Correction.  Notification of an important error made by the journal or the author(s) that affects the publication record or the scientific integrity of the paper, or the reputation of the authors or of the journal. We expect authors to inform the journal’s Editors of any errors they have noticed (or have been informed of) in their article once published as print or electronic correspondence. We recognize our responsibility to publish a correction notice as soon as possible detailing changes from and citing the original publication; the correction is published on a numbered print page to ensure proper indexing. We also post a new article version with details of the changes and the dates on which the changes were made.

Scientific misconduct. Scientific misconduct includes but is not necessarily limited to data fabrication; data falsification, including deceptive manipulation of images; and plagiarism. When scientific misconduct is alleged, the editors initiate appropriate procedures and if the investigation proves scientific misconduct, we publish a retraction of the article. Retracted articles remain in the public domain and are clearly labelled as retracted.

Expressions of concern.  When scientific misconduct is alleged, or concerns are otherwise raised about the conduct or integrity of work described in submitted or published papers, the editors may choose to publish an expression of concern pending the outcomes of those procedures. EoCs specifies clearly the nature of the concern, which differentiates possible misconduct from honest error. EoCs indicates which aspects of the paper are problematic (i.e., which specific data or conclusions are invalid) and indicates what factors (feedback from readers, individuals, institutional officials, etc.) ultimately led to the publication of the EoC. Expression of concern is included in the journal’s table of contents with page number and freely available.

Retraction. Notification of invalid results that affect the reliability of a previously published article. Retractions are considered by journal editors in cases of evidence of unreliable data or findings, plagiarism, duplicate publication, and unethical research. The original article is marked as retracted but remains available to readers, and the retraction statement notifying readers of the invalidity of the published paper is bi-directionally linked to the original published paper. The text of the retraction explains why the article is being retracted and includes a complete citation reference to that article.