Long-term exposure to ambient particulate matter is associated with prognosis in people living with HIV/AIDS: Evidence from a longitudinal study.

BACKGROUND: Evidence on the association between particulate matter (PM) exposure and prognosis in people living with HIV/AIDS (PWHA) is scarce. We aim to investigate the associations of long-term exposure to PM with AIDS-related deaths and complications. METHODS: We collected follow-up information on 7444 PWHAs from 2000 to 2021 from the HIV/AIDS Comprehensive Response Information Management System of the Wuhan Center for Disease Control and Prevention. The AIDS-related deaths and complications were assessed by physicians every 3 to 6 months, and the monthly average PM concentrations for each PWHA were extracted from the China High Air Pollutants dataset. We employed time-varying Cox regression models to evaluate the associations of the average cumulative PM exposure concentrations with AIDS-related deaths and complications, as well as the mediating effects of AIDS-related complications in PM-induced AIDS-related deaths. RESULTS: For each 1 µg/m3 increase in PM1, PM2.5, and PM10, the adjusted hazard ratios (HRs) for AIDS-related deaths were 1.021 (1.009, 1.033), 1.012 (1.005, 1.020), and 1.010 (1.005, 1.015), respectively; and the HRs for AIDS-related complications were 1.049 (1.034, 1.064), 1.029 (1.020, 1.038), and 1.031 (1.024, 1.037), respectively. AIDS-related complications mediated 18.38 % and 18.68 % of the association of exposure to PM1 and PM2.5 with AIDS-related deaths, respectively. The association of PM exposure with AIDS-related deaths was more significant in older PWHA. Meanwhile, the association between PM exposure and AIDS-related complications was stronger in PWHA with a BMI ≥ 24 kg/m2. CONCLUSION: Long-term exposure to PM is positively associated with AIDS-related deaths and complications, and AIDS-related complications have mediating effects in PM-induced AIDS-related deaths. Our evidence emphasizes that enhanced protection against PM exposure for PWHAs is an additional mitigation strategy to reduce AIDS-related deaths and complications.

Feasibility of a Mobile Health Intervention for Providing a Continuum of HIV Services for MSM: Pilot Study of the WeTest Program in 3 Cities in China.

BACKGROUND: Men who have sex with men (MSM) in China have a high risk for HIV infection but experience suboptimal rates of HIV testing and service engagement due to various social and structural barriers. We developed a mobile health (mHealth) intervention entitled "WeTest-Plus" (WeTest+) as a user-centered "one-stop service" approach for delivering access to comprehensive information about HIV risk, HIV self-testing, behavioral and biomedical prevention, confirmatory testing, treatment, and care. OBJECTIVE: The goal of the current study was to investigate the feasibility of WeTest+ to provide continuous HIV services to high-risk MSM. METHODS: Participants completed a 3-week pilot test of WeTest+ to examine acceptability, feasibility, and recommendations for improvement. Participants completed a structured online questionnaire and qualitative exit interviews facilitated by project staff. "Click-through" rates were assessed to examine engagement with online content. RESULTS: 28 participants were included, and the average age was 27.6 years (standard deviation = 6.8). Almost all participants (96.4%) remained engaged with the WeTest+ program over a 3-week observational period. The majority (92.9%) self-administered the HIV self-test and submitted their test results through the online platform. Overall click-through rates were high (average 67.9%). Participants provided favorable comments about the quality and relevance of the WeTest+ information content, the engaging style of information presentation, and the user-centered features. CONCLUSION: This pilot assessment of WeTest+ supports the promise of this program for promoting HIV self-testing and linkage to in-person services for MSM in China. Findings underscore the utility of a user-centered approach to mHealth program design.

Short-Term Exposure to PM2.5 and O3 Impairs Liver Function in HIV/AIDS Patients: Evidence from a Repeated Measurements Study.

