Theory of parabolic pulse generation in tapered fiber

We examine similarities and differences between high-power parabolic pulse generation in an active medium and in tapered fiber with decreasing normal dispersion. Using a realistic tapered fiber design, we demonstrate the possibility of parabolic pulse generation without an external pump and determine the limitations of this approach

Passive nonlinear pulse shaping in normally dispersive fiber systems

We propose a novel approach to characterize the parabolically-shaped pulses that can be generated from more conventional pulses via nonlinear propagation in cascaded sections of commercially available normally dispersive (ND) fibers. The impact of the initial pulse chirp on the passive pulse reshaping is examined. We furthermore demonstrate that the combination of pulse pre-chirping and propagation in a single ND fiber yields a simple, passive method for generating various temporal waveforms of practical interest

Freezing-out of heavy isotopes of Kr

The separation of isotopes of natural Krypton at the gas-liquid and liquid-solid phase interfaces was studied under nonequilibrium conditions using a cryogenic cell and mass spectrometry. The formation of condensate upon cooling Kr from the ambient temperature begins at an equilibrium temperature, which corresponds to the partial pressure of the dominant isotope 84Kr, and is accompanied by depletion of the gas phase 84Kr with a separation coefficient of ~0.92; but the isotopic composition returns to the original under conditions close to equilibrium. The formation of a solid phase near the freezing point is accompanied by depletion of the gas phase by heavy isotopes. The separation coefficients 86Kr and 84Kr are ~2 and ~12, respectively, when ~3.2% of the atoms pass into the solid phase. The solid phase with its fraction below 8.8%, 5.8% and 5.7% does not contain 80Kr, 82Kr and 83Kr with separation coefficients above ~90, ~110 and ~70, respectively, to compensate for the enrichment of the gas and liquid phases. Pressure-selective condensation can be used to separate components with close boiling points when distillation and temperature-selective condensation methods are ineffective, and freezing-out of heavy isotopes can be used to enrich elements with practically important isotopes.Comment: 11 pages; 3 Figures; 3 Tables; 26 Reference

Associations of trust and healthcare provider advice with HPV vaccine acceptance among African American parents

OBJECTIVE: Healthcare providers (HCPs) are advised to give all parents a strong recommendation for HPV vaccination. However, it is possible that strong recommendations could be less effective at promoting vaccination among African Americans who on average have greater mistrust in the healthcare system. This study examines the associations of parental trust in HCPs and strength of HCP vaccination recommendation on HPV vaccine acceptance among African American parents. METHODS: Participants were recruited from an urban, academic medical center between July 2012 and July 2014. We surveyed 400 African American parents of children ages 10-12years who were offered HPV vaccine by their HCPs to assess sociodemographic factors, vaccine beliefs, trust in HCPs, and the HPV vaccine recommendation received. Medical records were reviewed to determine vaccination receipt. RESULTS: In multivariable analysis, children whose parents were "very strongly" recommended the HPV vaccine had over four times higher odds of vaccine receipt compared with those whose parents were "not very strongly" recommended the vaccine. Having a parent with "a lot of" versus "none" or only "some" trust in HCPs was associated with over twice the odds of receiving HPV vaccine. Very strong HCP recommendations were associated with higher odds of vaccination among all subgroups, including those with more negative baseline attitudes toward HPV vaccine and those with lower levels of trust. Adding the variables strength of HCP recommendation and parental trust in HCPs to a multivariable model already adjusted for sociodemographic factors and parental vaccine beliefs improved the pseudo R2 from 0.52 to 0.55. CONCLUSIONS: Among participants, receiving a strong vaccine recommendation and having a higher level of trust in HCPs were associated with higher odds of HPV vaccination, but did not add much to the predictive value of a model that already adjusted for baseline personal beliefs and sociodemographic factors

Multimedia advertising of cultural and mass activities as a means of development of cognitive interest of teenagers to music

This article presents the results of a study on the use of multimedia advertising of a mass cultural event as a means of developing adolescents' cognitive interest in musicВ настоящей статье представлены результаты исследования по применению мультимедийной рекламы культурно-массового мероприятия как средства развития познавательного интереса подростков к музык

THE USE OF VR-TRAINING COMPLEX AS A REPAIRMAN OF INDUSTRIAL EQUIPMENT IN THE EDUCATIONAL PROCESS

The article is devoted to the solution of the actual problem of the use of innovative training systems in the educational process in the preparation of specialists of working professions. The advantages of VR-training complex of industrial equipment repairman-fitter, the use of which in the process of training contributes to the solution of the personnel problem of employers, are considered.Представлено решение актуальной проблемы использования инновационных обучающих систем в учебном процессе при подготовке специалистов рабочих профессий. Рассмотрены преимущества VR- тренажерного комплекса слесаря-ремонтника промышленного оборудования, применение которого в процессе подготовки способствует решению кадровой проблемы работодателей

