DNA replication in Xenopus laevis is extremely reliable, failing to complete before cell division no more than once in 10 000 times; yet replication origin sites are located and initiated stochastically. Using a model based on 1D theories of nucleation and growth and using concepts from extreme-value statistics, we derive the distribution of replication times given a particular initiation funct...

Nuclear proliferation, because of its ability to threaten human survival, is fast coming to overshadow all other global issues.1-7 When the renowned explorer Jacques-Yves Cousteau addressed the UN General Assembly in 1976 he observed that atomic power had "reshaped what we may fear, what we may dream, how we live and how we may die." He was emphasising as many before him had done that since Aug...

The elimination tree plays an important role in many aspects of sparse matrix factorization. The height of the elimination tree presents a rough, but usually eeective, measure of the time needed to perform parallel elimination. Finding orderings that produce low elimination trees is therefore important. As the problem of nding minimum height elimination tree orderings is NP-hard, it is interest...