Night lights observations significantly improve the explainability of intra-annual vegetation growth globally.

Understanding the underlying mechanism of vegetation growth is of great significance to improve our knowledge of how vegetation growth responds to its surrounding environment, thereby benefiting the prediction of future vegetation growth and guiding environmental management. However, human impacts on vegetation growth, especially its intra-annual variability, still represent a knowledge gap. Night Lights (NL) have been demonstrated as an effective indicator to characterize human activities, but little is known about the potential improvement of intra-annual vegetation growth using seasonal NL observations. To address this gap, we investigated and quantified the explainability improvement of intra-annual vegetation growth by establishing a multiple linear regression model for vegetation growth (indicated by Normalized Difference Vegetation Index, NDVI) with human factor (indicated by NL observations here) and three climatic factors, i.e., temperature, water availability, and solar radiation using the Principal Components Regression (PCR) method. Results indicate that NL observations significantly improve our understanding of intra-annual vegetation growth globally. Model explainability, i.e., adjusted R2 metric of the PCR model, was comparatively improved by 54 % on average with a median value of 11 % when taking NL observations into consideration. Such improvement occurred in 82 % of the whole investigation pixels. We found that the improvement of model explanatory power was significant in regions where both NL and NDVI trends were large, except for the case where both of their trends were negative. At the country-level, the improvement of model explanatory power increases as GDP decreases, illustrating a greater improvement in a lower middle-income country than that in a high-income country. Our findings emphasize the importance of considering human activities (indicated by NL here) in vegetation growth, offering novel insights into the explanation of intra-annual vegetation growth.

Impact of Educational Interventions on Acceptance and Uptake of Male Circumcision in the General Population of Western China: A Multicenter Cohort Study.

To compare different intervention models for promoting male circumcision (MC) to prevent HIV transmission in Western China. A total of 1690 male participants from multiple study sites were cluster randomly allocated to three-stage (Model A), two-stage (Model B), and one-stage (Model C) educational interventions. In all three interventions models, knowledge about MC significantly increased and the reported willingness to accept MC increased to 52.6% (255/485), 67.0% (353/527), and 45.5% (219/481) after intervention, respectively (P < 0.05). Rate of MC surgery uptake was highest (23.7%; 115/485) among those who received Model A intervention, compared to those who received Model B (17.1%; 90/527) or Model C (9.4%; 45/481) interventions (P < 0.05). Multivariable Cox regression analysis identified that Model A or Model B had twice the effect of Model C on MC uptake, with relative risks of 2.4 (95%CI, 1.5-3.8) and 2.2 (95%CI, 1.3-3.6), respectively. Model B was the most effective model for improving participants' willingness to accept MC, while Model A was most successful at increasing uptake of MC surgery. Self-reported attitude towards MC uptake was not strongly correlated with actual behavior in this study focusing on the general male population in Western China.

Commercial Sexual Behaviors Among Male Rural-to-Urban Migrants in Western China: Implications for HIV Prevention.

Rural-to-urban migrants are at high risk of HIV infection. The goal of this survey was to explore the commercial sexual behavior and condom use among male rural-to-urban migrants in western China. A cross-sectional survey on male rural-to-urban migrants in western China was conducted. Among all the subjects surveyed, 140 (7.4%) had commercial sexual behavior, which is associated with being aged older than 24 years, being of Han or other ethnic minorities, being divorced, separated, or widowed, having experienced drug abuse, having had heterosexual behavior, having had casual sexual partners, having had sex with a homosexual, and being from Xinjiang. A total of 31.4% of them never use condoms when buying sex. Not using condoms is associated with being from Chongqing, having a high school or above education, and having commercial sex monthly. Commercial sexual behavior and not using condoms are common among male rural-to-urban migrants in western China. Strategies and appropriate education should be developed to prevent HIV transmission due to high-risk sexual behaviors.

Assessment of Different Intervention Models of Male Circumcision and Their Preliminary Effectiveness in Reducing HIV Incidence Among Drug Users in Western China.

World Health Organization (WHO) and Joint United Nations Program on AIDS (UNAIDS) recommend male circumcision (MC) as an additional HIV prevention measure. This study aimed to assess three models of promoting MC and their effects on preventing HIV infection among drug users in western China. We carried out a cohort study in three provinces of western China. HIV seronegative male drug users were recruited from methadone maintenance therapy clinics and cluster randomized into three intervention models. At baseline, 6, and 9 months of follow-up, changes in MC knowledge, the acceptability of MC, MC surgery uptake, and the costs of model implementation were analyzed. Of 1,304 male drug users who were screened, 1,218 were enrolled in the study. The participants' knowledge about MC was significantly increased after interventions by all three models. The one-stage model led to the highest increase in MC acceptability and the greatest increase in MC uptake. Multivariable Cox regression analysis showed that the one-stage model was also the most effective method to promote MC uptake, compared with the two-stage model [rate ratio (RR) = 0.602; 95% confidence interval (CI), 0.420-0.862] and three-stage model (RR = 0.555; 95% CI, 0.382-0.807). The HIV incidence rate in the MC group was lower than that in the non-MC group (RR = 0.234; 95% CI, 0.056-0.974). Moreover, the one-stage model required the lowest cost per circumcision. The one-stage model is the most effective and the most cost-effective intervention to increase MC uptake among male drug users in western China and could decrease the HIV incidence rate, based on a short follow-up investigation.