An empirical analysis of the nine Internet Gaming Disorder criteria

Internet Gaming Disorder (IGD) has received increased scientific attention since May 2013, and its assessment can be conducted using the nine criteria suggested by American Psychiatric Association (APA). This study examined the role of each IGD criterion using a conditional inference tree model. Methods: A total of 3,377 gamers (82.7% male, mean age 20 years, SD = 4.3 years) were recruited to the present study. In addition to collecting sociodemographic information, participants filled out the Internet Gaming Disorder Scale–Short-Form (IGDS9-SF) based on the DSM-5 criteria. Results: The conditional inference tree model revealed that endorsement of ‘withdrawal’ (criterion 2) and ‘loss of control’ (criterion 4) increased the likelihood of IGD by 77.77% (95%CI: 62.09–93.45) while endorsing ‘withdrawal’, ‘loss of control’ and ‘negative consequences’ (criterion 9) increased the likelihood of IGD by 26.66% (95%CI: 4.28–49.04). Finally, not endorsing ‘withdrawal’ but endorsing ‘preoccupation’ (criterion 1) increased the probability of IGD by 7.14% (95%CI: 1.63–12.65). Conclusions: Overall, these results suggest that not all IGD criteria carry the same diagnostic weight as each criterion can play a different role in the development of IGD. It is envisaged that these findings will help improve the assessment of IGD in the future

Liquid Drugs and High Dead Space Syringes May Keep HIV and HCV Prevalence High – A Comparison of Hungary and Lithuania

Despitevery similar political, drug policy and HIV prevention backgrounds, HIV and HCV prevalence is considerably different in Hungary (low HIV and moderate HCV prevalence) and Lithuania (high HCV and moderate HIV prevalence). Wecompared the drug use profile of Hungarian (n = 215) and Lithuanian (n = 300) injecting drug users (IDUs). Overall, compared with IDUs in Hungary, IDUs in Lithuania often injected opiates purchased in liquid form (‘shirka’), used and shared 2-piece syringes (vs. 1-piece syringes) disproportionately more often, were less likely to acquire their syringes from legal sources and had significantly more experience with injected and less experience with non-injected drugs. It may not be liquid drugs per se that contribute to a higher prevalence of HCV and/or HIV, but it is probably factors associated with the injecting of liquid drugs, such as the wide-spread use and sharing of potentially contaminated 2-piece syringes acquired often from non-legal sources, and syringe-mediated drug sharing with 2-piece syringes. Scaling up substitution therapy, especially heroin replacement, combined with reducing the supply of liquid drugs may decrease the prevalence of high-risk injecting behaviours related to the injecting of liquid drugs and drug injecting-related infections among IDUs in Lithuania

HIV Testing and Conspiracy Beliefs Regarding the Origins of HIV among African Americans

Abstract Conspiracy beliefs regarding the origins of HIV are common among African Americans, and have been associated with engaging in HIV risk behaviors but also with earlier diagnosis among HIV patients. The objective of the present study was to test the association of HIV serostatus testing with conspiracy beliefs. A total of 1430 African Americans from low-income neighborhoods with high rates of drug use were surveyed in 1997-1999 in face-to-face interviews. Two 4-point items assessed if participants agreed that AIDS was started by an experiment that went wrong and AIDS was created to kill blacks and poor folks. A binary variable indicated if the respondent agreed with the statements, on average. 22.5% of the sample endorsed conspiracy beliefs, 4.0% of whom reported not having had an HIV test, compared to 7.7% of those who did not endorse conspiracy beliefs. In multivariable logistic regression modeling, never having had an HIV test was significantly associated with conspiracy beliefs (adjusted odds ratio [AOR]=0.43, 95% confidence interval [CI]=1.3-4.3), having a high school education (AOR=0.55, CI=0.35-0.84), having depression (AOR=1.61, CI=1.02-2.52), female gender (AOR=0.54, CI=0.34-0.86), younger age, and a history of injection drug use (AOR=0.36, CI=0.23-0.56), but not sex risk behaviors (multiple partners, irregular condom use). The finding that individuals who have conspiracy beliefs are more likely to have been tested for HIV may partially explain why HIV-positive individuals who endorse conspiracy beliefs are more likely to obtain an earlier diagnosis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78123/1/apc.2009.0061.pd

A qualitative assessment of stakeholder perceptions and socio-cultural influences on the acceptability of harm reduction programs in Tijuana, Mexico

<p>Abstract</p> <p>Background</p> <p>The Mexico-U.S. border region is experiencing rising rates of blood-borne infections among injection drug users (IDUs), emphasizing the need for harm reduction interventions.</p> <p>Methods</p> <p>We assessed the religious and cultural factors affecting the acceptability and feasibility of three harm reduction interventions – Needle exchange programs (NEPs), syringe vending machines, and safer injection facilities (SIFs) – in Tijuana, Mexico. In-depth qualitative interviews were conducted with 40 community stakeholders to explore cultural and societal-related themes.</p> <p>Results</p> <p>Themes that emerged included Tijuana's location as a border city, family values, and culture as a mediator of social stigma and empathy towards IDUs. Perception of low levels of both awareness and socio-cultural readiness for harm reduction interventions was noted. Religious culture emerged as a theme, highlighting the important role religious leaders play in determining community responses to harm reduction and rehabilitation strategies for IDUs. The influence of religious culture on stakeholders' opinions concerning harm reduction interventions was evidenced by discussions of family and social values, stigma, and resulting policies.</p> <p>Conclusion</p> <p>Religion and politics were described as both a perceived benefit and deterrent, highlighting the need to further explore the overall influences of culture on the acceptability and implementation of harm reduction programs for drug users.</p