We report a 61-year-old man with multiple colored skin papules with central crusts in an archiform and linear pattern on his forehead as well as verrucus and hyperkeratotic plaques with central perforation on hands. Histologic examination of the lesions demonstrated a narrow channel of epidermal perforation containing notrophils, basophilic debris and elastic fibers with eosinophilic degenerati...

Today’s computer systems are large and complex. Œere have been tremendous research e‚orts to fully defend these systems, but it is still an elusive goal. Introducing radical design changes for security is not practical, or adding a small security enhancing component easily breaks the critical functionality of a system. Even if these issues are resolved, aŠackers are ever evolving, and they alwa...

As the standard method for solving systems of linear equations, Gaussian elimination (GE) is one of the most important and ubiquitous numerical algorithms. However, its successful use relies on understanding its numerical stability properties and how to organize its computations for efficient execution on modern computers. We give an overview of GE, ranging from theory to computation. We explai...

This paper presents some of our requirements for a Z type-checker: that the typechecker accept all well-typeable formulations, however contrived; that it gather information about uses of declarations as needed to support interactive browsing and formal reasoning; that it t the description given by draft standard Z; and that it be able to check some particular extensions to Z that are intended t...

Let B ∈Mn(C) be a row diagonally dominant matrix, i.e., σi|bii| = n ∑ j=1 j 6=i |bij |, i = 1, . . . , n, where 0 ≤ σi < 1, i = 1, . . . , n, with σ = max1≤i≤n σi. We show that no pivoting is necessary when Gaussian elimination is applied to A = B−1. Moreover, the growth factor for A does not exceed 1 + σ. The same results are true with row diagonal dominance being replaced by column diagonal d...

Quantifier elimination (QE) is a very powerful procedure for problems involving first­order formulas over real fields. The cylindrical algebraic decomposition (CAD) is a technique for the “efficient” im­ plementation of QE, that effectively reduces an seemingly infinite problem into a finite (but potentially large) instance. For much more information about QE and CAD (including a reprint of Tar...

The oligonucleotide [5'-32P]pdT8d(-)dT., containing an apurinic/apyrimidinic (AP) site [d(-)], yields three radioactive products when incubated at alkaline pH: two of them, forming a doublet approximately at the level of pdT8dA when analysed by polyacrylamide-gel electrophoresis, are the result of the f-elimination reaction, whereas the third is pdT8p resulting from ,8-elimination. The incubati...

A systematic approach is described for analysis of evolutionarily conserved cis-regulatory DNA using cis-Decoder, a tool for discovery of conserved sequence elements that are shared between similarly regulated enhancers. Analysis of 2,086 conserved sequence blocks (CSBs), identified from 135 characterized enhancers, reveals most CSBs consist of shorter overlapping/adjacent elements that are eit...

1 Problem The interaction energy of an electric charge q and a " point " electric dipole with moment p of fixed magnitude, both at rest, is, in Gaussian units,