Evolutionary Processes Acting on Candidate cis-Regulatory Regions in Humans Inferred from Patterns of Polymorphism and Divergence

Analysis of polymorphism and divergence in the non-coding portion of the human genome yields crucial information about factors driving the evolution of gene regulation. Candidate cis-regulatory regions spanning more than 15,000 genes in 15 African Americans and 20 European Americans were re-sequenced and aligned to the chimpanzee genome in order to identify potentially functional polymorphism and to characterize and quantify departures from neutral evolution. Distortions of the site frequency spectra suggest a general pattern of selective constraint on conserved non-coding sites in the flanking regions of genes (CNCs). Moreover, there is an excess of fixed differences that cannot be explained by a Gamma model of deleterious fitness effects, suggesting the presence of positive selection on CNCs. Extensions of the McDonald-Kreitman test identified candidate cis-regulatory regions with high probabilities of positive and negative selection near many known human genes, the biological characteristics of which exhibit genome-wide trends that differ from patterns observed in protein-coding regions. Notably, there is a higher probability of positive selection in candidate cis-regulatory regions near genes expressed in the fetal brain, suggesting that a larger portion of adaptive regulatory changes has occurred in genes expressed during brain development. Overall we find that natural selection has played an important role in the evolution of candidate cis-regulatory regions throughout hominid evolution

Panel III: Modernization of the Ballot Box: Voter Registration and Ballot Access in the Modern Era

The Past as Prologue: Defending Democracy on the Eve of the 2012 Elections Why Conservatives (As Well as Liberals) Should Be Interested in Modernizing Voter Registration Enforcing Election Laws in New Jersey Voting Restrictions in 2012: Ensuring Every Voter Has a Voic

Panel III: Modernization of the Ballot Box: Voter Registration and Ballot Access in the Modern Era

The Past as Prologue: Defending Democracy on the Eve of the 2012 Elections Why Conservatives (As Well as Liberals) Should Be Interested in Modernizing Voter Registration Enforcing Election Laws in New Jersey Voting Restrictions in 2012: Ensuring Every Voter Has a Voic

Quantifying the clinical relevance of a laboratory observer performance paradigm

We continue here the study of the recently introduced spiking neural P systems, which mimic the way that neurons communicate with each other by means of short electrical impulses, identical in shape (volt- age), but emitted at precise moments of time. The sequence of moments when a neuron emits a spike is called the spike train (of this neuron); by designating one neuron as the output neuron of a spiking neural P system ¦, one obtains a spike train of ¦. Given a speci¯c way of assigning sets of numbers to spike trains of ¦, we obtain sets of numbers computed by ¦. In this way, spiking neural P systems become number computing devices. We consider a number of ways to assign (code) sets of numbers to (by) spike trains, and prove then computational completeness: the computed sets of numbers are exactly Turing computable sets. When the number of spikes present in the system is bounded, a characterization of semilinear sets of numbers is obtained. A number of research problems is also formulated

The genome of the sea urchin Strongylocentrotus purpuratus.

International audienceWe report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes