150 years," says Rune Dietz. "This helps explain the lack of decline in Arctic mercury levels."

The research team is continuing their work on mercury isotopes across the Arctic through the "GreenPath" project, funded by the Independent Research Fund Denmark. The isotopic analyses also contribute to international projects such as WhaleAdapt and ArcSolutions.

Materialsprovided byAarhus University.Note: Content may be edited for style and length.

Astronomers using data from NASA's James Webb Space Telescope have identified dozens of small galaxies that played a starring role in a cosmic makeover that transformed the early universe into the one we know today.

"When it comes to producing ultraviolet light, these small galaxies punch well above their weight," said Isak Wold, an assistant research scientist at Catholic University of America in Washington and NASA's Goddard Space Flight Center in Greenbelt, Maryland. "Our analysis of these tiny but mighty galaxies is 10 times more sensitive than previous studies, and shows they existed in sufficient numbers and packed enough ultraviolet power to drive this cosmic renovation."

Wold discussed his findings Wednesday at the 246th meeting of the American Astronomical Society in Anchorage, Alaska. The study took advantage of existing imaging collected by Webb's NIRCam (Near-Infrared Camera) instrument, as well as new observations made with its NIRSpec (Near-Infrared Spectrograph) instrument.

The tiny galaxies were discovered by Wold and his Goddard colleagues, Sangeeta Malhotra and James Rhoads, by sifting through Webb images captured as part of the UNCOVER (Ultradeep NIRSpec and NIRCam ObserVations before the Epoch of Reionization) observing program, led by Rachel Bezanson at the University of Pittsburgh in Pennsylvania.

The project mapped a giant galaxy cluster known as Abell 2744, nicknamed Pandora's cluster, located about 4 billion light-years away in the southern constellation Sculptor. The cluster's mass forms a gravitational lens that magnifies distant sources, adding to Webb's already considerable reach.

For much of its first billion years, the universe was immersed in a fog of neutral hydrogen gas. Today, this gas is ionized — stripped of its electrons. Astronomers, who refer to this transformation as reionization, have long wondered which types of objects were most responsible: big galaxies, small galaxies, or supermassive black holes in active galaxies. As one of its main goals, NASA's Webb was specifically designed to address key questions about this major transition in the history of the universe.

Recent studies have shown that small galaxies undergoing vigorous star formation could have played an outsized role. Such galaxies are rare today, making up only about 1% of those around us. But they were abundant when the universe was about 800 million years old, an epoch astronomers refer to as redshift 7, when reionization was well underway.

The team searched for small galaxies of the right cosmic age that showed signs of extreme star formation, called starbursts, in NIRCam images of the cluster.

"Low-mass galaxies gather less neutral hydrogen gas around them, which makes it easier for ionizing ultraviolet light to escape," Rhoads said. "Likewise, starburst episodes not only produce plentiful ultraviolet light — they also carve channels into a galaxy's interstellar matter that helps this light break out."

The astronomers looked for strong sources of a specific wavelength of light that signifies the presence of high-energy processes: a green line emitted by oxygen atoms that have lost two electrons. Originally emitted as visible light in the early cosmos, the green glow from doubly ionized oxygen was stretched into the infrared as it traversed the expanding universe and eventually reached Webb's instruments.

This technique revealed 83 small starburst galaxies as they appear when the universe was 800 million years old, or about 6% of its current age of 13.8 billion years. The team selected 20 of these for deeper inspection using NIRSpec.

"These galaxies are so small that, to build the equivalent stellar mass of our own Milky Way galaxy, you'd need from 2,000 to 200,000 of them," Malhotra said. "But we are able to detect them because of our novel sample selection technique combined with gravitational lensing."

Similar types of galaxies in the present-day universe, such as green peas, release about 25% of their ionizing ultraviolet light into surrounding space. If the low-mass starburst galaxies explored by Wold and his team release a similar amount, they can account for all of the ultraviolet light needed to convert the universe's neutral hydrogen to its ionized form.

The James Webb Space Telescope is the world's premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).

Materialsprovided byNASA/Goddard Space Flight Center.Note: Content may be edited for style and length.

A rare and bewildering intermediate between crystal and glass can be the most stable arrangement for some combinations of atoms, according to a study from the University of Michigan.

