Local and remote forcing of the barotropic transport through a periodic gap in a basin with bottom topography

The effect of bottom topography H on the barotropic transport through a periodic gap in a basin with large-scale bottom topography is studied. The results obtained generalize previous findings for the case of a zonal channel (Wang and Huang, 1995; Krupitsky and Cane, 1994). An asymptotic approximation is found for the zonal transport on a β-plane when all f/H isolines are blocked by the solid boundaries. It is shown that to leading order, the transport through the gap (i) is independent of friction similar to a western boundary current; (ii) is inversely proportional to R, the range of values of f/H that exist on both parts of the solid boundary. The transport depends on the latitude of the equatorward side of the gap, but not on the poleward one. The transport is forced by a mean wind in the area poleward of the equatorward side of the gap and in two remote forcing regions discussed in the text

On topographic pressure drag in a zonal channel

The effect of bottom topography H on the barotropic transport in a periodic zonal channel is studied. An asymptotic approximation is found for the zonal transport on an f-plane and a β-plane when all f/H isolines are blocked by the zonal walls. It is shown that to leading order, the zonal channel transport is independent of friction. In this it is similar to the Sverdrup transport in a basin. To leading order, the transport is proportional to the bottom topographic wavelength, and inversely proportional to the height of the topography and to R, the range of values of f/H that exists on both sides of the channel. For sufficiently high topography the transport varies inversely with the topographic height squared. The analytic results are verified by numerical experiments

On the Utility and Disutility of JEBAR

The usefulness of the concept of JEBAR, the joint effect of baroclinicity and relief, in large-scale ocean dynamics is critically analyzed. The authors address two questions. Does the JEBAR term properly characterize the joint impact of stratification and bottom topography on the ocean circulation? Do estimates of the JEBAR term from observational data allow reliable diagnostic calculations? The authors give a negative answer to the first question. The JEBAR term need not give a true measure of the effect of bottom relief in a stratified ocean. A simple two-layer model provides examples. As to the second question, it is demonstrated that the large-scale pattern of the transport streamfunction is captured by the smoothed solution, especially with the Mellor et al. formulation of the JEBAR term. However, the calculated velocity field is very noisy and the relative errors are large

Implications of Cannabis Use and Heavy Alcohol Use on HIV Drug Risk Behaviors in Russian Heroin Users

Cannabis and heavy alcohol use potentially increase HIV transmission by increasing risky drug behaviors. We studied 404 subjects entering treatment for heroin dependence, in St. Petersburg, Russia. We used the HIV Risk Assessment Battery (RAB) drug subscale to measure risky drug behavior. Although all heavy alcohol users had risky drug behaviors, their drug RAB scores did not differ from non-heavy alcohol users in unadjusted or adjusted analyses. Cannabis use was significantly associated with drug RAB scores in unadjusted analyses (mean difference 1.7 points) and analyses adjusted for age, sex, and employment (mean difference 1.3 points). When also adjusting for stimulant use, the impact of cannabis use was attenuated and no longer statistically significant (mean difference 1.1 points). Because of the central role of risky drug behaviors in the Russian HIV epidemic, it is important to understand how the use of multiple substances, including cannabis and alcohol, impacts risky drug behaviors

World Addiction Medicine Reports : formation of the International Society of Addiction Medicine (ISAM) Global Expert Network (ISAM-GEN) and Its global surveys

Funding: All the infrastructure funding of this initiative is supported by the International Society of Addiction Medicine (ISAM). We will be open to fundraising for specific projects within the platform and future collaboration with external partners.Addiction medicine is a dynamic field that encompasses clinical practice and research in the context of societal, economic, and cultural factors at the local, national, regional, and global levels. This field has evolved profoundly during the past decades in terms of scopes and activities with the contribution of addiction medicine scientists and professionals globally. The dynamic nature of drug addiction at the global level has resulted in a crucial need for developing an international collaborative network of addiction societies, treatment programs and experts to monitor emerging national, regional, and global concerns. This protocol paper presents methodological details of running longitudinal surveys at national, regional, and global levels through the Global Expert Network of the International Society of Addiction Medicine (ISAM-GEN). The initial formation of the network with a recruitment phase and a round of snowball sampling provided 354 experts from 78 countries across the globe. In addition, 43 national/regional addiction societies/associations are also included in the database. The surveys will be developed by global experts in addiction medicine on treatment services, service coverage, co-occurring disorders, treatment standards and barriers, emerging addictions and/or dynamic changes in treatment needs worldwide. Survey participants in categories of (1) addiction societies/associations, (2) addiction treatment programs, (3) addiction experts/clinicians and (4) related stakeholders will respond to these global longitudinal surveys. The results will be analyzed and cross-examined with available data and peer-reviewed for publication.Peer reviewe

Punitive policing and associated substance use risks among HIV-positive people in Russia who inject drugs.

