Negotiation of entitlement in proposal sequences

Meetings are complex institutional events at which participants recurrently negotiate institutional roles, which are oriented to, renegotiated, and sometimes challenged. With a view to gaining further understanding of the ongoing negotiation of roles at meetings, this article examines one specific recurring feature of meetings: the act of proposing future action. Based on microanalysis of video recordings of two-party strategy meetings, the study shows that participants orient to at least two aspects when making proposals: 1) the acceptance or rejection of the proposal; and 2) questions of entitlement: who is entitled to launch a proposal, and who is entitled to accept or reject it? The study argues that there is a close interrelation between questions of entitlement, aligning and affiliating moves, and the negotiation of institutional roles. The multimodal analysis also reveals the use of various embodied practices by participants for the local negotiation of entitlement and institutional roles

Lipopolysaccharide Is a Potent Monocyte/Macrophage-specific Stimulator of Human Immunodeficiency Virus Type 1 Expression

Lipopolysaccharide (LPS) potently stimulates human immunodeficiency virus type 1-long terminal repeat (HIV-1-LTR) CAT constructs transfected into monocyte/macrophage-like cell lines but not a T cell line. This effect appears to be mediated through the induction of nuclear factor kappa B (NF-kappa B). Electrophoretic mobility shift assays demonstrate that LPS induces a DNA binding activity indistinguishable from NF-kappa B in U937 and THP-1 cells. LPS is also shown to dramatically increase HIV-1 production from a chronically infected monocyte/macrophage-like cloned cell line, U1, which produces very low levels of HIV-1 at baseline. The stimulation of viral production from this cell line occurs only if these cells are treated with granulocyte/macrophage colony-stimulating factor (GM-CSF) before treatment with LPS. This stimulation of HIV-1 production is correlated with an increase in the level of HIV-1 RNA and and activation of NF-kappa B. LPS is not able to induce HIV-1 production in a cloned T cell line. The effect of LPS on HIV-1 replication occurs at picogram per milliliter concentrations and may be clinically significant in understanding the variability of the natural history of HIV-1 infection

Switching between different vortex states in 2-dimensional easy-plane magnets due to an ac magnetic field

Using a discrete model of 2-dimensional easy-plane classical ferromagnets, we propose that a rotating magnetic field in the easy plane can switch a vortex from one polarization to the opposite one if the amplitude exceeds a threshold value, but the backward process does not occur. Such switches are indeed observed in computer simulations.Comment: 4 pages, 4 figures, submitted to Phys. Rev. Let

Transition between nuclear and quark-gluon descriptions of hadrons and light nuclei

We provide a perspective on studies aimed at observing the transition between hadronic and quark-gluonic descriptions of reactions involving light nuclei. We begin by summarizing the results for relatively simple reactions such as the pion form factor and the neutral pion transition form factor as well as that for the nucleon and end with exclusive photoreactions in our simplest nuclei. A particular focus will be on reactions involving the deuteron. It is noted that a firm understanding of these issues is essential for unraveling important structure information from processes such as deeply virtual Compton scattering as well as deeply virtual meson production. The connection to exotic phenomena such as color transparency will be discussed. A number of outstanding challenges will require new experiments at modern facilities on the horizon as well as further theoretical developments.Comment: 37 pages, 17 figures, submitted to Reports on Progress in Physic

Low Q^2 measurements of the proton form factor ratio mupGE/GMmu_p G_E / G_M

We present an updated extraction of the proton electromagnetic form factor ratio, mu_p G_E/G_M, at low Q^2. The form factors are sensitive to the spatial distribution of the proton, and precise measurements can be used to constrain models of the proton. An improved selection of the elastic events and reduced background contributions yielded a small systematic reduction in the ratio mu_p G_E/G_M compared to the original analysis.Comment: 12 pages, 5 figures, archival paper for proton form factor extraction from Jefferson Lab "LEDEX" experimen

Search for a new gauge boson in the A′A' Experiment (APEX)

We present a search at Jefferson Laboratory for new forces mediated by sub-GeV vector bosons with weak coupling $\alpha'$ to electrons. Such a particle $A'$ can be produced in electron-nucleus fixed-target scattering and then decay to an $e^+e^-$ pair, producing a narrow resonance in the QED trident spectrum. Using APEX test run data, we searched in the mass range 175--250 MeV, found no evidence for an $A'\to e^+e^-$ reaction, and set an upper limit of $\alpha'/\alpha \simeq 10^{-6}$. Our findings demonstrate that fixed-target searches can explore a new, wide, and important range of masses and couplings for sub-GeV forces.Comment: 5 pages, 5 figures, references adde