48 research outputs found

    Ion-Abrasion Scanning Electron Microscopy Reveals Surface-Connected Tubular Conduits in HIV-Infected Macrophages

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    HIV-1-containing internal compartments are readily detected in images of thin sections from infected cells using conventional transmission electron microscopy, but the origin, connectivity, and 3D distribution of these compartments has remained controversial. Here, we report the 3D distribution of viruses in HIV-1-infected primary human macrophages using cryo-electron tomography and ion-abrasion scanning electron microscopy (IA-SEM), a recently developed approach for nanoscale 3D imaging of whole cells. Using IA-SEM, we show the presence of an extensive network of HIV-1-containing tubular compartments in infected macrophages, with diameters of ∼150–200 nm, and lengths of up to ∼5 µm that extend to the cell surface from vesicular compartments that contain assembling HIV-1 virions. These types of surface-connected tubular compartments are not observed in T cells infected with the 29/31 KE Gag-matrix mutant where the virus is targeted to multi-vesicular bodies and released into the extracellular medium. IA-SEM imaging also allows visualization of large sheet-like structures that extend outward from the surfaces of macrophages, which may bend and fold back to allow continual creation of viral compartments and virion-lined channels. This potential mechanism for efficient virus trafficking between the cell surface and interior may represent a subversion of pre-existing vesicular machinery for antigen capture, processing, sequestration, and presentation

    Actors on High: The Skene Roof, the Crane, and the Gods in Attic Drama

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    Postprint of article "Actors on High: The Skene Roof, the Crane, and the Gods in Attic Drama" published in Classical Antiquity, volume 9, October 1990, pages 247-94, copyright 1990 by the Regents of the University of California.Discussion of the probable form of the roof as acting space in the fifth-century Theater of Dionysos in Athens, arguing for flat roof with no regular second story or superstructure above the one-story skene building; means of access to the roof by ladder or trapdoor or the theater crane; use of roof as acting space for human characters, gods, and ghosts; significance of spatial separation of human characters and divine characters and of the distinctiveness of divine locomotion. Appendix 1 lists uses of roof and crane and testimonia about the crane. Appendix 2 argues that crane had the form of a pivoted counterweighted beam (or shadouf) and offers speculation about its dimensions and operations

    Notes on Some Manuscripts of Euripides’ <i>Phoenissae</i>

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    Text and Transmission

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