341 research outputs found

    Laser thermoelastic generation in metals above the melt threshold

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    An approach is presented for calculating thermoelastic generation of ultrasound in a metal plate exposed to nanosecond pulsed laser heating, sufficient to cause melting but not ablation. Detailed consideration is given to the spatial and temporal profiles of the laser pulse, penetration of the laser beam into the sample, the appearance and subsequent growth and then contraction of the melt pool, and the time dependent thermal conduction in the melt and surrounding solid throughout. The excitation of the ultrasound takes place during and shortly after the laser pulse and occurs predominantly within the thermal diffusion length of a micron or so beneath the surface. It is shown how, because of this, the output of the thermal simulations can be expressed as axially symmetric transient radial and normal surface force distributions. The epicentral displacement response to these force distributions is obtained by two methods, the one based on the elastodynamic Green’s functions for plate geometry determined by the Cagniard generalized ray method and the other using a finite element numerical method. The two approaches are in very close agreement. Numerical simulations are reported on the epicentral displacement response of a 3.12mm thick tungsten plate irradiated with a 4 ns pulsed laser beam with Gaussian spatial profile, at intensities below and above the melt threshol

    Assessing the experience of using synthetic cannabinoids by means of interpretative phenomenological analysis

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    BACKGROUND: New psychoactive substances (NPS) have been increasingly consumed by people who use drugs in recent years, which pose a new challenge for treatment services. One of the largest groups of NPS is synthetic cannabinoids (SCs), which are intended as a replacement to cannabis. While there is an increasing body of research on the motivation and the effects associated with SC use, little is known about the subjective interpretation of SC use by the people who use drugs themselves. The aim of this study was to examine the experiences and personal interpretations of SC use of users who were heavily dependent on SC and are in treatment. METHODS: A qualitative research method was applied in order to explore unknown and personal aspects of SC use. Semi-structured interviews were conducted with six participants who had problematic SC use and entered treatment. The research was conducted in Hungary in 2015. We analyzed data using interpretative phenomenological analysis (IPA). RESULTS: Participants perceived SCs to be unpredictable: their initial positive experiences quickly turned negative. They also reported that SCs took over their lives both interpersonally and intrapersonally: the drug took their old friends away, and while initially it gave them new ones, in the end it not only made them asocial but the drug became their only friend, it hijacked their personalities and made them addicted. CONCLUSIONS: Participants experienced rapid development of effects and they had difficulties interpreting or integrating these experiences. The rapid alteration of effects and experiences may explain the severe psychopathological symptoms, which may be important information for harm reduction and treatment services. Since, these experiences are mostly unknown and unpredictable for people who use SCs, a forum where they could share their experiences could have a harm reducing role. For a harm reduction point of view of SCs, which are underrepresented in literature, it is important to emphasize the impossibility of knowing the quantity, purity, or even the number of different SC compounds in a particular SC product. Our study findings suggest that despite the adverse effects, including a rapid turn of experiences to negative, rapid development of addiction and withdrawal symptoms of SCs, participants continued using the drug because this drug was mostly available and cheap. Therefore, a harm reduction approach would be to make available and legal certain drugs that have less adverse effects and could cause less serious dependence and withdrawal symptoms, with controlled production and distribution (similarly to cannabis legalization in the Netherlands)

    User Experiences of Development of Dependence on the Synthetic Cannabinoids, 5f-AKB48 and 5F-PB-22, and Subsequent Withdrawal Syndromes