Studies investigating the relationship between ambient air pollutants and liver function are scarce. Our objective was to examine the associations of acute exposure to PM2.5 and O3 with levels of hepatic enzymes in people living with HIV/AIDS (PWHA). Our study involved 163 PWHA, who were evaluated for serum hepatic enzymes up to four times within a year. We extracted daily average concentrations of PM2.5, PM2.5 components, and O3 for each participant, based on their residential address, using the Tracking of Air Pollution in China database. Linear mixed-effect models were utilized to assess the associations of acute exposure to PM2.5 and O3 with hepatic enzymes. Weighted quantile sum regression models were employed to identify the major constituents of PM2.5 that affect hepatic enzymes. The percent change of aspartate aminotransferase (AST) concentration was positively correlated with a 10 µg/m3 increase in PM2.5, ranging from 1.92 (95% CI: 3.13 to 4.38) to 6.09 (95% CI: 9.25 to 12.38), with the largest effect observed at lag06. Additionally, acute O3 exposure was related to increased levels of alanine aminotransferase (ALT), AST, and alkaline phosphatase (ALP) concentrations. Co-exposure to high levels of PM2.5 and O3 had an antagonistic effect on the elevation of AST. Further analysis revealed that SO42- and BC were major contributors to elevated AST concentration due to PM2.5 constituents. A stronger association was found between O3 exposure and ALT concentration in female PWHA. Our study found that short-term exposure to PM2.5 and O3 was associated with increased levels of hepatic enzymes, indicating that PM2.5 and O3 exposure may contribute to hepatocellular injury in PWHA. Our study also found that PWHA may be more vulnerable to air pollution than the general population. These findings highlight the relationship between air pollutants and liver function in PWHA, providing a scientific basis for the implementation of measures to protect susceptible populations from the adverse effects of air pollution. A reduction in the burning of fossil fuels and reduced exposure to air pollutants may be effective hazard reduction approaches.

Short-term associations of PM2.5 and PM2.5 constituents with immune biomarkers: A panel study in people living with HIV/AIDS.

Studies on associations of fine particulate matter (PM2.5) with immunity in people living with HIV/AIDS (PLWHA) were absent. We aimed to explore whether changes of immune biomarkers were associated with short-term exposure to PM2.5 in PLWHA. Based on a panel study in Wuhan, we selected 163 PLWHA as participants with up to 4 repeated visits from March 2020 to January 2021. Immune biomarkers, including CD4+T cell count, CD8+T cell count, HIV viral load (VL) and CD4+T/CD8+T ratio were tested for all participants at each visit. Residential exposures of PM2.5 and PM2.5 constituents for each participant were assessed using spatial-temporal models. Linear mixed-effect models and general linear mixed models were applied to evaluate the associations between PM2.5 and immune biomarkers. To estimate the combined effect of PM2.5 constituents, weighted quantile sum regression and Bayesian kernel machine regression were employed. Each 10 µg/m3 increase of 7-day average PM2.5 concentrations was associated with an 8.75 cells/mm3 (95%CI: -15.55, -1.98) decrease in CD4+T cell count and a 92% (OR: 1.92, 95%CI: 1.43, 2.58) increased odds ratio of detectable HIV VL. However, the odds ratio of inverted CD4+T/CD8+T was only positively associated with PM2.5 concentrations at lag2 day (OR:1.27, 95%CI:1.02, 1.57). CD4+T may be a potential mediator between PM2.5 and detectable HIV VL with 3.83% mediated proportion. Besides, the combined effect of PM2.5 chemical constituents indicated that NO3- and SO42- were the main constituents in reducing CD4+T cell count and increasing odds ratio of detectable HIV VL. Our finding revealed that short-term exposure to PM2.5 was negatively associated with CD4+T cell count but positively related to the odds ratio of detectable HIV VL in PLWHA. This research may provide new evidence in associations between PM2.5 and immune biomarkers as well as improving prognosis of PLWHA.

Effects of Case Management on Risky Sexual Behaviors and Syphilis Among HIV-Infected Men Who Have Sex With Men in China: A Randomized Controlled Study.

BACKGROUND: The prevalence of syphilis is very high in human immunodeficiency virus (HIV)-positive men who have sex with men (MSM), and effective interventions are needed to educate HIV-positive individuals about behavioral and biological risk factors. Therefore, we developed a standard case management process and conducted a randomized controlled study to investigate the impact on risky sexual behaviors and syphilis in HIV-positive MSM. METHODS: Men who have sex with men (n = 220) were enrolled and randomized to the case management intervention group and the control group between May 2016 and January 2017. The control group received routine HIV-related care. In addition to routine HIV-related care, those in the intervention group regularly received extended services from a well-trained case manager. Epidemiological information was collected during the baseline face-to-face interviews by a trained investigator. Serological tests for syphilis and assessments of risky sexual behaviors were performed at baseline and 6 and 12 months after the initiation of treatment. RESULTS: The syphilis incidence rates in the intervention and control groups were 11.3 per 100 person-years and 20.6 per 100 person-years, respectively. The multivariable-adjusted hazard ratio (95% confidence inter) for syphilis in case management group was 0.34 (0.14-0.87). The percentages of participants who resumed risky sexual behaviors in both groups were significantly reduced (P < 0.05) but did not significantly differ between the 2 groups. CONCLUSIONS: A case management intervention reduced the incidence of syphilis in HIV-positive MSM. We should further increase the content of case management on the basis of providing routine HIV-related care to those people.

