Washington University has been selected by the Commission on Presidential Debates to host more presidential and vice-presidential debates than any other institution in history. United States presidential election debates were held at the Washington University Athletic Complex in 1992, 2000, 2004, and 2016. A presidential debate was planned to occur in 1996, but owing to scheduling difficulties between the candidates, the debate was canceled. The university hosted the only 2008 vice presidential debate, between Republican Sarah Palin and Democrat Joe Biden, on October 2, 2008, also at the Washington University Athletic Complex.
What years were presidential debates held at Washington University?
1992, 2000, 2004, and 2016

Light is the signal by which plants synchronize their internal clocks to their environment and is sensed by a wide variety of photoreceptors. Red and blue light are absorbed through several phytochromes and cryptochromes. One phytochrome, phyA, is the main phytochrome in seedlings grown in the dark but rapidly degrades in light to produce Cry1. Phytochromes B–E are more stable with phyB, the main phytochrome in seedlings grown in the light. The cryptochrome (cry) gene is also a light-sensitive component of the circadian clock and is thought to be involved both as a photoreceptor and as part of the clock's endogenous pacemaker mechanism. Cryptochromes 1–2 (involved in blue–UVA) help to maintain the period length in the clock through a whole range of light conditions.
What do plants use to sense light?
photoreceptors

The massive work was arranged according to a "tree of knowledge." The tree reflected the marked division between the arts and sciences, which was largely a result of the rise of empiricism. Both areas of knowledge were united by philosophy, or the trunk of the tree of knowledge. The Enlightenment's desacrilization of religion was pronounced in the tree's design, particularly where theology accounted for a peripheral branch, with black magic as a close neighbour. As the Encyclopédie gained popularity, it was published in quarto and octavo editions after 1777. The quarto and octavo editions were much less expensive than previous editions, making the Encyclopédie more accessible to the non-elite. Robert Darnton estimates that there were approximately 25 000 copies of the Encyclopédie in circulation throughout France and Europe before the French Revolution. The extensive, yet affordable encyclopedia came to represent the transmission of Enlightenment and scientific education to an expanding audience.
How many copies of the Encyclopedie were estimated to be in circulation throughout France and Europe before the French Revolution?
25 000