Application of the generalized Kudryashov method to the Eckhaus equation

In this paper, the generalized Kudryashov method is presented to seek exact solutions of the Eckhaus equation. From these solutions, we can derive solitary wave solutions as a special case. The proposed method is direct, effective and convenient and can be applied to many nonlinear evolution equations in mathematical physics

The effect of on-site and outreach-based needle and syringe programs in people who inject drugs in Kermanshah, Iran

Background: Needle and syringe programs (NSPs) are widely used to reduce harms associated with drug injecting. This study assessed the effect of facility-based (on-site services at drop-in centre) and outreach models of NSP on injection risk behaviours. Methods: Self-reported data from 455 people who injected drugs (PWID) during 2014 in Kermanshah, Iran, were examined to measure demographic characteristics and risk behaviors. Self-reported and program data were also assessed to identify their main source of injection equipment. Participants were divided into three sub-groups: facility-based NSP users, outreach NSP users and non-users (comparison group). Coarsened exact matching was used to make the three groups statistically equivalent based on age, place of residence, education and income, and groups were compared regarding the proportion of borrowing or lending of syringes/cookers, reusing syringes and recent HIV testing. Results: Overall, 76% of participants reported any NSP service use during the two months prior to interview. Only 23% (95%CI: 17-27) reported outreach NSP as their main source of syringes. Using facility-based NSP significantly decreased recent syringe borrowing (OR: 0.27, 95%CI: 0.10-0.70), recent syringe reuse (OR: 0.38, 95%CI: 0.23-0.68) and increased recent HIV testing (OR: 2.60, 95%CI: 1.48-4.56). Similar effects were observed among outreach NSP users; in addition, the outreach NSP model significantly reduced the chance of lending syringes (OR: 0.31, 95%CI: 0.15-0.60), compared to facility-based NSP (OR: 1.25, 95%CI: 0.74-2.17). Conclusion: These findings suggest that the outreach NSP model is as effective as facility-based NSP in reducing injection risk behaviours and increasing the rate of HIV testing. Outreach NSP was even more effective than facility-based in reducing the lending of syringes to others. Scaling up outreach NSP is an effective intervention to further reduce transmission of HIV via needle sharing

Client-Level Coverage of Needle and Syringe Program and High-Risk Injection Behaviors: A Case Study of People Who Inject Drugs in Kermanshah, Iran

Background: Needle-syringe programs (NSP) have been running in Iran since 2002. However, the coverage of such program among the NSP clients at the individual level was not studies yet. This study aimed to determine the client coverage of NSP and its correlation with high injection-related risk behaviors. Methods: A cross-sectional survey was conducted in Kermanshah province, Iran, in 2014. 230 people who inject drugs (PWID) recruited from two drop-in centers (DICs) from April to September 2014, participated in a face-to-face interview to provide information related individual coverage of NSP, demographic characteristics, and injecting behaviors 30 days prior to the interview. Findings: Overall, the average of syringe coverage was 158% [95% confidence interval (CI) = 65.7-205.5], while 56% (95% CI = 40-97) have individual converge less than 100%. Needle/syringe sharing was significantly higher among individual with low NSP coverage [adjusted odds ratio (AOR) = 2.6, 95% CI = 1.3-6.2]. About 85% participants with coverage of less than 100% reported reuse of syringe within the last 30 days (AOR = 3.2, 95% CI = 1.4-7.7). Conclusion: PWID are different regarding their NSP individual-level converges. There are certain clusters of PWID, who do not receive sufficient number of syringes. Given that insufficient individual syringe coverage level is highly associated with injection risk behaviors, reasons for such low converge need to be assessed and addressed carefully

Modelling the COVID-19 pandemic in context : An international participatory approach

Funding RA is funded by the Bill and Melinda Gates Foundation (OPP1193472). LW is funded by the Li Ka Shing Foundation. CF is funded by grant #2017/26770-8, São Paulo Research Foundation (FAPESP). The CoMo Consortium has support from the Oxford University COVID-19 Research Response Fund (ref: 0009280). Scientific writing assistance and editorial support was provided by Adam Bodley, according to Good Publication Practice guidelines.Peer reviewedPublisher PD

