Requirement for the coexpression of T3 and the T cell antigen receptor on a malignant human T cell line.

The association between T3 and the T cell antigen receptor was examined using the T3 bearing T cell leukemic line Jurkat. A monoclonal antibody, C305, was produced, which reacted with idiotypic-like determinants expressed on Jurkat. The molecule with which this antibody reacted was a disulfide-linked heterodimer of 90 kD, composed of polypeptides of 42 and 54 kD. Thus, C305 reacted with a molecule with characteristics of the putative T cell antigen receptor described by others. A series of mutants of Jurkat, induced with ethyl methane sulfonate or radiation, was selected for T3 or antigen receptor negativity. In every instance, there was a concomitant loss of both T3 and the antigen receptor as assessed by quantitative absorption, indirect immunofluorescence, and antibody plus complement-mediated cytotoxicity. The absence of antigen receptor molecules was confirmed on diagonal gels, excluding the possibility that conformational changes of the antigen receptor on such T3-negative mutants were responsible for the failure of such mutants to react with C305. Moreover, in a mutant that expressed a marked decrease in the level of T3 expression, there was a comparable decrease in the expression of antigen receptor determinants. These results suggest that there is an obligate requirement for the coexpression of T3 and the T cell antigen receptor. Furthermore, attempts to activate such mutants with the lectin phytohemagglutinin suggested that the expression of T3 and/or the antigen receptor was required for activation of these cells

Resonant-state expansion for open optical systems: Generalization to magnetic, chiral, and bi-anisotropic materials

The resonant-state expansion, a recently developed powerful method in electrodynamics, is generalized here for open optical systems containing magnetic, chiral, or bi-anisotropic materials. It is shown that the key matrix eigenvalue equation of the method remains the same, but the matrix elements of the perturbation now contain variations of the permittivity, permeability, and bi-anisotropy tensors. A general normalization of resonant states in terms of the electric and magnetic fields is presented.Comment: 4 page

Low-luminosity Extragalactic Water Masers toward M82, M51, and NGC4051

Sub-arcsecond observations using the Very Large Array (VLA) are presented for low-luminosity water maser in M82, M51, and NGC4051. New maser features have been detected within the M82 starburst complex. They are largely associated with star-forming activity, such as optically identified starburst-driven winds, H II regions, or the early phase of star formation in the galaxy. The water maser in M51 consists of blueshifted and redshifted features relative to thesystemic velocity of the galaxy. The redshifted features are measured to the northwest of the nuclear radio source, while the location of the blueshifted counterpart is displaced by about 2" from the radio source. A small velocity gradient closely aligned with the radio jet is detected from the redshifted features. The redshifted maser most likely amplifies the background radio continuum jet, while the blueshifted counterpart marks off-nuclear star formation in the galaxy. All of the detected maser features in the narrow-line Seyfert 1 galaxy NGC 4051 remain unresolved by new VLA observations. Due to the low luminosity of the maser, the maser excitation is not directly related to the active galactic nucleus.Comment: 20 pages, 10 figures. Accepted for publication in AJ (17/Oct/2006

Testing Higher-Order Lagrangian Perturbation Theory Against Numerical Simulations - 1. Pancake Models

We present results showing an improvement of the accuracy of perturbation theory as applied to cosmological structure formation for a useful range of quasilinear scales. The Lagrangian theory of gravitational instability of an Einstein-de Sitter dust cosmogony investigated and solved up to the third order in the series of papers by Buchert (1989, 1992, 1993a), Buchert \& Ehlers (1993), Buchert (1993b), Ehlers \& Buchert (1993), is compared with numerical simulations. In this paper we study the dynamics of pancake models as a first step. In previous work (Coles \etal 1993, Melott \etal 1993, Melott 1993) the accuracy of several analytical approximations for the modeling of large-scale structure in the mildly non-linear regime was analyzed in the same way, allowing for direct comparison of the accuracy of various approximations. In particular, the ``Zel'dovich approximation'' (Zel'dovich 1970, 1973, hereafter ZA) as a subclass of the first-order Lagrangian perturbation solutions was found to provide an excellent approximation to the density field in the mildly non-linear regime (i.e. up to a linear r.m.s. density contrast of $\sigma \approx 2$). The performance of ZA in hierarchical clustering models can be greatly improved by truncating the initial power spectrum (smoothing the initial data). We here explore whether this approximation can be further improved with higher-order corrections in the displacement mapping from homogeneity. We study a single pancake model (truncated power-spectrum with power-index $n=-1$) using cross-correlation statistics employed inComment: TeX, 18 pages excl.figures; contact [email protected] ; [email protected] . submitted to Astron. & Astrophy

Nuclear physics with a medium-energy Electron-Ion Collider

A polarized ep/eA collider (Electron-Ion Collider, or EIC) with variable center-of-mass energy sqrt(s) ~ 20-70 GeV and a luminosity ~ 10^{34} cm^{-2} s^{-1} would be uniquely suited to address several outstanding questions of Quantum Chromodynamics (QCD) and the microscopic structure of hadrons and nuclei: (i) the three-dimensional structure of the nucleon in QCD (sea quark and gluon spatial distributions, orbital motion, polarization, correlations); (ii) the fundamental color fields in nuclei (nuclear parton densities, shadowing, coherence effects, color transparency); (iii) the conversion of color charge to hadrons (fragmentation, parton propagation through matter, in-medium jets). We briefly review the conceptual aspects of these questions and the measurements that would address them, emphasizing the qualitatively new information that could be obtained with the collider. Such a medium-energy EIC could be realized at Jefferson Lab after the 12 GeV Upgrade (MEIC), or at Brookhaven National Lab as the low-energy stage of eRHIC.Comment: 9 pages, 5 figures. Mini-review compiled in preparation for the MEIC Conceptual Design Report, Jefferson Lab (2011