A theory of the kinetics of the absorption of calcium into bone based on a previously published theory of chromatographic kinetics has been developed by G. Weiss and collaborators. The model has been tested on a number of different normal populations, yielding results to be expected from general physiological principles. The model has been applied to patients with dermatomyositis being treated with steroids, showing that the drug-regimen impairs bone absorption to a considerable degree. Preliminary measurements have been made on different disease populations. These studies will be continued in the forthcoming year. J. Bryngelson has developed a theoretical basis for protein folding, based on statistical properties of conformational energies. The theory has been used to improve the performance of currently used protein structure prediction programs. A continuation of this project relates to the effects of water exclusion in the initial collapse phase in protein folding. It has been shown that hydrogen bonds are increasingly effective in determining secondary structure, as the protein collapses. A theory has been developed by G. Weiss to estimate the time for a gradient gel to separate peaks in electrophoresis, when diffusion effects are small but not negligible. This is combined with a concurrent measurement by M. Garner and A.Chrambach of boundary spreading as a function of the gel concentration.

Agency
National Institute of Health (NIH)
Institute
Center for Information Technology (CIT)
Type
Intramural Research (Z01)
Project #
1Z01CT000024-18
Application #
3752804
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
18
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Center for Information Technology
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Shvartsman, Stanislav Y; Coppey, Mathieu; Berezhkovskii, Alexander M (2008) Dynamics of maternal morphogen gradients in Drosophila. Curr Opin Genet Dev 18:342-7
Vazquez, Marco-Vinicio; Berezhkovskii, Alexander M; Dagdug, Leonardo (2008) Diffusion in linear porous media with periodic entropy barriers: A tube formed by contacting spheres. J Chem Phys 129:046101
Berezhkovskii, Alexander M; Bezrukov, Sergey M (2008) Fluctuation theorem for channel-facilitated membrane transport of interacting and noninteracting solutes. J Phys Chem B 112:6228-32
Berezhkovskii, Alexander M; Weiss, George H (2008) Propagators and related descriptors for non-Markovian asymmetric random walks with and without boundaries. J Chem Phys 128:044914
Berezhkovskii, Alexander M; Bezrukov, Sergey M (2008) Counting translocations of strongly repelling particles through single channels: fluctuation theorem for membrane transport. Phys Rev Lett 100:038104
Coppey, Mathieu; Boettiger, Alistair N; Berezhkovskii, Alexander M et al. (2008) Nuclear trapping shapes the terminal gradient in the Drosophila embryo. Curr Biol 18:915-9
Bezrukov, Sergey M; Berezhkovskii, Alexander M; Szabo, Attila (2007) Diffusion model of solute dynamics in a membrane channel: mapping onto the two-site model and optimizing the flux. J Chem Phys 127:115101
Dagdug, Leonardo; Berezhkovskii, Alexander M; Makhnovskii, Yurii A et al. (2007) Transient diffusion in a tube with dead ends. J Chem Phys 127:224712
Berezhkovskii, A M; Pustovoit, M A; Bezrukov, S M (2007) Diffusion in a tube of varying cross section: numerical study of reduction to effective one-dimensional description. J Chem Phys 126:134706
Berezhkovskii, A M; Barzykin, A V (2007) Simple formulas for the trapping rate by nonspherical absorber and capacitance of nonspherical conductor. J Chem Phys 126:106102

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