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1.  EEG Classification for Hybrid Brain-Computer Interface Using a Tensor Based Multiclass Multimodal Analysis Scheme 
Electroencephalogram- (EEG-) based brain-computer interface (BCI) systems usually utilize one type of changes in the dynamics of brain oscillations for control, such as event-related desynchronization/synchronization (ERD/ERS), steady state visual evoked potential (SSVEP), and P300 evoked potentials. There is a recent trend to detect more than one of these signals in one system to create a hybrid BCI. However, in this case, EEG data were always divided into groups and analyzed by the separate processing procedures. As a result, the interactive effects were ignored when different types of BCI tasks were executed simultaneously. In this work, we propose an improved tensor based multiclass multimodal scheme especially for hybrid BCI, in which EEG signals are denoted as multiway tensors, a nonredundant rank-one tensor decomposition model is proposed to obtain nonredundant tensor components, a weighted fisher criterion is designed to select multimodal discriminative patterns without ignoring the interactive effects, and support vector machine (SVM) is extended to multiclass classification. Experiment results suggest that the proposed scheme can not only identify the different changes in the dynamics of brain oscillations induced by different types of tasks but also capture the interactive effects of simultaneous tasks properly. Therefore, it has great potential use for hybrid BCI.
PMCID: PMC4735917  PMID: 26880873
2.  Sexual partnerships with men and women among men who have sex with men in Beijing and Chongqing, China, 2010 
AIDS and behavior  2014;18(1):180-188.
HIV is spreading among Chinese MSM and may possibly lead to infection of female partner. Pressure to marry may drive a greater proportion of Chinese MSM to have female partners than MSM elsewhere in the world. Measurement of the size of the potential risk to female partners of Chinese MSM is inconsistent in literature. From samples of MSM in two Chinese cities, we documented numbers of sexual partners and sexual activity with those partners. About 500 MSM were sampled in each city. 11.0% and 12.6% of men reported having any female partners in the past six months in Chongqing and Beijing, respectively. Men also reported that only 7.3% and 6.7% of their entire partnerships were with women in Chongqing and Beijing, respectively. Defining transmission risk accounting for receptive anal sex among men and condom non-use with both male and female partners 3.4% of MSM in both Chongqing and Beijing would have the potential to transmit HIV to female partners. Only 9 (1.8%) men in Chongqing and 2 (0.4%) in Beijing were HIV-positive and also had unprotected intercourse with females. The majority of HIV transmission risk among MSM in China is not from MSM to females.
PMCID: PMC4441273  PMID: 23666182
MSM, sexual partnerships; China; HIV; risk taking; bridging; female partners
3.  The AIDS epidemic and economic input impact factors in Chongqing, China, from 2006 to 2012: a spatial-temporal analysis 
BMJ Open  2015;5(3):e006669.
To analyse the spatial-temporal clustering of the HIV/AIDS epidemic in Chongqing and to explore its association with the economic indices of AIDS prevention and treatment.
Data on the HIV/AIDS epidemic and economic indices of AIDS prevention and treatment were obtained from the annual reports of the Chongqing Municipal Center for Disease Control for 2006–2012. Spatial clustering analysis, temporal-spatial clustering analysis, and spatial regression were used to conduct statistical analysis.
The annual average new HIV infection rate, incidence rate for new AIDS cases, and rate of people living with HIV in Chongqing were 5.97, 2.42 and 28.12 per 100 000, respectively, for 2006–2012. The HIV/AIDS epidemic showed a non-random spatial distribution (Moran’s I≥0.310; p<0.05). The epidemic hotspots were distributed in the 15 mid-western counties. The most likely clusters were primarily located in the central region and southwest of Chongqing and occurred in 2010–2012. The regression coefficients of the total amount of special funds allocated to AIDS and to the public awareness unit for the numbers of new HIV cases, new AIDS cases, and people living with HIV were 0.775, 0.976 and 0.816, and −0.188, −0.259 and −0.215 (p<0.002), respectively.
The Chongqing HIV/AIDS epidemic showed temporal-spatial clustering and was mainly clustered in the mid-western and south-western counties, showing an upward trend over time. The amount of special funds dedicated to AIDS and to the public awareness unit showed positive and negative relationships with HIV/AIDS spatial clustering, respectively.
PMCID: PMC4386237  PMID: 25818270
4.  HIV-Testing Behavior and Associated Factors Among MSM in Chongqing, China 
Medicine  2014;93(27):e124.
The high and climbing human immunodeficiency virus (HIV) rates among Chinese men who have sex with men (MSM) bring huge pressure and challenge to acquired immune deficiency syndrome response work in China. This study examined HIV-testing behavior and describes the characteristics of recently tested MSM in Chongqing to address targeting HIV prevention interventions.
