Finding the optimal evolutionary history for a set of taxa is a challenging computational problem, even when restricting possible solutions to be “tree-like” and focusing on the maximum-parsimony optimality criterion. This has led to much work on using heuristic tree searches to find approximate solutions. We present an approach for finding exact optimal solutions that employs and complements the current heuristic methods for finding optimal trees. Given a set of taxa and a set of...

Objectives: Human brain development follows a unique pattern characterized by a prolonged period of postnatal growth and reorganization, and a postnatal peak in glucose utilization. The molecular processes underlying these developmental changes are poorly characterized. The objectives of this study were to determine developmental trajectories of gene expression and to examine the evolutionary history of genes differentially expressed as a function of age. Methods: We used microarrays to determine age-related patterns of mRNA expression in...

Stacey Engels narrates the pilgrim body in ‘From the Dark Green Hill to Our Lady of the Harbour’ by bringing her reader along on a pilgrimage that sprang up almost instantly in downtown Montreal on the day that Leonard Cohen’s death was announced. In her travelogue-style vignettes, even a sausage sandwich becomes a sacred relic when mingled with community and intention.