Artist's impression of neutron stars merging, producing gravitational waves and resulting in a kilonova. Credit: University of Warwick/Mark Garlick via Wikipedia, CC BY 4.0 https://creativecommons.org/licenses/by/4.0 Researchers reported this week a deadly outbreak of plague in Siberia 5,500 years ago, revealing that Yersinia pestis evolved lethal genetic traits far earlier than suspected. A drug developed for heart tissue repair may also help kidney tissue repair and regeneration.