Phonon-assisted decoherence in the production of polarization-entangled photons in a single semiconductor quantum dot.

We theoretically investigate the production of polarization-entangled photons through the biexciton cascade decay in a single semiconductor quantum dot. In the intermediate state the entanglement is encoded in the polarizations of the first emitted photon and the exciton, where the exciton state can be effectively "measured" by the solid-state environment through the formation of a lattice distortion. We show that the resulting loss of entanglement becomes drastically enhanced if the phonons contributing to the lattice distortion are subject to elastic scatterings at the device boundaries, which might constitute a serious limitation for quantum-dot based entangled-photon devices.

[Does public access to defibrillators have a chance in Germany?--On the US model, legal considerations and justification].

Purpose: The introduction of public access to defibrillation via automated external defibrillators makes it possible to reduce the incidence of sudden cardiac arrest cases. Since they may expect civil and criminal liability after negligence causing damage, many German potential First Responders might hesitate to use an AED.

Methods: After we demonstrate the medical reasons and compare the legal situation of Public Access Defibrillation between the USA and Germany we analyse a possible hesitation of German First Responders.

Sleep related respiratory disorders in end-stage renal disease patients on peritoneal dialysis.

Study Objective: To assess the possible effects of peritoneal dialysis (PD) on sleep-related respiration, which might result from dialysate bulk load in the abdomen and/or alterations in metabolic control of respiration during sleep.

Design: Subjective and objective measures of sleep were prospectively compared on randomly assigned nights with PD fluid (2.0 L) and without PD fluid in the peritoneal cavity in 11 end-stage renal disease (ESRD) patients on PD.