Porfirio Barba Jacob: la ira sostenida

Ira Gerhardt

SYMMETRIC INCLUSION - EXCLUSION Ira

One form of the inclusion-exclusion principle asserts that if A and B are functions of finite sets then the formulas A(S) = ∑ T⊆S B(T ) and B(S) = ∑ T⊆S(−1) |A(T ) are equivalent. If we replace B(S) by (−1)|S|B(S) then these formulas take on the symmetric form A(S) = ∑

Ira Herskowitz (1946–2003)

breadth and the intensity of Ira's interests. It also revealed Photo courtesy of Kay Chernush. his modus operandi: using simple genetics to ask and answer big questions. transduction by studying crosstalk between pathways, In 1971, in his last year of graduate school, Ira accepted and examined sporulation as a developmental program. an Assistant Professorship in the University of Oregon's Recen...

Serially Concatenated IRA Codes

We address the error floor problem of low-density parity check (LDPC) codes on the binary-input additive white Gaussian noise (AWGN) channel, by constructing a serially concatenated code consisting of two systematic irregular repeataccumulate (IRA) component codes connected by an interleaver. The interleaver is designed to prevent stopping-set error events in one of the IRA codes from propagati...

Jacob de la Motta, M.D.: an early American Jewish medical pioneer.

The city of Philadelphia was not only the cradle of American independence, but it was also the birthplace of formal medical education. Up until the latter colonial period, becoming a physician was accomplished by spending several years as an apprentice to a doctor already in practice. It has been estimated that at the beginning of the Revolutionary War, of the thirty-five hundred practicing phy...