Arizona State University scientists report that larger dogs age faster because of "jumping genes," according to a paper in Science. The authors analyzed DNA methylation data from 864 dogs in the Dog Aging Project. Their analysis linked aging to reduced methylation control over LINE1 jumping genes, which can move between chromosomes and damage DNA. Giant breeds lost roughly 35 percent more LINE1 methylation each year than small breeds. Co-author Blaise Mariner said, "This is one of the clearest molecular signatures we've seen that aligns with the well-known size-lifespan trade-off in dogs." He added that faster aging in larger dogs "may be driven, at least in part, by reduced control over these jumping genes."
Physicists at Northwestern University trapped a single positron, an antimatter particle, for months at a time, according to a paper in Physical Review Letters. The team cooled the positron to 300 millikelvins, keeping it in its quantum ground state. They used tuned microwaves to manipulate and detect its quantum energy state, the first step toward measuring its magnetic properties. The Standard Model predicts no difference between the electron and positron measurements. Co-author Gerald Gabrielse said that if they are not equal, "that would be the biggest discovery in physics in the last century."
A separate paper in Matter & Light describes multicolored tattoo inks, called PhotoTat, that are invisible under normal light and appear only under UV light. Co-author Carson Bruns of the University of Colorado Boulder said, "There's a stigma, in science and in many cultures, around body art. I'm proud to be pushing against that."