Hieroglyphs on the wall of a Maya building record calculations concerning the orbits of Earth, Mars and Venus, as well as the name of a mathematician who wrote the text around 1200 years ago
Since gravitational waves were first detected in 2015, instruments including LIGO, Virgo and KAGRA have picked up a steady stream of signals from colliding black holes, building a catalog that now numbers in the hundreds. Yet despite this wealth of data, a fundamental question has remained stubbornly unresolved: How do these black holes actually form?
Now, two independent research teams have used fresh theoretical approaches to comb through the data, and both arrived at a similar conclusion: Merging black holes don’t form a single uniform group, but instead separate into distinct subpopulations, each bearing the fingerprints of different formation mechanisms. Both studies have been published in Physical Review Letters.
Researchers at Paul Scherrer Institute (PSI) have developed the world’s first achromatic lens for neutron imaging. The lens overcomes a longstanding obstacle in the field: focusing neutrons of different wavelengths well enough to form a sharp, magnified image. With the lens, researchers can now image thick samples and follow processes inside bulky equipment such as furnaces, cryostats or pressure cells.
Neutrons can provide unique insights into the structure of materials—but they are hard to manipulate. Neutrons, like X-rays, are produced as a beam at research facilities such as the Swiss Spallation Neutron Source SINQ and are used to image inside materials and objects. Unlike X-rays, however, neutrons can penetrate deeply into many metals while remaining highly sensitive to light elements such as hydrogen and lithium. In this way, they can be used to observe oil, polymer or lithium distribution inside dense metallic structures such as engines or batteries, reveal water uptake in plants or nondestructively examine priceless archaeological artifacts.
Yet the same weak interaction with matter that makes neutrons such a useful tool also makes them notoriously difficult to deflect or focus—a fact that has limited the development of advanced imaging techniques. Now, PSI scientists have reported in Nature Communications a new type of lens that overcomes this barrier.
The researchers have uncovered a mechanism that determines why a neuron usually forms a single, long extension called “axon” – a phenomenon that is fundamental to how our brain functions. Contrary to the common view that external cues drive axon formation, the team of scientists comes to the conclusion that its growth originates primarily inside the cell. Their work, based on cell cultures and was published in the journal “Nature” reveals how a neuron’s structure is remodeled to generate the axon.
Neurons in the brain and spinal cord form a vast network in which each cell receives many inputs but sends output through only a single, long extension: the “axon”. “If our neurons had multiple axons, this would cause chaos in the brain,” says the senior author. “Nature has therefore found a clever way to make sure that neurons generate only one axon. This applies not only to humans, but across the entire animal kingdom. So, we’re dealing with very fundamental processes that shape the wiring of the brain and nervous system.”
An impressive paper where entire human torso cross sections were imaged via ultrasound. I’m also curious if this has any ties to Midjourney’s announcement of a similar-sounding technology in their new biomedical division.
An ultrasound tomography system composed of a custom 512-element circular receiver array combined with a single-element transmitter that rotates around the participant enables whole cross-sectional ultrasound imaging of the human body.
An incredible paper by Meng et al. showing how the fluorescence of the flavoproteins iLOV and cryptochrome can be modulated by RF signals when held under certain magnetic fields. This work may provide a foundation for more RF tools which allow manipulation of biological processes.
Radio waves are shown to modulate fluorescence and associate spin chemistry in proteins.