The Role of the PD-1 Immunoreceptor in Pregnancy

During pregnancy, the maternal immune system must be carefully modulated as the fetus is immunologically foreign to her leukocytes. We propose that the CD28 family immune receptor, PD-1, functions during pregnancy to control maternal immune reactions. PD-1 is expressed on T lymphocytes and following interaction with its ligand, B7-H1, prevents T cell activation. B7-H1 is expressed in the human placenta throughout gestation, therefore we studied the role of the PD-1 receptor in modulating maternal T cells during pregnancy. PD-1 is preferentially expressed on human decidual T cells and B7-H1 inhibits the inflammatory cytokine production of activated decidual T lymphocytes. In addition, possibly through B7-H1:PD-1 interactions, trophoblasts induce regulatory T cell expansion in vitro. Finally, in murine pregnancy, PD-1 controls the accumulation of paternal antigen-specific T cells in the uterus-draining lymph nodes. Overall, these studies suggest that the PD-1:B7-H1 pathway functions to help maintain maternal-fetal tolerance

Crystal effects in the Neutralization of He+ ions in the low energy ion scattering regime

4 pages.-- PACS nrs.: 34.35.+a, 68.47.De, 68.49.Sf, 79.20.Rf.Investigating possible crystal effects in ion scattering from elemental surfaces, measurements of the positive ion fraction P+ are reported for He+ ions scattered from single and polycrystalline Cu surfaces. In the Auger neutralization regime, the ion yield is determined by scattering from the outermost atomic layer. For Cu(110) P+ exceeds that for polycrystalline Cu by up to a factor of 2.5, thus exhibiting a strong crystal effect. It is much less pronounced at higher energies, i.e., in the reionization regime. However, there a completely different angular dependence of the ion yield is observed for poly- and single crystals, due to massive subsurface contributions in nonchanneling directions.This work was partially supported by the Austrian Science Fund FWF, project number P16469.Peer reviewe

Crystal effects in the Neutralization of He+ ions in the low energy ion scattering regime

4 pages.-- PACS nrs.: 34.35.+a, 68.47.De, 68.49.Sf, 79.20.Rf.Investigating possible crystal effects in ion scattering from elemental surfaces, measurements of the positive ion fraction P+ are reported for He+ ions scattered from single and polycrystalline Cu surfaces. In the Auger neutralization regime, the ion yield is determined by scattering from the outermost atomic layer. For Cu(110) P+ exceeds that for polycrystalline Cu by up to a factor of 2.5, thus exhibiting a strong crystal effect. It is much less pronounced at higher energies, i.e., in the reionization regime. However, there a completely different angular dependence of the ion yield is observed for poly- and single crystals, due to massive subsurface contributions in nonchanneling directions.This work was partially supported by the Austrian Science Fund FWF, project number P16469.Peer reviewe

Electron spin polarization in field emission from nickel: effects of surface adsorbates

Müller N. Electron spin polarization in field emission from nickel: effects of surface adsorbates. Physics Letters, A. 1975;54(5):415-416.Spin polarization of electrons field emitted from certain faces of more or less clean nickel is observed. The preferential spin direction is proved to depend on the crystal direction and on the adsorbate contamination of the face

The History Of Lutheran Elementary Education In Catawba County

The history of schools is sometimes viewed with an air of lightness. The purpose of this study was to assemble the historical data of the Lutheran elementary schools of Catawba County. It was hoped that this study would reveal the role of the schools in the life of the local church and community

Time-resolved measurements of hydrogen and deuterium fluxes in the ASDEX plasma boundary

Hydrogen and deuterium fluxes parallel to the toroidal magnetic field were measured in the plasma boundary of ASDEX using graphite collector probes. Time resolution of the order of 100 ms can be obtained by rotating the cylindrical probes behind an aperture during the discharge. The trapped amount of hydrogen was determined by subsequent thermal desorption; in the analyses of deuterium the D(/sup 3/He,p)/sup 4/He nuclear reaction was used. Both methods yield quantitative results. Measurements were done for limiter and divertor discharges in the range of 4 to 20 cm outside the limiter or separatrix. The time distributions show a maximum flux at the beginning and the end of the discharge. The relatively lower flux during the plateau phase of the discharge is in the range 10/sup 15/ to 2 x 10/sup 17/ cm/sup -2/ sec/sup -1/, depending on the radial probe position; the maximum values are higher by a factor of 5 to 50. During neutral hydrogen injection, an additional maximum can be observed. The radial l/e-decay length is about 0.9 cm in front and 0.4 cm behind the fixed limiter. The results are compared with independent measurements in ASDEX and other plasma machines