The findings come from the first quantum-mechanical simulations of quasicrystals — a type of solid that scientists once thought couldn't exist. While the atoms in quasicrystals are arranged in a lattice, as in a crystal, the pattern of atoms doesn't repeat like it does in conventional crystals. The new simulation method suggests quasicrystals — like crystals — are fundamentally stable materials, despite their similarity to disordered solids like glass that form as a consequence of rapid heating and cooling.

"We need to know how to arrange atoms into specific structures if we want to design materials with desired properties," said Wenhao Sun, the Dow Early Career Assistant Professor of Materials Science and Engineering, and the corresponding author of the paper published today in Nature Physics. "Quasicrystals have forced us to rethink how and why certain materials can form. Until our study, it was unclear to scientists why they existed."

Quasicrystals seemed to defy physics when they were first described by Israeli scientist Daniel Shechtman in 1984. While experimenting with alloys of aluminum and manganese, Shechtman realized that some of the metals' atoms were arranged in an icosahedral structure resembling many 20-sided dice joined at their faces. This shape gave the material five-fold symmetry — identical from five different vantage points.

Scientists at the time thought that the atoms inside crystals could only be arranged in sequences repeating in each direction, but five-fold symmetry precluded such patterns. Shechtman initially faced intense scrutiny for suggesting the impossible, but other labs later produced their own quasicrystals and found them in billion-year-old meteorites.

Shechtman eventually earned the Nobel Prize in Chemistry in 2011 for his discovery, but scientists still couldn't answer fundamental questions on how quasicrystals formed. The roadblock was that density-functional theory — the quantum-mechanical method for calculating a crystal's stability — relies on patterns that infinitely repeat in a sequence, which quasicrystals lack.

"The first step to understanding a material is knowing what makes it stable, but it has been hard to tell how quasicrystals were stabilized," said Woohyeon Baek, a U-M doctoral student in materials science and engineering and the study's first author.

The atoms in any given material usually arrange into crystals so that the chemical bonds achieve the lowest possible energy. Scientists call such structures enthalpy-stabilized crystals. But other materials form because they have high entropy, meaning there are a lot of different ways for its atoms to be arranged or vibrate.

Glass is one example of an entropy-stabilized solid. It forms when melted silica quickly cools, flash-freezing the atoms into a patternless form. But if the cooling rates slow, or a base is added to heated silica, the atoms can arrange into quartz crystals — the preferred, lowest energy state at room temperature. Quasicrystals are a puzzling intermediate between glass and crystal. They have locally ordered atomic arrangements like crystals, but like glass, they do not form long-range, repeating patterns.

To determine if quasicrystals are enthalpy- or entropy-stabilized, the researcher's method scoops out smaller nanoparticles from a larger simulated block of quasicrystal. The researchers then calculate the total energy in each nanoparticle, which doesn't require an infinite sequence because the particle has defined boundaries.

Since the energy in a nanoparticle is related to its volume and surface area, repeating the calculations for nanoparticles of increasing sizes allows the researchers to extrapolate the total energy inside a larger block of quasicrystal. With this method, the researchers discovered that two well-studied quasicrystals are enthalpy-stabilized. One is an alloy of scandium and zinc, the other of ytterbium and cadmium.

The most accurate estimates of quasicrystal energy require the largest particles possible, but scaling up the nanoparticles is difficult with standard algorithms. For nanoparticles with only hundreds of atoms, doubling the atoms increases the computing time eightfold. But the researchers found a solution for the computing bottleneck, too.

"In conventional algorithms, every computer processor needs to communicate with one another, but our algorithm is up to 100 times faster because only the neighboring processors communicate, and we effectively use GPU acceleration in supercomputers," said study co-author Vikram Gavini, a U-M professor of mechanical engineering and materials science and engineering.

"We can now simulate glass and amorphous materials, interfaces between different crystals, as well as crystal defects that can enable quantum computing bits."

The research is funded by the U.S. Department of Energy and relied on computing resources housed at the University of Texas, Lawrence Berkeley National Laboratory and Oak Ridge National Laboratory.

Materialsprovided byUniversity of Michigan.Note: Content may be edited for style and length.

Scientists know the stomach talks to the brain, but two new studies from Rutgers Health researchers suggest the conversation is really a tug-of-war, with one side urging another bite, the other signaling "enough."

Together, the papers inNature MetabolismandNature Communicationstrace the first complementary wiring diagram of hunger and satiety in ways that could refine today's blockbuster weight-loss drugs and blunt their side effects.