Brief Report: Virologic and Immunologic Outcomes for HIV Patients With Coronavirus Disease 2019.

BACKGROUND: To describe the virologic and immunologic outcomes among people living with HIV (PLHIV) coinfected with SARS-CoV-2. SETTING: Wuhan, China. METHODS: Thirty-five coinfected patients were identified by matching the reported cases in National Notifiable Infectious Disease Report system for COVID-19 and HIV in Wuhan by time of April 19, 2020. Questionnaire-based survey and follow-up with blood sample collection were used to obtain characteristics before COVID-19 and after recovery. Nonparametric Mann-Whitney U test, χ2, or Fisher exact test, Mcnemar test, and Wilcoxon test were conducted. RESULTS: Twenty of the 35 coinfected patients were identified as asymptomatic/mild/moderate COVID-19 (nonsevere group) and 15 were identified as severe/critical (severe group). The severe and nonsevere group had no differences in demographics, HIV baseline status, the intervals between last tests and follow-up tests for CD4+ cell count and HIV-1 viral load (all P > 0.05). Overall, there was a significantly increased number of coinfected patients with HIV-1 viral load ≥20 copies/mL after recovery (P = 0.008). The median viral load increased significantly after recovery in severe group (P = 0.034), whereas no significant change of HIV-1 viral load was observed in the nonsevere group. Limited change of CD4+ cell count was found (all P > 0.05). CONCLUSION: The coinfection of SARS-CoV-2 may put PLHIV at greater risk for HIV-1 viral rebound especially for severe/critical COVID-19, whereas it had limited impacts on CD4+ cell count. Whether continuous antiretroviral therapy against HIV infection would have significant impacts on CD4+ cell count among PLHIV coinfected with SARS-CoV-2 needs further research.

Epidemiological, Virological and Serological Features of Coronavirus Disease 2019 (COVID-19) Cases in People Living With Human Immunodeficiency Virus in Wuhan: A Population-based Cohort Study.

BACKGROUND: We aimed to describe the epidemiological, virological, and serological features of coronavirus disease 2019 (COVID-19) cases in people living with human immunodeficiency virus (HIV; PLWH). METHODS: This population-based cohort study identified all COVID-19 cases among all PLWH in Wuhan, China, by 16 April 2020. The epidemiological, virological, and serological features were analyzed based on the demographic data, temporal profile of nucleic acid test for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the disease, and SARS-CoV-2-specific immunoglobin (Ig) M and G after recovery. RESULTS: From 1 January to 16 April 2020, 35 of 6001 PLWH experienced COVID-19, with a cumulative incidence of COVID-19 of 0.58% (95% confidence interval [CI], .42-.81%). Among the COVID-19 cases, 15 (42.86) had severe illness, with 2 deaths. The incidence, case-severity, and case-fatality rates of COVID-19 in PLWH were comparable to those in the entire population in Wuhan. There were 197 PLWH who had discontinued combination antiretroviral therapy (cART), 4 of whom experienced COVID-19. Risk factors for COVID-19 were age ≥50 years old and cART discontinuation. The median duration of SARS-CoV-2 viral shedding among confirmed COVID-19 cases in PLWH was 30 days (interquartile range, 20-46). Cases with high HIV viral loads (≥20 copies/mL) had lower IgM and IgG levels than those with low HIV viral loads (<20 copies/ml; median signal value divided by the cutoff value [S/CO] for IgM, 0.03 vs 0.11, respectively [P < .001]; median S/CO for IgG, 10.16 vs 17.04, respectively [P = .069]). CONCLUSIONS: Efforts are needed to maintain the persistent supply of antiretroviral treatment to elderly PLWH aged 50 years or above during the COVID-19 epidemic. The coinfection of HIV and SARS-CoV-2 might change the progression and prognosis of COVID-19 patients in PLWH.

