Searching low-energy conformations of two elastin sequences

The three-dimensional structures of two common repeat motifs Val$^1$-Pro$^2$-Gly$^3$-Val$^4$-Gly$^5$ and Val$^1$-Gly$^2$-Val$^3$-Pro$^4$-Gly$^5$-Val$^6$-Gly$^7$-Val$^8$-Pro$^9$ of tropoelastin are investigated by using the multicanonical simulation procedure. By minimizing the energy structures along the trajectory the thermodynamically most stable low-energy microstates of the molecule are determined. The structural predictions are in good agreement with X-ray diffraction experiments.Comment: 16 pages, 5 figure

Jews, Jesus, and the problem of postcolonial French identity

In 2004 a French Jewish student union ran an ad against anti-Semitism using defaced images of Jesus and Mary. Denounced by an antiracist organization affiliated with Jewish interests, the ad was immediately pulled. Why? While the union intended the campaign to be provocative for what it suggested about anti-Semitism, it may ultimately have been most problematic for what it implied about “Frenchness.” This article argues that the campaign’s polysemy and ambiguity destabilized religious and national differences presumed to be self-evident in contemporary France. In doing so, it may have undermined mainstream Jewish institutional strategies that relied on the evocation of a stable French national “identity” to both fight anti-Semitism and produce Jewish belonging in France

Appreciation of the Machinations of the Blind Watchmaker

One danger in using the language of engineering to describe the patterns and operations of the evident products of natural selection is that invoking principles of design runs the risk of invoking a designer. But as we analyze the increasing amount of data on the genome and its organization across a wide array of organisms, we are discovering there are patterns and dynamics reminiscent of designs that we, as imperfect human designers, recognize as serving an engineering purpose, including the purpose to be designable and evolvable. There is no doubt that biological artifacts are the product of Dawkins’ Blind Watchmaker, natural selection. But natural selection has at its heart one of engineering’s most prized principles, optimization. Survival of the fittest, while not directly specifying an objective function that an organism must meet, nonetheless provides a clear figure of merit for long term biological success, persistence of lineages through reproduction of organisms, and is a well-formed if ever-changing specification. The mechanisms which provide the optimization algorithm for an organism to meet the demands of this changeable requirement, composed of a program subject to operations of mutation and interorganismal transfer and inheritance, are themselves under selection. Repeated rounds of this process leads, some argue, to architectures that facilitate evolution itself, the evolving of evolvability