Crystal structures of four indole derivatives as possible cannabinoid allosteric antagonists

Acknowledgements We thank the EPSRC National Crystallography Service (University of Southampton) for the data collections and the EPSRC National Mass Spectrometry Service (University of Swansea) for the HRMS data. We thank John Low for carrying out the Cambridge Database survey.Peer reviewedPublisher PD

Gene set bagging for estimating replicability of gene set analyses

Background: Significance analysis plays a major role in identifying and ranking genes, transcription factor binding sites, DNA methylation regions, and other high-throughput features for association with disease. We propose a new approach, called gene set bagging, for measuring the stability of ranking procedures using predefined gene sets. Gene set bagging involves resampling the original high-throughput data, performing gene-set analysis on the resampled data, and confirming that biological categories replicate. This procedure can be thought of as bootstrapping gene-set analysis and can be used to determine which are the most reproducible gene sets. Results: Here we apply this approach to two common genomics applications: gene expression and DNA methylation. Even with state-of-the-art statistical ranking procedures, significant categories in a gene set enrichment analysis may be unstable when subjected to resampling. Conclusions: We demonstrate that gene lists are not necessarily stable, and therefore additional steps like gene set bagging can improve biological inference of gene set analysis.Comment: 3 Figure

Recombination coefficients for O II lines in nebular conditions

We present the results of a calculation of recombination coefficients for O2++ e− using an intermediate coupling treatment that fully accounts for the dependence of the distribution of population among the ground levels of O2+ on electron density and temperature. The calculation is extended down to low electron temperatures, where dielectronic recombination arising from Rydberg states converging on the O2+ ground levels is an important process. The data that consist of emission coefficients for 8889 recombination lines and recombination coefficients for the ground and metastable states of O+ are in Cases A, B and C, and are organized as a function of the electron temperature and number density, as well as wavelength. An interactive fortran 77 data server is also provided as an accessory for mining the line emission coefficients and obtaining Lagrange interpolated values for any choice of the two variables between the explicitly provided values for any set of wavelengths. Some illustrations of the application of the new data to nebular observations are also provided

Thermodynamic properties of Bi2Sr2CaCu2O8 calculated from the electronic dispersion

The electronic dispersion for Bi2Sr2CaCu2O(8+d) has been determined from angle-resolved photoelectron spectroscopy (ARPES). From this dispersion we calculate the entropy and superfluid density. Even with no adjustable parameters we obtain an exceptional match with experimental data across the entire phase diagram, thus indirectly confirming both the ARPES and thermodynamic data. The van Hove singularity is crossed in the overdoped region giving a distinctive linear-in-T temperature dependence in the superfluid density there.Comment: 5 pages, 4 figures, submitted to Physical Review Letter

Saddle-point van Hove singularity and the phase diagram of high-Tc cuprates

We examine the generic phase behavior of high-Tc cuprate superconductors in terms a universal van Hove singularity in the strongly overdoped region. Using a rigid ARPES-derived dispersion we solve the BCS gap equation and show that the pairing interaction or pairing energy cutoff must be a rapidly declining function of doping. This result is prejudicial to a phonon-based pairing interaction and more consistent with a magnetic or magnetically enhanced interaction.Comment: 5 pages, 2 figures, submitted to Physical Review

Bistability in a simple fluid network due to viscosity contrast

We study the existence of multiple equilibrium states in a simple fluid network using Newtonian fluids and laminar flow. We demonstrate theoretically the presence of hysteresis and bistability, and we confirm these predictions in an experiment using two miscible fluids of different viscosity--sucrose solution and water. Possible applications include bloodflow, microfluidics, and other network flows governed by similar principles

Thinking about growth : a cognitive mapping approach to understanding small business development

School of Managemen

Overcoming the boundary layer turbulence at Dome C: ground-layer adaptive optics versus tower

The unique atmospheric conditions present at sites such as Dome C on the Antarctic plateau are very favorable for high spatial resolution astronomy. At Dome C, the majority of the optical turbulence is confined to a 30 to 40 m thick stable boundary layer that results from the strong temperature inversion created by the heat exchange between the air and the ice-covered ground. To fully realize the potential of the exceptionally calm free atmosphere, this boundary layer must be overcome. In this article we compare the performance of two methods proposed to beat the boundary layer: mounting a telescope on a tower that physically puts it above the turbulent layer, and installing a telescope at ground level with a ground-layer adaptive optics system. A case is also made to combine these two methods to further improve the image quality

A new application of emulsions to measure the gravitational force on antihydrogen

We propose to build and operate a detector based on the emulsion film technology for the measurement of the gravitational acceleration on antimatter, to be performed by the AEgIS experiment (AD6) at CERN. The goal of AEgIS is to test the weak equivalence principle with a precision of 1% on the gravitational acceleration g by measuring the vertical position of the anni- hilation vertex of antihydrogen atoms after their free fall in a horizontal vacuum pipe. With the emulsion technology developed at the University of Bern we propose to improve the performance of AEgIS by exploiting the superior position resolution of emulsion films over other particle de- tectors. The idea is to use a new type of emulsion films, especially developed for applications in vacuum, to yield a spatial resolution of the order of one micron in the measurement of the sag of the antihydrogen atoms in the gravitational field. This is an order of magnitude better than what was planned in the original AEgIS proposal.Comment: 17 pages, 14 figure