32 research outputs found
Synchrotron measurements of the absolute X-ray quantum efficiency of CsI coated microchannel plates
This document describes a Fortran 95 package for carrying out DGLAP evolution
and other common manipulations of parton distribution functions (PDFs). The
PDFs are represented on a grid in x-space so as to avoid limitations on the
functional form of input distributions. Good speed and accuracy are obtained
through the representation of splitting functions in terms of their convolution
with a set of piecewise polynomial basis functions, and Runge-Kutta techniques
are used for the evolution in Q. Unpolarised evolution is provided to NNLO,
including heavy-quark thresholds in the MSbar scheme, and longitudinally
polarised evolution to NLO. The code is structured so as to provide simple
access to the objects representing splitting functions and PDFs, making it
possible for a user to extend the facilities already provided. A streamlined
interface is also available, facilitating use of the evolution part of the code
from F77 and C/C++.Comment: 60 pages, 5 figures. Code available from
http://projects.hepforge.org/hoppet
Trace amine-associated receptors and their ligands
Classical biogenic amines (adrenaline, noradrenaline, dopamine, serotonin and histamine) interact with specific families of G protein-coupled receptors (GPCRs). The term ‘trace amines' is used when referring to p-tyramine, β-phenylethylamine, tryptamine and octopamine, compounds that are present in mammalian tissues at very low (nanomolar) concentrations. The pharmacological effects of trace amines are usually attributed to their interference with the aminergic pathways, but in 2001 a new gene was identified, that codes for a GPCR responding to p-tyramine and β-phenylethylamine but not to classical biogenic amines. Several closely related genes were subsequently identified and designated as the trace amine-associated receptors (TAARs). Pharmacological investigations in vitro show that many TAAR subtypes may not respond to p-tyramine, β-phenylethylamine, tryptamine or octopamine, suggesting the existence of additional endogenous ligands. A novel endogenous thyroid hormone derivative, 3-iodothyronamine, has been found to interact with TAAR1 and possibly other TAAR subtypes. In vivo, micromolar concentrations of 3-iodothyronamine determine functional effects which are opposite to those produced on a longer time scale by thyroid hormones, including reduction in body temperature and decrease in cardiac contractility. Expression of all TAAR subtypes except TAAR1 has been reported in mouse olfactory epithelium, and several volatile amines were shown to interact with specific TAAR subtypes. In addition, there is evidence that TAAR1 is targeted by amphetamines and other psychotropic agents, while genetic linkage studies show a significant association between the TAAR gene family locus and susceptibility to schizophrenia or bipolar affective disorder