Efficacy of rehabilitation interventions in rheumatic conditions

All industrialized nations are facing a crisis in health care financing. Rising expectations coupled with increasing specialization and technologic capacities have forced health care payers to examine their assumptions and to seek data on the outcomes of medical interventions. Clinical investigators who have been taught to use randomized controlled trials that evaluate efficacy under experimental conditions have been redirected toward studies that can help answer health policy questions. Such studies examine the effectiveness of interventions in more realistic settings on a richer array of patient-centered outcomes such as function and consider cost effectiveness and relative cost effectiveness. Rehabilitation interventions, which are by and large pragmatic, have never had a strong scientific basis grounded in controlled trials, and this lack of evidence has put tremendous pressure on clinicians to justify their practices. In this article, we review the recent literature on effectiveness of rehabilitation interventions in rheumatic disorders

Is Misoprostol Cost-effective in the Prevention of Nonsteroidal Anti-inflammatory Drug—Induced Gastropathy in Patients With Chronic Arthritis?

Whether misoprostol, a synthetic prostaglandin E1 analogue, should be routinely prescribed along with nonsteriodal anti-inflammatory drugs (NSAIDS) to prevent gastric damage is of great clinical importance and has profound cost implications. No consensus exists on whether misoprostol cotherapy results in a cost-saving, is cost-effective, or is costly. The different conclusions reached by five economic evaluations of misoprostol can be explained solely by the assumed absolute risk reduction of symptomatic ulcer, which was more than seven times greater in the studies that concluded that misoprostol was cost-effective than in a study that concluded misoprostol to be costly. Since no study has directly shown the effectiveness of misoprostol cotherapy in preventing clinically significant ulcer disease (ie, hemorrhage and preforation), it is impossible to judge which assumptions are most appropriate. The absence of firm data on the rate of NSAID-induced gastric ulcers reduced by misoprostol makes it impossible to conclude whether it is cost-effective in patients with chronic arthritis who use NSAIDS

Quantum Key Distribution over 67 km with a plug & play system

We present a fibre-optical quantum key distribution system. It works at 1550nm and is based on the plug & play setup. We tested the stability under field conditions using aerial and terrestrial cables and performed a key exchange over 67 km between Geneva and Lausanne.Comment: 8 pages, 3 figures, 2 tables. Submitted to the New Journal of Physic

Quantum cryptography protocols robust against photon number splitting attacks for weak laser pulses implementations

We introduce a new class of quantum quantum key distribution protocols, tailored to be robust against photon number splitting (PNS) attacks. We study one of these protocols, which differs from the BB84 only in the classical sifting procedure. This protocol is provably better than BB84 against PNS attacks at zero error.Comment: 4 pages, 2 figure

A Fabry-Perot like two-photon interferometer for high-dimensional time-bin entanglement

We generate high-dimensional time-bin entanglement using a mode-locked laser and analyze it with a 2-photon Fabry-Perot interferometer. The dimension of the entangled state is limited only by the phase coherence between subsequent pulses and is practically infinite. In our experiment a pico-second mode-locked laser at 532 nm pumps a non-linear potassium niobate crystal to produce photon pairs by spontaneous parametric down-conversion at 810 and 1550 nm.Comment: 9 pages, 9 figure

High rate, long-distance quantum key distribution over 250km of ultra low loss fibres

We present a fully automated quantum key distribution prototype running at 625 MHz clock rate. Taking advantage of ultra low loss fibres and low-noise superconducting detectors, we can distribute 6,000 secret bits per second over 100 km and 15 bits per second over 250km

Experimental ancilla-assisted qubit transmission against correlated noise using quantum parity checking

We report the experimental demonstration of a transmission scheme of photonic qubits over unstabilized optical fibers, which has the plug-and-play feature as well as the ability to transmit any state of a qubit, regardless of whether it is known, unknown, or entangled to other systems. A high fidelity to the noiseless quantum channel was achieved by adding an ancilla photon after the signal photon within the correlation time of the fiber noise and by performing quantum parity checking. Simplicity, maintenance-free feature and robustness against path-length mismatches among the nodes make our scheme suitable for multi-user quantum communication networks.Comment: 8 pages, 4 figures; published in New J. Phys. and selected in IOP Selec

Characterization of A Novel Avalanche Photodiode for Single Photon Detection in VIS-NIR Range

In this work we investigate operation in the Geiger mode of the new single photon avalanche photo diode (SPAD) SAP500 manufactured by Laser Components. This SPAD is sensitive in the range 400-1000nm and has a conventional reach-through structure which ensures good quantum efficiency at the long end of the spectrum. By use of passive and active quenching schemes we investigate detection efficiency, timing jitter, dark counts, afterpulsing, gain and other important parameters and compare them to the "standard" low noise SPAD C30902SH from Perkin Elmer. We conclude that SAP500 offers better combination of detection efficiency, low noise and timing precision

Description of a quantum convolutional code

We describe a quantum error correction scheme aimed at protecting a flow of quantum information over long distance communication. It is largely inspired by the theory of classical convolutional codes which are used in similar circumstances in classical communication. The particular example shown here uses the stabilizer formalism, which provides an explicit encoding circuit. An associated error estimation algorithm is given explicitly and shown to provide the most likely error over any memoryless quantum channel, while its complexity grows only linearly with the number of encoded qubits.Comment: 4 pages, uses revtex4. Minor correction in the encoding and decoding circuit