Two consecutive cross-sectional surveys were conducted among Chongqing MSM using respondent-driven sampling in 2009 and 2010. Information was collected regarding details on demographic characteristics, sexual practices with male and female partners, and HIV-testing experiences. Univariate and multivariate logistic regression analyses were performed to identify factors independently associated with recent HIV testing.
The final sample size included in our analyses was 992. The overall HIV prevalence was 13.4%, and HIV prevalence increased significantly from 11.6% in 2009 to 15.4% in 2010 (P = 0.08). The overall rate of HIV testing in the past 12 months was 44.6%, and the self-reported rates decreased significantly from 47.8% in 2009 to 41.1% in 2010 (P = 0.03). Factors independently associated with recent HIV testing included living in Chongqing >1 year (adjusted odds ratio [AOR] 1.8, 95% confidence interval [CI] 1.1–2.9), the age of most recent male partner ≤25 (AOR 1.5, 95% CI 1.1–2.1), not having unprotected insertive anal sex with most recent male partner in the past 6 months (AOR 1.5, 95% CI 1.1–2.0), disclosing HIV status to most recent male partner (AOR 2.8, 95% CI 2.0–3.8), and holding lower level of HIV-related stigma (AOR 1.1 per scale point, 95% CI 1.0–1.1).
The extremely high HIV prevalence and low annual testing level put MSM at high risk of HIV infection and transmission, and it is a priority to promote regular HIV testing among this group in order to control the spread of HIV in Chongqing, China.
PMCID: PMC4602788  PMID: 25501047
5.  HIV Prevention Services and Testing Utilization Behaviors among Men Who Have Sex with Men at Elevated Risk for HIV in Chongqing, China 
BioMed Research International  2014;2014:174870.
Objective. To investigate barriers and correlates of the use of HIV prevention services and HIV testing behaviors among men who have sex with men in Chongqing. Methods. Three consecutive cross-sectional surveys provided demographic, sexual behavior, HIV/syphilis infection, HIV prevention service, and testing behavior data. Results. Of 1239 participants, 15.4% were infected with HIV, incidence was 12.3 per 100 persons/year (95% CI: 9.2–15.3), 38% of the participants reported ever having unprotected insertive anal sex, 40% ever received free condom/lubricants in the past year, and 27.7% ever obtained free sexually transmitted infection examination/treatment in the past year. Multivariable logistic regression revealed that lower levels of HIV/AIDS related stigmatizing/discriminatory attitudes, full-time jobs, and sex debut with men at a younger age were independently associated with use of free condom/lubricants. Large social networks, higher incomes, and sexual debut with men at a younger age were associated with use of any HIV prevention and HIV testing services. Lower levels of stigmatizing/discriminatory attitudes were also associated with HIV testing. Fearing needles and being unaware of the venues for testing were top barriers for testing service utilization. Conclusion. It is imperative to address HIV/AIDS related stigmatizing/discriminatory attitudes and other barriers while delivering intervention and testing services.
PMCID: PMC3982458  PMID: 24783195
6.  The Dynamic Trends of HIV Prevalence, Risks, and Prevention among Men Who Have Sex with Men in Chongqing, China 
BioMed Research International  2014;2014:602719.
Objective. This study was to characterize the continuously changing trends of HIV prevalence, risks, sexual behaviors, and testing behaviors among men who have sex with men (MSM) in Chongqing, China. Methods. Five consecutive cross-sectional surveys were conducted among MSM in 2006, 2008, 2010, 2012, and 2013. Testing for HIV and syphilis was performed, and HIV risks, sexual behavior, prevention, and HIV testing behavior were collected using the same questionnaire. Results. HIV prevalence increased from 13.0% to 19.7% from 2006 to 2013 (P = 0.004), with an increase of 1.0% per year. Syphilis prevalence peaked in 2008 with a positive rate of 11.6% and then experienced a sharp drop to 2.8% in 2012 and 2.9% in 2013. Percentage of those who ever received HIV testing in the last year increased from 17.0% to 43.3% (P < 0.001); condom use at the last anal intercourse and reported consistent condom use in the last 6 months increased from 51.8% to 71.0% (P < 0.001) and from 24.7% to 47.9% (P < 0.001), respectively. Conclusions. HIV continued to spread among MSM in Chongqing even when a decline in prevalence of syphilis and increase in awareness rate, condom use, and HIV testing seeking behaviors seemed to occur.
PMCID: PMC3982456  PMID: 24783216
7.  Predictors of HIV testing among men who have sex with men in a large Chinese city 
Sexually transmitted diseases  2013;40(3):235-240.
HIV testing is the gateway for prevention and care. We explored factors associated with HIV testing among Chinese men who have sex with men (MSM).
In Chongqing City, we recruited 492 MSM in 2010 using respondent driven sampling in a cross-sectional study. Computer-assisted self-interviews were conducted to collect information on history of HIV testing.
