Refining and Testing CHARMM Lipid Parameters for Biologically Important Membranes

Modification of the CHARMM force field for DMPC lipid bilayer

The CHARMM force field for DMPC lipids was modified in order to improve agreement with experiment for a number of important properties of hydrated lipid bilayer. The modification consists in introduction of a scaling factor 0.83 for 1-4 electrostatic interactions (between atoms separated by three covalent bonds), which provides correct transgauche ratio in the alkane tails, and recalculation of...

technical and legal parameters for determination of river boundary,( case study haraz river)

چکیده با توسعه شهر نشینی و دخل و تصرف غیر مجاز در حریم رودخانه ها خسارات زیادی به رودخانه و محیط زیست اطراف آن وارده می شود. در حال حاضر بر اساس آئین نامه اصلاح شده بستر و حریم رودخانه ها، حریم کمی رودخانه که بلافاصله پس از بستر قرار می گیرد از 1 تا20 متر از منتهی الیه طرفین بستر رودخانه تعیین، که مقدار دقیق آن در هر بازه از رودخانه مشخص نیست. در کشورهای دیگر روشهای متفاوتی من جمله: درصد ریسک...

Applications of Biologically Inspired Membranes

All-atom lipid bilayer self-assembly with the AMBER and CHARMM lipid force fields.

This communication reports the first example of spontaneous lipid bilayer formation in unbiased all-atom molecular dynamics (MD) simulations. Using two different lipid force fields we show simulations started from random mixtures of lipids and water in which four different types of phospholipids self-assemble into organized bilayers in under 1 microsecond.

Robust tests for testing the parameters of a normal population

This article aims to provide a simple robust method to test the parameters of a normal population by using the new diagnostic tool called the “Forward Search” (FS) method. The most commonly used procedures to test the mean and variance of a normal distribution are Student’s t test and Chi-square test, respectively. These tests suffer from the presence of outliers. We introduce the FS version of...