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How Intestinal Aging Encourages Harmful Bacteria

In Aging Cell, researchers have elucidated the relationship between intestinal aging and age-related changes to the gut microbiome.

Two interdependent biologies

The human gut works through the interaction of two entirely different sets of cells. The first is the body’s actual cells, including the intestinal barrier between the gut and the rest of the body, various types of ordinary immune cells, and Peyer’s patches with follicle-associated epithelium (FAE) areas that contain microfold cells (M cells), which perform crucial immunoregulatory tasks [1]. The second is the gut microbiome, the various types of bacteria that help us digest food.

How Neutrino Oscillations Affect Supernovae

Numerical models of core-collapse supernovae have matured greatly over the past few decades. With impressive accuracy, they now couple relativistic gravity, magnetohydrodynamics, nuclear physics, and neutrino transport. Neutrinos, copiously produced in the collapsed core, are the main driver of most of these supernovae. Neutrino oscillations are probably the most crucial ingredient that is still missing from the majority of models, even though their presence and possible importance have long been suggested. The reason for this gap in modeling is twofold: Many relevant physical parameters are poorly known, and the most important oscillation processes are very difficult to simulate. Now Ryuichiro Akaho at Waseda University in Japan and colleagues have made a key step toward a self-consistent model and revealed some complexities that arise when incorporating neutrino oscillations [1].

Stars are supported against their own gravity primarily by gas pressure, which is maintained by exothermic nuclear reactions. In high-mass stars, nuclear burning starts with the fusion of hydrogen into helium and continues through progressively heavier elements until the core is dominated by iron-group nuclei, at which point fusion no longer releases energy. Pressure support then no longer suffices to stabilize the core, and it collapses to a protoneutron star, a hot compact object with about 1.5 solar masses concentrated in a radius of a few tens of kilometers. During the collapse, a shock wave forms at this object’s surface and stalls after propagating outward for only about 100 km (Fig. 1). Neutrinos generated in and around the protoneutron star can heat the surrounding gas, increasing its energy.

This tiny grain-of-rice sensor gives robots a new sense and changes what delicate tools can detect

Researchers have developed a sensor about the size of a grain of rice that can measure forces and twisting motions in all directions using light instead of traditional electronics. The new sensor could help robotic tools and medical devices “feel” what they are touching, especially at very small scales.

“Although modern imaging systems can show structures clearly, they do not provide information about physical interaction, such as force or torque, and existing force sensors are often too bulky or complex to fit into miniature tools,” said research team leader Jianlong Yang from Shanghai Jiao Tong University in China. “By allowing machines to measure contact force, pressure, shear and twisting, our technology could make it possible for robots to detect unsafe contact early and adjust their actions in real time, especially in small and sensitive environments.”

In Optica journal, the researchers describe their new sensor, which measures just 1.7 millimeters and uses a single optical signal to measure forces and torques in all directions at once. Proof-of-concept tests showed that the sensor can detect stiffness variations and locate hidden structures in models that mimic a tumor embedded in tissue.

JWST spots two early black holes growing far faster than their galaxies

Astronomers have discovered two early-universe galaxies where the central black holes appear to have grown far faster than their host galaxies. Observations with the James Webb Space Telescope (JWST) reveal that the black holes in these galaxies, seen just 800 million years after the Big Bang, are significantly more massive relative to their host galaxies, as opposed to what astronomers see in the nearby universe. The study is published on the arXiv preprint server.

Astronomers have long discovered quasars—extraordinarily luminous galaxies powered by accreting black holes weighing billions of solar masses—in the first billion years of the universe. For these to exist so early, the black holes must have started as large as heavy seeds and grown at their maximum rate possible for most of their lives. These early black holes appear oversized compared to the galaxies they live in.

On the other hand, when JWST began its operation in 2022, it made a huge splash in astronomy with the discovery of an astonishingly large number of mature galaxies and black holes in the first billion years of the universe. Among them were some “overmassive” black holes weighing billions of times the mass of our sun, but rarely as massive as those found in luminous quasars.

