As a scientist I have seen numerous instances of plagarism usually from scientists in foreign countries. For example my Ph.D. advisor showed me an article published in an Indian scientific journal that was a direct copy of one of his papers except for the authors names. I have personally received manuscripts for review where entire paragraphs were lifted out of my papers. As far as fraud numerous times I have talked to professors who are unable to reproduce promising experiments done by foreign students who graduate and then return to their home countries. I cant prove they faked their data to graduate but I have strong suspicions.
Results that cannot be reliably and consistently reproduced using valid methodology should be viewed with some measure of skepticism, as it indicates either fraud (faked data) or sloppy methods. This is one aspect of the scientific method I have been taught. In either case, it is a black mark against both the author of the study, the adviser, and the institution that granted the degree. There have been cases where degrees have been withdrawn when fraud has come to light. Credibility and reputation is everything to anyone who purports to be a scientist. Or so I am told.
“As a scientist I have seen numerous instances of plagarism usually from scientists in foreign countries.”
...and then there is the pressure to add the names of others to your research papers so they can fake their research accomplishments. I’ve seen this at two universities where the pressure is put on the junior faculty. That is fraudulent. There is also the fraud associated with “blind peer review” where the field of scholars is small and everyone can readily tell who wrote and who is reviewing a research paper submitted for publication. That could result in exclusion of papers by those who want to control the publication pipeline. There is also fraud in other areas of science and I suspect, considering the quality of measurement and the claims made, that a lot of data should be examined for integrity.