Robust layout optimization for intelligent reflecting surfaces-based visible light communication systems.

Due to the inherent tendency to be blocked by obstacles, reliability is a major challenge for visible light communication (VLC). The intelligent reflective surface (IRS) is an effective way to reduce or eliminate the influence of blockage in the VLC system. However, the complexity increases correspondingly due to complex shadow analysis when access points (APs), IRSs, and obstacles coexist. We proposed a robust layout optimization scheme for the IRS-VLC system to resist blockages. First, we model the random obstructions based on spatial geometry methods. Second, we build the optimization problem model considering consistent illumination, achievable data rate (ADR), the positions of the APs, and the directions of the IRS array. In order to achieve this objective, we develop an anti-occlusion method based on the non-dominated sorting genetic algorithm-II (NSGA-II) to get the Pareto front and use enhanced measurement functions (ASFs) to extract the best solution. Simulation results show that the proposed scheme works well in the IRS-VLC system. It is noteworthy that the rectangle layout has always demonstrated superior performance in the IRS-VLC system compared to other traditional layouts.

Optimal design of integrated visible light communication and positioning system with energy harvesting.

In this paper, an optimization scheme that can simultaneously transmit communication information, positioning the information and energy in a visible light communication and positioning (VLCP) system with energy harvesting is proposed. The time switching-power splitting (TS-PS) method is applied, where the power and time allocation factors are defined as optimization variables, so that the system can maximize the harvested energy under the constraints of the information rate and positioning error. The multi-verse optimization (MVO) algorithm is introduced to obtain the optimal power and time allocation. In addition, the performance of the integrated system using the TS-PS method is investigated and compared with that using other conventional methods. The results show that a maximized harvested energy solution using the TS-PS method can harvest the most energy. Moreover, the effects of main external environment conditions, namely, the room height and field of view (FoV) of a photo diode (PD) on the system performance are also analyzed. The increase of the room height and FoV of the PD reduces the harvested energy, but does not change the information rate and positioning accuracy in the optimized system adopted in this paper.

Adaptive feedback threshold based demodulation for mobile visible light communication and positioning integrated system.

In this paper, a novel adaptive feedback threshold (AFT) based demodulation for mobile visible light communication and positioning (VLCP) integrated system is proposed. The AFT can vary with the received signal without excessive fluctuation and support communication and positioning in mobile environment. For the VLCP integrated system with single light emitting diodes (LED) and multiple photodetectors (PDs), maximal ratio combining (MRC) and received optical power ratio (ROPR) based on the AFT is further achieved for communication and positioning with high performance, respectively. It is demonstrated that high credible communication and high accuracy positioning for the mobile integrated VLCP system can be realized by using the proposed AFT based demodulation. As a result, the implemented VLCP system with a moving speed of 1 m/s is evaluated experimentally. Average positioning error of 3.43 cm with 800 mA current and the bit error ratio (BER) with different currents are also obtained.

Integrated visible light communication and positioning CDMA system employing modified ZCZ and Walsh code.

In this paper, an integrated visible light communication and positioning (VLCP) code division multiple access (CDMA) system is proposed for recovering original user data and obtaining positioning information simultaneously. A generalized modification method for balanced bipolar code set is presented, which can be applied to VLCP-CDMA system with intensity modulation. Both modified bipolar code sets, zero correlation zone (ZCZ) code set and Walsh code set, are employed and evaluated in VLCP-CDMA systems. When considering synchronous and quasi-synchronous (QS) systems, it is demonstrated that the modified ZCZ code set with ideal zero correlation zone properties performs better communication and positioning performance than the modified Walsh code set by system simulations and experiments. As a result, a bit error rate (BER) of 1.8×10-3 and an average positioning error of 1.50 cm are successfully obtained by adopting modified ZCZ code set in a 4-user real-time VLCP-CDMA system. It will offer a promising solution to meet both communication and positioning requirements of future intelligent systems.

Research on a Partial Aperture Factor Measurement Method for the AGRI Onboard Calibration Assembly.

