October science roundup: why big dogs age faster and how a single positron was trapped for months
Ars Technica's monthly roundup covers research on why large dogs age faster, a single antimatter particle held for months, and tattoo inks visible only under UV light.
The science outlet Ars Technica has published its monthly roundup of October studies that did not get a full article of their own. They span biology, physics, archaeology and art history.
Why large dogs age faster
In many mammal species, larger animals live longer, but dogs break that pattern: bigger dogs die younger. Scientists at Arizona State University report in the journal Science that so-called "jumping genes" may be involved. The team used data on 864 dogs from the Dog Aging Project to map DNA methylation, a chemical marker that influences how active genes are, across the whole genome. Aging in dogs was linked to weakening methylation-based regulation, especially in regions containing jumping genes. These genes can damage DNA and contribute to cancer and other age-related diseases. Giant breeds lost roughly 35 percent more LINE1 methylation per year than small breeds.
A single positron held for months
Physicists at Northwestern University report in Physical Review Letters that they trapped a single positron, the antimatter counterpart of the electron, for months. The particle was harvested from sodium-22 nuclei and guided into a vacuum trap of electric and magnetic fields, where it was chilled to 0.3 degrees above absolute zero. This is a first key step toward precisely measuring its magnetic properties. The Standard Model of particle physics predicts no difference between positron and electron measurements; if one were found, co-author Gerald Gabrielse said it would be the biggest discovery in physics in the last century.
Invisible tattoo inks
Researchers at the University of Colorado, Boulder developed an ink called PhotoTat that is invisible until illuminated with UV light, when it turns blue, magenta or yellow. The colors fade after a few hours. The technology is still a proof of concept, but it could also be used to mark cancer patients for radiation therapy.
The Westminster skeleton
A skeleton found in a Roman sarcophagus at Westminster Abbey most likely belonged to a high-ranking medieval monk, possibly Abbot Aelfwig, who died around 1020, or his successor Wulboth.
