A Precise Measurement of the Weak Mixing Angle in Neutrino-Nucleon Scattering

We report a precise measurement of the weak mixing angle from the ratio of neutral current to charged current inclusive cross-sections in deep-inelastic neutrino-nucleon scattering. The data were gathered at the CCFR neutrino detector in the Fermilab quadrupole-triplet neutrino beam, with neutrino energies up to 600 GeV. Using the on-shell definition, ${\rm sin ^2\theta_W} \equiv 1 - \frac{{\rm M_W} ^2}{{\rm M_Z} ^2}$, we obtain ${\rm sin ^2\theta_W} = 0.2218 \pm 0.0025 ({\rm stat.}) \pm 0.0036 ({\rm exp.\: syst.}) \pm 0.0040 ({\rm model})$.Comment: 10 pages, Nevis Preprint #1498 (Submitted to Phys. Rev. Lett.

β3 integrins regulate lymphocyte migration and cytokine responses in heart transplant rejection

Integrin \u3b1v\u3b23 is important for cell survival, signaling and migration, particularly during angiogenesis and tumorigenesis, where it has been proposed as a therapeutic target. \u3b1v\u3b23 is up-regulated following transplantation and \u3b23 polymorphisms are associated with increased acute kidney rejection, suggesting that \u3b1v\u3b23 may also play a role in transplant rejection. Here, using a model of allogeneic heart transplantation, we show that allograft survival is prolonged in \u3b23 integrin-deficient (\u3b23-/-) mice. This is associated with Th2-type immune responses and reduced T-cell infiltration into grafts and T cells from \u3b23-/- mice show impaired adhesion and migration, consistent with a role for \u3b1v\u3b23 in transmigration. These studies provide evidence that targeting \u3b23 integrins impairs recruitment of effector cells and alters cytokine production, so prolonging graft survival. We also show that low doses of blocking antibodies against leukocyte function associated antigen-1 (LFA-1)/\u3b1L\u3b22 and very late antigen-4 (VLA-4)/\u3b14\u3b21, when combined with deletion of \u3b23, lead to long-term survival of allografts with no evidence of chronic rejection. Hence we provide strong mechanistic evidence supporting previous genetic studies, demonstrate the involvement of \u3b23 integrins in both acute and chronic rejection and identify \u3b23 as a new target for immunosuppressive therapy