listing authorship, but also includes the act of conferring authorship on those who have not made substantial contributions to the research. This is done by senior researchers who muscle their way onto the papers of inexperienced junior researchers as well as others that stack authorship in an effort to guarantee publication. This is much harder to prove due to a lack of consistency in defining "authorship" or "substantial contribution". Scientific misconduct can also occur during the peer-review process by a reviewer or editor with a conflict of interest. Reviewer-coerced citation can also inflate the perceived citation impact of a researcher's work and their reputation in the scientific community, similar to excessive self-citation. Reviewers are expected to be impartial and assess the quality of their work. They are expected to declare a conflict of interest to the editors if they are colleagues or competitors of the authors. A rarer case of scientific misconduct is editorial misconduct, where an editor does not declare conflicts of interest, creates pseudonyms to review papers, gives strongly worded editorial decisions to support reviews suggesting to add excessive citations to their own unrelated works or to add themselves as a co-author or their name to the title of the manuscript. Publishing in a predatory journal, knowingly or unknowingly, was discussed as a form of potential scientific misconduct. Photo manipulation Compared to other forms of scientific misconduct, image fraud (manipulation of images to distort their meaning) is of particular interest since it can frequently be detected by external parties. In 2006, the Journal of Cell Biology gained publicity for instituting tests to detect photo manipulation in papers that were being considered for publication. This was in response to the increased usage of programs such as Adobe Photoshop by scientists, which facilitate photo manipulation. Since then more publishers, including the Nature Publishing Group, have instituted similar tests and require authors to minimize and specify the extent of photo manipulation when a manuscript is submitted for publication. However, there is little evidence to indicate that such tests are applied rigorously. One Nature paper published in 2009 has subsequently been reported to contain around 20 separate instances of image fraud. Although the type of manipulation that is allowed can depend greatly on the type of experiment that is presented and also differ from one journal to another, in general the following manipulations are not allowed: splicing together different images to represent