A partial aperture onboard calibration method can solve the onboard calibration problems of some large aperture remote sensors, which is of great significance for the development trend of increasingly large apertures in optical remote sensors. In this paper, the solar diffuser reflectance degradation monitor (SDRDM) in the onboard calibration assembly (CA) of the FengYun-4 (FY-4) advanced geostationary radiance imager (AGRI) was used as the reference radiometer. It was designed for measuring the partial aperture factor (PAF) for the AGRI onboard calibration. First, the linear response count variation relationship between the two was established under the same radiance source input. Then, according to the known bidirectional reflection distribution function (BRDF) of the solar diffuser (SD) in the CA, the relative reflectance ratio coefficient between the AGRI observation direction and the SDRDM observation direction was calculated. On this basis, the response count value of the AGRI and the SDRDM was used to realize the high-precision measurement of the PAF of the AGRI B1~B3 bands by simulating the AGRI onboard calibration measurement under the illumination of a solar simulator in the laboratory. According to the determination process of the relevant parameters of the PAF, the measurement uncertainty of the PAF was analyzed; this uncertainty was greater than 2.04% and provided an important reference for the evaluation of the onboard absolute radiometric calibration uncertainty after launch.

The relationship between the minor allele content and Alzheimer's disease.

Alzheimer's disease (AD) is a chronic neurodegenerative disease. The genetic risk factors of AD remain better understood. Using previously published dataset of common single nucleotide polymorphisms (SNPs), we studied the association between the minor allele content (MAC) in an individual and AD. We found that AD patients have higher average MAC values than matched controls. We identified a risk prediction model that could predict 2.19% of AD cases. We also identified 49 genes whose expression levels correlated with both MAC and AD. By pathway and process enrichment analyses, these genes were found in pathways or processes closely related to AD. Our study suggests that AD may be linked with too many genetic variations over a threshold. The method of correlations with both MAC and traits appears to be effective in high efficiency identification of target genes for complex traits.

Onboard absolute radiometric calibration and validation of the satellite calibration spectrometer on HY-1C.

As the reference radiometric calibration standard of sensors on the Haiyang-1C (HY-1C) satellite platform, the satellite calibration spectrometer (SCS) is equipped with an onboard calibration system composed of double solar diffusers and an erbium-doped diffuser to monitor the postlaunch radiometric response change. Herein, through onboard calibration data analysis, the calibration diffuser performance remains stable without degradation, and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra is adopted as a reference to repeatedly verify onboard radiometric calibration results by selecting different dates and reflectance scenes. The SCS equivalent reflectance is obtained by combining the mean digital number (DN) of the SCS crossing area image with the radiometric calibration coefficient. The spectral reflectance is obtained via interpolation and iteration, which is adopted as the actual MODIS incident pupil spectral reflectance because the small imaging time interval can be ignored and almost vertically observed, and it is convoluted with the MODIS spectral response function to obtain the predicted equivalent reflectance. Validation is completed by comparing the predicted MODIS equivalent reflectance to the measured value based on the onboard calibration coefficient. The results show that (1) the difference between the measured and predicted MODIS band equivalent reflectance is between -0.00466 and 0.0039, and (2) the percentage difference between the measured and predicted MODIS band equivalent reflectance ranges from 4.17% and 1.24%, indicating that the calibration system carried on HY-1C can perform high-precision SCS radiometric calibration, meeting the cross-calibration accuracy requirements of other loads on the same platform.

Anticipated suicidal ideation among female injecting drug users who are sex workers of negative or unknown HIV status in China.

In China, female injection drug users who are also sex workers (IDUFSW) have a high prevalence of HIV and low prevalence of HIV testing. They are concerned about HIV infection and may be subjected to the risk of suicidal ideation if they become infected, due to stress and discrimination. During 2005-2006, we recruited 199 IDUFSW who self-reported negative/unknown HIV sero-status in Dazhou, Sichuan, China, to investigate the prevalence of and factors associated with suicidal ideation if they became HIV positive. Among the participants, 40.7% responded affirmatively to the question "Whether you would commit suicide if you were infected with HIV in the future?" In multivariate analyses, hatred toward oneself, perception of dying within 2-3 years, perceived nonavailability of HIV-related treatment, inability to cope with HIV-related trauma, and inclination to leave one's family if one contracted HIV were significant factors related to anticipated suicidal ideation under the hypothetical situation of HIV infection. The odds ratios (OR) ranged from 2.38 to 10.36 (p < .05). These findings can facilitate the planning of primary suicidal prevention services targeting high-risk, non-HIV-positive IDUFSW. Such programs may enhance psychosocial support, empowerment, cultivation of positive coping strategies, and perceived accessibility to treatment, and be integrated with HIV testing.

[On-Orbit Multispectral Sensor Characterization Based on Spectral Tarps].

