Permission to reuse content from an article published by Portland Press:

• If the content that you are seeking to re-use is in a Portland Press article that is published open access under a CC BY licence NO permissions are required, although you must cite the published article and credit the authors when you re-use it (or part of it).

• If the article you are seeking to re-use is published open access under any other type of licence (e.g. CC BY NC-ND) or a Portland Press license to publish then please complete a re-use permission-request form via copyright.com.

• To find out what licence the article is published under look for the copyright line on the published article, which can be found underneath the abstract or full text, depending on what view you are seeing for the article. Where there is no creative commons license attached, please complete a re-use permission request form via copyright.com.

• FOR AUTHORS: if you are a named author on the article you wish to re-use then you will not need to seek any permissions except for re-use of non-open access papers that involves commercial re-selling or bulk distribution. For the latter, please visit copyright.com.