One study, led by Zhiping Pang of Robert Wood Johnson Medical School's Center for NeuroMetabolism, pinpointed a slender bundle of neurons that runs from the hypothalamus to the brainstem.

The cells bristle with GLP-1 receptors, the proteins mimicked by weight-loss drugs such as Ozempic. When Pang's team hit the pathway with pulses of light, well-fed mice quit eating; when they silenced the circuit or deleted the receptor, the animals packed on weight. Fasting weakened the connection until a burst of natural or synthetic GLP-1 restored it.

"The synapse is a volume knob that only turns up when energy stores are low," Pang said, warning that drugs that keep the signal high around the clock could disrupt the brain's normal rhythm and create some of the side effects of GLP-1 drugs such as nausea, vomiting, constipation or diarrhea and muscle wasting.

For the other paper, Mark Rossi, who co-leads the Center for NeuroMetabolism with Pang, charted the circuit that triggers hunger. His group traced inhibitory neurons in the stria terminalis to similar cells in the lateral hypothalamus.

When researchers triggered the connection, a suddenly hungry mouse would sprint for sugar water; when they blocked it, the animals lounged even after a long fast.

Hormones modulated the effect. An injection of ghrelin, the gut's hunger messenger, revved food seeking, while leptin, the satiety signal, slammed it shut. Overfed mice gradually lost the response, but it returned after diets made them thin again.

"Pang's pathway shuts things down," Rossi said. "Ours steps on the accelerator."

Although the circuits sit in different corners of the brain, members of both teams saw the same principle: Energy state rewires synapses quickly. During a fast, the hunger circuit gains sensitivity while the satiety circuit loosens; after a meal, the relationship flips.

It is the first time researchers have watched the push-pull mechanism operate in parallel pathways, a yin-yang arrangement that may explain why diets and drugs that treat only one side of the equation often lose power over time and may help in making drugs that work even better than today's generation of GLP-1 medications.

GLP-1 mimics such as Wegovy and Zepbound can trigger double-digit weight loss but also nausea, diarrhea and, in some cases, muscle wasting. Pang's data suggest a therapy targeting only the brainstem circuit and sparing peripheral organs might curb eating without the side effects. Conversely, Rossi's work hints that restoring the body's response to the hunger-regulating hormone ghrelin could help dieters who plateau after months of calorie cutting.

Both projects relied on the modern toolkit of neural biology – optogenetics to fire axons with laser light, chemogenetics to silence them, fiber-optic photometry to watch calcium pulses and old-fashioned patch-clamp recordings to monitor single synapses. Those techniques allowed the researchers to tune individual pathways with a precision that has only recently become possible.

Follow-up work from both teams will explore more questions that could improve drug design. Pang wants to measure GLP-1 release in real time to see whether short bursts, rather than constant exposure, are enough to calm appetite. Rossi is cataloging the molecular identity of his hunger-trigger cells in hopes of finding drug targets that steer craving without crushing the joy of eating.

"You want to keep the system's flexibility," Rossi said. "It's the difference between dimming the lights and flicking them off."

Allowing the brain to correctly rebalance the desire to eat or stop eating throughout the day, rather than using drugs to keep desire constantly low, may be an important ingredient in tomorrow's weight-loss prescriptions.

Materialsprovided byRutgers University.Note: Content may be edited for style and length.

The vast majority of pangolin hunting in African forest landscapes is done for meat consumed by people in the region, rather than for scales shipped to East Asia, a new study led by the University of Cambridge suggests.

Pangolins are the most heavily trafficked wild mammal in the world. A solitary, insect-eating animal about the size of a large domestic cat*, pangolins are famous for their highly prized keratin scales — a staple of traditional Chinese medicine.

All eight existing pangolin species are threatened with extinction and on the IUCN's Red List, with three Asian species categorised as critically endangered.

As Asian pangolins have declined dramatically, Nigeria has seen a boom in the export of pangolin scales to Asia. While hunting pangolins is illegal in Nigeria the West African country is now the world's largest hub for the criminal trade in pangolin products.

However, a new study published in the journalNature Ecology & Evolutionsuggests that some 98% of Nigerian pangolins are caught for meat first and foremost, with around two-thirds of scales from these animals simply thrown away.

A research team led by Cambridge collected data from over eight hundred hunters and traders in thirty-three locations across Nigeria's Cross River Forest region, primarily between 2020 and 2023, during which time the conservationists estimate that around 21,000 pangolins were killed annually in the area.

