Login to access subscriber-only resources.
We are working to improve this site's accessibility for users who may have disabilities of various kinds. More information will be posted as we continue updating to meet the highest international standards. We are currently aware of the following features of this website:
Perceivable information and user interface
* We are adding alt text wording for non-text content on our user-facing webpages
* We are improving the captioning language used by authors in their articles to describe data represented in charts, diagrams, and illustrations
Navigation and navigation by keyboard or voice recognition (speech input)
* Section headings and labels are used to organize the content and they describe topic or purpose
* We are aware that navigation should be possible without the use of a mouse or keyboard. This website is keyboard functional meeting Level AA standards: All functionality of the content is operable through a keyboard interface without requiring specific timings for individual keystrokes, except where the underlying function requires input that depends on the path of the user's movement and not just the endpoints.
* More than one way is available to locate a Web page within a set of Web pages
Seizures & Physical Reaction
* this website is not designed in a way that is known to cause seizures or physical reactions; the site's pages do not contain anything that flashes.
* Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user.
* Components that have the same functionality within a set of Web pages are identified consistently.
* Labels or instructions are provided when content requires user input.
* Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element except where blue designates a hyperlink
* The visual presentation of text and images of text has a contrast ratio of at least 4.5:1
* Users accessing published content (PDF articles) can zoom to enlarge pages, search by word, enter/exit full screen
* Web pages (not PDF articles) are reflowable and can be presented without loss of information or functionality, and without requiring scrolling in two dimensions for: Vertical scrolling content at a width equivalent to 320 CSS pixels;Horizontal scrolling content at a height equivalent to 256 CSS pixels; Except for parts of the content which require two-dimensional layout for usage or meaning. Web page content (not PDF articles) does not restrict its view and operation to a single display orientation, such as portrait or landscape, unless a specific display orientation is essential.
* our reader adjusts itself to the user’s particular hardware (e.g. PC, Mac, mobile, tablet) and browser software (at a minimum being compatible with IE7) on PCs. For the best results we recommend a modern HTML5-compatible browser or any “multi-touch” compatible Android / Apple smartphone or tablet)
* The default human language of each Web page can be programmatically determined.
* The human language of each passage or phrase in the content can be programmatically determined except for proper names, technical terms, words of indeterminate language, and words or phrases that have become part of the vernacular of the immediately surrounding text.
* Content can be read by screen-reading software