We mechanistically explored the effect of increased hydrophobicity of the polycation on the efficacy and specificity of gene delivery in mice. N-Alkylated linear PEIs with varying alkyl chain lengths and extent of substitution were synthesized and characterized by biophysical methods. Their in vivo transfection efficiency, specificity, and biodistribution were investigated. N-Ethylation improve...

ABSTRACT. A Diophantine m-tuple is a set A of m positive integers such that ab + 1 is a perfect square for every pair a, b of distinct elements of A. We derive an asymptotic formula for the number of Diophantine quadruples whose elements are bounded by x. In doing so, we extend two existing tools in ways that might be of independent interest. The Erdős-Turán inequality bounds the discrepancy be...

This article explores the political determinants of congressional investigatory activity. Using Mayhew’s list of high-profile probes updated through 2006, we developed five measures of the frequency and intensity of investigative oversight. Contra Mayhew, we found that divided government spurs congressional investigatory activity. A shift from unified to divided government yields a five-fold in...

We present circular polarization results from a 5 GHz survey of the parsec-scale polarization properties of 40 AGN made with the VLBA. We find 11 circular polarization detections at the 3σ level or higher. This nearly quadruples the number of sources detected in circular polarization at VLBI resolution. We find no correlation between fractional linear and circular polarization across our sample...

PP attachment has attracted considerable interest the last two decades. The standard set-up has been to extract quadruples of verbs, direct objects, prepositions and prepositional complements from the Wall Street Journal and classify them as either low or high attachments. State-of-the-art results almost equal human performance in the standard set-up. Recently, however, Atterer and Schütze (200...

The proliferation of portable electronic devices with high data-rate wireless communication capabilities and the increasing emphasis on energy efficiency is continuously applying pressure on the performance and power consumption of ADCs and other mixed-signal systems. Power scalable designs enable an ADC core to be reusable under different input and sampling frequency conditions improving syste...

Splicing systems are generative mechanisms introduced by Tom Head in 1987 to model the biological process of DNA recombination. The computational engine a splicing system is “splicing operation”, cut-and-paste binary string operation defined set rules”, quadruples [Formula: see text] where words over an alphabet text]. For two strings and text], applying rule produces In this paper we focus on ...

Delaunay triangulations of a point set in the Euclidean plane are ubiquitous in a number of computational sciences, including computational geometry. Delaunay triangulations are not well defined as soon as 4 or more points are concyclic but since it is not a generic situation, this difficulty is usually handled by using a (symbolic or explicit) perturbation. As an alternative, we propose to def...

Let F ∈ C[x, y, s, t] be an irreducible constant-degree polynomial, and let A,B,C,D ⊂ C be finite sets of size n. We show that F vanishes on at most O(n8/3) points of the Cartesian product A × B × C × D, unless F has a special group-related form. A similar statement holds for A,B,C,D of unequal sizes, with a suitably modified bound on the number of zeros. This is a fourdimensional extension of ...

We study the problem of ordinal embedding: given a set of ordinal constraints of the form distance(i, j) < distance(k, l) for some quadruples (i, j, k, l) of indices, the goal is to construct a point configuration x̂1, ..., x̂n in R that preserves these constraints as well as possible. Our first contribution is to suggest a simple new algorithm for this problem, Soft Ordinal Embedding. The key fe...