Acceptability of Male Circumcision among College Students in Medical Universities in Western China: A Cross-Sectional Study.

BACKGROUND: Male circumcision (MC) has been shown to reduce the risk of female to male transmission of HIV. The goal of this survey was to explore MC's acceptability and the factors associated with MC among college students in medical universities in western China. METHODS: A cross-sectional study was carried out in three provinces in western China (Guangxi, Chongqing and Xinjiang) to assess the acceptability of MC as well as to discover factors associated with the acceptability among college students in medical universities. A total of 1,790 uncircumcised male students from three medical universities were enrolled in this study. In addition, 150 students who had undergone MC were also enrolled in the survey, and they participated in in-depth interviews. RESULTS: Of all the uncircumcised participants (n = 1,790), 55.2% (n = 988) were willing to accept MC. Among those who accepted MC, 67.3% thought that MC could improve their sexual partners' hygiene, 46.3% believed that HIV and sexually transmitted diseases (STDs) could be partially prevented by MC. The multivariable logistic regression indicates that MC's acceptability was associated with three factors: the redundant foreskin (OR = 10.171, 95% CI = 7.629-13.559), knowing the hazard of having a redundant foreskin (OR = 1.597, 95% CI = 1.097-2.323), and enhancing sexual pleasure (OR = 1.628, 95% CI = 1.312-2.021). The in-depth interviews for subjects who had undergone MC showed that the major reason for having MC was the redundant foreskin (87.3%), followed by the benefits and the fewer complications of having MC done. In addition, most of these participants (65.3%) said that the MC could enhance sexual satisfaction. CONCLUSIONS: MC's acceptance among college students in medical universities is higher than it is among other populations in western China. An implementation of an MC programme among this population is feasible in the future.

Comparison of three intervention models for promoting circumcision among migrant workers in western China to reduce local sexual transmission of HIV.

OBJECTIVE: Three models for promoting male circumcision (MC) as a preventative intervention against HIV infection were compared among migrant worker populations in western China. METHODS: A cohort study was performed after an initial cross-sectional survey among migrant workers in three provincial level districts with high HIV prevalence in western China. A total of 1,670 HIV seronegative male migrants were cluster-randomized into three intervention models, in which the dissemination of promotional materials and expert- and volunteer-led discussions are conducted in one, two, and three stage interventions. Changes in knowledge of MC, acceptability of MC, MC surgery uptake, and the costs of implementation were analyzed at 6-month and 9-month follow-up visits. RESULTS: All three models significantly increased the participants' knowledge about MC. The three-stage model significantly increased the acceptability of MC among participants and led to greatest increase in MC uptake. At the end of follow-up, 9.2% (153/1,670) of participants underwent MC surgery; uptake among the one-, two-, and three-stage models were 4.9%, 9.3%, and 14.6%, respectively. Multivariable Cox regression analysis showed that three-stage model was the most effective method to scale up MC, with RR = 2.0 (95% CI, 1.3-3.1, P=0.002) compared to the on-site session model. The two-stage intervention model showed no significant difference with either the on-site session model (RR=1.5, 95% CI, 0.92-2.4, P=0.12) or three-stage model (P=0.10). CONCLUSIONS: A three-stage intervention with gradual introduction of knowledge led to the significantly increase in MC uptake among migrant workers in western China, and was also the most cost-effective method among the three models.

Acceptance of male circumcision among male rural-to-urban migrants in western China.

To describe the acceptability of male circumcision (MC) and explore potential factors associated with MC acceptability among male rural-to-urban migrants in western China, a cross-sectional survey of MC acceptability was conducted with 1,904 subjects in three western provinces with high HIV prevalence (Guangxi, Chongqing, and Xinjiang) in China between June 2009 and November 2009. Through face-to-face interviews, the participants completed a self-administered questionnaire about demographics, MC knowledge, willingness and reasons to accept or refuse MC, sexual behaviors, and other psychosocial variables. Factors associated with acceptability of MC were identified by multiple logistic regression analysis. Of the participants (n=1,904), 710 men were willing to accept MC (37.3%); the reasons included promotion of the partners' genital hygiene (54.9%), redundant prepuce or phimosis (43.1%), enhancement of sexual pleasure (40.6%), prevention of penile inflammation or cancer (35.5%), and protection against HIV and sexual transmitted diseases (STDs)(31.1%). A multivariable logistic regression showed that four factors were associated with acceptability of MC, including education level (OR=1.286, 95% CI=1.025~1.614), redundant prepuce or phimosis (OR=13.751, 95% CI=10.087~18.745), having one or more circumcised friends (OR=2.468, 95% CI=1.953~3.119), and having sexual intercourse with a temporary partner in the past year (OR=1.543, 95% CI=1.101~2.162). Compared with previously published data among the general population in China or worldwide, the acceptability of MC (37.3%) was low among the male rural-to-urban migrants in western China. Nevertheless, appropriate education could greatly improve the acceptability of MC. More public campaigns and health education on MC are needed to increase the rate of MC in China.

