Background Although poppers are increasingly popular among MSM in China, little is known about the patterns of poppers use. The objectives of this study were to describe the patterns of poppers use and examine its association with sexual behaviors and HIV infection among MSM in Beijing, China. Methods As part of a multi-component HIV intervention trial, 3588 MSM were surveyed between March 2013 and March 2014 in Beijing, China. Blood samples were collected and tested for HIV and syphilis. The questionnaire collected information about socio-demographic and behavioral characteristics. Univariate and multivariable logistic regression analyses were performed to evaluate the correlates of poppers use. Results Over a quarter of men (27.5%) reported having used at least one type of drugs in the past three months. Poppers were the most popular one (26.8%). Poppers use was correlated with a higher HIV prevalence [odds ratio (OR): 1.38, 95% confidence interval (CI): 1.11–1.70]. Demographic and sexual behavioral factors associated with poppers use included: younger age [adjusted OR (AOR): 1.56, 95% CI: 1.25–1.94], higher education (AOR: 1.61, 95% CI: 1.33–1.96), alcohol use (AOR: 1.32, 95% CI: 1.10–1.60), seeking male partners mainly via the internet (AOR: 1.60, 95% CI: 1.28–2.00), multiple male sex partnership (AOR: 2.22, 95% CI: 1.90–2.60), and unprotected receptive anal intercourse (AOR: 1.52, 95% CI: 1.28–1.81). Conclusions In this study, poppers use was positively associated with HIV infection and unprotected anal intercourse. Intervention efforts should be devoted to promote safer sex and HIV testing and counseling among MSM who use poppers.

In this paper, a simple genetic algorithm (GA) method has been applied in a real-time experiment on a liquid-level control system for online autotuning proportional-integral-derivative (PID) parameters. Our proposed method can automatically choose the best PID parameters for each generation. Then, using the reproduction, crossover and mutation to create the new population for other PID parameters, it can continuously control the liquid-level system until the preset iteration number is reached. Finally, the best PID parameters can be obtained. Furthermore, two selection methods, roulette wheel and tournament, have been compared in real-time experiments. Real-time experimental results are given to demonstrate the effectiveness and usefulness for online tuning PID parameters via this evolution process.

The HIV epidemic in China started among intravenous drug users in the late 1980s. The second wave of the epidemic was caused by an outbreak in the paid plasma donors in central China in the mid-1990s. Sexually transmitted HIV cases have steadily increased and comprised more than half the reported HIV/AIDS infections since 2007. In the last 5 years, there has been a sharp increase of HIV infection in men who have sex with men. The HIV epidemic in China has expanded from high-risk groups to the general population and from rural regions to urban areas. This brief article discusses the history of HIV epidemics in China and the challenges facing the current AIDS control efforts in the country. It explains that only scientific approaches can sustain the national AIDS control programs and introduce the type of research needed to address those challenges. The selected research areas include molecular epidemiology, drug resistance surveillance, and the Chinese HIV vaccine research.

In this paper, the global adaptive neural control with finite-time (FT) convergence learning performance for a general class of nonlinear robot manipulators has been investigated. The scheme proposed in this paper offers a subtle blend of neural controller with robust controller, which palliates the limitation of neural approximation region to ensure globally uniformly ultimately bounded (GUUB) stability by integrating a switching mechanism. Morever, the proposed scheme guarantees the estimated neural weights converging to optimal values in finite time by embedding an adaptive learning algorithm driven by the estimated weights error. The optimal weights obtained through the learning process of the neural networks (NNs) will be reused next time for repeated tasks, and can thus reduce computational load, improve transient performance and enhance robustness. The simulation studies have been carried out to demonstrate the superior performance of the controller in comparison to the conventional methods.

Science and technology parks (STPs) are established to promote the firm innovation performance via agglomeration economy and government support in China. On-site qualified firms obtain government R&D funding as a type of government support, and they are offered differential innovation service caused by the differential capabilities of subparks which scatter throughout a single city. It is debatable whether those government supports at firm and sub-park levels can promote firm innovation capabilities. This study takes Zhangjiang National Innovation Demonstration Zone, Shanghai as an example. It applies a Tobit regression model to analyse the databases of Zhangjiang Annual Sampling Survey of Firms 2015 and Zhangjiang Development Report 2015. We find out at the firm level, government R&D funding has a significant and positive influence on firms' innovation, but government R&D funding generates a crowing-out effect the innovation performance of on-site firms with more R&D investment themselves. At the sub-park level, innovation service agencies of sub-parks do not exert an important role in influencing firms' innovation, and they even have negative moderating effects on the relationship 750 |