Eleutherodactylus chlorophenax

Number of Pages: 2Integrative BiologyGeological Science

Dynamic facilitation explains democratic particle motion of metabasin transitions

Transitions between metabasins in supercooled liquids seem to occur through rapid "democratic" collective particle rearrangements. Here we show that this apparent homogeneous particle motion is a direct consequence of dynamic facilitation. We do so by studying metabasin transitions in facilitated spin models and constrained lattice gases. We find that metabasin transitions occur through a sequence of locally facilitated events taking place over a relatively short time frame. When observed on small enough spatial windows these events appear sudden and homogeneous. Our results indicate that metabasin transitions are essentially "non-democratic" in origin and yet another manifestation of dynamical heterogeneity in glass formers.Comment: 6 pages, 6 figure

Developing Improved Bridge Parapet Designs

The Ohio Department of Transportation has identified that premature parapet cracking is a significant problem in Northeast Ohio. Background research related to concrete cracking and parapet cracking was conducted to determine possible causes of the premature cracking that ODOT has discovered. To further look at possible causes of this cracking, current ODOT bridge parapet practices were reviewed. In addition to ODOT practices, ten other state DOTs were surveyed to identify the bridge parapet practices used. These practices include the parapet design characteristics, construction joint spacing and depth, and the class of concrete used for construction. Various differences among all of these characteristics were identified and discussed to determine an improved bridge parapet design. Many of the districts located within ODOT were also surveyed and asked to identify premature bridge parapet cracking repair or replacement projects. Four of the districts were able to present twelve separate bridge parapet cracking projects. From these projects, it was determined that ODOT spends on average $188,175 per bridge parapet replacement project, or$283 per linear foot ($86 per meter) of parapet. Based on the state DOTs that confirmed parapet cracking was not a problem for their state, parapet improvements were determined. These improvements include decreasing the maximum construction joint spacing, and increasing the joint cut dept

After-School Programs for High School Students: An Evaluation of After School Matters

Evaluates outcomes for teens in Chicago's After School Matters apprenticeship-like program, finding statistically significant benefits on some measures of youth development and reduced problem behaviors but not in job skills or school performance

Matrix elements of atomic interaction operators for d sup n configurations

Tabulation of matrix elements of atomic interaction operators for various configuration

From the margins of the genome: Mobile elements shape primate evolution

As is the case with mammals in general, primate genomes are inundated with repetitive sequence. Although much of this repetitive content consists of molecular fossils inherited from early mammalian ancestors, a significant portion of this material comprises active mobile element lineages. Despite indications that these elements played a major role in shaping the architecture of the genome, there remain many unanswered questions surrounding the nature of the host-element relationship. Here we review advances in our understanding of the host-mobile element dynamic and its overall impact on primate evolution. © 2005 Wiley Periodicals, Inc

Fast Simulation of Facilitated Spin Models

We show how to apply the absorbing Markov chain Monte Carlo algorithm of Novotny to simulate kinetically constrained models of glasses. We consider in detail one-spin facilitated models, such as the East model and its generalizations to arbitrary dimensions. We investigate how to maximise the efficiency of the algorithms, and show that simulation times can be improved on standard continuous time Monte Carlo by several orders of magnitude. We illustrate the method with equilibrium and aging results. These include a study of relaxation times in the East model for dimensions d=1 to d=13, which provides further evidence that the hierarchical relaxation in this model is present in all dimensions. We discuss how the method can be applied to other kinetically constrained models.Comment: 8 pages, 4 figure

Retrotransposition of Alu elements: How many sources?

It is generally thought that only a few Alu elements are capable of retrotransposition and that these \u27master\u27 sources produce inactive copies. Here, we use a network phylogenetic approach to demonstrate that recently integrated human-specific Alu subfamilies typically contain 10-20% of secondary source elements that contributed 20-40% of all subfamily members. This multiplicity of source elements provides new insight into the remarkably successful amplification strategy of the Alu family