The jQuery.UI.Combined NuGet package combines the jQueryUI controls and a base theme. In 1.11.0, the jQuery UI team has renamed the files in the base theme. The change was to drop “jquery.ui” from all the CSS and Javascript filenames. This change was done to add AMD support.

http://blogs.msdn.com/b/webdev/archive/2014/08/19/upgrading-to-jquery-ui-combined-1-11-0.aspx