30,455 research outputs found

    School-Community Linkages:Success Factors of Conservation Clubs in Tanzania

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    Finite dimensional approximations to Wiener measure and path integral formulas on manifolds

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    Certain natural geometric approximation schemes are developed for Wiener measure on a compact Riemannian manifold. These approximations closely mimic the informal path integral formulas used in the physics literature for representing the heat semi-group on Riemannian manifolds. The path space is approximated by finite dimensional manifolds consisting of piecewise geodesic paths adapted to partitions PP of [0,1][0,1]. The finite dimensional manifolds of piecewise geodesics carry both an H1H^{1} and a L2L^{2} type Riemannian structures GPiG^i_P. It is proved that as the mesh of the partition tends to 00, 1/ZPie1/2E(σ)VolGPi(σ)ρi(σ)ν(σ) 1/Z_P^i e^{- 1/2 E(\sigma)} Vol_{G^i_P}(\sigma) \to \rho_i(\sigma)\nu(\sigma) where E(σ)E(\sigma ) is the energy of the piecewise geodesic path σ\sigma, and for i=0i=0 and 11, ZPiZ_P^i is a ``normalization'' constant, VolGPiVol_{G^i_P} is the Riemannian volume form relative GPiG^i_P, and ν\nu is Wiener measure on paths on MM. Here ρ1=1\rho_1 = 1 and ρ0(σ)=exp(1/601Scal(σ(s))ds) \rho_0 (\sigma) = \exp( -1/6 \int_0^1 Scal(\sigma(s))ds ) where ScalScal is the scalar curvature of MM. These results are also shown to imply the well know integration by parts formula for the Wiener measure.Comment: 48 pages, latex2e using amsart and amssym

    Charmed scalar resonances -- Conventional and four-quark mesons

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    We propose that there coexist two scalar mesons of different structures (a conventional meson and a four-quark meson) in the recently observed broad bumps just below the large peak of the tensor meson in the D-pi mass distribution. We base this proposal on the interpretation of the charm-strange scalar meson of mass 2317 MeV as a four-quark meson. The strange counterparts of these scalar mesons are also studied.Comment: 4 pages, 0 figures, Revte

    Distribution of enzymes cleaving pyridine nucleotides in animal tissues

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    A number of enzymes capable of splitting the pyridine nucleotides have been found in animal tissues. A portion of the DPNase (1) that hydrolyzes the nicotinamide ribose bond of DPN and TPN was reported in the microsomes of rat liver (1). The DPN pyrophosphorylase, first described by Kornberg (2), has been found by Hogeboom and Schneider to be largely localized in the nucleus (3). In previous investigations (4) an enzyme from pigeon liver which splits DPNH and not DPN at the pyrophosphate linkage was described. The present communication deals with the intracellular distribution of enzymes from various species that attack the pyridine coenzymes at the pyrophosphate linkage. The distribution and properties of DPNases from different species and tissues will also be presented
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