orbit4-5/app/assets/javascripts/lib/items/items.js.erb

  var $openSlide = $('.open-slide'),
      $pageslideW;
 $(window).width() > 1440 ? $pageslideW = 1024 : $pageslideW = 954;
  $(window).resize(function() {
      $(this).width() > 1440 ? $pageslideW = 1024 : $pageslideW = 954;
});
$iFrame = $openSlide.filter('.view-page.open-slide');
$iFrame.pageslide({
    W: $pageslideW,
    iframe: true
  });