The analysis in the paper suggests that (i) if news sites were less vertically differentiated, segregation would increase considerably, and (ii) if users did not visit multiple sites, more users would have extremely high or low conservative exposure. To make these hypotheses more precise, we specify and estimate a simple model of Internet news demand, and use it to simulate segregation and cons...

A proximity drawing of a graph is one in which pairs of adjacent vertices are drawn relatively close together according to some proximity measure while pairs of non-adjacent vertices are drawn relatively far apart. The fundamental question concerning proximity drawability is: Given a graph G and a deenition of proximity, is it possible to construct a proximity drawing of G? We consider this que...

conclusion non-mass-like lesions, lesions with focal or segmental distribution, with a “plateau” enhancement curve type were the most frequent findings of dcis lesions on mri. background adequate diagnosis of ductal carcinoma in situ (dcis) could lead to efficacious treatment. due to the fact that dcis lesions can progress to invasive carcinomas and that the sensitivity of the standard examinat...

today, chronic viral hepatitis is considered as a public health problem in the world. totally, 5% of the world population, especially in asia and africa suffer from this problem. the prevalence of acute hepatitis in america is 0.1-0.2 percent, 50% of those with hepatitis c (hcv) and 5-10% of them with hepatitis b (hcv) develop chronic hepatitis. determining hbv and hcv genotypes is important to...

We investigate n-vertex graphs in which Pr(degree(v) = d) = c/d for appropriate constant c, that is, the degree sequence exhibits a so-called Zipfian distribution. We apply several well known theorems to show the existence of such graphs. Introduction: The probability distribution on a set S = { 1, 2, . . . , n } defined by Pr(k) = 1/(Hnk), where Hn in the nth harmonic number, is commonly calle...