Faithful qubit distribution assisted by one additional qubit against collective noise

We propose a distribution scheme of polarization states of a single photon over collective-noise channel. By adding one extra photon with a fixed polarization, we can protect the state against collective noise via a parity-check measurement and post-selection. While the scheme succeeds only probabilistically, it is simpler and more flexible than the schemes utilizing decoherence-free subspace. An application to BB84 protocol through collective noise channel, which is robust to the Trojan horse attack, is also given.Comment: 4 pages, 3 figures; published version in Phys. Rev. Let

Search for long-lived states in antiprotonic lithium

The spectrum of the (L_i^3 + p-bar + 2e) four-body system was calculated in an adiabatic approach. The two-electron energies were approximated by a sum of two single-electron effective charge two-center energies as suggested in [6]. While the structure of the spectrum does not exclude the existence of long-lived states, their experimental observability is still to be clarified

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

Attenuation of ischemic liver injury by prostaglandin E<inf>1</inf> analogue, misoprostol, and prostaglandin I<inf>2</inf> analogue, OP-41483

Background: Prostaglandin has been reported to have protective effects against liver injury. Use of this agent in clinical settings, however, is limited because of drugrelated side effects. This study investigated whether misoprostol, prostaglandin E1 analogue, and OP-41483, prostaglandin I2 analogue, which have fewer adverse effects with a longer half-life, attenuate ischemic liver damage. Study Design: Thirty beagle dogs underwent 2 hours of hepatic vascular exclusion using venovenous bypass. Misoprostol was administered intravenously for 30 minutes before ischemia and for 3 hours after reperfusion. OP-41483 was administered intraportally for 30 minutes before ischemia (2 μg/kg/min) and for 3 hours after reperfusion (0.5 μg/kg/min). Animals were divided into five groups: untreated control group (n = 10); high-dose misoprostol (total 100 μg/kg) group (MP-H, n = 5); middle-dose misoprostol (50 μg/kg) group (MP-M, n = 5); low-dose misoprostol (25 μg/kg) group (MP-L, n = 5); and OP-41483 group (OP, n = 5). Animal survival, hepatic tissue blood flow (HTBF), liver function, and histology were analyzed. Results: Two-week animal survival rates were 30% in control, 60% in MP-H, 100% in MP-M, 80% in MP-L, and 100% in OP. The treatments with prostaglandin analogues improved HTBF, and attenuated liver enzyme release, adenine nucleotrides degradation, and histologic abnormalities. In contrast to the MP-H animals that exhibited unstable cardiovascular systems, the MP- M, MP-L, and OP animals experienced only transient hypotension. Conclusions: These results indicate that misoprostol and OP-41483 prevent ischemic liver damage, although careful dose adjustment of misoprostol is required to obtain the best protection with minimal side effects

Attenuation of ischemic liver injury by monoclonal anti-endothelin antibody, awETN40

Background: Enhanced production of endothelin-1 (ET1), vasoconstrictive 21 amino acids produced by endothelial cells during ischemia and after reperfusion of the liver, is known to cause sinusoidal constriction and microcirculatory disturbances, which lead to severe tissue damage. Using a 2- hour hepatic vascular exclusion model in dogs, we tested our hypothesis that neutralization of ET-1 by monoclonal anti-ET-1 and anti-ET-2 antibody (AwETN40) abates vascular dysfunction and ameliorates ischemia/reperfusion injury of the liver. Study Design: After skeletonization, the liver was made totally ischemic by cross-clamping the portal vein, the hepatic artery, and the vena cava (above and below the liver). Venovenous bypass was used to decompress splanchnic and inferior systemic congestion. AwETN40, 5 mg/kg, was administered intravenously 10 minutes before ischemia (treatment group, n = 5). Nontreated animals were used as controls (control group, n = 10). Animal survival, hepatic tissue blood flow, liver function tests; total bile acid, high-energy phosphate, ET-1 levels, and liver histopathology were studied. Results: Treatment with AwETN40 improved 2-week animal survival from 30% to 100%. Hepatic tissue blood flow after reperfusion was significantly higher in the treatment group. The treatment significantly attenuated liver enzyme release, total bile acid, and changes in adenine nucleotides. Immunoreactive ET-1 levels in the hepatic venous blood of the control group showed a significant increase and remained high for up to 24 hours after reperfusion. Histopathologic alterations were significantly lessened in the treatment group. Conclusions: These results indicate that ET-1 is involved in ischemia/reperfusion injury of the liver, which can be ameliorated by the monoclonal anti-ET-1 and antiET-2 antibody AwETN40

Improved control of exogenous attention in action video game players

Action video game players (VGPs) have demonstrated a number of attentional advantages over non-players. Here, we propose that many of those benefits might be underpinned by improved control over exogenous (i.e., stimulus-driven) attention. To test this we used an anti-cueing task, in which a sudden-onset cue indicated that the target would likely appear in a separate location on the opposite side of the fixation point. When the time between the cue onset and the target onset was short (40 ms), non-players (nVGPs) showed a typical exogenous attention effect. Their response times were faster to targets presented at the cued (but less probable) location compared with the opposite (more probable) location. VGPs, however, were less likely to have their attention drawn to the location of the cue. When the onset asynchrony was long (600 ms), VGPs and nVGPs were equally able to endogenously shift their attention to the likely (opposite) target location. In order to rule out processing-speed differences as an explanation for this result, we also tested VGPs and nVGPs on an attentional blink (AB) task. In a version of the AB task that minimized demands on task switching and iconic memory, VGPs and nVGPs did not differ in second target identification performance (i.e., VGPs had the same magnitude of AB as nVGPs), suggesting that the anti-cueing results were due to flexible control over exogenous attention rather than to more general speed-of-processing differences

An Analysis of the Quantum Penny Flip Game using Geometric Algebra

We analyze the quantum penny flip game using geometric algebra and so determine all possible unitary transformations which enable the player Q to implement a winning strategy. Geometric algebra provides a clear visual picture of the quantum game and its strategies, as well as providing a simple and direct derivation of the winning transformation, which we demonstrate can be parametrized by two angles. For comparison we derive the same general winning strategy by conventional means using density matrices.Comment: 8 Pages, 1 Figure, accepted for publication in the Journal of Physical Society of Japa