The eggshell serves as a depository for proteins that play an important role in early embryonic development. In particular, the Drosophila eggshell is responsible for transferring asymmetries from the egg chamber to specify the regions at both ends of the embryo through the uneven activation of the Torso (Tor) receptor in its membrane. This process relies on the restricted expression of the gen...

When lymphocytes obtained from persons or animals exhibiting delayed hypersensitivity are stimulated in vitro by specific antigen, they produce a number of soluble substances with various biologic activities including migration inhibitory factor (MIF) 1 and lymphocyte mitogenic factor (LMF) (1-4). Since delayed hypersensitivity reactions have been generally assumed to be mediated by thymus-depe...

This memo defines a portion of the Management Information Base (MIB) for use with network management protocols in TCP/IP-based internets. In particular, it defines objects for managing objects for SMDS access interfaces. This includes the following access protocols: SIP [13] SIP/DXI [18] and [20] SIP/FR [19] SIP/ATM [24] This memo replaces RFC 1304 [12], and defines a MIB module which is both c...

A strategy used by some pathogenic microorganisms for survival in their hosts is antigenic variation (1, 2). Borrelia hermsii, an etiologic agent o f relapsing fever, is a bacterium capable of manifesting 26 or more serotypes during the course of infection (3, 4). The spontaneous switching from one antigen type to another occurs at a rate estimated to be 10 -4 to 10 -~ per cell per generation (...