Search

A deep learning approach based on big data is proposed to locate broadband acoustic sources using a single hydrophone in ocean waveguides with uncertain bottom parameters. Several 50-layer residual neural networks, trained on a huge number of sound field replicas generated by an acoustic propagation model, are used to handle the bottom uncertainty in source localization. A two-step training strategy is presented to improve the training of the deep models. First, the range is discretized in a coarse (5 km) grid. Subsequently, the source range within the selected interval and source depth are discretized on a finer (0.1 km and 2 m) grid. The deep learning methods were demonstrated for simulated magnitude-only multi-frequency data in uncertain environments. Experimental data from the China Yellow Sea also validated the approach. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Internal waves are one of the primary causes of sea water mass variations in shallow water. The time stability of an acoustic channel may be degraded by the activities of internal waves. Based on the oceanographic data of Asian Seas International Acoustics Experiment (ASIAEX), the characteristics of the internal waves in the East China Sea (ECS) are analyzed and the effects of linear and solitary internal waves on broadband acoustic field correlation are numerically investigated. The numerical results of the length of the correlation time affected by the internal waves are compared with the experimental data. It was found that the existence of both linear internal waves and soliton packets may be one of the explanations of the experimental correlation drop. [ABSTRACT FROM AUTHOR]

• We used an automatic detection method to locate and track a warm mesoscale eddy from satellite data. • We deployed hydrophone and temperature-sensor arrays in the center and outside the eddy. • We recorded acoustic signals from explosive sources and chirped signals from a transceiver. • We combined the measured hydrological data to create a spatially and temporally dependent empirical model of the eddy. • We compared the simulations with and without an eddy to investigate the effects of the eddy on sound propagation. • We utilized the measured data to analyze the effects of the eddy on transmission losses to the two hydrographic arrays. • We employed recordings of the chirped signals to study the effects of the eddy on sound-energy fluctuations. The spatial and temporal redistribution of sound energy caused by a warm eddy was measured via a multiday experiment conducted in the South China Sea, utilizing two vertical line arrays, a mooring source, and some wide-band explosive sources. In the experiment area, a warm eddy was identified and tracked using an automatic detection method combined with the empirically reconstructed data. During the experimental period, the warm eddy diminished in size and kinetic energy until it vanished. The influence of the warm eddy on sound propagation during its lifespan is comprehensively analyzed and explained. The experimental acoustic results and simulations based on dynamic hydrographic data demonstrate that energy is redistributed both spatially and temporally due to the presence of the warm eddy. In comparison to the environment without an eddy, the first convergence zone disappears and the high-energy region appears in the typical position of the first shadow zone. The oscillating disturbance in energy is mainly affected by the fluctuation of sound speed caused by the warm eddy. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

High-altitude hypoxic environment exposure is considered one of the risk factors for congenital heart disease (CHD), but the genetic factors involved are still unclear. CCN1, one of the synergistic molecules in the hypoxic response, is also an indispensable molecule in cardiac development. Considering that CCN1 may play an important role in the occurrence of CHD in high-altitude areas, we investigated the association between CCN1 polymorphisms and CHD susceptibility in Northwest Chinese population from different high-altitude areas. We conducted a case-control study with a total of 395 CHD cases and 486 controls to evaluate the associations of CCN1 polymorphisms with CHD risk. Our results showed that the protective alleles rs3753793-C (OR = 0.59, 95% CI = 0.42-0.81, P = 0.001), rs2297141-A (OR = 0.66, 95% CI = 0.49-0.90, P = 0.001), and C-A haplotype of rs3753793-rs2297141 (OR = 0.58, 95% CI = 0.42-0.82, P = 0.002) were significantly associated with a decreased atrial septal defect (ASD) risk. Further subgroup analysis in different geography populations revealed robust association of SNP rs2297141 with ASD risk in a Han population residing in high altitude of 2500-4287 m. We also found that the frequency of protective alleles was higher in high-altitude population, and the alleles were responsible for the difference of oxygen physiology-related erythrocyte parameters in different high-altitude populations. rs3753793-C and rs2297141-A are likely related to high altitude and hypoxia adaptation, which may also be the reason for the association between CCN1 polymorphism and ASD risk., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The unprecedented outbreak of the Coronavirus Disease 2019 (COVID-19) caused an economic downturn and increased the unemployment rate in China. In this context, employees face health and social economic stressors. To assess their mental health (i.e., anxiety, depression, insomnia and somatization) and work attitudes (i.e., work engagement, job satisfaction and turnover intention) as well as the associated factors, we conducted a cross-sectional study among people who resumed work after the Spring Festival holiday during the COVID-19 pandemic. The results show that the prevalence of anxiety, depression, insomnia and somatization among these people was 12.7%, 13.5%, 20.7% and 6.6%, respectively. The major risk factor for mental health was worrying about unemployment, and the main protective factors were psychological strengths (i.e., resilience and optimism). Regarding work attitudes, the percentage of people who felt more satisfied with their job (43.8%) was larger than that of those who felt less satisfied (26.9%), while the percentage of people who thought about quitting their job more frequently (15.7%) was smaller than that of those who considered it less frequently (63.2%). However, work engagement was lower than usual. Similar to the factors associated with mental health, the major risk factor for work attitudes was also worrying about unemployment, and the main protective factors were resilience and optimism. In addition, the nature of the organization, job status, age, position and income changes were also related to these work attitudes. Our findings shed light on the need for organization administrators to be aware of the status of and factors associated with employees' mental health and work attitudes during the COVID-19 pandemic. Policies or interventions could be developed based on our findings.

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.