Infinite Groups
Mostrando 25-35 de 35 artigos, teses e dissertações.
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25. Compact negatively curved manifolds (of dim [unk] 3,4) are topologically rigid
Let M be a complete (connected) Riemannian manifold having finite volume and whose sectional curvatures lie in the interval [c1, c2] with -∞ < c1[unk]c2 < 0. Then any proper homotopy equivalence h:N → M from a topological manifold N is properly homotopic to a homeomorphism, provided the dimension of M is >5. In particular, if M and N are both compact (co
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26. Vertex algebras, Kac-Moody algebras, and the Monster
It is known that the adjoint representation of any Kac-Moody algebra A can be identified with a subquotient of a certain Fock space representation constructed from the root lattice of A. I define a product on the whole of the Fock space that restricts to the Lie algebra product on this subquotient. This product (together with a infinite number of other produ
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27. Short-term absence from industry: III The inference of `proneness' and a search for causes
Froggatt, P. (1970).Brit. J. industr. Med.,27, 297-312. Short-term absence from industry. III. The inference of `proneness' and a search for causes. The abilities of five hypotheses (`chance', `proneness', and three of `true contagion' - as defined in the text) to explain the distributions of one-day and two-day absences among groups of male and female indus
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28. A molecular dynamics simulation study of oriented DNA with polyamine and sodium counterions: diffusion and averaged binding of water and cations
Four different molecular dynamics (MD) simulations have been performed for ordered DNA decamers, d(5′-ATGCAGTCAG)·d(5′-TGACTGCATC). The counterions were the two natural polyamines spermidine3+ (Spd3+) and putrescine2+ (Put2+), the synthetic polyamine diaminopropane2+ (DAP2+) and Na+. The simulation set-up corresponds to an infinite array of parallel DNA
Oxford University Press.
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29. Double helix conformation, groove dimensions and ligand binding potential of a G/C stretch in B-DNA.
The self-complementary DNA fragment CCGGCGCCGG crystallizes in the rhombohedral space group R3 with unit cell parameters a = 54.07 A and c = 44.59 A. The structure has been determined by X-ray diffraction methods at 2.2 A resolution and refined to an R value of 16.7%. In the crystal, the decamer forms B-DNA double helices with characteristic groove dimension
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30. Infinite pleated β-sheet formed by the β-hairpin Boc-β-Phe-β-Phe-d-Pro-Gly-β-Phe-β-Phe-OMe
A β-hairpin conformation and extended β-pleated sheet assembly have been characterized by single crystal x-ray diffraction for the synthetic peptide t-butoxycarbonyl—β-Phe-β-Phe-d-Pro-Gly-β-Phe-β-Phe-methyl ester [β-Phe: (S)-β3 homophenylalanine]. The centrally located d-Pro-Gly segment nucleates a chain reversal in a type II′ β-turn conformatio
National Academy of Sciences.
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31. Conformation for a beta-cyclodextrin monosubstituted with a cyclic dipeptide.
The structural characterization of a beta-cyclodextrin monosubstituted with the peptide cyclo(L-His-L-Leu) is reported. This work provides an x-ray example of a covalently bound group that folds in such a way that the terminal apolar side chain is retained in the hydrophobic interior of the cone-shaped cyclodextrin cavity. 6-Deoxy-6-cyclo(L-histidyl-L-leucyl
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32. Crystal structure of an RNA octamer duplex r(CCCIUGGG)2 incorporating tandem I.U wobbles.
The crystal structure of the RNA octamer duplex r(CCCIUGGG)2has been elucidated at 2.5 A resolution. The crystals belong to the space group P21and have unit cell constants a = 33.44 A, b = 43.41 A, c = 49.39 A and beta = 104.7 degrees with three independent duplexes (duplexes 1-3) in the asymmetric unit. The structure was solved by the molecular replacement
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33. Crystal structure of an RNA duplex r(G GCGC CC)2 with non-adjacent G*U base pairs.
The crystal structure of a self-complementary RNA duplex r(GGGCGCUCC)2with non-adjacent G*U and U*G wobble pairs separated by four Watson-Crick base pairs has been determined to 2.5 A resolution. Crystals belong to the space group R3; a = 33.09 A,alpha = 87.30 degrees with a pseudodyad related duplex in the asymmetric unit. The structure was refined to a fin
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34. Vntr Allele Frequency Distributions under the Stepwise Mutation Model: A Computer Simulation Approach
Variable numbers of tandem repeats (VNTRs) are a class of highly informative and widely dispersed genetic markers. Despite their wide application in biological science, little is known about their mutational mechanisms or population dynamics. The objective of this work was to investigate four summary measures of VNTR allele frequency distributions: number of
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35. The redox properties of cytochromes b imposed by the membrane electrostatic environment.
The effect of the dipole potential field of extended membrane spanning alpha-helices on the redox potentials of b cytochromes in energy transducing membranes has been calculated in the context of a three phase model for the membrane. In this model, the membrane contains three dielectric layers; (i) a 40-A hydrophobic membrane bilayer, with dielectric constan