Use of Cookies by this Site

As explained in our privacy policy, this Site collects information through the use of "cookies" or similar technologies. Cookies are widely used in order to make websites work, or work more efficiently, as well as to provide information to the owners of the site.

The table below explains the main cookies set by this site and their purpose.

Service	Cookie Name	Purpose	More Info
WebLogic Server	JSESSIONID	This session cookie, provided by Oracle, identifies a user’s current interaction session.

The table below explains the unique site-specific cookies set by this site and their purpose.

Service	Cookie Name	Purpose	More Info
Store.Elsevier.com	X-RE-Persist	This security cookie, set by a JavaScript package (jquery.crypt.js), is used to encrypt the user’s password.
ATG	ATG_SESSION_ID	This session cookie, provided by ATG, stores and tracks data for a user while travelling through a series of pages on the site.
Google Preview	NID PREF	These persistent cookies, provided by Google Inc., are used to store user preference information for Google applications.	See Google Privacy Policy

The table below explains the web analytics cookies set by this site and their purpose.

Service	Cookie Name	Purpose	More Info
Google Analytics	__utma, __utmb, __utmc, __utmz	These web analytics cookies, provided by Google Inc., are used to collect information about how visitors use our site. We use the information to compile reports and to help us improve the site. The cookies collect information in an anonymous form, including the number of visitors to the site, where visitors have come to the site from and the pages they visited.	See Cookies Set by Google Analytics and Google Analytics Privacy Overview
Google Analytics for Display Advertisers	ad.doubleclick.net	Re-target a customer with an ad through the GDN (Google Display Network) by placing a cookie on his computer. It is a way to follow-up with people that has already visit our website before.	See Google Analytics for Display Advertisers Policy

The table below explains the cookies presented by social media websites due to "share" buttons containing widgets placed on this site.

Service	Cookie Name	Purpose	More Info
Facebook	Datr lsd, reg_ext_ref, reg_fb_gate, reg_fb_ref act wd	These cookies, provided by Facebook, are set when a visitor is logged in to or otherwise using their service. This allows a user to easily comment or share an article with their peers through the social network.	See How does Facebook use cookies
AddThis	di/dt, psc, uid/uit, uvc, siteaud, ana_svc, atuvc	These cookies, provided by Clearspring Technologies, Inc., are used in conjunction with the AddThis Button to enable you to share our content through email, social networking sites, blogs and more.	See AddThis Privacy and Data Practices
Twitter	guest_id, twll, k, _twitter_sess, original_referer, external_referer	These cookies, provided by Twitter, are used in conjunction with the Twitter social plugins in order to allow following our Twitter accounts easily, share content via Twitter, and to display the latest tweet. Twitter makes use of cookies to improve its own service.	See Twitter Privacy Policy
YouTube	SID, HSID	These cookies, provided by YouTube LLC, help maintain the integrity of video statistics, prevent fraud and improve their own service.	See Google YouTube Help Center
Google+	APISID, HSID, SAPISID, SID, SSID	These cookies, provided by Google Inc., are used in conjunction with the Google+1 button to enable you to share information publicly, as part of your Google Profile.	See Google Privacy Policy

Option to decline use of cookies

You can prevent your browser from accepting certain cookies, have the browser require your consent before a new cookie is placed in your browser, or block cookies altogether by selecting the appropriate settings on your browser's privacy preferences menu. To avoid receiving cookies on the browser of your mobile device, you will need to refer to its user manual. For information on how to opt-out of cookies set by our suppliers, please visit the applicable links listed in the tables above.

Last revised: 07 June 2012