Epidemiology of COVID-19 in older persons, Wuhan, China.

BACKGROUND: the epidemiological characteristics of older patients with COVID-19 was far from clear. OBJECTIVE: to explore the epidemiology of older patients with COVID-19 in Wuhan, China. DESIGN: a retrospective cross-sectional study. SETTING: a population-based study. SUBJECTS: the resident older patients (>65 years) diagnosed with COVID-19. METHODS: city-wide case series reported to Wuhan Center for Disease Control and Prevention from 12 December 2019 to 17 March 2020 were included. The epidemic curves were constructed by dates of disease onset. RESULTS: 14,238 confirmed COVID-19 cases were older persons. The number of male cases were slightly less than female cases (1:1.01). The attack rate of COVID-19 in the older persons was 11.49‰ in Wuhan. There was a rapid increase of disease at the early stage of the epidemic and then a gradual and steady decrease was performed. 3,723 (26.15%) and 734 (5.16%) patients were diagnosed as severe and critical cases, respectively. The attributable crude fatality ratio of COVID-19 in the older population was 222.57/100,000, and the crude fatality ratio of COVID was 19.37%. The proportion of severe and critical cases, and fatality ratio were both higher in downtown area and increased with age. CONCLUSIONS: the older persons are sensitive to COVID-19. The proportion of severe and critical cases and fatality ratio are higher than that in children and younger adults. Strengthen the protection and control strategies for the older adults are of priorities. More detailed epidemiological and clinical information should be measured in further studies.

[Mode of antiretroviral treatment based on the medical needs of people living with HIV/AIDS].

OBJECTIVE: To explore and evaluate the model of antiretroviral treatment that oriented to the medical needs of people living with HIV/AIDS (HIV/AIDS), based on the local prevalence of HIV/AIDS. METHODS: A total of 268 HIV/AIDS were selected the CDC of 13 administrative district in Wuhan from 2012 to 2013 and 275 HIV/AIDS were selected in the hospitals of 13 administrative district in Wuhan from 2013 to 2014. The antiretroviral effect of the two groups was compared and the related factors were analyzed. RESULTS: An antiretroviral treatment network that oriented to the medical needs of HIV/AIDS was developed. Data showed that the adherence of patients was better than that when the treatment was carried out at the CDC offices and the status of immuno-recovery on HIV/AIDS was more effective than the hospital-based treatment (P<0.05). Data from multivariable logistic regression analysis showed that different patterns did play different roles on the effects of treatment. CONCLUSIONS: The mode of antiretroviral treatment that oriented to the medical needs of HIV/AIDS could effectively improve the adherence and outcomes of treatment. We believe this model could also be adopted elsewhere.

[Social support for 330 HIV/AIDS patients under antiretroviral treatment and related factors in Wuhan].

OBJECTIVE: To investigate the current status of social support for HIV/AIDS patients under antiretroviral treatment (ART) and related factors in Wuhan. METHODS: Social Support Rating Scale (SSRS) was used to analyze the current status of social support for HIV/AIDS patients under ART in Wuhan. Student's t test, analysis of variance (ANOVA) and multiple linear regression model were used to identify the related factors. RESULTS: The scores of subjective support, objective support, utilization of social support, and overall social support for 330 HIV/AIDS patients were significant lower than the national norm (P < 0.05). Multiple linear regression analysis showed that the subjective support (ß' = -0.260), objective support (ß' = -0.196) and overall social support (ß' = -0.141) for the patients who were unmarried, divorced or widowed were worse than those for the patients who were married (P < 0.05). The patients with higher educational level had more objective support (ß' = 0.250) and utilization of social support (ß' = 0.232) than those with lower educational level (P < 0.05). The subjective support for patients without HIV related symptoms in the past two weeks was better than those with HIV related symptoms (ß' = 0.232, P < 0.05). CONCLUSION: The current status of social support for HIV/AIDS patients under ART in Wuhan was worse than that for healthy people. More attention should be paid to HIV/AIDS patients with worse social support.

Late HIV Diagnosis: Proposed Common Definitions and Associations With Short-Term Mortality.

