Similarity measuring between patient traces for clinical pathway analysis

Clinical pathways leave traces, described as activity sequences with regard to a mixture of various latent treatment behaviors. Measuring similarities between patient traces can profitably be exploited further as a basis for providing insights into the pathways, and complementing existing techniques of clinical pathway analysis, which mainly focus on looking at aggregated data seen from an external perspective. In this paper, a probabilistic graphical model, i.e., Latent Dirichlet Allocation, is employed to discover latent treatment behaviors of patient traces for clinical pathways such that similarities of pairwise patient traces can be measured based on their underlying behavioral topical features. The presented method, as a basis for further tasks in clinical pathway analysis, are evaluated via a real-world data-set collected from a Chinese hospital

Similarity measuring between patient traces for clinical pathway analysis

Clinical pathways leave traces, described as activity sequences with regard to a mixture of various latent treatment behaviors. Measuring similarities between patient traces can profitably be exploited further as a basis for providing insights into the pathways, and complementing existing techniques of clinical pathway analysis, which mainly focus on looking at aggregated data seen from an external perspective. In this paper, a probabilistic graphical model, i.e., Latent Dirichlet Allocation, is employed to discover latent treatment behaviors of patient traces for clinical pathways such that similarities of pairwise patient traces can be measured based on their underlying behavioral topical features. The presented method, as a basis for further tasks in clinical pathway analysis, are evaluated via a real-world data-set collected from a Chinese hospital

Robust Quantum State Transfer in Random Unpolarized Spin Chains

We propose and analyze a new approach for quantum state transfer between remote spin qubits. Specifically, we demonstrate that coherent quantum coupling between remote qubits can be achieved via certain classes of random, unpolarized (infinite temperature) spin chains. Our method is robust to coupling strength disorder and does not require manipulation or control over individual spins. In principle, it can be used to attain perfect state transfer over arbitrarily long range via purely Hamiltonian evolution and may be particularly applicable in a solid-state quantum information processor. As an example, we demonstrate that it can be used to attain strong coherent coupling between Nitrogen-Vacancy centers separated by micrometer distances at room temperature. Realistic imperfections and decoherence effects are analyzed.Comment: 4 pages, 2 figures. V2: Modified discussion of disorder, added references - final version as published in Phys. Rev. Let

Chaotic Properties of Subshifts Generated by a Non-Periodic Recurrent Orbit

The chaotic properties of some subshift maps are investigated. These subshifts are the orbit closures of certain non-periodic recurrent points of a shift map. We first provide a review of basic concepts for dynamics of continuous maps in metric spaces. These concepts include nonwandering point, recurrent point, eventually periodic point, scrambled set, sensitive dependence on initial conditions, Robinson chaos, and topological entropy. Next we review the notion of shift maps and subshifts. Then we show that the one-sided subshifts generated by a non-periodic recurrent point are chaotic in the sense of Robinson. Moreover, we show that such a subshift has an infinite scrambled set if it has a periodic point. Finally, we give some examples and discuss the topological entropy of these subshifts, and present two open problems on the dynamics of subshifts

Enhancing SWAT with remotely sensed LAI for improved modelling of ecohydrological process in subtropics

Vegetation growth in Soil and Water Assessment Tool (SWAT) is a crucial process for quantifying ecohydrological modelling, as it influences evapotranspiration, interception, soil erosion and biomass production. The simplified version of Environmental Policy Integrated Climate (EPIC) in SWAT was originally designed for temperate regions and naturally based on temperature to simulate growth cycles of vegetation. However, tropical or subtropical vegetation growth is mainly controlled by rainfall. Due to this limitation, current SWAT simulations in tropics and subtropics have been facing a series of problems on vegetation dormancy, water balance and sediment yield. Therefore, we proposed an approach to enhance the modelling of SWAT vegetation dynamics with remotely sensed leaf area index (LAI), to finally increase the applicability of SWAT in tropical or subtropical areas. Spatially and temporally continuous LAI products (1 day, 500 m) from Moderate Resolution Imaging Spectroradiometer (MODIS) observations were integrated into SWAT to replace the LAI simulated by built-in EPIC module. Two advanced filter algorithms were employed to derive a downscaled LAI (30 m) to keep a consistent spatial scale with the size of Hydrological Response Units (HRU) and open data (i.e. SRTM, 30 m), and the source code of the plant growth module were correspondingly modified to incorporate the downscaled LAI into SWAT. To examine the performance of our proposed approach, a case study was conducted in a representative middle-scale (6384 km 2) subtropical watershed of Meichuan basin, China, and detailed analysis was performed to investigate its ecohydrological effects, such as streamflow, sediment yield and LAI dynamics from 2001 to 2014. Model performances were compared among three scenarios: (1) original SWAT, (2) SWAT with a corrected plant dormancy function, and (3) modified SWAT after integration of MODIS LAI (our proposed method). Results showed that the modified SWAT took advantage of downscaled MODIS LAI and produced more reasonable seasonal curves of vegetation cover factor (C) of plants than the original model. Correspondingly, the modified SWAT substantially improved streamflow and sediment simulations. The findings demonstrated that SWAT model can be a useful tool for simulating ecohydrological process for subtropical ecosystems when integrated with our proposed method

Influence of uniaxial tensile stress on the mechanical and piezoelectric properties of short-period ferroelectric superlattice

Tetragonal ferroelectric/ferroelectric BaTiO3/PbTiO3 superlattice under uniaxial tensile stress along the c axis is investigated from first principles. We show that the calculated ideal tensile strength is 6.85 GPa and that the superlattice under the loading of uniaxial tensile stress becomes soft along the nonpolar axes. We also find that the appropriately applied uniaxial tensile stress can significantly enhance the piezoelectricity for the superlattice, with piezoelectric coefficient d33 increasing from the ground state value by a factor of about 8, reaching 678.42 pC/N. The underlying mechanism for the enhancement of piezoelectricity is discussed

Interdimensional degeneracies for a quantum three-body system in D dimensions

A new approach is developed to derive the complete spectrum of exact interdimensional degeneracies for a quantum three-body system in D-dimensions. The new method gives a generalization of previous methods

Observation of the reversed Cherenkov radiation

This work was supported by the National Natural Science Foundation of China (Grant Nos 61471091, 61611130067 and 61531010)