A quantum algorithm for heat conduction with symmetrization.

Heat conduction, driven by thermal non-equilibrium, is the transfer of internal thermal energy through physical contacts, and it exists widely in various engineering problems, such as spacecraft and state-of-the-art dilution refrigerators. The mathematical equation for heat conduction is a prototypical partial differential equation. Here we report a quantum algorithm for heat conduction (QHC) that significantly outperforms classical algorithms. We represent the original heat conduction system by a symmetric system with an ancilla qubit so that the quantum circuit complexity is polylogarithmic in the number of discretized grid points. Compared with the existing algorithms based on solving linear equations via the Harrow-Hassidim-Lloyd (HHL) algorithm, our method evolves the linear process directly without phase estimation, which involves complex quantum operations and large output error. Therefore, this algorithm is experimental-friendly and without output error after the discretization procedure. We experimentally implemented the algorithm for a one-dimensional thermal conduction process with two-edge constant temperatures and adiabatic conditions on a nuclear spin quantum processor. The spatial and temporal distributions of the temperature are accurately determined from the experimental results. Our work can be naturally applied to any physical processes that can be reduced to the heat equation.

Measurement-device-independent quantum communication without encryption.

Security in communication is vital in modern life. At present, security is realized by an encryption process in cryptography. It is unbelievable if a secure communication is achievable without encryption. In quantum cryptography, there is a unique form of quantum communication, quantum secure direct communication, where secret information is transmitted directly over a quantum channel. Quantum secure direct communication is drastically distinct from our conventional concept of secure communication, because it does not require key distribution, key storage and ciphertext transmission, and eliminates the encryption procedure completely. Hence it avoids in principle all the security loopholes associated with key and ciphertext in traditional secure communications. For practical implementation, defects always exist in real devices and it may downgrade the security. Among the various device imperfections, those with the measurement devices are the most prominent and serious ones. Here we report a measurement-device-independent quantum secure direct communication protocol using Einstein-Podolsky-Rosen pairs. This protocol eradicates the security vulnerabilities associated with the measurement device, and greatly enhances the practical security of quantum secure direct communication. In addition to the security advantage, this protocol has an extended communication distance, and a high communication capacity.

Comparison of National Institutes of Health-Chronic Prostatitis Symptom Index with International Index of Erectile Function 5 in Men with Chronic Prostatitis/Chronic Pelvic Pain Syndrome: A Large Cross-Sectional Study in China.

The purpose of the study is to evaluate the relationship between NIH-CPSI and IIEF-5 in Chinese men with CP/CPPS. A large cross-sectional and multicenter survey was conducted from July 2012 to January 2014. Men were recruited from urology clinics which were located at the five cities in China. All men participated in the survey by completing a verbal questionnaire (consisted of sociodemographics, past medical history, sexual history, and self-estimated scales). The results showed that 1,280 men completed the survey. Based on the CP/CPPS definition, a total of 801 men were diagnosed as having CP/CPPS. Men with CP/CPPS reported higher scores of NIH-CPSI and lower scores of IIEF-5 than men without CP/CPPS. NIH-CPSI scores were significantly negatively correlated with IIEF-5 scores. The total scores of NIH-CPSI were significantly more strongly correlated with question 5 than other questions of IIEF-5. The total scores of IIEF-5 were significantly more strongly correlated with pain symptoms scores of NIH-CPSI. Strongest correlation was found between QoL impact and question 5 of IIEF-5. The findings suggested that NIH-CPSI scores were significantly negatively correlated with IIEF-5 scores. Strongest correlation was found between QoL impact and question 5 of IIEF-5.

Two-family outbreak of botulism associated with the consumption of smoked ribs in Sichuan Province, China.

BACKGROUND: On September 22, 2013, two patients from Sichuan Province, China presented with symptoms of food-borne botulism, a rare but fatal illness caused by the consumption of foods containing Clostridium botulinum neurotoxins. METHODS: Investigators reviewed the medical charts and food consumption histories, and interviewed patients and family members. Food samples and clinical specimens were tested for botulinum toxin and neurotoxin-producing Clostridium species by standard methods. RESULTS: The first two index cases presented with cranial neuropathies and flaccid paralysis, and required mechanical ventilation. There were 12 confirmed outbreak-associated cases. Botulinum toxin type A was identified in the smoked ribs, and all of the patients had consumed the smoked ribs from the same local restaurant. The smoked ribs contained no added salt, sugar, or preservative. Botulinum toxin production likely resulted from the cold-smoking preparation method and inappropriate refrigeration. CONCLUSIONS: Smoked ribs produced by a local restaurant, contaminated with type A botulism, was the contributor to this outbreak. The supervision of food safety should be strengthened to prevent future outbreaks in China.

Assessing the influence of land use and land cover datasets with different points in time and levels of detail on watershed modeling in the North River Watershed, China.

Land use and land cover (LULC) information is an important component influencing watershed modeling with regards to hydrology and water quality in the river basin. In this study, the sensitivity of the Soil and Water Assessment Tool (SWAT) model to LULC datasets with three points in time and three levels of detail was assessed in a coastal subtropical watershed located in Southeast China. The results showed good agreement between observed and simulated values for both monthly and daily streamflow and monthly NH(4)+-N and TP loads. Three LULC datasets in 2002, 2007 and 2010 had relatively little influence on simulated monthly and daily streamflow, whereas they exhibited greater effects on simulated monthly NH(4)+-N and TP loads. When using the two LULC datasets in 2007 and 2010 compared with that in 2002, the relative differences in predicted monthly NH(4)+-N and TP loads were -11.0 to -7.8% and -4.8 to -9.0%, respectively. There were no significant differences in simulated monthly and daily streamflow when using the three LULC datasets with ten, five and three categories. When using LULC datasets from ten categories compared to five and three categories, the relative differences in predicted monthly NH(4)+-N and TP loads were -6.6 to -6.5% and -13.3 to -7.3%, respectively. Overall, the sensitivity of the SWAT model to LULC datasets with different points in time and levels of detail was lower in monthly and daily streamflow simulation than in monthly NH(4)+-N and TP loads prediction. This research provided helpful insights into the influence of LULC datasets on watershed modeling.

[Preliminary analysis of spatiotemporal variation of water quality and its influencing factors in the Jiulong River watershed].

Twenty one sub-watersheds in the Jiulong River watershed were chosen for in-situ monitoring water quality of baseflow in flood season, dry season and average season in 2010. Geographical information system and multivariate analysis were coupled to characterize the spatiotemporal variation of water quality and identify its influencing factors. The results show that the water quality in dry season is the worst whereas the water quality in flood season is comparatively good. The first principal component representing sanitary and industrial wastewater pollution, explained 45.58% of the total variance of water quality. The second principal component concerning pollution due to agricultural activities, explained 21.28% of the total variance. NH4(+) -N, SRP, potassium permanganate index, K+, Cl-, Mg2+ and Na had a significantly positive correlation with percentage of built-up and density of population. NO3(-) -N was correlated positively with percentage of cropland. The sub-watersheds with high proportion of build-up area and density of population show high concentration of NH4(+) -N, SRP, potassium permanganate index, K+, Cl-. Comparatively, the sub-watersheds with high percentage of cropland show high level of nitrate concentration. Improvement of the wastewater treatment efficiency and increased recognition of agricultural non-point source pollution were finally highlighted from watershed management perspectives.