Compulsory voting papers. Compulsory voting is increasingly resented by citizens in some countries such as Brazil, the largest country where compulsory voting is enforced: at the last presidential election in 2014, some 30 million voters, about 21% of registered voters, did not vote, despite the fact that Brazil has some of the most severe penalties enforced against non voters. A study of a Swiss canton where compulsory voting was enforced found that compulsory voting significantly increased electoral support for leftist policy positions in referenda by up to 20 percentage points. Another study found that the effects of universal turnout in the United
Catalytic cycle Heck reaction show catalytic cycles. A catalytic cycle is not necessarily a full reaction mechanism. For example, it may be that the intermediates have been detected, but it is not known by which mechanisms the actual elementary reactions occur. Precatalysts are not catalysts but are "precursors" to catalysts. Precatalysts are converted in the reactor to the actual catalytic species. The identification of catalysts vs precatalysts is an important theme in catalysis research. The conversion of a precatalyst to a catalyst is often called catalyst activation. Many metal halides are precatalysts for olefin polymerization, see Kaminsky catalyst and Ziegler-Natta catalysis. The