Most posts on this website are about duplications within or between figures in the same paper, or about duplications found between papers by the same group of authors. But now, our small group of image forensics detectives has come across a large set of papers – over 400 as of today – from different authors and affiliations that all appear to have been generated by the same source. Based on the resemblance of the Western blot bands to tadpoles (the larval stage of an amphibian, such as a frog or a toad), we will call this the Tadpole Paper Mill.
Update: for those who cannot access the Google Sheets link above, here is a PDF version embedded in WordPress which I hope will work for all (generated March 3, 2020):
In the past week, I looked at papers from the group of Catherine Verfaillie, who previously worked at the University of Minnesota (USA) and later became the director of the Stem Cell Institute at the Catholic University of Leuven (KU Leuven; Belgium). The outcome of this renewed look at a “cold case” was first described by Leonid Schneider in a December 4 post on his For Better Science blog.
Because I recently posted concerns about a set of over 50 papers from a Chinese immunologist, several journalists and scientists have asked me why I targeted a specific professor from a specific country. My answer is that I search for problematic papers, regardless of what country they are from.
As of today, I have posted concerns on PubPeer about 1300 papers. About half of these, 775, were posted in the last 6 months (1 June 2019 – 23 November 2019). I started scanning the biomedical literature for image duplications, plagiarism, and other concerns in 2013. Because I quit my job earlier this year, I now have much more time to spend on finding and reporting papers, which is why more than half of these posts were done in the last 6 months. In total, I have found over 2,000 papers, but I have not yet reported all of these to PubPeer.
My 775 PubPeer posts from the last 6 months discussed papers in 32 different countries on six continents (as determined by the affiliation of the first author). Of these, almost 200 are from the US, and 106 are from China. Here is a map:
So no, I am not specifically targeting anyone or any country. I am, however, targeting problematic papers, no matter where they come from.
This blog post is not an accusation of misconduct, and reflects my personal opinion.
This paper has it all. The authors are from Stanford University’s School of Medicine and Harvard Medical School. It was published in 2002 in Nature Medicine, and has been cited over 900 times, as per Google Scholar. It even received a prestigious F1000 Recommendation. And it was supported by six NIH grants.
Five years ago, in 2014, I reported three papers from the same lab with possible image duplications to the journals in which they had been published. One of these papers has since then been corrected – although I argued in a previous post about this paper that a retraction might have been a better decision. The other two papers are still untouched, unfortunately.
Since the journals and authors had had 5 years to respond, I posted my concerns about these three papers on PubPeer, so that at least researchers with the PubPeer extension can see that they have been “flagged”. I also found a couple more papers from this lab – headed by Dr. Xuetao Cao – that appeared to have problems and I posted these as well.
And then someone pointed out that the senior author on these papers was one of the top immunologists in China.