Optimal teleportation via thermal entangled states of a two-qubit Heisenberg Chain

We study the optimal teleportation based on Bell measurements via the thermal states of a two-qubit Heisenberg XXX chain in the presence of Dzyaloshinsky-Moriya (DM) anisotropic antisymmetric interaction and obtain the optimal unitary transformation. The explicit expressions of the output state and the teleportation fidelity are presented and compared with those of the standard protocol. It is shown that in this protocol the teleportation fidelity is always larger and unit fidelity is achieved at zero temperature. The DM interaction can enhance the teleportation fidelity at finite temperatures, as opposed to the effect of the interaction in the standard protocol. Cases with other types of anisotropies are also discussed.Comment: Accepted by EP

Decentralized Ride-Sharing and Vehicle-Pooling Based on Fair Cost-Sharing Mechanisms

Ride-sharing or vehicle-pooling allows commuters to team up spontaneously for transportation cost sharing. This has become a popular trend in the emerging paradigm of sharing economy. One crucial component to support effective ride-sharing is the matching mechanism that pairs up suitable commuters. Traditionally, matching has been performed in a centralized manner, whereby an operator arranges ride-sharing according to a global objective (e.g., total cost of all commuters). However, ride-sharing is a decentralized decision-making paradigm, where commuters are self-interested and only motivated to team up based on individual payments. Particularly, it is not clear how transportation cost should be shared fairly between commuters, and what ramifications of cost-sharing are on decentralized ride-sharing. This paper sheds light on the principles of decentralized ride-sharing and vehicle-pooling mechanisms based on stable matching, such that no one would be better off to deviate from a stable matching outcome. We study various fair cost-sharing mechanisms and the induced stable matching outcomes. We compare the stable matching outcomes with a social optimal outcome (that minimizes total cost) by theoretical bounds of social optimality ratios, and show that several fair cost-sharing mechanisms can achieve high social optimality. We also corroborate our results with an empirical study of taxi sharing under fair cost-sharing mechanisms by a data analysis on New York City taxi trip dataset, and provide useful insights on effective decentralized mechanisms for practical ride-sharing and vehicle-pooling.Comment: To appear in IEEE Trans. on Intelligent Transportation System

Complete analysis on QED corrections to Bq → τ+ τ−B_{q}\, \to\, \tau^+\, \tau^-

Motivated by a dynamical enhancement of the electromagnetic corrections by a power of $\Lambda_{\mathrm{QCD}}/m_b$ in $B_{d,s}\, \to\, \mu^+\, \mu^-$ at next-to-leading order (NLO), we extend the QED factorization effects on the leptonic $B$ meson decays with light muon leptons to tauonic final states, $B_{d,s} \, \to\, \tau^+\, \tau^-$, using soft-collinear effective theory (SCET). This extension is necessary owing to the appearance of the large $\tau$ mass, which will lead to different power counting in SCET and also different results. We provide a complete NLO electromagnetic corrections to $B_{d,s} \, \to\, \tau^+\, \tau^-$, which include hard functions and hard-collinear functions below the bottom quark mass scale $\mu_b$. The power enhanced electromagnetic effects from hard-collinear contributions on $B_{d,s}\, \to\, \mu^+\, \mu^-$ discussed before also exist in $B_{d,s} \, \to\, \tau^+\, \tau^-$. However the logarithm term arising from contributions of hard-collinear photon and lepton virtualities for $B_{d,s}\, \to\, \tau^+\, \tau^-$ is not large as it is in muon case due to the hard-collinear scale of $\tau$ mass, which lead to only approximately $0.04\%$ QED corrections to the branching fraction of $B_{d,s} \, \to\, \tau^+\, \tau^-$ compared with overall reduction about $0.5\%$ in $B_{d,s}\, \to\, \mu^+\, \mu^-$.Comment: 29 pages, 3 figure

Transformation Model With Constraints for High Accuracy of 2D-3D Building Registration in Aerial Imagery

