NEST: A Comprehensive Model for Scintillation Yield in Liquid Xenon

A comprehensive model for explaining scintillation yield in liquid xenon is introduced. We unify various definitions of work function which abound in the literature and incorporate all available data on electron recoil scintillation yield. This results in a better understanding of electron recoil, and facilitates an improved description of nuclear recoil. An incident gamma energy range of O(1 keV) to O(1 MeV) and electric fields between 0 and O(10 kV/cm) are incorporated into this heuristic model. We show results from a Geant4 implementation, but because the model has a few free parameters, implementation in any simulation package should be simple. We use a quasi-empirical approach, with an objective of improving detector calibrations and performance verification. The model will aid in the design and optimization of future detectors. This model is also easy to extend to other noble elements. In this paper we lay the foundation for an exhaustive simulation code which we call NEST (Noble Element Simulation Technique).Comment: 24 pages, 9 figures, 3 table

Health inequalities, fundamental causes and power:Towards the practice of good theory

Reducing health inequalities remains a challenge for policy makers across the world. Beginning from Lewin’s famous dictum that “there is nothing as practical as a good theory”, this paper begins from an appreciative discussion of ‘fundamental cause theory’, emphasizing the elegance of its theoretical encapsulation of the challenge, the relevance of its critical focus for action, and its potential to support the practical mobilisation of knowledge in generating change. Moreover, it is argued that recent developments in the theory, provide an opportunity for further theoretical development focused more clearly on the concept of power (Dickie et al. 2015). A critical focus on power as the essential element in maintaining, increasing or reducing social and economic inequalities – including health inequalities – can both enhance the coherence of the theory, and also enhance the capacity to challenge the roots of health inequalities at different levels and scales. This paper provides an initial contribution by proposing a framework to help to identify the most important sources, forms and positions of power, as well as the social spaces in which they operate. Subsequent work could usefully test, elaborate and adapt this framework, or indeed ultimately replace it with something better, to help focus actions to reduce inequalities

Frequency of fatigue and its changes in the first 6 months after traumatic brain injury: results from the CENTER-TBI study

Background: Fatigue is one of the most commonly reported subjective symptoms following traumatic brain injury (TBI). The aims were to assess frequency of fatigue over the first 6 months after TBI, and examine whether fatigue changes could be predicted by demographic characteristics, injury severity and comorbidities. Methods: Patients with acute TBI admitted to 65 trauma centers were enrolled in the study Collaborative European NeuroTrauma Effectiveness Research in TBI (CENTER-TBI). Subj

Semi-national surveillance of fungaemia in Denmark 2004-2006: increasing incidence of fungaemia and numbers of isolates with reduced azole susceptibility

AbstractA semi-national laboratory-based surveillance programme for fungaemia was initiated in 2003 that now covers c. 3.5 million inhabitants (64%) of the Danish population. In total, 1089 episodes of fungaemia were recorded during 2004–2006, corresponding to an annual incidence of 10.4/100 000 inhabitants. The annual number of episodes increased by 17% during the study period. Candida spp. accounted for 98% of the fungal pathogens. Although Candida albicans remained predominant, the proportion of C. albicans decreased from 66.1% in 2004 to 53.8% in 2006 (p <0.01), and varied considerably among participating departments, e.g., from 51.1% at a university hospital in Copenhagen to 67.6% in North Jutland County. Candida glabrata ranked second, and increased in proportion from 16.7% to 22.7% (p 0.04). Candida krusei was isolated rarely (4.1%), but the proportion doubled during the study period from 3.2% to 6.4% (p 0.06). MIC distributions of amphotericin B and caspofungin were in close agreement with the patterns predicted by species identification; however, decreased susceptibility to voriconazole, defined as an MIC of >1 mg/L, was detected in one (2.5%) C. glabrata isolate in 2004 and in 12 (14.0%) isolates in 2006 (p 0.03). Overall, the proportion of isolates with decreased susceptibility to fluconazole exceeded 30% in 2006. The incidence of fungaemia in Denmark was three-fold higher than that reported from other Nordic countries and is increasing. Decreased susceptibility to fluconazole is frequent, and a new trend towards C. glabrata isolates with elevated voriconazole MICs was observed

Intermediates in the methanol-to-hydrocarbons (MTH) reaction: a gas phase study of the unimolecular reactivity of multiply methylated benzenium cations

Svelle S, Bjorgen MA, Kolboe S, et al. Intermediates in the methanol-to-hydrocarbons (MTH) reaction: a gas phase study of the unimolecular reactivity of multiply methylated benzenium cations. CATALYSIS LETTERS. 2006;109(1-2):25-35.In order to reach a deeper insight into the reaction mechanism of the zeolite catalyzed methanol to hydrocarbons reaction (MTH), the proposed reaction intermediates, i.e., a series of multiply methyl-substituted benzenium ions has been generated in the gas phase by chemical ionization. The fragmentations of the corresponding long-lived (metastable) ions have been investigated. While expulsion of H-2 dominates for the lower homologues, elimination of methane dominates for the higher homologues, accompanied by increasing amounts CH3 center dot. Loss of larger fragments relevant to the MTH-reaction, in particular ethene, propene and even butene, is also observed in minor amounts. This latter finding is consistent with a proposed reaction cycle in the MTH reaction known as the paring mechanism, and the feasibility of this mechanism has thus been demonstrated. The metastable gas-phase ions studied here are considerably more energetic than those residing in a zeolite catalyst, but they were found to decompose with markedly higher selectivity towards alkenes as compared to those activated by collision-induced dissociation (CID)

Post-Maastricht Civil Society and Participatory Democracy

The Treaty of Maastricht and even more so the sceptical public response to the further deepening of European integration triggered a new approach to civil society. This contribution explores why the concept of civil society became so prominent in Brussels and why such high expectations were placed in the democratic strengthening of Europe by involving civil society in EU governance and by starting a civil dialogue. The main part of the contribution presents the findings of an empirical investigation demonstrating and explaining how much aspirations differ from reality. At the end of the contribution the democratic potential of civil dialogue is compared with expectations regarding the European Citizens’ Initiative