General considations
Journals will not accept papers that have been published elsewhere in any publishable format in any other journal, irrespective of whether the language used differs between the two papers. This is mainly due to copyright restrictions from publishing companies that publish journal content. Once accepted, your paper is under copyright laws for that publisher. Therefore, publishing the same material elsewhere is considered a breach of these laws. The second reason is due to academic ethics, where publishing the same content twice is considered unethical research practice as it only seeks to improve the author’s bibliography and increase their citations.
Practical example for Life Sciences
Journals within the life sciences are bounded by copyright laws from publishing companies. Therefore, they will not accept papers or results that have been published or that are being considered for publication elsewhere. For example, in the ecology journal Methods in Ecology and Evolution under ‘Author Guidelines’, § 2.2. Article Submission states that, as an author, you are required to agree to an Author’s Declaration stating you acknowledge your work has not been published elsewhere:
http://www.methodsinecologyandevolution.org/view/0/authorGuidelines.html#submission
‘The work as submitted has not been published or accepted for publication, nor is being considered for publication elsewhere, either in whole or substantial part’.
Authors are required to check the box stating they agree to the Author’s Declaration in their Author Centre before submitting their final manuscript.