The multispectral remote sensing technology has been a primary means in the research of biomass monitoring, climate change, disaster prediction and etc. The spectral sensitivity is essential in the quantitative analysis of remote sensing data. When the sensor is running in the space, it will be influenced by cosmic radiation, severe change of temperature, chemical molecular contamination, cosmic dust and etc. As a result, the spectral sensitivity will degrade by time, which has great implication on the accuracy and consistency of the physical measurements. This paper presents a characterization method of the degradation based on man-made spectral targets. Firstly, a degradation model is established in the paper. Then, combined with equivalent reflectance of spectral targets measured and inverted from image, the degradation characterization can be achieved. The simulation and on orbit experiment results showed that, using the proposed method, the change of center wavelength and band width can be monotored. The method proposed in the paper has great significance for improving the accuracy of long time series remote sensing data product and comprehensive utilization level of multi sensor data products.

Development of a Nomogram Using the Inflammatory Risk Score for Prognostication in Moderate and Advanced Hepatocellular Carcinoma Associated with Hepatitis B Virus.

Background: The changes in risk scores of inflammatory markers among patients diagnosed with hepatocellular carcinoma (HCC) remain unknown. Aims: To investigate the relationship between the inflammation risk score and other contributing factors and the prognostic outcomes in patients with moderate and advanced hepatitis B virus (HBV)-related HCC. Study Design: A retrospective cohort study. Methods: A total of 174 patients with moderate and advanced HBV related HCC were recruited to investigate the impact of stratified inflammatory risk scores and other associated risk factors on disease prognosis. Based on the optimal cut-off values calculated by the Youden index, the patients were divided into high-risk and low-risk groups based on their inflammation risk scores. Results: The study found a significant difference in median survival time between the low-risk and high-risk groups based on the inflammation risk score. Furthermore, the inflammation risk score, alpha-fetoprotein levels, transarterial chemoembolization treatment, and Barcelona Clinic Liver Cancer stage were identified as independent prognostic factors. The four variables were used to construct a prognostic nomogram for HCC. Subsequent evaluations using time-dependent receiver operating characteristic analysis and calibration curve tests revealed the nomogram's commendable discriminatory ability. As a result, the nomogram proved to be an effective tool for predicting survival at 2- to 4-years. Conclusion: The inflammation risk score has been identified as a significant prognostic factor for HBV-related HCC. The development of nomogram models has provided a practical and effective tool for determining the prognosis of patients affected by HBV-related HCC.

Cyclical palmitoylation regulates TLR9 signalling and systemic autoimmunity in mice.

Toll-like receptor 9 (TLR9) recognizes self-DNA and plays intricate roles in systemic lupus erythematosus (SLE). However, the molecular mechanism regulating the endosomal TLR9 response is incompletely understood. Here, we report that palmitoyl-protein thioesterase 1 (PPT1) regulates systemic autoimmunity by removing S-palmitoylation from TLR9 in lysosomes. PPT1 promotes the secretion of IFNα by plasmacytoid dendritic cells (pDCs) and TNF by macrophages. Genetic deficiency in or chemical inhibition of PPT1 reduces anti-nuclear antibody levels and attenuates nephritis in B6.Sle1yaa mice. In healthy volunteers and patients with SLE, the PPT1 inhibitor, HDSF, reduces IFNα production ex vivo. Mechanistically, biochemical and mass spectrometry analyses demonstrated that TLR9 is S-palmitoylated at C258 and C265. Moreover, the protein acyltransferase, DHHC3, palmitoylates TLR9 in the Golgi, and regulates TLR9 trafficking to endosomes. Subsequent depalmitoylation by PPT1 facilitates the release of TLR9 from UNC93B1. Our results reveal a posttranslational modification cycle that controls TLR9 response and autoimmunity.

Mental health and interpersonal factors associated with HIV-related risk behaviors among non-institutionalized female injection drug users who are also sex workers in China.