The aim of this study was to present a definition of late presentation according to different time periods between initial diagnosis of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS) diagnosis which would reliably identify individuals with high risk of mortality within 1 year of diagnosis, and could be used as a suggested common definition.Data of individuals diagnosed from 1994 to February 2012 in Wuhan, China were extracted retrospectively from the national HIV surveillance system. Four time periods (1, 3, 6, and 12 months) combined with the European consensus definition of advanced HIV disease (AHD) were compared. The predictive ability of each definition for identifying an individual who died within 1 year after HIV diagnosis was assessed.A total of 980 patients were included, of whom 289 (29.49%), 324 (33.06%), 353 (36.02%), and 387 (39.49%) were defined as AHD according to the definition of a CD4 count <200 cells/µL or AIDS-defining event (ADE) within 1, 3, 6, and 12 months of HIV diagnosis, respectively. One hundred twenty-seven (12.96%) patients died within 1 year of diagnosis. The highest Youden's index and largest area under the curve were presented in time period within 3 months. Time period within 1 month presented the highest consistency rate, positive likelihood ratio, and kappa value. Longer time periods increased the sensitivity but decreased the specificity.Given the European consensus definitions and the current results, we suggested that AHD could be defined as "a first-reported CD4 count <200 cells/µL or an ADE within 1 month after HIV diagnosis." "Late presentation" could be defined as "a first-reported CD4 count <350 cells/µL or an ADE within 1 month after HIV diagnosis."

Risk Factors for Advanced HIV Disease and Late Entry to HIV Care: National 1994-2012 HIV Surveillance Data for Wuhan, China.

Few studies in China have focused on advanced human immunodeficiency virus (HIV) disease (AHD) and late entry to HIV care, which are associated with increased morbidity and mortality. A population-based retrospective study was conducted using 980 national HIV surveillance reports from 1994 to February 2012 in Wuhan, China. AHD was defined as presence of a first-reported CD4 count<200 cells/µL or an acquired immune deficiency syndrome (AIDS)-defining event within 1 month of HIV diagnosis. Late entry to HIV care was defined as patients with a first-reported CD4 cell count>6 months after diagnosis. Non-conditional logistic regression analysis was used to identify factors associated with AHD, late entry to HIV care, and AIDS within 1 year of HIV diagnosis. The proportions of AHD, AIDS within 1 year of HIV diagnosis, and late entry to HIV care were 29.49%, 39.39%, and 20.84%, respectively. Most of the deaths (74.27%, 127/171) occurred within 1 year of diagnosis. Short-term mortality, proportion of AHD, and late entry to HIV care showed a similar downward trend from pre-2003 to 2011 (p<0.001). Age, transmission category, sample source, and occupation were associated with AHD, late entry to HIV care, and AIDS within 1 year of HIV diagnosis in the multivariate logistic regression analysis. These findings indicate that AHD and late entry to HIV care were associated with an increased incidence of AIDS or death, particularly within 1 year of diagnosis. More effort should be made to assure early diagnosis and timely entry to care.

Hepatitis C seroconversion in methadone maintenance treatment programs in Wuhan, China.

BACKGROUND AND AIMS: To decrease infectious disease transmission, China is expanding methadone maintenance treatment (MMT). This study evaluated the prevalence of hepatitis C virus (HCV) infection at MMT entry, seroconversion rates after admission and potential risk factors for HCV seroconversion during MMT in Wuhan, China. DESIGN: Cross-sectional survey of all patients entering MMT and prospective follow-up of patients HCV seronegative at admission. SETTING: All MMT clinics in Wuhan, China. PARTICIPANTS: A total of 12 755 opiate-dependent individuals entering MMT between May 2006 and June 2011; 1200 participants HCV seronegative at admission were followed. MEASUREMENTS: Serological tests for HCV and self-report data on risk behaviors at MMT admission; urine toxicology results and repeated assessments of serological status and risk behaviors during treatment on patients HCV seronegative at admission. FINDINGS: HCV seroprevalence at admission was 72.1% [95% confidence interval (CI) = 71.3-72.9%] and 555/1200 (46.3%, 95% CI = 43.5-49.1%) patients seroconverted to HCV during MMT. The mean time to HCV seroconversion was 3 (95% CI = 2.84-3.07) years with a cumulative seroconversion rate of 34.5 (95% CI = 31.5-36.9) per 100 person-years. Significant predictors of HCV conversion included injection drug use in the past 30 days [relative hazard (RH) 2.0, 95% CI: 1.6 - 2.4, P=0.002] and the rate of opiate-positive urine tests during MMT (RH 2.0, 95% CI = 1.3-3.1, P<0.001). CONCLUSIONS: Methadone maintenance treatment patients in Wuhan, China show a high prevalence of hepatitis C virus at admission (72.1%) and a high rate of seroconversion during treatment (46.3%). Seroconversion is associated with continuing injection drug use.

