Far Infrared Slab Lensing and Subwavelength Imaging in Crystal Quartz

We examine the possibility of using negative refraction stemming from the phonon response in an anisotropic crystal to create a simple slab lens with plane parallel sides, and show that imaging from such a lens should be possible at room temperature despite the effects of absorption that are inevitably present due to phonon damping. In particular, we consider the case of crystal quartz, a system for which experimental measurements consistent with all-angle negative refraction have already been demonstrated. Furthermore, we investigate the possibility of subwavelength imaging from such materials, and show that it should be possible for certain configurations.Comment: 12 pages, 10 figure

Self-reported testing, HIV status and associated risk behaviours among people who inject drugs in Europe : Important differences between East and West

Aims: To describe HIV-related risk behaviours, HIV testing and HIV status among people who inject drugs (PWIDs) in the 2000 in European countries with high-prevalence HIV epidemics among PWID. Methods: Data from 12 cross-sectional studies among PWID from seven countries were used. Meta-analysis was used to synthesize the data and meta-regression to explain heterogeneity [in addition to deriving adjusted odds ratios (AORmeta)]. Results: Data on 1791 PWID from western (the West) and 3537 from central and eastern (the East) European countries were available. The mean age of participating PWIDs was 30.6 years (SD 7.9), 75% were men, and 36% [95% confidence interval 34-37%) were HIV-infected (30% West, 38% East); 22% had not previously been tested for HIV. The prevalence of reported high-risk behaviour was significantly higher among PWID from the East. Comparison of HIV-infected and uninfected PWID within countries yielded similar results across all countries: HIV-infected PWID were less likely to be sexually active [AORmeta 0.69 (0.58-0.81)], reported less unprotected sex [AORmeta 0.59 (0.40-0.83)], but reported more syringe sharing [AORmeta 1.70 (1.30-2.00)] and more frequent injecting [AORmeta 1.40 (1.20-1.70)] than their HIV-uninfected counterparts. Conclusion: Despite the absolute differences in reported risk behaviours among PWID in western and eastern Europe, the associations of risk behaviours with HIV status were similar across the sites and regions. There is a substantial potential for further HIV transmission and acquisition based on the continuous risk behaviours reported. HIV prevention and harm reduction interventions targeting PWID should be evaluated.publishersversionPeer reviewe

Prevention of HIV and Associated Infections among Adolescents and Young People at High Risk of Infection : Methodology Guide

Methodology Guide on Prevention of HIV and Associated Infections among Adolescents and Young People at High Risk of Infection was prepared as part of project “Building capacity in prevention of HIV and associated infections among youth at high risk in the Northern Dimension area” (cf. www.ndphs.org/?database,view,project,1467) co-funded by the European Union. The project was implemented from September 1, 2013 to August 31, 2015 by the project consortium led by Secretariat of the Northern Dimension Partnership in Public Health and Social Well-being (NDPHS) and including also Regional NGO “Stellit”, National Institute for Health and Welfare, Kaliningrad Regional Non-governmental Youth Organisation “Young Leaders Army” (YLA), Social AIDS Committee and Baltic HIV Association. The Methodology Guide contains overview of theories applicable for addressing the priorities of HIV and associated infections prevention among adolescents and young people at high risk of infection, theories which might be used to evaluate the effectiveness of prevention programs. It provides the results of assessment of needs of children and young people at high risk of infection in prevention programs, overview of prevention programs implemented in Russia, Latvia, Poland, Finland and Germany which might be recommended to be spread to other countries of the NDPHS and examples of tool which might be used in prevention work. The Methodology Guide might be useful for authorities, representatives of governmental organizations, NGOs, international organizations, public health specialists and other experts involved into HIV and associated infections prevention among children and young people. The Methodology Guide is available for downloading at: http://urn.fi/URN:NBN:fi-fe2015102715069. Other methodological materials produced within the project can be downloaded at: https://www.thl.fi/en/web/thlfi-en/about-us/organisation/departments-and-units/administration-and-development/planning/international-affairs-unit/projects

Runaway behavior among children in residential care in St. Petersburg: A qualitative study

Background. Runaway behavior among children in residential care is a serious social problem in all countries of the world. Existing scientific data on risk factors and motives of runaway from out-of-home care may not be absolutely relevant to the Russian cultural context. Objective. To describe risk factors and the motives that cause children to runaway from residential care. Design. A qualitative study that included 2 focus groups with staff and graduates of residential care supplemented by the analysis of 23 cases of child runaways from residential care in St. Petersburg. Results. The study revealed the following runaway risk factors and motives: 1) running to parents or relatives, 2) romantic and/or sexual relations, 3) interaction with peers, 4) psychiatric problems, 5) addictive behavior, 6) avoidance of conflicts, 7) physical or emotional violence, 8) unmotivated runaways for entertainment, 9) problems adapting to the care institution, 10) dissatisfaction with the conditions at the care institution. Moreover, in this study, two different types of runaways have been identified, including relatively “true” runaways and those who are not psychologically experienced as such, but are only disobeying the formal rules of the care institution. Conclusions. Runaways of children from residential care are extremely heterogeneous in nature. In further empirical studies, it should be taken into account that runaways may be true and formal. There can be multiple reasons for running away: the care institution itself, a child’s personality, or his or her social network outside of the care institution