198 research outputs found

    An {\it ab initio} relativistic coupled-cluster theory of dipole and quadrupole polarizabilities: Applications to a few alkali atoms and alkaline earth ions

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    We present a general approach within the relativistic coupled-cluster theory framework to calculate exactly the first order wave functions due to any rank perturbation operators. Using this method, we calculate the static dipole and quadrupole polarizabilities in some alkali atoms and alkaline earth-metal ions. This may be a good test of the present theory for different rank and parity interaction operators. This shows a wide range of applications including precise calculations of both parity and CP violating amplitudes due to rank zero and rank one weak interaction Hamiltonians. We also give contributions from correlation effects and discuss them in terms of lower order many-body perturbation theory.Comment: Three tables and one figur

    New Method for Estimation of Aeolian Sand Transport Rate Using Ceramic Sand Flux Sensor (UD-101)

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    In this study, a new method for the estimation of aeolian sand transport rate was developed; the method employs a ceramic sand flux sensor (UD-101). UD-101 detects wind-blown sand impacting on its surface. The method was devised by considering the results of wind tunnel experiments that were performed using a vertical sediment trap and the UD-101. Field measurements to evaluate the estimation accuracy during the prevalence of unsteady winds were performed on a flat backshore. The results showed that aeolian sand transport rates estimated using the developed method were of the same order as those estimated using the existing method for high transport rates, i.e., for transport rates greater than 0.01 kg m−1 s−1

    Towards an understanding of how appraisal of doctors produces its effects: a realist review

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    CONTEXT: Revalidation was launched in the UK to provide assurances to the public that doctors are up to date and fit to practice. Appraisal is a fundamental component of revalidation. Approximately 150 000 doctors are appraised annually, costing an estimated £97 million over 10 years. There is little understanding of the theory of how and why appraisal is supposed to produce its effects. A realist review of the literature was utilised to explore these issues, as they generate context-mechanism-outcome (CMO) configurations, resulting in the creation of theories of how and why appraisal of doctors produces its effects. METHODS: A programme theory of appraisal was created by convening stakeholders in appraisal and searching a database of research on appraisal of doctors. Supplementary searches provided literature on theories identified in the programme theory. Relevant sections of texts relating to the programme theory were extracted from included articles, coded in NVivo and synthesised using realist logic of analysis. A classification tool categorised the included articles' contributions to programme theory. RESULTS: One hundred and twenty-five articles were included. Three mechanisms were identified: dissonance, denial and self-affirmation. The dissonance mechanism is most likely to cause outcomes of reflection and insight. Important contexts for the dissonance mechanism include the appraiser being highly skilled, the appraisee's working environment being supportive and the appraisee having the right attitude. The denial mechanism is more likely to be enacted if the opposite of these contexts occurs and could lead to game-playing behaviour. A skilled appraiser was also important in triggering the self-affirmation mechanism, resulting in reflection and insight. The contexts, mechanisms and outcomes identified were, however, limited by a lack of evidence that could enable further refining of the CMO configurations. CONCLUSION: This review makes a significant contribution to our understanding of appraisal by identifying different ways that appraisal of doctors produces its effects. Further research will focus on testing the CMO configurations

    Overdose Prevention and Naloxone Prescription for Opioid Users in San Francisco

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    Opiate overdose is a significant cause of mortality among injection drug users (IDUs) in the United States (US). Opiate overdose can be reversed by administering naloxone, an opiate antagonist. Among IDUs, prevalence of witnessing overdose events is high, and the provision of take-home naloxone to IDUs can be an important intervention to reduce the number of overdose fatalities. The Drug Overdose Prevention and Education (DOPE) Project was the first naloxone prescription program (NPP) established in partnership with a county health department (San Francisco Department of Public Health), and is one of the longest running NPPs in the USA. From September 2003 to December 2009, 1,942 individuals were trained and prescribed naloxone through the DOPE Project, of whom 24% returned to receive a naloxone refill, and 11% reported using naloxone during an overdose event. Of 399 overdose events where naloxone was used, participants reported that 89% were reversed. In addition, 83% of participants who reported overdose reversal attributed the reversal to their administration of naloxone, and fewer than 1% reported serious adverse effects. Findings from the DOPE Project add to a growing body of research that suggests that IDUs at high risk of witnessing overdose events are willing to be trained on overdose response strategies and use take-home naloxone during overdose events to prevent deaths

    Preventing Violence in Seven Countries: Global Convergence in Policies

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    Do governments take the measures that are supported by the best scientific evidence available? We present a brief review of the situation in: Australia, Canada, Germany, the Netherlands, Spain, the United Kingdom, and the United States. Our findings show surprisingly similar developments across countries. While all seven countries are moving towards evidence-based decision making regarding policies and programs to prevent violence, there remain a number of difficulties before this end can be achieved. For example, there continue to be few randomized controlled trials or rigorous quasi-experimental studies on aggression and violence. Results from experimental research are essential to both policy makers and researchers to determine the effectiveness of programs as well as increase our knowledge of the problem. Additionally, all noted that media attention for violence is high in their country, often leading to management by crisis with the result that policies are not based on evidence, but instead seek to appease public outrage. And perhaps because of attendant organizational problems (i.e., in many countries violence prevention was not under the guise of one particular agency or ministry), most have not developed a coordinated policy focusing on the prevention of violence and physical aggression. It is hypothesized that leaders in democratic countries, who must run for election every 4 to 6 years, may feel a need to focus on short-term planning rather than long-term preventive policies since the costs, but not the benefits for the latter would be incurred while they still served in office. We also noted a general absence of expertise beyond those within scientific circles. The need for these ideas to be more widely accepted will be an essential ingredient to real and sustaining change. This means that there must be better communication and increased understanding between researchers and policy makers. Toward those ends, the recent establishment of the Campbell Collaboration, formed to provide international systematic reviews of program effectiveness, will make these results more available and accessible to politicians, administrators and those charged with making key policy decision

    A tale of specialization in 2 professions: Comparing the development of radiology in chiropractic and medicine

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    Objective The purpose of this article is to describe the development of radiology as a specialty in chiropractic with a comparison to the development of the specialty of radiology in medicine. Discussion Specialization in medicine has been notably successful, with advanced training and enhanced capabilities in specialized skills leading to better outcomes for patients and increased prestige for practitioners. However, with chiropractic, as with other complementary and alternative medicine professions, no specialization has been recognized within it. Specialist radiology training in chiropractic bears a resemblance to that of medicine, with competitive entry for residencies, certification exams, and the creation of a journal and specialist professional organizations. To facilitate the comparison, I have divided the development of radiology into 4 phases from the chiropractic perspective. Phase 1 started with the discovery of x-rays in 1895, in which medicine adopted them but chiropractic did not. Phase 2 began in 1910 when B. J. Palmer introduced radiography to show chiropractic subluxations. Phase 3 started in 1942 when Waldo Poehner advocated for the mainstream diagnostic use of radiography in addition to subluxation analysis. Phase 4 started in 1957 when an examining board for certification in diagnostic radiology was assembled and many chiropractors began to embrace the mainstream medical use of radiography. Conclusion In this tale of 2 professions, radiology gained official specialty designation in the field of medicine. The medical profession had a monopoly on health care, and thus had few internal and external barriers to overcome. Chiropractic was oppressed by organized medicine, which helped to create the unofficial specialty of chiropractic radiology but which also later helped to limit the specialty. Chiropractic radiology has maintained its independence and autonomy, but also remains on the fringe of mainstream health care
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