Surprising finding challenges current theories on how galaxies grow. Three dozen dwarf galaxies far from each other had a simultaneous “baby boom” of new stars, an unexpected discovery that challenges current theories on how galaxies grow and may enhance our understanding of the universe.

Galaxies more than 1 million light-years apart should have completely independent lives in terms of when they give birth to new stars...

Scientists have discovered a new role for bile acids: they curb appetite by entering the brain. Their findings provide new insights into the signals and mechanisms by which satiety is controlled and may have implications for treating obesity.

Our brain is usually well protected from uncontrolled influx of molecules from the periphery thanks to the blood-brain barrier, a physical seal of cells lining the blood vessel walls. The hypothalamus, however, is a notable exception to this rule. Characterized by “leaky” blood vessels, this region, located at the base of the brain, is exposed to a variety of circulating bioactive molecules. This anatomical feature also determines its function as a rheostat involved in the coordination of energy sensing and feeding behavior.

Several hormone...

Researchers demonstrate long delays and narrow filtering of microwave signals in silicon-photonic circuits, based on surface acoustic waves. High-end wireless and cellular networks rely on light for the distribution of signals. The selective processing of such signals requires long delays: too long to support on a chip using light alone. A research team brought together light and ultrasonic waves to realize ultra-narrow filters of microwave signals, in silicon integrated circuits. The concept allows large freedom for filters design.

The continued growth of wireless and cellular data traffic relies heavily on light waves. Microwave photonics is the field of technology that is dedicated to the distribution and processing of electrical information signals using optical means...

Radio telescope images enable a new way to study magnetic fields in galaxy clusters millions of light years away. For the first time, researchers have observed plasma jets interacting with magnetic fields in a massive galaxy cluster 600 million light years away, thanks to the help of radio telescopes and supercomputer simulations. The findings, published in the journal Nature, can help clarify how such galaxy clusters evolve.

Galaxy clusters can contain up to thousands of galaxies bound to...