Heart Motu Cordis" (1628) by the English physician William Harvey. Harvey's book completely describes the systemic circulation and the mechanical force of the heart, leading to an overhaul of the Galenic doctrines. Otto Frank (1865–1944) was a German physiologist; among his many published works are detailed studies of this important heart relationship. Ernest Starling (1866–1927) was an important English physiologist who also studied the heart. Although they worked largely independently, their combined efforts and similar conclusions have been recognized in the name "Frank–Starling mechanism". Although Purkinje fibers and the bundle of His were discovered as early as the 19th century, their
To the Youth in Europe and North America to [them] through resentments and prejudices". A second open letter was written by Khamenei on 29 November 2015, following the November 2015 Paris attacks. Khamenei says that his letter, written in English, is addressed to young people who may still have open minds, not to Western leaders who, he writes, intentionally distort the truth. "I am addressing you, [the youth], not because I overlook your parents", but because "the future of your nations and countries will be in your hands; and also I find that the sense of quest for truth is more vigorous and attentive in your hearts". He