I18n.t('notification.update.'+ receiver.subject.class.to_s.underscore, 
              :sender => sender_name,
              :whose => I18n.t('notification.whose.'+ receiver.subject.class.to_s.underscore,
                               :receiver => receiver_name),
              :thing => I18n.t(direct_object.class.to_s.underscore+'.one'))