It is unknown whether independent neural damage may occur in the pre-/absent vascular diabetic retinopathy (DR). To exclude vasculopathy, it is important to measure the integrity of the blood-retinal barrier (BRB). This crosssectional study addressed this problem in type 1 diabetic patients with normal ocular fundus and absent breakdown of the BRB (confirmed with vitreous fluorometry). These we...

The CD19 cell surface molecule regulates signal transduction events critical for B lymphocyte development and humoral immunity. Increasing the density of CD19 expression renders B lymphocytes hyper-responsive to transmembrane signals, and transgenic mice that overexpress CD19 have increased levels of autoantibodies. The role of CD19 in tolerance regulation and autoantibody generation was theref...

We present a study of the fiber bundle model using equal load-sharing dynamics where the breaking thresholds of the fibers are drawn randomly from a power-law distribution of the form p(b)∼b-1 in the range 10-β to 10β. Tuning the value of β continuously over a wide range, the critical behavior of the fiber bundle has been studied both analytically as well as numerically. Our results are: (i) Th...

We review limiting models for fracture in bundles of fibers, with statistically distributed thresholds for breakdown of individual fibers. During the breakdown process, avalanches consisting of simultaneous rupture of several fibers occur, and the distribution D(∆) of the magnitude ∆ of such avalanches is the central characteristics in our analysis. For a bundle of parallel fibers two limiting ...

We present a preliminary study of a new phenomena associated with the Euler-Poisson equations — the so called critical threshold phenomena, where the answer to questions of global smoothness vs. finite time breakdown depends on whether the initial configuration crosses an intrinsic, O(1) critical threshold. We investigate a class of Euler-Poisson equations, ranging from one-dimensional problems...