Almost all pangolins were captured "opportunistically" or during general hunting trips (97%) rather than sought out, and caught primarily for meat (98%). Around 71% of pangolins were consumed by hunters themselves, with 27% traded locally as food.

Perhaps surprisingly, given their potential overseas value, around 70% of the scales were discarded, while less than 30% were sold on. However, researchers calculated that, per animal, pangolin meat fetched 3-4 times the price of scales at local Nigerian markets.

"Thousands of kilos of pangolin scales are seized at Nigeria's ports, creating the impression that the international demand for scales is behind pangolin exploitation in West Africa," said study lead author and Gates Cambridge Scholar Dr Charles Emogor, who conducted the research for his PhD at the University of Cambridge's Department of Zoology.

"When we spoke to hunters and traders on the ground around the Cross River forest, the largest stronghold for Nigeria's pangolins, it was obvious that meat was the motivation for almost all of the pangolin killings."

"We found that dedicated pangolin hunts are virtually non-existent. Most pangolins are killed by hunters out for any type of game," said Emogor, now a Schmidt Science Fellow split between Cambridge, UK, and Harvard, US.

"Around a third of pangolins are caught opportunistically, often while people are working in the fields. Pangolins curl into a ball when threatened, which sadly makes them easy to catch." Among frequent hunters, by far the most common method of catching pangolins was given as simply picking them up by hand.

While Emogor says the demands of traditional medicine markets are exacerbating the decline of African pangolins — his previous research showed that just shipments intercepted by Nigerian authorities between 2010 and 2021 amounted to 190,407 kilos of pangolin scales taken from around 800,000 dead creatures — pangolins have been exploited in West Africa long before being trafficked to Asia.

The meat is a delicacy in parts of Nigeria, often procured for pregnant women in the belief it helps produce strong babies. Emogor and colleagues surveyed hunters and Cross River locals on "palatability": asking them to rank the tastiness of almost a hundred different animals eaten in the region, from domestic beef and chicken to catfish, monkeys and antelope.

The three major African pangolin species were rated as the most palatable of all available meats, with average scores of almost nine out of ten, and the giant pangolin considered the topmost appetising meat in the region.

"Pangolins face a lethal combination of threats," said Emogor. "Pangolins are easy to hunt, breed slowly, taste good to humans, and are falsely believed to have curative properties in traditional medicines. In addition, their forest habitat is being destroyed."

Emogor's research led him to set up Pangolino in 2021, a global network of volunteers, scientists and pangolin enthusiasts committed to saving the endangered animal. He points out that the cost of policy interventions to tackle meat-driven pangolin trading might be cheaper than those for an international scales market.

These should include anti-poaching patrols as well as community programmes focused on food security. Through Pangolino, Emogor is piloting interventions in four Southeast Nigerian communities by helping create by-laws that prohibit pangolin killing, with financial rewards for compliance.

"Clearly in designing any intervention we need good information on what's motivating the hunters," said Prof Andrew Balmford, co-author from Cambridge's Department of Zoology. "That's why studies such as this are vital for effective conservation of endangered species."

While the latest study focused on Nigeria, researchers say their pangolin hunting and consumption data echo that from countries such as Cameroon and Gabon — suggesting these patterns may be Africa-wide.

Raised on the edge of the Cross River National Park, home to Nigeria's endangered white-bellied and black-bellied pangolins, Emogor grew up surrounded by wildlife. Yet during childhood he only ever saw dead pangolins, and didn't encounter a living animal until his mid-twenties.

"If we lose the pangolin, we lose 80 million years of evolution," said Emogor. "Pangolins are the only mammals with scales, and their ancestors existed when dinosaurs still roamed the planet," added Emogor.

The latest study was conducted by an international team of researchers from the University of Cambridge, Wildlife Conservation Society, Pangolin Protection Network, University of Washington, CIFOR, CARE International, as well as the UK universities of Oxford, Exeter and Kent.

*While this is a rough size for some African species, such as the White-bellied pangolin, the Giant Pangolin can grow up to 30kg in weight.

Materialsprovided byUniversity of Cambridge.Note: Content may be edited for style and length.

In a new study, physicists at the University of Colorado Boulder have used a cloud of atoms chilled down to incredibly cold temperatures to simultaneously measure acceleration in three dimensions — a feat that many scientists didn't think was possible.

The device, a new type of atom "interferometer," could one day help people navigate submarines, spacecraft, cars and other vehicles more precisely.

