Equilibrium density gradient ultracentrifugation: A simple computer program for routine DNA analysis

1969 ◽  
Vol 130 ◽  
pp. 685-687 ◽  
Author(s):  
Francis Quétier ◽  
Etienne Guillé ◽  
Lise Lejus
Keyword(s):  
Computer Program ◽  
Density Gradient ◽  
Dna Analysis ◽  
Equilibrium Density ◽  
Density Gradient Ultracentrifugation ◽  
Simple Computer ◽  
Simple Computer Program

scholarly journals The macromolecular properties of blood-group-specific glycoproteins. Characterization of a series of fractions obtained by density-gradient ultracentrifugation

1974 ◽  
Vol 143 (3) ◽  
pp. 669-679 ◽  
Author(s):  
K. Ramakrishnan Bhaskar ◽  
J. Michael Creeth
Keyword(s):  
Density Gradient ◽  
Blood Group ◽  
Buoyant Density ◽  
Physicochemical Characterization ◽  
Cyst Fluid ◽  
Equilibrium Density ◽  
Density Gradient Ultracentrifugation ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Blood Group Substances

1. Equilibrium density-gradient ultracentrifugation in caesium salts was used in two stages in the isolation and subfractionation of the glycoprotein component from a human ovarian-cyst fluid. The eight main subfractions thus obtained were the subject of detailed physicochemical characterization. 2. The fractions were unimodal in buoyant-density distribution, but had discrete ρ0 values ranging from 1.31 to 1.35. 3. Weight-average molecular weights and sedimentation coefficients decreased regularly with decreasing density of the fraction, whereas the partial specific volumes and selective solvation parameters increased. The latter behaviour correlates well with the increasing peptide content of the lighter fractions. 4. The fractions exhibited a range of analytical composition, although all were within the limits previously observed for blood-group substances of Lea specificity. All fractions had approximately equal Lea activity. The peptide content varied systematically from 7% for the densest fraction to 15% for the lightest, but the relative distributions of the amino acids remained essentially constant throughout the series. In particular, serine plus threonine plus proline made up about 50% of the peptide content of all the fractions. Fucose, galactose and N-acetylglucosamine contents decreased with increasing peptide content of the fractions, but N-acetylgalactosamine and sialic acid exhibited the opposite trend. Molar ratios of N-acetylgalactosamine to the sum of serine and threonine remained essentially constant at 0.8–0.9, implying a high degree of glycosylation of all the molecules, but the ratio of N-acetylglucosamine to N-acetylgalactosamine decreased steadily with increasing peptide content, suggesting the presence of oligosaccharide side chains of various lengths. The results are discussed in terms of the accepted structure of glycoprotein molecules. 5. Experiments on the glycoproteins extracted with phenol from the same cyst fluid have confirmed that equilibrium centrifugation in caesium salts does not remove any non-covalently bound protein nor cause any changes in the tertiary structures of these glycoprotein molecules.

A New Approach for Curvatures of Conjugate Surfaces

1996 ◽  
Author(s):  
Ningxin Chen
Keyword(s):  
Computer Program ◽  
Local System ◽  
New Approach ◽  
Simple Computer ◽  
Numerical Example ◽  
Surface System ◽  
Principal Directions ◽  
Conjugate Surfaces ◽  
Global Surface ◽  
Simple Computer Program

Abstract A new and general approach for curvatures of conjugate surfaces is provided in this paper. The main characteristic of the approach is that relative curvatures and geodesic torsions of the conjugate surfaces are directly calculated in terms of the normal curvatures and geodesic torsions of the generating surface on two non-orthogonal tangents of surface curvilinears in global surface system. In comparison with the current approaches that use two orthogonal tangents or the principal directions in local system at each calculating point, the approach developed in this paper has a simple calculating process and a simple computer program. Based on the curvature equations, sliding velocities and sliding ratios of the conjugate surfaces are studied. The approach is illustrated by a numerical example of a plane enveloping globoidal wormgear drive.

Computer Implementation of an Improved Kutzbach-Gru¨bler Mobility Criterion

2002 ◽  
Author(s):  
Daniel Aguilera ◽  
Jose´ Mari´a Rico ◽  
Jaime Gallardo
Keyword(s):  
Group Theory ◽  
Computer Program ◽  
Lie Algebra ◽  
Computer Implementation ◽  
Euclidean Group ◽  
Important Advance ◽  
Simple Computer ◽  
Number Synthesis ◽  
Simple Computer Program ◽  
Vector Subspaces

Recent results have shown that the application of group theory to the Euclidean group, E(3), and its subgroups yields a new and improved mobility criterion. Unlike the well known Kutzbach-Gru¨bler criterion, this improved mobility criterion yields correct results for both trivial and exceptional linkages. Unfortunately, this improved mobility criterion requires a little bit more than counting links and kinematic pairs. An important advance was made when it was proved that the improved mobility criterion, originally stated in a language of group theory and subsets and subgroups of the Euclidean group, E(3), can be translated into a language of the Lie algebra, e(3), of the Euclidean group, E(3), and its vector subspaces and its subalgebras. The language of the Lie algebra, e(3), is far simpler than the nonlinear language of the Euclidean group, E(3). Still, the computations required for the improved mobility criterion are more involved than those required for the Kutzbach-Gru¨bler criterion, and it might preclude the employment of the improved mobility criterion in prospective tasks such as the number synthesis of parallel and modular manipulators. This contribution dispels these doubts by showing that the improved criterion can be easily implemented by a simple computer program. Several examples are included.

Duplicates or Singletons?—An Analysis of the Need for Replication in Immunoassay and a Computer Program to Calculate the Distribution of Outliers, Error Rate and the Precision Profile from Assay Duplicates

1989 ◽  
Vol 26 (1) ◽  
pp. 26-37 ◽  
Author(s):  
P R Raggatt
Keyword(s):  
Computer Program ◽  
Error Rate ◽  
Sequential Analysis ◽  
Thyroid Stimulating Hormone ◽  
Rational Decision ◽  
Simple Computer ◽  
Immunometric Assay ◽  
Nature Frequency ◽  
Enzyme Amplification ◽  
Simple Computer Program

The nature, frequency, statistics and methods of detection of both Gaussian and catastrophic errors in immunoassay are described. The method of sequential analysis is applied to the rates of catastrophic errors and is used to calculate the number of results which must be examined in order to achieve a stated confidence that the error rate is acceptable so that a rational decision on use of duplicate or singleton assay can be made. A simple computer program is described, which allows computation of the precision profile and an analysis of errors using accumulated data from duplicate assays. These methods have been applied to an enzyme amplification immunometric assay for thyroid-stimulating hormone (TSH) and an analysis is made of the errors detected in a sample of 1419 patient results.

A Simple Computer Program for the H2+ Calculation

1974 ◽  
Vol 42 (7) ◽  
pp. 612-613 ◽  
Author(s):  
Eduardo A. Castro ◽  
Carlos Ferro ◽  
Valentín Amorebieta
Keyword(s):  
Computer Program ◽  
Simple Computer ◽  
Simple Computer Program
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