Abstract: Provided are compounds of Formula (I?): or pharmaceutically acceptable salts thereof, wherein the variables in the formula are as defined herein; and methods for their use and production.

Abstract: A teaching system comprising a visual aid printed on at least one side of a sheet material, a modeling implement, and an access indicia for connecting a user to remote resource materials. The visual aid may include at least one illustrated side containing information about a scientific theory, describing origins, descriptions, mechanisms, and evidence of the scientific theory. The modeling implement may be a die cutting tool having a tessellated array of cells in a panel, wherein each cell shares a portion of its border with an adjacent cell, and a die cutting edge extending from one side of the panel. The combination may be used as an efficient and interesting teaching aid in a variety of settings.