This gif of membrane-anchored Ras (red) and individual SOS molecules (green) shows individual SOS molecules corralled into nanofabricated patches where all the membrane-associated Ras molecules they activate can be trapped. A breakthrough discovery into how living cells process and respond to chemical information could help advance the development of treatments for a large number of cancers and other cellular disorders that have been resistant to therapy. An international collaboration of researchers, led by scientists with the U.S. Department of Energy (DOE)'s Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley, have unlocked the secret behind the activation of the Ras family of proteins, one of the most important components of cellular signaling networks in biology and major drivers of cancers that are among the most difficult to treat.

On the left is a coral-covered reef. On the right is one dominated by algae. A new study by biologists at San Diego State University and Scripps Institution of Oceanography shows that inhabited coral islands that engage in commercial fishing dramatically alter their nearby reef ecosystems, disturbing the microbes, corals, algae and fish that call the reef home.

One of the knots grows in size, while the other diffuses along the contour of the former. Physicists of Johannes Gutenberg University Mainz (JGU) and the Graduate School of Excellence "Materials Science in Mainz" (MAINZ) have been able with the aid of computer simulations to confirm and explain a mechanism by which two knots on a DNA strand can interchange their positions. For this, one of the knots grows in size while the other diffuses along the contour of the former. Since there is only a small free energy barrier to swap, a significant number of crossing events have been observed in molecular dynamics simulations, i.e., there is a high probability of such interchange of positions.