Female injecting drug users who are sex workers (IDUFSWs) are an important bridge population in HIV transmission. Few studies have investigated the associations between mental health, interpersonal problems, and HIV-related risk behaviors among injecting drug users who are sex workers. A total of 234 non-institutionalized injecting drug users who are sex workers were recruited using the snowball method. Multiple logistic regression was used for data analysis. A high prevalence of mental health (depression, hopelessness, pessimism) and interpersonal (lack of social support and submissive gender power) problems was reported. Optimism and social support were negatively associated with inconsistent condom use during sex work in the last six months (adjusted odds ratios [AOR] = 0.62-0.86); positive associations were observed for depression, hopelessness, pessimism, and gender power (AOR = 1.17 to 1.68). Injecting with others' used syringes in the last six months was negatively associated with social support (AOR = 0.75) and positively associated with hopelessness and gender power (AOR = 1.13-1.27). In two summary models using all significant independent variables as candidates, optimism was negatively (OR = 0.62) and submissive gender powers were positively (OR = 1.67) associated with inconsistent condom use during sex work; submissive gender power was positively associated with injecting with others' used syringes (OR = 1.38). HIV interventions targeting mental health and interpersonal problems are needed among injecting drug users who are sex workers.

Using the Theory of Planned Behavior to investigate condom use behaviors among female injecting drug users who are also sex workers in China.

Female injecting drug users who are sex workers (IDUFSWs) is a strategic "bridge population" for HIV transmission. Goals of the study were to investigate condom use behaviors during commercial sex among IDUFSWs using the Theory of Planned Behavior (TPB), and to investigate moderating effects that modify the strength of associations between the TPB-related variables and inconsistent condom use during commercial sex. A total of 281 non-institutionalized IDUFSWs were recruited using snowball sampling method. Anonymous face-to-face interviews were administered by trained doctors. The results showed that the prevalence of inconsistent condom use during commercial sex in the last six months was 64%. After adjusting for some significant background variables (e.g. main venue of sex work), all associations between the five TPB-related variables and the studied condom use variable were statistically significant (Odds Ratio (OR) = 0.43-0.68, p<0.001). In the hierarchical nested models, three background variables (age, venue of sex work, and ever used HIV-related interventions) entered in the first step (-2LL = 294.98, p<0.001) and the Social Norm Scale, the Perceived Behavioral Control Scale and the Behavioral Intention Scale were selected by the second step (OR = 0.67 - 0.72, p<0.01; -2LL = 160.99, p<0.001). Significant moderating effects between some TPB-related variables (Positive Condom use Attitude Scale and Behavioral Intention Scale) and duration of sex work and duration of drug use were also reported. The results highlighted the potential of using the TPB to better understand condom use behaviors in IDUFSWs in China. Theory-based research and intervention work should be developed in China in the future.

Prevalence of needle sharing, commercial sex behaviors and associated factors in Chinese male and female injecting drug user populations.

The objective of this study is to investigate prevalence and associated factors of commercial sex behaviors and condom use at commercial sex, as well as prevalence of needle sharing among injecting drug users (IDUs) in China. In this study, 162 IDUs were recruited by peer workers in Dazhou, Sichuan and were anonymously interviewed by using a structured questionnaire. Univariate and multivariate logistic regression analyses were performed and interaction between gender and the studied independent variables were tested for significance. The results of this study showed that the male and female respondents, respectively 11.7 and 16.9% were HIV positive; 34.0 and 40.7% engaged in commercial sex and 23.3 and 11.9% shared needles with others in the last six months. Percent using a condom in the last episode of commercial sex was 30.3% for males and 76.2% for females. The multivariate analyses showed that higher drug dosage (OR=0.3, 95% CI: 0.1-0.9) and reduced sexual drive (OR=0.3, 95% CI: 0.1-0.9) were associated with lower likelihood for commercial sex among male IDUs while higher drug dosage (OR=9.1, 95% CI: 1.0-86.0), perceived difficulty in finding a job (OR=5.1, 95% CI: 1.3-20.1) and lack of family support (OR=4.0, 95% CI: 1.1-15.4) were associated with commercial sex among female IDUs. Similarly, unknown HIV status (OR=8.2, 95% CI: 1.7-9.2) and having a regular sex partner (OR=3.7, 95% CI: 1.3-10.9) was associated with needle sharing. It is concluded that male and female IDUs were sexually active and often engaged in commercial sex. Drug dosage and reduced sexual drive were relevant but did not stop commercial sex behaviors. More supportive social environment is required to prevent female IDUs to enter sex work.

Severity of drug dependence, economic pressure and HIV-related risk behaviors among non-institutionalized female injecting drug users who are also sex workers in China.

