The present invention relates to retroreflective elements and retroreflective articles such as pavement markings comprising retroreflective elements, methods of making retroreflective elements, and laminates. In certain example embodiments, the window structure includes a slidable window panel or sheet located between a pair of fixed window panels or sheets. The condition satisfaction determination unit determines whether each of at least one predetermined sleep-mode transition condition is satisfied, and determines whether an all-condition satisfaction state is present, which is a state wherein all of the at least one sleep-mode transition condition are satisfied. Entity models also provide feedback information, enabling users to easily share their experiences and opinions of the corresponding real-world entity. The invention also concerns the use of this enzyme in methods for screening various chemical compounds. A duct in the housing may have an inlet at a first end in the housing, and communicate with the exhaust outlet at a second end in the housing.