Cover image

“Moiré By the Sea.” A moiré pattern is an interference pattern that results from overlapping graphical elements, such as lines or dots. In the cover image, the overlapping lines in the ocean and overlapping dots in the clouds produce moiré patterns. In this issue, the PASTE2 algorithm to align spatial transcriptomics data from adjacent tissue slices is described. Spatial transcriptomics technologies measure gene expression at thousands of discrete locations, or spots, and thus images of aligned slices often yield moiré patterns (e.g., see Fig. 3 in Liu et al.). (Cover illustration by Lillian Raphael, www.lilymraphael.com. The cover art was generated using licensed versions of Procreate and Adobe Illustrator. Positions of points in clouds were computed in Mathematica using code from Stephen Wolfram, “Moiré Patterns,” http://demonstrations.wolfram.com/MoirePatterns/, Wolfram Demonstrations Project [published: March 7, 2011]. [For details, see Liu et al., pp. 1124–1132.])