Prevalence and correlates of sexual risk behaviors among drug users in western China: implications for HIV transmission.

The prevalence and correlates of sexual risk behaviors among drug users in western China and the implications for HIV transmission in this population are described. A cross-sectional survey of male drug users was conducted in methadone maintenance therapy clinics and detoxification centers in three western provinces of China between September 2009 and December 2010. Participants in the study completed a questionnaire about demographics, HIV/AIDS knowledge, drug use history, sexual risk behaviors, and other psychosocial variables. Factors associated with HIV sexual risk behaviors were identified by multiple logistic regression analysis. Of 1,304 drug users surveyed, nearly 54% never used condoms during sexual intercourse with a spouse or cohabitant, and this behavior was associated with coming from Chongqing (OR=1.86, p<0.05), being aged 36 and older (OR=5.03, p<0.05), being married or cohabiting (OR=1.68, p<0.05), having first taken drugs at age 30 and above (OR=1.80, p<0.05), and having received AIDS advice or detection from authorities in the past year (OR=1.95, p<0.05). Twenty-six percent had had sex with casual sexual partners in the past year, and this behavior was associated with being married or cohabiting (OR=0.30, p<0.05), first taking drugs at age 31 and above (OR=0.42, p<0.05), and receiving AIDS advice or HIV detection from authorities in the past year (OR=0.70, p<0.05). About 34% never used a condom when having sex with casual sexual partners, and this behavior was associated with coming from Guangxi (OR=2.81, p<0.05) or Chongqing (OR=2.73, p<0.05). Almost 14% had had commercial sex in the past year, and this behavior was associated with coming from Guangxi (OR=6.26, p<0.05) or Chongqing (OR=5.44, p<0.05) and having exchanged needles or received clean needles from the Needle Exchange Centers in the past year (OR=2.76, p<0.05). Nearly 23% had never used condoms when having commercial sex, and this behavior was associated with having received free condoms from authorities in the past year (OR=0.26, p<0.05). Sexual risk behaviors among drug users in Guangxi, Chongqing, and Xinjiang are common. Additional intervention strategies are needed to control the spread of HIV in this population.

[Case-control study on the correlation of bladder cancer incidence and occupational factors].

OBJECTIVE: To explore the relationship between occupational factors and the incidence of bladder cancer. METHODS: The present research was based on a hospital-based case-control study. The cases were frequency matched. The non-conditional Logistic regression was used to calculate the odds ratio (OR) of each occupation. RESULTS: The OR of business and administration professionals, male electricians and electronic workers were 3.88 and 7.40; the OR of janitors and helpers was 0.21; the OR of handcrafted and printing clerks was 0.71, but there was no significant difference. CONCLUSION: Business and administration professionals, male electricians and electronic workers tend to have bladder cancer. The occupation of janitors and helpers has a protective effect on bladder cancer while the occupation of printing clerks shows no statistical significance on bladder cancer.

Factors influencing Chinese male's willingness to undergo circumcision: a cross-sectional study in western China.

BACKGROUND: Male circumcision (MC) has been shown to reduce the risk of female to male transmission of HIV. The goal of this survey was to explore the acceptability of MC among the Chinese and to identify factors associated with circumcision preference. METHODS: A cross-sectional survey was conducted between September 2009 and December 2010. We interviewed 2,219 male community participants, from three high HIV prevalence provinces in western China. A structured questionnaire was used to collect data on MC knowledge, willingness to accept MC, reasons to accept or refuse MC, and sexual behaviors and health. For those who refused MC, a health education intervention providing information on the benefits of circumcision was conducted. We used multiple logistic regression models to identify factors associated with the acceptability of MC. RESULTS: Of the respondents (n = 2,219), 44.6% (989/2,219) reported they would accept MC for the following reasons: promotion of female partners' hygiene (60.3%), redundant foreskin (59.4%), prevention of penile cancer (50.2%), enhanced sexual pleasure (41.4%), and protection against HIV and STDs (34.2%). The multivariable logistic regression showed that five factors were associated with MC willingness: long foreskin (OR = 15.98), residing in Xinjiang province (OR = 3.69), being younger than 25 (OR = 1.60), knowing hazards of redundant foreskin (OR = 1.78), and having a friend who underwent circumcision (OR = 1.36). CONCLUSION: The acceptability of male circumcision was high among the general population in China. Our study elucidates the factors associated with circumcision preference and suggests that more health education campaigns about positive health effects are necessary to increase the MC rate in China.