This journal provides direct open access to its content with the principle that making research freely available to the public supports a greater global exchange of knowledge. It is an Open Access journal, meaning that all content is freely available without charge to users or their institutions. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of articles, or use them for any other lawful purpose, without prior permission from the publisher or author. This is in accordance with the definition of Open Access from the Budapest Open Access Initiative (BOAI).