9 research outputs found
Probabilistic Anonymity
The concept of anonymity comes into play in
a wide range of situations, varying from voting
and anonymous donations to postings on bulletin
boards and sending mails. A formal definition of
this concept has been given in literature in
terms of nondeterminism. In this paper, we
investigate a notion of anonymity based on
probability theory, and we we discuss the relation
with the nondeterministic one. We then formulate
this definition in terms of observables for
processes in the probabilistic -calculus, and
propose a method to verify automatically the
anonymity property. We illustrate the method by
using the example of the dining cryptographers
Technical design report for the PANDA (AntiProton Annihilations at Darmstadt) Straw Tube Tracker
<p>This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.</p>
The mechanisms of coronary restenosis: insights from experimental models
Since its introduction into clinical practice, more than 20 years ago, percutaneous transluminal coronary angioplasty (PTCA) has proven to be an effective, minimally invasive alternative to coronary artery bypass grafting (CABG). During this time there have been great improvements in the design of balloon catheters, operative procedures and adjuvant drug therapy, and this has resulted in low rates of primary failure and short-term complications. However, the potential benefits of angioplasty are diminished by the high rate of recurrent disease. Up to 40% of patients undergoing angioplasty develop clinically significant restenosis within a year of the procedure. Although the deployment of endovascular stents at the time of angioplasty improves the short-term outcome, ‘in-stent’ stenosis remains an enduring problem. In order to gain an insight into the mechanisms of restenosis, several experimental models of angioplasty have been developed. These have been used together with the tools provided by recent advances in molecular biology and catheter design to investigate restenosis in detail. It is now possible to deliver highly specific molecular antagonists, such as antisense gene sequences, to the site of injury. The knowledge provided by these studies may ultimately lead to novel forms of intervention. The present review is a synopsis of our current understanding of the pathological mechanisms of restenosis