Problem 2. The diamond The four-node diamond pattern occurs when X regulates Y and Z, and both Y and Z regulate gene W. a. Illustrate the distinct types of sign combinations of the diamond (where each edge is either activation + or repression -)? Indicate which ones are coherent (Hint: 10 combinations, of which 6 are coherent). b. Consider a diamond with four activation arrows. Assign activation thresholds to all edges. Analyze the dynamics of W following a step of Sx, for both AND and OR logic at the W promoter. Are there sign-sensitive delays?