A list of the 100 most talked-about scientific papers for 2016 has been published, and the biggest surprise has to be the #1 spot: a paper published in The Journal of the American Medical Association (JAMA), with a single author: Barack Obama.
Obama's paper got the highest score ever in terms of attention from the scientific community, the media, and the public, beating the discovery of a lifetime - gravitational waves - plus Zika, Planet Nine, and the 'Big Sugar' controversy.
The top 100 list is published annually by Altmetric, a UK-based firm that tracks and analyses the online activity around scholarly research outputs.
This year's report tracked over 17 million mentions of 2.7 million different publications, compiling mentions in the news, social media, policy documents, and peer-review.
Obama's paper, entitled, "United States Health Care Reform: Progress to Date and Next Steps," featured in 315 news stories, 8,943 tweets, 200 Facebook posts, and 14 Reddit posts.
It's the first academic paper to be published by a sitting president, and in it, Obama assesses the effect of the Affordable Care Act, while recommending additional healthcare priorities for future governments.
While the fact that he's the President means he didn't really have to do much to garner attention for his paper, it exemplifies a number of trends in scientific publishing that solidified in 2016.
The paper, while published in a peer-reviewed journal, was not peer-reviewed itself, and as Altmetric founder Euan Adie told Scientific American, this year saw the first hints of non-peer-reviewed, pre-print articles getting more attention than usual.
"This was the first time we saw preprints from the life sciences in the Top 100," he says, with a study from the preprint server bioRxiv ranked at number 21, and a pre-print from PeerJ getting the 28th spot.
Obama's paper is also Open Access - another trend that came to the fore in 2016.
"The trend towards making content openly available continued this year, with 30 articles in the list published under a gold Open Access licence - meaning they'll always be freely accessible," Altmetric reports.
The rise in public interest in science - particularly when it came to the spread of Zika virus this year - also saw traditional journals veer towards Open Access too, although not completely.
"The commitment to enable science to advance as quickly as possible to help find a cure for Zika virus meant that articles in journals such as Nature, the New England Journal of Medicine, and The Lancet, which do not normally offer an Open Access option, have been made available for anyone to access," says the report.
So, what's in the top 10?
- United States Health Care Reform: Progress to Date and Next Steps (JAMA)
- Medical error - the third leading cause of death in the US (British Medical Journal)
- Observation of Gravitational Waves from a Binary Black Hole Merger (Physical Review Letters)
- Evidence for a Distant Giant Planet in the Solar System (The Astronomical Journal)
- Sugar Industry and Coronary Heart Disease Research: A Historical Analysis of Internal Industry Documents (JAMA Internal Medicine)
- Zika Virus and Birth Defects - Reviewing the Evidence for Causality (New England Journal of Medicine)
- The Association Between Income and Life Expectancy in the United States, 2001-2014 (JAMA)
- Effect of Wearable Technology Combined With a Lifestyle Intervention on Long-term Weight Loss: The IDEA Randomised Clinical Trial (JAMA)
- Mastering the game of Go with deep neural networks and tree search (Nature)
- The new world atlas of artificial night sky brightness (Science Advances)
Adie told Scientific American the fact that two physics papers - gravitational waves and Planet Nine - made it into the top 10 doesn't usually happen, which means 2016 was a great year for physics discoveries.
It wasn't such a great year for rats and mobile phones, on the other hand, because the pre-print study that made #21 was one of the most controversial and widely criticised papers we saw all year.
But, as Adie explains, their list does not distinguish between positive versus negative attention - just what papers have gotten people taking, for better or worse.
"These are just the ones that are capturing the imagination," he says.
Check out the full top 100 list here, and you can access the raw data and more findings here.