Two ways to compactness

Two ways to condense

Two ways to condense G ene-rich euchromatin and largely untranscribed heterochromatin may follow different rules to prepare for mitosis, according to J. Robert Manak, Joseph Lipsick, and colleagues (Stanford University, Stanford, CA). From S phase to prophase, chromatin must replicate and then condense to prepare for mitosis. In most eukaryotic cells, euchromatin starts the process by replicati...

Two Ways to Common Knowledge

It is not clear what a system for evidence-based common knowledge should look like if common knowledge is treated as a greatest fixed point. This paper is a preliminary step towards such a system. We argue that the standard induction rule is not well suited to axiomatize evidence-based common knowledge. As an alternative, we study two different deductive systems for the logic of common knowledg...

Two Ways to Frustrate a Desire

Suppose that a person, call him Andrew, has a desire to drink a cup of tea. He boils the kettle, pours the hot water into the teacup, places the teacup on a side table, and sits down next to it to wait for the tea to brew. When Andrew looks away, and before he is able to satisfy his desire, Beata quickly pours Andrew’s tea into a nearby plant pot because she believes that caffeine is bad for An...

Two ways to make great contributions.

Two new ways to eat beans

A cryptic collagen epitope (green) is exposed on some tumor blood vessels. collagen type IV in directing the growth of new blood vessels. Recent work has shown that proteolytic enzymes like the matrix metalloproteinases are required for normal angiogenesis, but the significance of these findings remained unclear. In the new work, the authors analyzed a monoclonal antibody that binds to proteoly...