In these notes we first offer an overview of two core areas in the dynamics of probability measure preserving systems, the Kolmogorov-Sinai theory of entropy and the theory of orbit equivalence. Entropy is a nontrivial invariant that, said simply, measures the exponential growth rate of the number of orbits in a dynamical system, a very rough measure of the complexity of the orbit structure. On...

California Youth Connection (CYC) is the state's only non-profi t youth advocacy and leadership organization dedicated to giving current and former foster youth the skills necessary to engage directly with policymakers to improve the foster care system. Formed out of the fundamental belief that policymakers can benefi t from the input of those who have experienced fi rst-hand the impact of chil...

Every year scores of new pharmaceuticals enter the market, almost never with human fetal safety data. Such data typically accumulate during the "rst years of clinical use, in the form of case reports, case series, prospective and retrospective cohorts and case control studies. All of these methods su#er from serious sources of bias, o$en leading to alarming signals of teratogenicity that are la...