Parameterization of a coarse-grained model of cholesterol with point-dipole electrostatics

© 2018, Springer Nature Switzerland AG. We present a new coarse-grained (CG) model of cholesterol (CHOL) for the electrostatic-based ELBA force field. A distinguishing feature of our CHOL model is that the electrostatics is modeled by an explicit point dipole which interacts through an ideal vacuum permittivity. The CHOL model parameters were optimized in a systematic fashion, reproducing the electrostatic and nonpolar partitioning free energies of CHOL in lipid/water mixtures predicted by full-detailed atomistic molecular dynamics simulations. The CHOL model has been validated by comparison to structural, dynamic and thermodynamic properties with experimental and atomistic simulation reference data. The simulation of binary DPPC/cholesterol mixtures covering the relevant biological content of CHOL in mammalian membranes is shown to correctly predict the main lipid behavior as observed experimentally

A lower bound to the social cost of CO2 emissions

Many studies have estimated the social cost of carbon (SCC). We critically evaluate SCC estimates, focusing on omitted cost categories, discounting, uncertainties about damage costs and risk aversion. This allows for the calculation of a lower bound to the SCC. Dominant SCC values turn out to be gross underestimates, notably, but not only, for a low discount rate. The validity of this lower bound is supported by a precautionary approach to reflect risk aversion against extreme climate change. The results justify a more stringent climate policy than is suggested by most influential past studies. © 2014 Macmillan Publishers Limited. All rights reserved