Half sphere exposure Half sphere exposure Half Sphere Exposure (HSE) is a protein solvent exposure measure that was first introduced by . Like all solvent exposure measures it measures how buried amino acid residues are in a protein. It is found by counting the number of amino acid neighbors within two half spheres of chosen radius around the amino acid. The calculation of HSE is found by dividing a contact number (CN) sphere in two halves by the plane perpendicular to the Cβ-Cα vector. This simple division of the CN sphere results in two strikingly different measures, HSE-up and HSE-down. HSE-up is defined
Science On a Sphere runs on Linux. SOS was invented by Alexander E. MacDonald, the former director of the National Oceanographic and Atmospheric Administration (NOAA) Earth System Research Laboratory in Boulder, CO, and OAR Deputy Assistant Administrator for the NOAA Research Laboratories and Cooperative Institutes. MacDonald devised the original idea for Science On a Sphere in 1995 as part of other data visualization work he oversaw in what was the former NOAA Forecast Systems Laboratory. A small but highly motivated and inventive team of NOAA staff led by chief designer David Himes wrote the SOS software and developed the SOS hardware and system architecture.