Resilient quantum sensor monitors Earth’s magnetic field from space for 10 months

From navigation to solar weather forecasting, many different areas of research require space-based sensors to measure Earth’s magnetic field as accurately as possible at any given moment. So far, however, existing sensors have consistently struggled with effects including drift, interference from the spacecraft itself, and the harsh conditions of orbit.

Through new research published in Physical Review Applied, Yarne Beerden and colleagues at Hasselt University in Belgium have developed a diamond-based quantum sensor which could offer a promising solution to these problems.

New alien-life test could help Mars and Europa missions read organic molecules

For decades, the search for life beyond Earth has revolved around a key question: What molecules should scientists be looking for on other planets or moons? A new study, published in Nature Astronomy, suggests that the more revealing clue may not be the molecules themselves, but the hidden order connecting them.

“We’re showing that life does not only produce molecules,” said Fabian Klenner, UC Riverside assistant professor of planetary sciences and co-author of the study. “Life also produces an organizational principle that we can see by applying statistics.”

The researchers found that amino acids are consistently more diverse and more evenly distributed in a material sample created by a living thing than those found in abiotic or nonliving things. In contrast, the pattern reverses for fatty acids: Abiotically produced fatty acids are distributed more evenly than those produced by biological processes.

More Star Wars-like worlds emerge as 27 planet candidates with two suns discovered

There’s so little we know about circumbinary planets—planets that orbit two stars instead of one—that they can feel like the stuff of fantasy. And for good reason: to date, we’ve only confirmed the existence of 18 circumbinary planets, compared to the more than 6000 planets we know about in single star systems.

Quantum dot emitter delivers near-identical telecom photons at 40 million per second

Quantum technologies, devices that perform specific functions leveraging quantum mechanical effects, could soon outperform their classical counterparts on some tasks. Quantum emitters, devices that release individual particles of light (i.e., photons), are central components of many of these technologies, including quantum communication systems and quantum computers.

To enable the reliable operation of quantum technologies, emitters should emit photons with high consistency and coherence. In other words, they should ensure that the quantum properties of emitted photons remain stable and predictable.

Researchers at University of Copenhagen’s Niels Bohr Institute, Ruhr-University Bochum, University of Basel and Sparrow Quantum ApS recently developed a new photon emitter based on quantum dots, tiny structures that can trap electrons in confined regions and enable the controlled emission of individual photons.

Hybrid AI architecture could turn neuromorphic systems into reliable discovery machines

The artificial intelligence (AI) machines that guide the world can be grouped into three main categories: inference machines, learning machines and discovery machines. Researchers at Washington University in St. Louis are tackling the rarest of these machines. A new study points to a better way to build discovery machines, thanks to recent research led by Shantanu Chakrabartty, the Clifford W. Murphy Professor and vice dean for research in the McKelvey School of Engineering at Washington University in St. Louis.

The work, now published in Nature Communications, builds off previous research on establishing a hybrid systems architecture, one that employs “neuromorphic” architecture modeled on human neurobiology functions combined with systems that leverage quantum mechanics to find optimal solutions to complex problems.

The research shows that these machines can consistently produce state-of-the-art solutions with high reliability and with competitive time-to-solution metrics, Chakrabartty said.

How a single star can reshape an entire galaxy

Astronomers who simulate galaxies do not always get the same result, even when they start from identical conditions. New research from Leiden University shows that this is not a flaw, but a consequence of how galaxies behave—and how they are modeled.

The findings offer, for the first time, a way to address a long-standing question: how chaotic is a galaxy like the Milky Way really? The computer simulations by Tetsuro Asano and Simon Portegies Zwart (Leiden Observatory) will soon be published in Astronomy & Astrophysics and are available now on the arXiv preprint server.

The researchers created hundreds of models of Milky Way-like galaxies: flat disks of stars, embedded in a large, invisible cloud of dark matter that holds the system together. In each experiment, they ran two almost identical simulations, differing by just one tiny detail—for instance, a small shift in the position of a single star. Over time, that slight difference grows into visible structural changes: the spiral arms develop differently and the central bar rotates in another way.

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