0000000000408554
AUTHOR
Christian Weiss
Exploring hyperon structure with electromagnetic transverse densities
We explore the structure of the spin-1/2 flavor-octet baryons (hyperons) through their electromagnetic transverse densities. The transverse densities describe the distribution of charge and magnetization at fixed light-front time and enable a spatial representation of the baryons as relativistic systems. At peripheral distances b~1/M_pi the transverse densities are computed using a new method that combines chiral effective field theory and dispersion analysis. The peripheral isovector densities arise from two-pion exchange, which includes the rho-meson resonance through elastic unitarity. The isoscalar densities are estimated from vector meson exchange (omega, phi). We find that the "pion c…
Rationale for and design of the CREATIVE-AF trial: randomized, double-blind, placebo-controlled, crossover study of the effect of irbesartan on oxidative stress and adhesion molecules in patients with persistent atrial fibrillation.
Background and objective: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Recent studies suggest there is an angiotensin II-dependent increase in adhesion molecules and oxidative stress parameters during AF. These alterations appear to contribute to inflammatory and prothrombotic changes in the atrial endocardium (‘endocardial remodelling’), suggesting that patients with increased levels of these factors might be at risk of thromboembolic events. The purpose of the CREATIVE-AF (Impact of Irbesartan on Oxidative Stress and C-Reactive Protein Levels in Patients with Persistent Atrial Fibrillation) trial is to prove the principle concept that blockade of angiotensin II type 1 r…
QCD NLO with Powheg matching and top threshold matching in WHIZARD
We present the status of the automation of NLO processes within the event generator WHIZARD. The program provides an automated FKS subtraction and phase space integration over the FKS regions, while the (QCD) NLO matrix element is accessed via the Binoth Les Houches Interface from an externally linked one-loop program. Massless and massive test cases and validation are shown for several e+e- processes. Furthermore, we discuss work in progress and future plans. The second part covers the matching of the NRQCD prediction with NLL threshold resummation to the NLO continuum top pair production at lepton colliders. Both the S-wave and P-wave production of the top pair are taken into account in t…
The COGNITION Study Rationale and Design: Influence of Closed Loop Stimulation on Cognitive Performance in Pacemaker Patients
Background: Several studies showed the beneficial effect of pacemaker implantation on cognitive performance in patients with bradycardia. But it has never been investigated if patients with chronotropic incompetence may improve their cognitive performance if treated by a rate-adaptive system reacting to mental stress in comparison to the most frequently used accelerometer-driven pacing. Methods: The randomized, single-blind, multicenter COGNITION study evaluates if closed loop stimulation (CLS) offers incremental benefit in the speed of cognitive performance and the overall well-being of elderly patients with bradycardia compared with accelerometer-based pacing. Four hundred chronotropicall…
Electron Ion Collider: The Next QCD Frontier - Understanding the glue that binds us all
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics and, in particular, the focused ten-week program on "Gluons and quark sea a…
Managed ventricular pacing vs. conventional dual-chamber pacing for elective replacements: the PreFER MVP study: clinical background, rationale, and design
Udgivelsesdato: 2008-Mar AIMS: Several clinical studies have shown that, in patients with intact atrioventricular (AV) conduction, unnecessary chronic right ventricular (RV) pacing can be detrimental. The managed ventricular pacing (MVP) algorithm is designed to give preference to spontaneous AV conduction, thus minimizing RV pacing. The clinical outcomes of MVP are being studied in several ongoing trials in patients undergoing a first device implantation, but it is unknown to what extent MVP is beneficial in patients with a history of ventricular pacing. The purpose of the Prefer for Elective Replacement MVP (PreFER MVP) study is to assess the superiority of the MVP algorithm to convention…
Supersymmetric type-III seesaw mechanism: Lepton flavor violation and LHC phenomenology
We study a supersymmetric version of the type-III seesaw mechanism considering two variants of the model: a minimal version for explaining neutrino data with only two copies of 24 superfields and a model with three generations of 24-plets. The latter predicts, in general, rates for mu -> e gamma inconsistent with experimental data. However, this bound can be evaded if certain special conditions within the neutrino sector are fulfilled. In the case of two 24-plets, lepton flavor violation constraints can be satisfied much more easily. After specifying the corresponding regions in the minimal supergravity parameter space, we show that under favorable conditions one can test the corresponding …
Gold vs. platinum-iridium tip catheter for cavotricuspid isthmus ablation: the AURUM 8 study
Aims Gold electrodes have the theoretical advantage of creating bigger lesions than platinum–iridium (Pt–Ir) electrodes. We performed a prospective randomized study to compare the clinical efficacy of standard 8 mm Pt–Ir tip catheter (control) and 8 mm gold-tip catheters in the ablation of the cavotricuspid isthmus (CTI)-dependent atrial flutter. Methods and results A total of 463 patients undergoing CTI ablation in 19 clinical centres were randomized to receive the treatment by gold-tip or control catheter. The primary endpoint was cumulative radiofrequency (RF) application duration until achieving bidirectional CTI block. It did not differ significantly for the two catheters. The gold-tip…
In vitro comparison of platinum-iridium and gold tip electrodes: lesion depth in 4 mm, 8 mm, and irrigated-tip radiofrequency ablation catheters
Aims We compared a newly developed irrigated gold tip electrode ablation catheter and a gold tip 4 and 8 mm catheter with the corresponding platinum–iridium (Pt) tip catheters in an in vitro setting. Methods and results In a flow chamber simulating physiological flow conditions, radiofrequency catheter ablation was performed on tissue samples of porcine endomyocardium and liver. Lesion depth, energy and temperature delivery, and popping frequency were determined. Two hundred and fifty-three ablations were conducted. Four and eight millimetre, gold tip electrode catheters produced significantly deeper lesions compared with the Pt tip electrode (liver 4 mm: 4.67 ± 1.7 vs. 2.9 ± 1.0 mm, P < 0.…
Automation of NLO processes and decays and POWHEG matching in WHIZARD
Journal of physics / Conference Series 762, 012059 (2016). doi:10.1088/1742-6596/762/1/012059
Peripheral transverse densities of the baryon octet from chiral effective field theory and dispersion analysis
The baryon electromagnetic form factors are expressed in terms of two-dimensional densities describing the distribution of charge and magnetization in transverse space at fixed light-front time. We calculate the transverse densities of the spin-1/2 flavor-octet baryons at peripheral distances b = O(M_\pi^{-1}) using methods of relativistic chiral effective field theory (\chi EFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the two-pion cut t > 4 M_\pi^2 are calculated using relativistic \chi EFT including octet and decuplet baryons.…