The rockefeller university

There has been a lack of software available to ecologists for the management, visualisation and analysis of ecological community and food web data. Researchers have been forced to implement their own data formats and software, often from scratch, resulting in duplicated effort and bespoke solutions that are difficult to apply to future analyses and comparative studies. We introduce Cheddar an R package that provides standard, transparent implementations of a wide range of food web and community-level analyses and plots, focussing on ecological network data that are augmented with estimates of body mass and/or numerical abundance. The package allows analysis of individual communities, as well as collections of communities, allowing examination of changes in structure through time, across environmental gradients, or due to experimental manipulations. Several commonly analysed food web data sets are included and used in worked examples. This is the first time these important!

We derive the quadratic action of the fluctuations around the classical world sheet underlying the jet quenching from AdS/CFT. After obtaining the correspondence partition function, the expansion of the jet quenching parameter of N = 4 super symmetric Yang-Mills theory is carried out to the sub-leading term in the large 't Hooft coupling lambda at a nonzero temperature. The strong coupling corresponds to the semi-classical expansion of the string-sigma model, the gravity dual of the Wilson loop operator, with the sub-leading term expressed in terms of functional determinants of fluctuations. The contribution of these determinants are evaluated numerically. We find the jet quenching parameter is reduced due to world sheet fluctuations by a factor (1 - 1.97 lambda(-1/2)).

Immune response to pathogens depends on coordinated regulation of numerous genes that contribute collectively to pathogen elimination and restoration of the integrity of the affected tissue. The pathogen-induced gene expression is governed largely by the signal-induced posttranslational histone modifications that facilitate assembly of the functionally distinct chromatin complexes. In this review, we describe the principles of chromatin-based gene regulation during innate immune responses. We discuss the ability of pathogens to hijack the host response by interfering with various arms of transcriptional machinery involved in the responses. In particular, we discuss the phenomenon of the histone mimicry where interaction between histones and transcriptional regulators is targeted by pathogens that carry the histone-like sequences (histone mimics). We show how the principle of isotone mimicry as an efficient way to control host gene expression has been sued for the development of novel anti-inflammatory pharmacological approaches.

Bacteriophage T7 encodes an essential inhibitor of the Escherichia coli host RNA polymerase (RNAP), the product of gene 2 (Gp2). We determined a series of X-ray crystal structures of E. coli RNAP holoenzyme with or without Gp2. The results define the structure and location of the RNAP sigma(70) subunit domain 1.1 inside the RNAP active site channel, where it must be displaced by the DNA upon formation of the open promoter complex. The structures and associated data, combined with previous results, allow for a complete delineation of the mechanism for Gp2 inhibition of E. coli RNAP. In the primary inhibition mechanism, Gp2 forms a protein-protein interaction with , preventing the normal egress of from the RNAP active site channel. Gp2 thus misappropriates a domain of the RNAP holoenzyme, , to inhibit the function of the enzyme.

Clicking thiols onto a core fluorous phthalocyanine (Pc) platform yields alkyl and fluoroalkyl derivatives. The Zn(II) Pc with 16 thioalkanes self-organizes with fullerene C-60 into nearly monodispersed nanoparticles when cast on ITO surfaces. Particle size and surface density is controlled by varying the Pc/fullerene ratio and concentration. Fluorescence quenching indicates electronic interaction between the component molecules in the films of nanoparticles. The strong supramolecular interactions between the Pc with 8 or 16 fluorous alkanes inhibit incorporation of the fullerene.

A search for supersymmetry in final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of root s = 7 TeV. The data sample corresponds to an integrated luminosity of 4.98 fb(-1) collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, alpha(T), is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. The search is performed in a signal region that is binned in the scalar sum of the transverse energy of jets and the number of jets identified as originating from a bottom quark. No excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of the constrained minimal supersymmetric extension of the standard model, and also in simplified models, with a special emphasis on compressed spectra and third-generation scenarios.

A large-scale RNA in vitro selection study systematically identified RNA recognition elements for 205 RNA-binding proteins belonging to families conserved in most eukaryotes.

Regular tessellations of three dimensional space are characterized through their Schlafli symbols {p, q, r}, where each cell has regular p-gonal sides, q sides meeting at each vertex of a cell, and r cells meeting around each edge. Regular tessellations with symbols {p, 3, 3} all satisfy Plateau's laws for equilibrium foams. For general p, however, these regular tessellations do not embed in Euclidean space, but require a uniform background curvature. We study a class of regular foams on S-3 which, through conformal, stereographic projection to R-3 define irregular cells consistent with Plateau's laws. We analytically characterize a broad classes of bulk foam bubbles, and extend and explain recent observations on foam structure and shape distribution.