The RNA folding map, understood as the relationship between sequences and secondary structures or shapes, exhibits robust statistical properties summarized by three notions: (1) the notion of a typical shape (that among all sequences of fixed length certain shapes are realized much more...

The immune system is a complex system that learns, remembers what it has learned, and acts to protect us from a variety of pathogens. Here we address the question of how the immune system is able to recognize and learn about pathogens that can rapidly evolve and hence potentially change so as to...