Treatment adherence and health outcomes in MSM with HIV/AIDS: patients enrolled in "one-stop" and standard care clinics in Wuhan China.

BACKGROUND: Conducted in Wuhan China, this study examined follow-up and health markers in HIV patients receiving care in two treatment settings. Participants, all men who have sex with men, were followed for 18-24 months. METHOD: Patients in a "one-stop" service (ACC; N = 89) vs those in standard care clinics (CDC; N = 243) were compared on HIV treatment and retention in care outcomes. RESULTS: Among patients with CD4 cell count ≦350 cells/µL, the proportion receiving cART did not differ across clinic groups. The ACC was favored across five other indicators: proportion receiving tests for CD4 cell count at the six-month interval (98.2% vs. 79.4%, 95% CI 13.3-24.3, p = 0.000), proportion with HIV suppression for patients receiving cART for 6 months (86.5% vs. 57.1%, 95% CI 14.1-44.7, p = 0.000), proportion with CD4 cell recovery for patients receiving cART for 12 months (55.8% vs. 22.2%, 95% CI 18.5-48.6, p = 0.000), median time from HIV confirmation to first test for CD4 cell count (7 days, 95% CI 4-8 vs. 10 days, 95% CI 9-12, log-rank p = 0.000) and median time from first CD4 cell count ≦350 cells/µL to cART initiation (26 days, 95% CI 16-37 vs. 41.5 days, 95% CI 35-46, log-rank p = 0.031). Clinic groups did not differ on any biomedical indicator at baseline, and no baseline biomedical or demographic variables remained significant in the multivariate analysis. Nonetheless, post-hoc analyses suggest the possibility of self-selection bias. CONCLUSIONS: Study findings lend preliminary support to a one-stop patient-centered care model that may be useful across various HIV care settings.

Image classification using multiscale information fusion based on saliency driven nonlinear diffusion filtering.

In this paper, we propose saliency driven image multiscale nonlinear diffusion filtering. The resulting scale space in general preserves or even enhances semantically important structures such as edges, lines, or flow-like structures in the foreground, and inhibits and smoothes clutter in the background. The image is classified using multiscale information fusion based on the original image, the image at the final scale at which the diffusion process converges, and the image at a midscale. Our algorithm emphasizes the foreground features, which are important for image classification. The background image regions, whether considered as contexts of the foreground or noise to the foreground, can be globally handled by fusing information from different scales. Experimental tests of the effectiveness of the multiscale space for the image classification are conducted on the following publicly available datasets: 1) the PASCAL 2005 dataset; 2) the Oxford 102 flowers dataset; and 3) the Oxford 17 flowers dataset, with high classification rates.

Bin Ratio-Based Histogram Distances and Their Application to Image Classification.

Large variations in image background may cause partial matching and normalization problems for histogram-based representations, i.e., the histograms of the same category may have bins which are significantly different, and normalization may produce large changes in the differences between corresponding bins. In this paper, we deal with this problem by using the ratios between bin values of histograms, rather than bin values' differences which are used in the traditional histogram distances. We propose a bin ratio-based histogram distance (BRD), which is an intra-cross-bin distance, in contrast with previous bin-to-bin distances and cross-bin distances. The BRD is robust to partial matching and histogram normalization, and captures correlations between bins with only a linear computational complexity. We combine the BRD with the ℓ1 histogram distance and the χ(2) histogram distance to generate the ℓ1 BRD and the χ(2) BRD, respectively. These combinations exploit and benefit from the robustness of the BRD under partial matching and the robustness of the ℓ1 and χ(2) distances to small noise. We propose a method for assessing the robustness of histogram distances to partial matching. The BRDs and logistic regression-based histogram fusion are applied to image classification. The experimental results on synthetic data sets show the robustness of the BRDs to partial matching, and the experiments on seven benchmark data sets demonstrate promising results of the BRDs for image classification.

Application of the protection motivation theory in predicting cigarette smoking among adolescents in China.