This paper proposes a novel rigorous transformation model for 2D-3D registration to address the difficult problem of obtaining a sufficient number of well-distributed ground control points (GCPs) in urban areas with tall buildings. The proposed model applies two types of geometric constraints, co-planarity and perpendicularity, to the conventional photogrammetric collinearity model. Both types of geometric information are directly obtained from geometric building structures, with which the geometric constraints are automatically created and combined into the conventional transformation model. A test field located in downtown Denver, Colorado, is used to evaluate the accuracy and reliability of the proposed method. The comparison analysis of the accuracy achieved by the proposed method and the conventional method is conducted. Experimental results demonstrated that: (1) the theoretical accuracy of the solved registration parameters can reach 0.47 pixels, whereas the other methods reach only 1.23 and 1.09 pixels; (2) the RMS values of 2D-3D registration achieved by the proposed model are only two pixels along the x and y directions, much smaller than the RMS values of the conventional model, which are approximately 10 pixels along the x and y directions. These results demonstrate that the proposed method is able to significantly improve the accuracy of 2D-3D registration with much fewer GCPs in urban areas with tall buildings

Up-Regulation of Th17 Cells May Underlie Inhibition of Treg Development Caused by Immunization with Activated Syngeneic T Cells

BACKGROUND: Our previous work showed that mice immunized with attenuated activated syngeneic T cells (aTCV) led to damping Treg function which resulted in enhancing anti-tumor immunity. It is well known that DC plays a very important role in controlling Th cell differentiation; whether DC involves Treg attenuation in immunized mice remained unknown. In this study, we provided evidence that increased mature DC (mDC) after immunization with aTCV skewed Th17 differentiation, which resulted in inhibition of Treg differentiation through IL-6 signaling pathway. PRINCIPAL FINDINGS: In the present study, we found that the frequency of mDCs increased dramatically in the immunized mice accompanied by lower Treg cells compared to the controls. Moreover, both DCs and serum derived from the immunized mice suppressed Treg differentiation in vitro, respectively. mDCs generated from bone marrow precursor cells in vitro strongly inhibited Treg development and simultaneously drove Th17 differentiation with elevated IL-6 production. However, PD-L1, a potent Treg inducer did not show effect on Treg down-regulation. Assay with transwell systems showed that cell-cell contact was necessary for IL-6 production to a threshold to activate Th17 transcriptional factor RORγt and to inhibit Treg counterpart Foxp3. CONCLUSIONS: Our results implicate up-regulated Th17 development might be one of mechanisms of enhancing anti-tumor immunity induced by immunization with aTCV, which provide a novel insight in numerous mechanisms responsible for anti-tumor immunity

A new and facile co-modification by introducing oxygen vacancies and loading Ag nanoparticles to promote the photocatalytic activities of Bi 2 WO 6

Abstract(#br)A new and facile co-modification by introducing oxygen vacancies and loading Ag nanoparticles to largely promote the visible-light-driven photocatalytic activities of Bi 2 WO 6 semiconductor photocatalyst has been studied. Bi 2 WO 6 (BWO) flower-like micro-spheres were prepared by a hydrothermal method. Oxygen vacancies (OV) were introduced by a hydrogen reduction method and the concentration of OV was controlled by the heat treatment temperature under H 2 atmosphere. After OV modification, Ag nanoparticles were loaded on the BWO micro-sphere surface by a photo-reduction method and the Ag loaded content was controlled by the concentration of AgNO 3 solution. Results of visible-light-driven photocatalytic characterizations show that photocatalytic reaction rate constants of OV introduced modified type (BWO@OV) and Ag loaded modified type (BWO@Ag) increase by 1.47 and 1.67 times, respectively, comparing with BWO. Moreover, the reaction rate constant of co-modified type (OV@BWO@Ag) reaches as high as 2.53 times. Introducing OV into BWO enhances the separation of photo-generated electron/hole pairs, and the co-modification by both introducing OV and loading Ag nanoparticles has a synergy promotion effect on photocatalytic activity, which is believed to be a new technical route to enhance semiconductor photocatalytic properties