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    Emergence of synthetic cannabinoids (SCBs) in herbal smoking mixtures is a public health concern. New SCB’s such as 5f-AKB48 and 5F-PB-22 have been detected in French seizures and in sudden death post mortems in the US. The aim was to describe development of dependence on herbal smoking mixtures containing the SCB’s, 5f-AKB48 and 5F-PB-22 and subsequent withdrawal syndromes. Dependent users of herbal smoking mixtures known to contain the SCB’s 5f-AKB48 and 5F-PB-22 with an average Severity of Dependence Score (SDS) of 13 were interviewed using a structured guide (three males/three females). Narratives were analysed using the Empirical Phenomenological Psychological (EPP) five step method. Six themes with 68 categories emerged from the analysis. Themes are illustrated as 1) Networks and Product Availability; 2) Drivers and Motives for Use; 3) Effect and Pathways toward Dependence; 4) Poly Substance Use and Comparisons to Natural Cannabis; 5) Dependence and Withdrawal and 6) Self-detoxification Attempts. Two higher levels of abstraction above these theme-levels emerged from the data, with sole use of herbal smoking mixtures containing 5f-AKB48 and 5F-PB-22 centering on the interplay between intense cravings, compulsive all-consuming seeking, use and re-dose behaviours, and fear of the psychiatric and self-harms caused when in withdrawal. This is the first study describing dependence and withdrawal experiences in users dependent on 5f-AKB48 and 5F-PB-22. Given the potential for adverse psychiatric and physical consequences of dependent use, further development of specific clinical responses and clinical research around toxicity and withdrawal severity are warranted

    Women, literacy and health: comparing health and education sectoral approaches in Nepal

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    Functional adult literacy interventions have been regarded for many decades by policy makers as an effective way of imparting health knowledge. Supported by research on the statistical relationships between women’s literacy rates and health indicators, this dominant policy discourse is based on assumptions that non-literate women lack understanding and confidence, and that formal programmes and institutions constitute the main sites of learning. Proposing a broader conceptualisation of literacy as a social practice and of health as connected with social justice, this article draws on policy analysis and the authors’ earlier research in Nepal to re-examine the relationship between gender, literacy and health. By comparing health and literacy approaches used within the education and health sectors and taking account of new and indigenous informal learning practices, the article points to ways of investigating the complex interaction of factors that influence inequalities in gender and health at community level

    Impact of on-site cardiac catheterization on resource utilization and fatal and non-fatal outcomes after acute myocardial infarction

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    BACKGROUND: Patterns of care for acute myocardial infarction (AMI) strongly depend on the availability of on-site cardiac catheterization facilities. Although the management found at hospitals without on-site catheterization does not lead to increased mortality, little it known about its impact on resource utilization and non-fatal outcomes. METHODS: We identified all patients (n = 35,289) admitted with a first AMI in the province of Quebec between January 1, 1996 and March 31, 1999 using population-based administrative databases. Medical resource utilization and non-fatal and fatal outcomes were compared among patients admitted to hospitals with and without on-site cardiac catheterization facilities. RESULTS: Cardiac catheterization and PCI were more frequently performed among patients admitted to hospitals with catheterization facilities. However, non-invasive procedures were not used more frequently at hospitals without catheterization facilities. To the contrary, echocardiography [odds ratio (OR), 2.04; 95% confidence interval (CI), 1.93–2.16] and multi-gated acquisition imaging (OR, 1.24; 95% CI, 1.17–1.32) were used more frequently at hospitals with catheterization, and exercise treadmill testing (OR, 1.02; 95% CI, 0.91–1.15) and Sestamibi/Thallium imaging (OR, 0.93; 95% CI, 0.88–0.98) were used similarly at hospitals with and without catheterization. Use of anti-ischemic medications and frequency of emergency room and physician visits, were similar at both types of institutions. Readmission rates for AMI-related cardiac complications and mortality were also similar [adjusted hazard ratio, recurrent AMI: 1.02, 95% CI, 0.89–1.16; congestive heart failure: 1.02; 95% CI, 0.90–1.15; unstable angina: 0.93; 95% CI, 0.85–1.02; mortality: 0.99; 95% CI, 0.93–1.05)]. CONCLUSION: Although on-site availability of cardiac catheterization facilities is associated with greater use of invasive cardiac procedures, non-availability of catheterization did not translate into a higher use of non-invasive tests or have an impact on the fatal and non-fatal outcomes available for study in our administrative database

    Neonatal and child mortality data in retrospective population-based surveys compared with prospective demographic surveillance: EN-INDEPTH study.

