Charge-Symmetry Violation in Pion Scattering from Three-Body Nuclei

We discuss the experimental and theoretical status of charge-symmetry violation (CSV) in the elastic scattering of pi+ and pi- on 3H and 3He. Analysis of the experimental data for the ratios r1, r2, and R at Tpi = 142, 180, 220, and 256 MeV provides evidence for the presence of CSV. We describe pion scattering from the three-nucleon system in terms of single- and double-scattering amplitudes. External and internal Coulomb interactions as well as the Delta-mass splitting are taken into account as sources of CSV. Reasonable agreement between our theoretical calculations and the experimental data is obtained for Tpi = 180, 220, and 256 MeV. For these energies, it is found that the Delta-mass splitting and the internal Coulomb interaction are the most important contributions for CSV in the three-nucleon system. The CSV effects are rather sensitive to the choice of pion-nuclear scattering mechanisms, but at the same time, our theoretical predictions are much less sensitive to the choice of the nuclear wave function. It is found, however, that data for r2 and R at Tpi = 142 MeV do not agree with the predictions of our model, which may indicate that there are additional mechanisms for CSV which are important only at lower energies.Comment: 26 pages of RevTeX, 16 postscript figure

Linking Distributive and Procedural Justice to Employee Engagement Through Social Exchange: A Field Study in India

Research linking justice perceptions to employee outcomes has referred to social exchange as its central theoretical premise. We tested a conceptual model linking distributive and procedural justice to employee engagement through social exchange mediators, namely, perceived organizational support and psychological contract, among 238 managers and executives from manufacturing and service sector firms in India. Findings suggest that perceived organizational support mediated the relationship between distributive justice and employee engagement, and both perceived organizational support and psychological contract mediated the relationship between procedural justice and employee engagement. Theoretical and practical implications with respect to organizational functions are discussed

Partial purification and characterization of the N-acetylglucosaminyl-phosphatidylinositol De-N-acetylase of glycosylphosphatidylinositol anchor biosynthesis in African trypanosomes

N-Acetylglucosaminylphosphatidylinositol (GlcNAc-PI) de-JV-acetylase was solubilized from the bloodstream form of African trypanosomes using Zwittergent 3-14. The solubilized GlcNAc-PI de-JV-acetylase was assayed using radiolabeled GlcNAc-PI substrates. The enzyme was partially purified about 140-fold from washed trypanosome membranes using conventional liquid chromatography. The enzyme has a Km of 1.5 UM. Replacement of the di-O-substituted D-myo-inositol of the natural GlcNAc-PI substrate by the L-myo-inositol isomer did not significantly alter the ability of the compound to act as a substrate for the de-N-acetylase, suggesting that the C-2 to C-5 hydroxyl groups of the myoinositol ring do not play a critical role in substrate recognition. A substrate analogue lacking fatty acids was a relatively poor substrate for the enzyme, indicating that the lipid component plays an important role in substrate recognition and/or presentation of the substrate to the enzyme in detergent micelles. Substrate analogues lacking the glycerophosphate component were not recognized by the enzyme, suggesting that this component is important in the substrate recognition process

The 14-C(p,n) Reaction and the Interaction Strength Ratio IJ,/ J~

This work was supported by the National Science Foundation Grant NSF PHY 81-14339 and by Indiana Universit