Minimal qudit code for a qubit in the phase-damping channel

Using the stabilizer formalism we construct the minimal code into a D-dimensional Hilbert space (qudit) to protect a qubit against phase damping. The effectiveness of this code is then studied by means of input-output fidelity.Comment: 9 pages, 3 figures. REVTe

Using MINEHOUND in Cambodia and Afghanistan

The HALO Trust uses the MINEHOUND dual sensor detector in Cambodia and Afghanistan to reduce false-alarm rates. MINEHOUND combines a metal detector with ground-penetrating radar to improve efficiency of mine removal in areas highly contaminated with metallic false alarms

Resection Cavity Contraction Effects in the Use of Radioactive Sources (1-25 versus Cs-131) for Intra-Operative Brain Implants.

Background and Objectives Intra-parenchymal brain surgical resection cavities usually contract in volume following low dose rate (LDR) brachytherapy implants. In this study, we systematically modeled and assessed dose variability resulting from such changes for I-125 versus Cs-131 radioactive sources. Methods Resection cavity contraction was modeled based on 95 consecutive patient cases, using surveillance magnetic resonance (MR) images. The model was derived for single point source geometry and then fully simulated in 3D where I-125 or Cs-131 seeds were placed on the surface of an ellipsoidal resection cavity. Dose distribution estimated via TG-43 calculations and biological effective dose (BED) calculations were compared for both I-125 and Cs-131, accounting for resection cavity contractions. Results Resection cavity volumes were found to contract with an effective half-life of approximately 3.4 months (time to reach 50% of maximum volume contraction). As a result, significant differences in dose distributions were noted between I-125 and Cs-131 radioactive sources. For example, when comparing with static volume, assuming no contraction effect, I-125 exhibited a 31.8% and 30.5% increase in D90 and D10 values (i.e., the minimal dose to 90% and 10% of the volume respectively) in the peripheral target areas over the follow-up period of 20.5 months. In contrast, Cs-131 seeds only exhibited a 1.44% and 0.64% increase in D90 and D10 values respectively. Such discrepancy is likewise similar for BED calculations. Conclusion Resection cavity contractions affects Cs-131 dose distribution significantly less than that of I-125 for permanent brain implants. Care must be taken to account for cavity contractions when prescribing accumulative doses of a radioactive source in performing the brain implant procedures

Information Flow in Entangled Quantum Systems

All information in quantum systems is, notwithstanding Bell's theorem, localised. Measuring or otherwise interacting with a quantum system S has no effect on distant systems from which S is dynamically isolated, even if they are entangled with S. Using the Heisenberg picture to analyse quantum information processing makes this locality explicit, and reveals that under some circumstances (in particular, in Einstein-Podolski-Rosen experiments and in quantum teleportation) quantum information is transmitted through 'classical' (i.e. decoherent) information channels.Comment: PostScript version now available: http://www.qubit.org/people/patrickh/Papers/InformationFlow.p

Threshold values of Random K-SAT from the cavity method

Using the cavity equations of \cite{mezard:parisi:zecchina:02,mezard:zecchina:02}, we derive the various threshold values for the number of clauses per variable of the random $K$-satisfiability problem, generalizing the previous results to $K \ge 4$. We also give an analytic solution of the equations, and some closed expressions for these thresholds, in an expansion around large $K$. The stability of the solution is also computed. For any $K$, the satisfiability threshold is found to be in the stable region of the solution, which adds further credit to the conjecture that this computation gives the exact satisfiability threshold.Comment: 38 pages; extended explanations and derivations; this version is going to appear in Random Structures & Algorithm

a combined structural, electrochemical and spectroscopic study

Reactions of [(az-H)Pd(μ-Cl)2Pd(az-H)] (az = azobenzene) with the zwitterionic, p-benzoquinonemonoimine-type ligands 4-(n-butylamino)-6(n-butylimino)-3-oxocyclohexa-1,4-dien-1-olate (Q1) or 4-(isopropylamino)-6(isopropylimino)-3-oxocyclohexa-1,4-dien-1-olate) (Q2) in the presence of a base leads to the formation of the mononuclear complexes [(az-H)Pd(Q1-H)] (1) and [(az-H)Pd(Q2-H)] (2) respectively. Structural characterization of 2 shows an almost square planar coordination geometry around the Pd(II) centre, a short Pd–C bond, a slight elongation of the N[double bond, length as m-dash]N double bond of the az-H ligand and localization of the double bonds within the Q2-H ligand. Additionally, intermolecular N–H–O interactions exist between the uncoordinated N–H and O groups of two different molecules. Cyclic voltammetry of the complexes reveals an irreversible oxidation and two reversible reduction processes. A combination of electrochemical and UV-vis-NIR and EPR spectroelectrochemical studies are used to show that both coordinated ligands participate successively in the redox processes, thus revealing their non-innocent character

Global clinical response in C ushing's syndrome patients treated with mifepristone

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106755/1/cen12332.pd

weak intermolecular interactions and catalytic ethylene oligomerisation

The ligands 1-(cyclohexyl)-4-(2-pyridyl)-1,2,3-triazole (1), 1-(2,6-diisopropylphenyl)-4-(2-pyridyl)-1,2,3-triazole (2), 1-(4-butoxyphenyl)-4-(2-pyridyl)-1,2,3-triazole (3) and 1-(methyl)-4-(2-pyridyl)-1,2,3-triazole (4) were synthesized by the Cu(I) catalyzed “Click” reaction between 2-pyridylacetylene and the corresponding azides. The ligands were then reacted with NiBr2·3H2O to generate the complexes (1)2NiBr2 (1a), (2)2NiBr2 (2a), (3)2NiBr2 (3a) and (4)2NiBr2 (4a). Structural characterization of 1a confirmed the mononuclear and distorted octahedral environment around the Ni(II) center, with the pyridyl-triazole ligands coordinating in a bis-chelating fashion. Bond length analysis inside the 1,2,3-triazole ring shows a short N[double bond, length as m-dash]N double bond that is flanked by two longer C–N and N–N bonds pointing to the existence of “azo” character in the ring. The highly polar five-membered 1,2,3-triazole ring makes its C–H bond acidic, and these bonds participate in an extended weak intermolecular C–HBr interactions with the Br-groups of neighboring molecules, resulting in a 3-D network. The nickel complexes with these “Click” ligands were tested as pre-catalysts for ethylene oligomerization, and the complexes showed moderate activity in that reaction with good selectivity towards C4 oligomers

Dynamic Reflectarray Technology for Electro-Optical Sensors

An array of two or more tunable electro-optical reflecting elements where the phase response of one to more elements may be adjusted by a variety of approaches including, but not limited to a liquid crystal superstrate, schottky contact(s), ultra-violet radiation pulses, and illumination of photoconductive substances. Methods and apparatus for direct and/or adaptive control of phase response via the above approaches are also discussed

Minimum detection efficiency for a loophole-free violation of the Braunstein-Caves chained Bell inequalities

The chained Bell inequalities of Braunstein and Caves involving N settings per observer have some interesting applications. Here we obtain the minimum detection efficiency required for a loophole-free violation of the Braunstein-Caves inequalities for any N > 2. We discuss both the case in which both particles are detected with the same efficiency and the case in which the particles are detected with different efficiencies.Comment: REVTeX4, 8 page