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    BACKGROUND: Global mortality estimates remain heavily dependent on household surveys in low- and middle-income countries, where most under-five deaths occur. Few studies have assessed the accuracy of mortality data or determinants of capturing births in surveys. METHODS: The Every Newborn-INDEPTH study (EN-INDEPTH) included a large, multi-country survey of women aged 15-49 interviewed about livebirths and their survival status in five Health and Demographic Surveillance Systems (HDSSs). The HDSSs undertake regular household visits to register births and deaths for a given population. We analysed EN-INDEPTH survey data to assess background factors associated with not recalling a complete date-of-birth. We calculated Kaplan-Meier survival estimates for both survey and HDSS data and describe age-at-death distributions during the past 5 years for children born to the same women. We assessed the proportion of HDSS-births that could be matched on month-of-birth to survey-births and used regression models to identify factors associated with matching. RESULTS: 69,176 women interviewed in the survey reported 109,817 births and 3064 deaths in children under 5 years in the 5 years prior to the survey. In the HDSS data, the same women had 83,768 registered births and 2335 under-five deaths in the same period. A complete date-of-birth was not reported for 1-7% of survey-births. Birthdates were less likely to be complete for dead children and children born to women of higher parity or with little/no education. Distributions of reported age-at-death indicated heaping at full weeks (neonatal period) and at 12 months. Heaping was more pronounced in the survey data. Survey estimates of under-five mortality rates were similar to HDSS estimates of under-five mortality in two of five sites, higher in the survey in two sites (15%, 41%) and lower (24%) in one site. The proportion of HDSS-births matched to survey-births ranged from 51 to 89% across HDSSs and births of children who had died were less likely to be matched. CONCLUSIONS: Mortality estimates in the survey and HDSS were not markedly different for most sites. However, neither source is a "gold standard" and both sources miss some events. Research is required to improve capture and accuracy to better track newborn and child survival targets

    Development and evaluation of an ovarian hormone profile classification tool for female athletes: step one of a two-step process to determine ovarian hormone profiles.

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    OBJECTIVE: This study aimed to develop a reliable, comprehensive and fit-for-purpose tool for classifying ovarian hormone profiles (OHPs) (step one of a two-step process) in postmenarcheal to perimenopausal female athletes. METHODS: The OHP classification tool was designed by a team of sport scientists, practitioners and medics and is intended for use by sport practitioners. It incorporates self-reported data and guides subsequent verification methods. Written feedback was received from practitioners currently working with elite female athletes (n=5), ensuring its applicability in an applied sport setting. In addition, inter-user (n=2) and intra-user (n=30) repeatability was assessed. RESULTS: All practitioners agreed that the online tool was user-friendly. Four (out of five) practitioners stated they would include the tool in their practice, with the fifth stating that they did not have the capacity to incorporate it in their practice at present. The OHP classification tool showed excellent test-retest reliability with Cronbach's alpha values exceeding 0.9. CONCLUSION: This tool facilitates the classification of OHPs and promotes discussions between athletes and practitioners, enhancing understanding and management of ovarian hormone health in sportswomen

    The Discursive Denial of Racism by Finnish Populist Radical Right Politicians Accused of Anti-Muslim Hate-Speech

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    This chapter explores Finnish populist radical right politicians’ discursive denials of racism against Muslims following the 2015 European “refugee crisis”. The critical discursive psychological analysis of the politicians’ Facebook accounts identifies four ways in which racism was denied: first, through constructing the statements as mere displays of undisputable facts and common-sense; second, through personal narratives and ontological gerrymandering that acted as ‘proof’ of the politician’s non-racist disposition; third, through transferring the discussion from issues about race to concern matters of cultural threats; and, fourth, through reversing racism to the politicians’ political antagonists. The analyses show that in their discursive denial of racist hate-speech against Muslims, the Finnish politicians relied more on cultural arguments than welfare-protectionist ones. That is, the denials were primarily warranted through nostalgic references to Finnish national identity, people and values, and rhetorical promises that the hope of saving these rests on resisting the cultural threat posed by Islam.Peer reviewe
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