Only 58% of participants reported ever having taken an HIV test. MSM who had a college degree [adjusted odds ratio (AOR): 1.7; 95% confidence interval (CI): 1.2-2.6; P=0.008] were more likely to take a test; those who preferred a receptive role in anal sex were less likely to do so than those with insertive sex preference (AOR: 0.6; 95% CI: 0.35-0.94; P=0.03); those who used condoms with the recent male partner during the past 6 months were more likely to get tested (AOR: 2.87; 95%CI: 1.25-6.62; P=0.01). Principal perceived barriers to testing included: fear of knowing a positive result, fear of discrimination if tested positive, low perceived risk of HIV infection, and not knowing where to take a test. Factors reported to facilitate testing were sympathetic attitudes from health staff and guaranteed confidentiality. Prevalence was high: 11.7% HIV-positive and 4.7% syphilis positive.
The HIV testing rate among MSM in Chongqing is still low, though MSM prevalence is high compared to other Chinese cities. MSM preferring receptive anal sex are less likely to get testing and perceive having lower HIV risk. Along with expanded education and social marketing, a welcoming and non-judgmental environment for HIV testing is needed.
PMCID: PMC3725775  PMID: 23403605
Human immunodeficiency virus; syphilis; men who have sex with men; HIV testing; respondent driven sampling; China
8.  Participation of HIV prevention programs among men who have sex with men in two cities of China—a mixed method study 
BMC Public Health  2012;12:847.
Although various HIV prevention programs targeting men who have sex with men (MSM) are operating in China, whether and how these programs are being utilized is unclear. This study explores participation of HIV prevention programs and influencing factors among MSM in two cities in China.
This is a mixed-method study conducted in Beijing and Chongqing. A qualitative study consisting of in-depth interviews with 54 MSM, 11 key informants, and 8 focus group discussions, a cross-sectional survey using respondent-driven sampling among 998 MSM were conducted in 2009 and 2010 respectively to elicit information on MSM’s perception and utilization of HIV prevention programs. Qualitative findings were integrated with quantitative multivariate factors to explain the quantitative findings.
Fifty-six percent of MSM in Chongqing and 75.1% in Beijing ever participated in at least one type of HIV prevention program (P=0.001). Factors related to participation in HIV prevention programs included age, ethnicity, income, HIV risk perception, living with boyfriend, living in urban area, size of MSM social network, having talked about HIV status with partners, and knowing someone who is HIV positive. Reasons why MSM did not participate in HIV prevention programs included logistical concerns like limited time for participation and distance to services; program content and delivery issues such as perceived low quality services and distrust of providers; and, cultural issues like HIV-related stigma and low risk perception.
The study shows that there is much room for improvement in reaching MSM in China. HIV prevention programs targeting MSM in China may need to be more comprehensive and incorporate the cultural, logistic and HIV-related needs of the population in order to effectively reach and affect this population’s risk for HIV.
PMCID: PMC3570394  PMID: 23039880
MSM; HIV prevention programs; Utilization; Participation; China
9.  Predictors of HIV and Syphilis among Men Who Have Sex with Men in a Chinese Metropolitan City: Comparison of Risks among Students and Non-Students 
PLoS ONE  2012;7(5):e37211.
Men who have sex with men (MSM) are at a substantial risk of HIV, given rising HIV prevalence in urban China. Adolescent and adult students often take HIV-related risk as part of sexual exploration. We compared the risks of HIV and syphilis infections and risky sexual behaviors between student and non-student among urban MSM.
Respondent driven sampling approach was used to recruit men who were self-identified as MSM in Chongqing Metropolitan City in southwestern China in 2009. Each participant completed a computer-assisted self-interview which collected demographic and behavioral data, and provided blood specimens for HIV and syphilis testing. Multivariable logistic regression analyses identified predictors for HIV and syphilis infections while comparing student and non-student MSM.
Among 503 MSM participants, 36.4% were students, of whom 84.2% were in college. The adjusted prevalence of HIV infection was 5.5% (95% confidence interval [CI]: 2.1%–10.2%) in students and 20.9% (95% CI: 13.7%–27.5%) in non-students; the adjusted prevalence of syphilis was 4.4% (95% CI: 0.7%–9.0%) in students and 7.9% (95% CI: 3.6%–12.9%) in non-students (P = 0.12). Two groups had similar risky sexual behaviors such as number of sexual partners and exchanging sex for money. Multivariate analysis showed that students had lower HIV prevalence than non-students (adjusted odds ratio [AOR]: 0.3; 95% CI: 0.1–0.8) adjusting for age, ethnicity and other variables.
Student MSM have lower HIV and similar syphilis prevalence compared with non-student MSM. However, due to a shorter duration of sexual experience and high prevalence of at-risk sexual behaviors among student MSM, HIV risk might be quite high in students as in non-students.
PMCID: PMC3356386  PMID: 22623994

Results 1-9 (9)