In Part 1 of the experiment, rats responded under a variable-interval (VI) 30-s schedule and a VI 120-s schedule, with each in effect for a block of consecutive sessions. That is, the two VI schedules were presented in successive conditions. In Part 2 the VI schedules alternated each day, and in Part 3 the schedules alternated within the session as a multiple schedule. For half of the rats in P...

We present Far Ultraviolet Spectroscopic Explorer observations of the magnetic cataclysmic variable V405 Aurigae. Together with four other DQ Her type binaries, V405 Aur forms a small subclass of intermediate polars which are likely to evolve into low magnetic field strength polars, similar to AM Her. Our coadded FUSE spectrum exhibits broad O VI and C III emission-lines as well as a narrow O V...

Collagen VI is an extracellular matrix protein with broad distribution in several tissues. Although Col6a1 is expressed by Schwann cells, the role of collagen VI in the peripheral nervous system (PNS) is yet unknown. Here we show that Schwann cells, but not axons, contribute to collagen VI deposition in peripheral nerves. By using Col6a1-null mice, in which collagen VI deposition is compromised...

We investigate in this paper a simple intramolecular model for gene assembly in ciliates. Unlike the general intramolecular model, the folds that a micronuclear chromosome may form to assemble the genes is very restricted (minimal) here: between any two pointers there may be at most one coding block. It has been known that the general model is universal, being able to assemble any gene pattern ...

Order the vertices of a directed random graph v1, . . . , vn; edge (vi, vj) for i < j exists independently with probability p. This random graph model is related to certain spreading processes on networks. We consider the component reachable from v1 and prove existence of a sharp threshold p∗ = logn/n at which this reachable component transitions from o(n) to Ω(n).

Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation ex...

After observers see an object or pattern, their visual memory of what they have seen decays slowly over time. Nearly all current theories of vision assume that decay of short-term memory occurs because visual representations are progressively and randomly corrupted as time passes. We tested this assumption using psychophysical noise-masking methods, and we found that visual memory decays in a c...

This paper presents three curious findings about deterministic public-key encryption (D-PKE) that further our understanding of its security, in particular because of the contrast with standard, randomized public-key encryption (R-PKE): • It would appear to be a triviality, for any primitive, that security in the standard model implies security in the random-oracle model, and it is certainly tru...