Reducing tobacco use among adolescents in China represents a significant challenge for global tobacco control. Existing behavioral theories developed in the West - such as the Protection Motivation Theory (PMT) - may be useful tools to help tackle this challenge. We examined the relationships between PMT factors and self-reported cigarette smoking behavior and intention among a random sample of vocational high school students (N=553) in Wuhan, China. Tobacco-related perceptions were assessed using the PMT Scale for Adolescent Smoking. Among the total sample, 45% had initiated cigarette smoking, and 25% smoked in the past month. Among those who never smoked, 15% indicated being likely or very likely to smoke in a year. Multiple regression modeling analysis indicated the significance of the seven PMT constructs, the four PMT perceptions and the two PMT pathways in predicting intention to smoke and actual smoking behavior. Overall, perceived rewards of smoking, especially intrinsic rewards, were consistently positively related to smoking intentions and behavior, and self-efficacy to avoid smoking was negatively related to smoking. The current study suggests the utility of PMT for further research examining adolescent smoking. PMT-based smoking prevention and clinical smoking cessation intervention programs should focus more on adolescents' perceived rewards from smoking and perceived efficacy of not smoking to reduce their intention to and actual use of tobacco.

Determinants of progression to AIDS and death following HIV diagnosis: a retrospective cohort study in Wuhan, China.

OBJECTIVE: To identify determinants associated with disease progression and death following human immunodeficiency virus (HIV) diagnosis. METHODS: Disease progression data from the diagnosis of HIV infection or acquiring immunodeficiency syndrome (AIDS) to February 29, 2012 were retrospectively collected from the national surveillance system databases and the national treatment database in Wuhan, China. Kaplan-Meier method, Logistic regression and Cox proportional hazards model were applied to identify the related factors of progression to AIDS or death following HIV diagnosis. RESULTS: By the end of February 2012, 181 of 691 HIV infectors developed to AIDS, and 129 of 470 AIDS patients died among whom 289 cases received concurrent HIV/AIDS diagnosis. Compared with men infected through homosexual behavior, injection drug users possessed sharply decreased hazard ratio (HR) for progression to AIDS following HIV diagnosis [HR = 0.31, 95% confidence interval (CI), 0.18-0.54, P = 4.01×10(-5)]. HIV infectors at least 60 years presented 1.15-fold (HR = 2.15, 95% CI, 1.15-4.03, P = 0.017) increased risk to develop AIDS when compared with those aged 17-29 years. Similarly, AIDS patients with diagnosis ages between 50 and 59 years were at a 1.60-fold higher risk of death (HR = 2.60, 95% CI, 1.18-5.72, P = 0.017) compared to those aged 19-29 years. AIDS patients with more CD4(+) T-cells within 6 months at diagnosis (cell/µL) presented lower risk of death (HR = 0.29 for 50- vs <50, 95% CI, 0.15-0.59, P = 0.001). The highly active antiretroviral therapy (HAART) delayed progression to AIDS from HIV diagnosis (HR = 0.15, 95% CI, 0.07-0.34, P = 6.46×10(-6)) and reduced the risk of death after AIDS diagnosis (HR = 0.02, 95% CI, 0.01-0.04, P = 7.25×10(-25)). CONCLUSIONS: Progression to AIDS and death following HIV diagnosis differed in age at diagnosis, transmission categories, CD4(+) T-cell counts and HAART. Effective interventions should target those at higher risk for morbidity or mortality, ensuring early diagnosis and timely treatment to slow down the disease progression.

Unsupervised active learning based on hierarchical graph-theoretic clustering.

Most existing active learning approaches are supervised. Supervised active learning has the following problems: inefficiency in dealing with the semantic gap between the distribution of samples in the feature space and their labels, lack of ability in selecting new samples that belong to new categories that have not yet appeared in the training samples, and lack of adaptability to changes in the semantic interpretation of sample categories. To tackle these problems, we propose an unsupervised active learning framework based on hierarchical graph-theoretic clustering. In the framework, two promising graph-theoretic clustering algorithms, namely, dominant-set clustering and spectral clustering, are combined in a hierarchical fashion. Our framework has some advantages, such as ease of implementation, flexibility in architecture, and adaptability to changes in the labeling. Evaluations on data sets for network intrusion detection, image classification, and video classification have demonstrated that our active learning framework can effectively reduce the workload of manual classification while maintaining a high accuracy of automatic classification. It is shown that, overall, our framework outperforms the support-vector-machine-based supervised active learning, particularly in terms of dealing much more efficiently with new samples whose categories have not yet appeared in the training samples.