President's report, 1989-90

ALGEBRA III (Curso 1989-90) Teoŕia de conjuntos

Ejercicio 1. Probar que para cualesquiera conjuntos a, b y c se tiene que: (1) a ⊆ a. (2) a ⊆ b ∧ b ⊆ a =⇒ a = b. (3) a ⊆ b ∧ b ⊆ c =⇒ a ⊆ c. (4) ∅ ⊆ a. Ejercicio 2. Probar que para cualesquiera conjuntos a, b y c Idenpotentes a ∪ a = a a ∩ a = a Conmutativas a ∪ b = b ∪ a a ∩ b = b ∩ a Asociativas a ∪ (b ∪ c) = (a ∪ b) ∪ c a ∩ (b ∩ c) = (a ∩ b) ∩ c Absorcin a ∩ (a ∪ b) = a a ∪ (a ∩ b) = a Dist...

Influenza-related excess mortality in The Netherlands 1989/90.

Health of the foreign-born population: United States, 1989-90.

The health status of immigrants is of vital interest to health policy planners as the number of immigrants in the United States increases. This report has shown that, overall, foreign-born persons had better health than the U.S.-born population, although this health advantage varied by length of residence in the United States. In virtually every measure of health status, and with regard to almo...

Presidents, Vice Presidents, and Death: Closing the Constitution's Succession Gap

Underwriting the presidents.

The United States has had 43 presidents. We examined whether they survive significantly longer or shorter than their contemporaries. We found that survival was better for presidents elected in the 1789-1841 and 1933-2001 periods (SMRs of 0.7 and 0.6, respectively), but worse for those elected in 1845-1929 (SMR = 2.9). We also found increased mortality during the years lived in office (SMR = 1.4...