BACKGROUND: Female injecting drug users (IDUs) who are also sex workers (FSW-IDUs) is an important bridge population transmitting HIV from the IDU population to clients of FSWs. Little is known about the relationships between severity of drug dependence, economic pressure and relevant HIV-related risk behaviors. METHODS: 281 non-institutionalized participants were recruited using snowball sampling methods. Anonymous face-to-face interviews were administered by trained doctors. RESULTS: 64.1% of participants used condoms inconsistently with their clients in the past 6 months; 28.5% served at least 2 clients per day and 48.4% practiced at least one of the three studied needle sharing behaviors. Severity of drug dependence (adjusted OR=1.05, p<0.01) and economic pressure (adjusted OR=1.07 to 2.52, p<0.05) were significantly associated with inconsistent condom use with clients in the last 6 months. Severity of drug dependence (adjusted OR=1.15, p<0.01) and variables related to perceived economic pressure (adjusted OR=1.09-3.05, p<0.05) were significantly associated with higher frequency of commercial sex transaction. Severity of drug dependence (adjusted OR=1.07, p<0.01) were also associated with needle sharing behaviors. In summary models, severity of drug dependence (OR=1.17, p<0.001), economic pressure (OR=1.39, p<0.001) and their interaction term (OR=0.98, p<0.001) were all associated with inconsistent condom use with clients in the last 6 months. CONCLUSIONS: Prevalence of unprotected commercial sex was high and was independently associated with severity of drug dependence and economic pressure; severity of drug dependence was also associated with needle sharing behaviors. Such issues need to be fully considered when planning research studies and interventions.

Validation of the Chinese version of the Opiate Addiction Severity Inventory (OASI) and the Severity of Dependence Scale (SDS) in non-institutionalized heroin users in China.

No fully validated Chinese instrument measuring severity of drug dependence exists. The Chinese Opiate Addiction Severity Inventory (OASI) and the translated Chinese version of the Severity of Dependence Scale (SDS) were validated in this study. A total of 178 eligible participants were recruited using snowballing method. The 11-item revised version of OASI (OASI-R) exhibited good reliability (item-total correlation coefficients ranged from 0.50 to 0.73, Cronbach's alpha was 0.85, test-retest Intra-class Correlation Coefficient was 0.81, p < 0.001). Two factors were identified by principal component method and correlated significantly with the Quality of Life-Drug Addiction (QOL-DA). The 3-item revised version of SDS (SDS-R) was one of the two factors of SDS (item-total correlation coefficients were 0.79 to 0.86, Cronbach's alpha was 0.78, test-retest Intra-class Correlation Coefficient was 0.64, p < 0.001). It correlated significantly with QOL-DA. OASI-R and SDS-R were also significantly correlated with each other and with some heroin-related characteristics. The validation of the Chinese version of OASI-R and SDS-R would facilitate research in different Chinese populations. SDS has been translated to different languages and the Chinese version allows for international comparison.

Effects of CIK on hypoxia inducible factor-1α and T-cell subsets on colon 26 cancer xenograft mice.

Colorectal cancer is a common malignancy of the digestive tract with a high mortality rate. However, current treatment approaches such as radiotherapy and chemotherapy are ineffective. Thus, it is imperative to identify ways to treat recurrence and metastasis. The aim of the present study was to investigate the effects of cytokine-induced killer (CIK) cells on the hypoxia microenvironment and immune function in colon 26 cancer xenograft mice. A murine model of colon 26 carcinoma tumors were divided into CIK, normal saline (NS) and control groups. Hypoxia inducible factor-1α (HIF-1α) mRNA in tumor tissue and the small intestine of mice was detected by FQ-PCR. The percentage of the CD4+, CD8+ and CD4+/CD8+ ratio in the spleen of mice was detected by flow cytometry. The tumor volume in the CIK group was smaller than that in the NS group and the difference was not significant (P>0.05). HIF-1α gene expression was present in the tumor tissue and small intestine. HIF-1α gene expression in tumor tissue was significantly higher than that in the small intestine (P<0.05), and lower in tumor tissue of the CIK group compared to the NS group (P<0.05) of xenograft mice. However, no HIF-1α expression was observed in the small intestine of healthy control mice. CD4+ T-cell percentage and CD4+/CD8+ ratio in the spleen of xenograft mice was significantly lower than that of normal mice (P<0.05). Compared to the NS group, the CD4+ T-cell percentage was higher, whereas the CD8+ T-cell percentage was lower in the CIK group (P<0.05). In conclusion, HIF-1α gene expression was present in the tumor tissue and small intestine. The immune function of colon 26 transplanted in tumor mice was decreased. Additionally, CIK improved the microenvironment of tumor hypoxia and promoted immune reconstitution.