Using GIS in explaining spatial distribution of brucellosis in an endemic district in Iran

Background: To check the feasibility of using geographical information system (GIS) methods, we linked the brucellosis data of human and animals. Methods: In a village-based ecological study in Bardsir - a district in Kerman Province located nearly to the central part of Iran - data of human brucellosis, socio-economic level, and livestock characteristics (2001-3) were linked by using GIS methods. Results: Annual incidence of human brucellosis was 141.6 cases per 100,000 inhabitants. Most of the high risk villages were seen in the north and south of Bardsir (3.6% of villages). A positive association was observed between the frequency of brucellosis and density of cattle (OR = 1.81, P = 0.007). In addition, the size of human population was an independent determinant factor (OR = 1.94, P < 0.001). No association was found between frequency of the disease and socio-economic indicators and also the density of sheep. Conclusion: Our study showed that we could generate informative risk maps of brucellosis using health and veterinary data which might improve the quality of control programme in Iran

Syringe Sharing in Drug Injecting Dyads: A Cross-Classified Multilevel Analysis of Social Networks

We examined the association of dyadic-level factors with syringe sharing among people who inject drugs (PWID) in Kerman, Iran. In a cross-sectional study, we collected data on 329 drug-injecting dyads by individual face-to-face interviews. An injecting dyad was defined as 2 PWID who knew each other and injected drugs together during the last 6&nbsp;months. If they reported at least 1 occasion of syringe sharing, the dyad was considered high-risk. Dyadic-level factors associated with syringe sharing were assessed using cross-classified multilevel logistic regression. The rate of syringe sharing was significantly higher for dyads who were more intimate (adjusted odds ratio [AOR] 4.5, CI 95%, 2.3-8.6), who had instrumental support (AOR 2.1, 95% CI 1.1-4.5), and who pooled money for drugs (AOR 4.1, 95% CI 2.0-8.3). The rate was lower in same-sex dyads (AOR 0.4, 95% CI 0.2-0.9) and in dyads who shared health information (AOR 0.5, 95% CI 0.2-0.9). Findings highlight close-peer influences on syringe-sharing behavior

Solitons and Other Solutions to Complex-Valued Klein-Gordon Equation in ϕ-4 Field Theory

The integrability aspects of complex-valued Klein-Gordon equation is studied in this paper. Three integration algorithms applied. Several solutions are obtained using such integration machineries. Solutions range from plane waves to shock waves and solitons as well as singular periodic solutions

Social and structural determinants of health associated with drug use patterns among female sex workers in Iran: A latent class analysis

BACKGROUND: Female sex workers (FSWs) experience adversities regarding social determinants of health (SDH) and behavioural factors including illicit drug use. This study aimed to assess the clustered impact of SDH on illicit drug use among FSWs in Iran. METHODS: We surveyed 1,347 FSWs in 13 major cities in 2015. Latent class analysis was conducted to identify distinct classes of five measured SDH including low education, unemployment, unstable housing, last-year incarceration and sexual violence. We examined the association of these classes with five illicit drug use patterns using multivariable generalized linear model with Poisson family and log link, and reported adjusted prevalence ratios (aPR) and their 95% confidence intervals (CI). RESULTS: We identified five SDH classes: Class 1: no SDH adversities; Class 2: mainly unemployment; Class 3: low education and unemployment; Class 4: sexual violence and unemployment; and Class 5: multiple SDH adversities. The prevalence of last-month drug use ranged from 7.0% in Class 1 to 53.3% in Class 5. Compared to FSWs in Class 1, those in Class 2 (aPR: 2.47, 95% CI: 1.15, 5.27), Class 3 (aPR: 3.69, 95% CI: 1.62, 8.36), Class 4 (aPR: 4.49, 95% CI: 1.71, 11.78) and Class 5 (aPR: 6.35, 95% CI: 2.42, 16.69) were more likely to report last-month drug use. The same patterns were observed for specific drugs of opium use, crystal methamphetamine use, and heroin-crack use, as well as poly-drug use. CONCLUSION: Socio-structural determinants are clustered together and elevate the likelihood of illicit drug use among FSWs. Our findings highlighted the significance of assessing and addressing such key determinants of health in drug use harm reduction programs targeting FSWs