"Traditional atom interferometers can only measure acceleration in a single dimension, but we live within a three-dimensional world," said Kendall Mehling, a co-author of the new study and a graduate student in the Department of Physics at CU Boulder. "To know where I'm going, and to know where I've been, I need to track my acceleration in all three dimensions."

The researchers published their paper, titled "Vector atom accelerometry in an optical lattice," this month in the journalScience Advances. The team included Mehling; Catie LeDesma, a postdoctoral researcher in physics; and Murray Holland, professor of physics and fellow of JILA, a joint research institute between CU Boulder and the National Institute of Standards and Technology (NIST).

In 2023, NASA awarded the CU Boulder researchers a $5.5 million grant through the agency's Quantum Pathways Institute to continue developing the sensor technology.

The new device is a marvel of engineering: Holland and his colleagues employ six lasers as thin as a human hair to pin a cloud of tens of thousands of rubidium atoms in place. Then, with help from artificial intelligence, they manipulate those lasers in complex patterns — allowing the team to measure the behavior of the atoms as they react to small accelerations, like pressing the gas pedal down in your car.

Today, most vehicles track acceleration using GPS and traditional, or "classical," electronic devices known as accelerometers. The team's quantum device has a long way to go before it can compete with these tools. But the researchers see a lot of promise for navigation technology based on atoms.

"If you leave a classical sensor out in different environments for years, it will age and decay," Mehling said. "The springs in your clock will change and warp. Atoms don't age."

Interferometers, in some form or another, have been around for centuries — and they've been used to do everything from transporting information over optical fibers to searching for gravitational waves, or ripples in the fabric of the universe.

The general idea involves splitting things apart and bringing them back together, not unlike unzipping, then zipping back up a jacket.

In laser interferometry, for example, scientists first shine a laser light, then split it into two, identical beams that travel over two separate paths. Eventually, they bring the beams back together. If the lasers have experienced diverging effects along their journeys, such as gravity acting in different ways, they may not mesh perfectly when they recombine. Put differently, the zipper might get stuck. Researchers can make measurements based on how the two beams, once identical, now interfere with each other — hence the name.

In the current study, the team achieved the same feat, but with atoms instead of light.

Here's how it works: The device currently fits on a bench about the size of an air hockey table. First, the researchers cool a collection of rubidium atoms down to temperatures just a few billionths of a degree above absolute zero.

In that frigid realm, the atoms form a mysterious quantum state of matter known as a Bose-Einstein Condensate (BEC). Carl Wieman, then a physicist at CU Boulder, and Eric Cornell of JILA won a Nobel Prize in 2001 for creating the first BEC.

Next, the team uses laser light to jiggle the atoms, splitting them apart. In this case, that doesn't mean that groups of atoms are separating. Instead, each individual atom exists in a ghostly quantum state called a superposition, in which it can be simultaneously in two places at the same time.

When the atoms split and separate, those ghosts travel away from each other following two different paths. (In the current experiment, the researchers didn't actually move the device itself but used lasers to push on the atoms, causing acceleration).

"Our Bose-Einstein Condensate is a matter-wave pond made of atoms, and we throw stones made of little packets of light into the pond, sending ripples both left and right," Holland said. "Once the ripples have spread out, we reflect them and bring them back together where they interfere."

When the atoms snap back together, they form a unique pattern, just like the two beams of laser light zipping together but more complex. The result resembles a thumb print on a glass.

"We can decode that fingerprint and extract the acceleration that the atoms experienced," Holland said.

The group spent almost three years building the device to achieve this feat.

"For what it is, the current experimental device is incredibly compact. Even though we have 18 laser beams passing through the vacuum system that contains our atom cloud, the entire experiment is small enough that we could deploy in the field one day," LeDesma said.

One of the secrets to that success comes down to an artificial intelligence technique called machine learning. Holland explained that splitting and recombining the rubidium atoms requires adjusting the lasers through a complex, multi-step process. To streamline the process, the group trained a computer program that can plan out those moves in advance.

So far, the device can only measure accelerations several thousand times smaller than the force of Earth's gravity. Currently available technologies can do a lot better.

But the group is continuing to improve its engineering and hopes to increase the performance of its quantum device many times over in the coming years. Still, the technology is a testament to just how useful atoms can be.

"We're not exactly sure of all the possible ramifications of this research, because it opens up a door," Holland said.

Materialsprovided byUniversity of Colorado at Boulder.Note: Content may be edited for style and length.