Abstract: The present invention provides a pneumatic tire that can exhibit sufficient wet grip performance on roads in different areas. The present invention relates to a pneumatic tire including a tread, the tread showing a loss tangent (tan ?) versus temperature curve whose peak position is at ?20.0° C. to 0.0° C. and whose tan ? at the peak position is 0.80 or higher, the curve being obtained by plotting tan ? as a function of measurement temperature, the curve having a tan ? at an intersection of a tangent line to the curve at a temperature lower by 20° C. than the peak position temperature and a tangent line to the curve at a temperature higher by 20° C. than the peak position temperature that satisfies the following relationship (1): (tan ? at peak position?0.05)?(tan ? at intersection)?(tan ? at peak position+0.05)??(1).

Abstract: For the purpose of providing a staircase which has a lightweight structure, high efficiency in manufacturing and constructing, and creates a sense of lightness in weight, a staircase is composed with a pair of right and left stringers made of truss structural members (10), and treads (12). The truss structural members (10) are composed of the upper chord members (1) and the lower chord members (2) inclined with the slope of the staircase, and a plurality of lattice members (4) for linking the upper chord members (1) and the lower chord members (2), and between the truss structural members (10) are fixed a plurality of linking members (11) which are laid horizontally at each riser height and on which the treads (12) are fixedly supported.