IntroductionDrug law enforcement is part of the HIV risk environment among people who inject drugs (PWID). Punitive policing practices such as extrajudicial arrests for needle possession and police planting of drugs have been described anecdotally in Russia, but these experiences and their associations with risky drug behaviours have not been quantified. This study aims to quantify the burden of extrajudicial police arrests among a cohort of HIV-positive PWID in Russia and to explore its links to drug-related health outcomes.MethodsIn a cross-sectional study of 582 HIV-positive people with lifetime injection drug use (IDU) in St. Petersburg, Russia, we estimated the prevalence of self-reported extrajudicial police arrests. We used multiple logistic regression to evaluate associations between arrests and the following outcomes: overdose, recent IDU and receptive needle sharing.FindingsThis cohort's mean age was 29.8 years, 60.8% were male; 75.3% reported non-fatal drug overdose, 50.3% recent IDU and 47.3% receptive needle sharing. Extrajudicial arrests were reported by more than half (60.5%, 95% confidence interval [CI]: 56.5-64.5) and were associated with higher odds of non-fatal drug overdose (AOR 1.52, 95% CI: 1.02-2.25) but not with recent IDU (AOR 1.17, arrests were associated with receptive needle sharing (AOR 1.84, 95% CI: 1.09-3.09).ConclusionsExtrajudicial police arrests were common among this cohort of Russian HIV-positive PWID and associated with non-fatal overdose and, among those with recent IDU, receptive needle sharing. As a part of the HIV risk environment of PWIDs, these practices might contribute to HIV transmission and overdose mortality. Further research is needed to relate these findings to the operational environment of law enforcement and to better understand how police interventions among PWIDs can improve the HIV risk environment

Linking Infectious and Narcology Care (LINC) in Russia: design, intervention and implementation protocol.

BackgroundRussia and Eastern Europe have one of the fastest growing HIV epidemics in the world. While countries in this region have implemented HIV testing within addiction treatment systems, linkage to HIV care from these settings is not yet standard practice. The Linking Infectious and Narcology Care (LINC) intervention utilized peer-led strengths-based case management to motivate HIV-infected patients in addiction treatment to obtain HIV care. This paper describes the protocol of a randomized controlled trial evaluating the effectiveness of the LINC intervention in St. Petersburg, Russia.Methods/designParticipants (n = 349) were recruited from the inpatient wards at the City Addiction Hospital in St. Petersburg, Russia. After completing a baseline assessment, participants were randomly assigned to receive either the LINC intervention or standard of care. Participants returned for research assessments 6 and 12 months post-baseline. Primary outcomes were assessed via chart review at HIV treatment locations.DiscussionLINC holds the potential to offer an effective approach to coordinating HIV care for people who inject drugs in Russia. The LINC intervention utilizes existing systems of care in Russia, minimizing adoption of substantial infrastructure for implementation. Trial Registration NCT01612455

Risk factors for recent nonfatal overdose among HIV-infected Russians who inject drugs

Overdoses and HIV infection are common among Russians who inject drugs, yet risk factors have not been studied. We analyzed baseline data of 294 participants with 30-day injection drug use from an HIV secondary prevention trial for persons reporting "heavy" alcohol use (National Institute on Alcohol Abuse and Alcoholism [NIAAA] risky drinking definition) and risky sex in the past 6 months. The outcome was any self-reported overdose in the previous 3 months. We examined demographic, HIV-related, criminal justice, mental health, substance use, and injection risk factors. Participants' characteristics included median age 29 years, 117/294 (40%) female, and median CD4 cell count 345/µl. Over three quarters 223/294 (76%) reported a history of overdose and 47/294 (16%) reported overdose in the past 3 months. Past month injection frequency (adjusted odds ratio [AOR] 4.77, 95% confidence interval [CI]: 1.63-14.0 highest vs. lowest quartile; AOR 3.58, 95% CI: 1.20-10.69 second highest vs. lowest quartile) and anti-retroviral therapy (ART) at time of interview (AOR 3.96 95% CI: 1.33-11.83) were associated with 3-month overdose. Nonfatal overdose among HIV-infected Russians who inject drugs is common. Risk factors include injection frequency and anti-retroviral therapy (ART), which warrant further study. Overdose prevention efforts are needed among HIV-infected Russians who inject drugs