[Analysis the treatment of sudden sensorineural hearing loss with steroid from different administration routes].

OBJECTIVE: To explore the treatment of sudden sensorineural hearing loss with steroid from different administration routes. METHOD: One hundred and eighty-eight patients with diagnosis of sudden sensorineural hearing loss were selected, in accordance with the random number table, and all patients were divided into three groups. With different administration routes, they were devided into systemic steroid therapy group, intratympanic steroid therapy group and postauricular steroid therapy group,and the curative effects were collected and analyzed. RESULT: The total effective rate was 78.26% in systemic steroid therapy group, 80.70% in intratympanic steroid therapy group and 80.65% in postauricularsteroid therapy group,and no statistical difference was detected among these three groups (P > 0.05). CONCLUSION: The treatment of sudden sensorineural hearing loss with steroid from different adminsthation routes all can achieve a relatively favorable prognosis, and there were no obvious different among those different treatments.

Prevalence of depressive symptoms and associated factors among people who inject drugs in China.

BACKGROUND: People who inject drugs (PWID) have a high prevalence of mental health problems (e.g., depression) which compromise the effects of HIV prevention. We investigated the prevalence of depression and associated factors among PWID in Dazhou, China. METHODS: Anonymous face-to-face interviews were administered to eligible participants by well-trained doctors. The Center of Epidemiological Studies Depression Scale (CES-D) was used to measure depression, using hierarchical linear regression models. RESULTS: Among the 257 participants, 7.0%, 11.3%, and 75.1% were probable cases of mild (16 ≤ CES-D < 21), moderate (21 ≤ CES-D < 25), and severe (CES-D ≥ 25) depression, respectively. Hopefulness (standardized ß = -0.34, p < 0.001) and emotional family support (ß = -0.21, p < 0.001) were negatively associated, whereas severity of drug dependence (ß = 0.12, p = 0.034) and unmet service needs (ß = 0.20, p < 0.001) were positively associated, respectively, with CES-D scores. The adjusted analysis showed that resilience was negatively associated with CES-D, but it was not selected by the stepwise model containing hopefulness and emotional family support. Protective factors (i.e., hopefulness and emotional family support) and risk factors (i.e., severity of drug dependence and unmet service needs) remained significant in the same regression model. CONCLUSION: Protective and risk factors were independently associated with depressive symptoms. Integrated interventions covering basic and psychosocial needs for PWID are warranted. Such interventions should strengthen emotional family support and cultivate positive factors such as hopefulness.

Prevalence and associated factors of condom use during commercial sex by female sex workers who were or were not injecting drug users in China.

OBJECTIVES: We compared the prevalence of inconsistent condom use during commercial sex between female sex workers (FSWs) who did or did not inject drugs (FSW-IDUs and FSW-NIDUs) and investigated factors associated with this inconsistent use within these two groups. METHODS: Some 158 FSW-NIDUs recruited from sex work venues and 218 FSW-IDUs recruited via the snowball sampling method were interviewed anonymously. RESULTS: Only 16.5% of the FSW-IDUs and 51.3% of the FSW-NIDUs had used condoms consistently during commercial sex in the last month (odds ratio (OR)=0.19). Factors significantly associated with inconsistent condom use in both groups included: behavioural intention for condom use (adjusted odds ratio (AOR)=0.05 and 0.13), condom unavailability (AOR=4.77 and 5.33), a perceived need to engage in unprotected sex if the client paid more (AOR=8.74 and 10.84) or insisted on demanding unprotected sex (AOR=19.78 and 7.59), and submissive gender power (AOR=11.65 and 2.58). One factor, perceived susceptibility (AOR=2.64), was significant only among FSW-NIDUs, whereas perceived efficacy of condom use in preventing HIV transmission (AOR=0.08), perceptions that peer FSWs would not use condoms with clients (AOR=2.23), self-hatred (AOR=2.25) and lack of social support (AOR=2.93) were significant only among FSW-IDUs. Injecting with used syringes was also associated with inconsistent condom use among FSW-IDUs (AOR=4.64). CONCLUSIONS: FSW-IDUs were more likely than FSW-NIDUs to possess the cognitive and psychosocial conditions associated with unprotected commercial sex. Interventions need to take these differences into account.