Threats to the future of US science dominated discussion at the first big gathering of researchers since President Donald Trump took office.

The scientific community at this year’s American Association for the Advancement of Science (AAAS) annual meeting expressed fears about the new administration. Their concerns ranged from the White House’s reluctance to accept scientific evidence to an anticipated assault on parts of the federal research budget as well as hostility to immigrants on whom US science depends.

“This is the first time in my 50-year career that I have seen people speaking up for science per se rather than about particular issues such as nuclear weapons,” Rush Holt, AAAS chief executive, said at the meeting in Boston. “I have never seen scientists more concerned about the process of science — and not just about where their grants are going to come from,” Mr Holt, a former physicist and Democratic congressman, said.