The Conformal Points of the Generalized Thirring Model II

In the large N limit, conditions for the conformal invariance of the generalized Thirring model are derived, using two different approaches: the background field method and the Hamiltonian method based on an operator algebra, and the agreement between them is established. A free field representation of the relevant algebra is presented, and the structure of the stress tensor in terms of free fields (and free currents) is studied in detail.Comment: 20 pages (latex, no other macros needed). This replaces an earlier version.A typo and some sign mistakes are corrected, and a paragraph added; Full postscript available from http://thoer1.lbl.gov/www/theorgroup/papers/36926.p

Investigating the performance of 410, PH13-8Mo and 300M steels in a turning process with a focus on surface finish

This study generated novel behavioural data for three engineering steels undergoing a turning process. The materials were hardened 410, PH13-8Mo and 300M, two stainless steels and one high strength steel respectively. A primary aim was obtaining low machined surface roughness. A surface finish investigation compared tool geometries and tool materials. Multi-response cutting parameter screening was undertaken using a novel trade study and iteration method, where the calculated cut quality was used to identify better feed rates and surface speeds. In addition the sub-surface machined microstructure was examined. Tools with a small nose radius produced the roughest surfaces. A surface roughness below 0.4 μm Ra could be consistently achieved on all three materials using rhombic wiper inserts and a feed rate up to 0.1 mm/rev. PH13-8Mo had the lowest machined surface roughness, as low as 0.11 μm in terms of Ra. In the parameter screening stage a generalised recommendation for good cut quality was a surface speed of at least 120 m/min and a feed rate of 0.088 mm/rev. The microstructure examination showed that for all materials under the conditions tested, there was no evidence of white amorphous layer formation and there was grain deformation for the 410 material only

Quasi-continuous Interpolation Scheme for Pathways between Distant Configurations

A quasi-continuous interpolation (QCI) scheme is introduced for characterizing physically realistic initial pathways from which to initiate transition state searches and construct kinetic transition networks. Applications are presented for peptides, proteins, and a morphological transformation in an atomic cluster. The first step in each case involves end point alignment, and we describe the use of a shortest augmenting path algorithm for optimizing permutational isomers. The QCI procedure then employs an interpolating potential, which preserves the covalent bonding framework for the biomolecules and includes repulsive terms between unconstrained atoms. This potential is used to identify an interpolating path by minimizing contributions from a connected set of images, including terms corresponding to minima in the interatomic distances between them. This procedure detects unphysical geometries in the line segments between images. The most difficult cases, where linear interpolation would involve chain crossings, are treated by growing the structure an atom at a time using the interpolating potential. To test the QCI procedure, we carry through a series of benchmark calculations where the initial interpolation is coupled to explicit transition state searches to produce complete pathways between specified local minima.This work was supported by the Engineering and Physical Sciences Research Council [grant number EP/H042660/1]This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in the Journal of Chemical Theory and Computation, copyright © American Chemical Society after peer review. To access the final edited and published work see http://dx.doi.org/10.1021/ct300483

The Immune Landscape of Cancer

We performed an extensive immunogenomic anal-ysis of more than 10,000 tumors comprising 33diverse cancer types by utilizing data compiled byTCGA. Across cancer types, we identified six im-mune subtypes\u2014wound healing, IFN-gdominant,inflammatory, lymphocyte depleted, immunologi-cally quiet, and TGF-bdominant\u2014characterized bydifferences in macrophage or lymphocyte signa-tures, Th1:Th2 cell ratio, extent of intratumoral het-erogeneity, aneuploidy, extent of neoantigen load,overall cell proliferation, expression of immunomod-ulatory genes, and prognosis. Specific drivermutations correlated with lower (CTNNB1,NRAS,orIDH1) or higher (BRAF,TP53,orCASP8) leukocytelevels across all cancers. Multiple control modalitiesof the intracellular and extracellular networks (tran-scription, microRNAs, copy number, and epigeneticprocesses) were involved in tumor-immune cell inter-actions, both across and within immune subtypes.Our immunogenomics pipeline to characterize theseheterogeneous tumors and the resulting data areintended to serve as a resource for future targetedstudies to further advance the field