1,604 research outputs found

    Survey of pickup ion signatures in the vicinity of Titan using CAPS/IMS

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    Pickup ion detection at Titan is challenging because ion cyclotron waves are rarely detected in the vicinity of the moon. In this work, signatures left by freshly produced pickup heavy ions (m/q ∼ 16 to m/q ∼ 28) as detected in the plasma data by the Cassini Plasma Spectrometer/Ion Mass Spectrometer (CAPS/IMS) instrument on board Cassini are analyzed. In order to discern whether these correspond to ions of exospheric origin, one of the flybys during which the reported signatures were observed is investigated in detail. For this purpose, ion composition data from time-of-flight measurements and test particle simulations to constrain the ions' origin are used. After being validated, the detection method is applied to all the flybys for which the CAPS/IMS instrument gathered valid data, constraining the region around the moon where the signatures are observed. The results reveal an escape region located in the anti-Saturn direction as expected from the nominal corotation electric field direction. These findings provide new constraints for the area of freshly produced pickup ion escape, giving an approximate escape rate of inline image ions· s−1

    Normative equations for central augmentation index:Assessment of inter-population applicability and how it could be improved

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    Common reference values of arterial stiffness indices could be effective screening tool in detecting vascular phenotypes at risk. However, populations of the same ethnicity may differ in vascular phenotype due to different environmental pressure. We examined applicability of normative equations for central augmentation index (cAIx) derived from Danish population with low cardiovascular risk on the corresponding Croatian population from the Mediterranean area. Disagreement between measured and predicted cAIx was assessed by Bland-Altman analysis. Both, cAIx-age distribution and normative equation fitted on Croatian data were highly comparable to Danish low-risk sample. Contrarily, Bland-Altman analysis of cAIx disagreement revealed a curvilinear deviation from the line of full agreement indicating that the equations were not equally applicable across age ranges. Stratification of individual data into age decades eliminated curvilinearity in all but the 30–39 (men) and 40–49 (women) decades. In other decades, linear disagreement independent of age persisted indicating that cAIx determinants other than age were not envisaged/compensated for by proposed equations. Therefore, established normative equations are equally applicable to both Nordic and Mediterranean populations but are of limited use. If designed for narrower age ranges, the equations’ sensitivity in detecting vascular phenotypes at risk and applicability to different populations could be improved

    Integration of decision support systems to improve decision support performance

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    Decision support system (DSS) is a well-established research and development area. Traditional isolated, stand-alone DSS has been recently facing new challenges. In order to improve the performance of DSS to meet the challenges, research has been actively carried out to develop integrated decision support systems (IDSS). This paper reviews the current research efforts with regard to the development of IDSS. The focus of the paper is on the integration aspect for IDSS through multiple perspectives, and the technologies that support this integration. More than 100 papers and software systems are discussed. Current research efforts and the development status of IDSS are explained, compared and classified. In addition, future trends and challenges in integration are outlined. The paper concludes that by addressing integration, better support will be provided to decision makers, with the expectation of both better decisions and improved decision making processes

    Carpal tunnel syndrome and the use of computer mouse and keyboard: A systematic review

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    <p>Abstract</p> <p>Background</p> <p>This review examines evidence for an association between computer work and carpal tunnel syndrome (CTS).</p> <p>Methods</p> <p>A systematic review of studies of computer work and CTS was performed. Supplementary, longitudinal studies of low force, repetitive work and CTS, and studies of possible pathophysiological mechanisms were evaluated.</p> <p>Results</p> <p>Eight epidemiological studies of the association between computer work and CTS were identified. All eight studies had one or more limitation including imprecise exposure and outcome assessment, low statistical power or potentially serious biases. In three of the studies an exposure-response association was observed but because of possible misclassification no firm conclusions could be drawn. Three of the studies found risks below 1. Also longitudinal studies of repetitive low-force non-computer work (n = 3) were reviewed but these studies did not add evidence to an association. Measurements of carpal tunnel pressure (CTP) under conditions typically observed among computer users showed pressure values below levels considered harmful. However, during actual mouse use one study showed an increase of CTP to potentially harmful levels. The long term effects of prolonged or repeatedly increased pressures at these levels are not known, however.</p> <p>Conclusion</p> <p>There is insufficient epidemiological evidence that computer work causes CTS.</p

    Nonanalytic quantum oscillator image of complete replica symmetry breaking

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    We describe the effect of replica symmetry breaking in the field distribution function P(h) of the T=0 SK-model as the difference between a split Gaussian and the first excited state ψ1\psi_1 of a weakly anharmonic oscillator with nonanalytic shift by means of the analogy P(h)ψ1(x)P(h)|\psi_1(x)|. New numerical calculations of the leading 100 orders of replica symmetry breaking (RSB) were performed in order to obtain P(h), employing the exact mapping between density of states ρ(E)\rho(E) of the fermionic SK-model and P(h) of the standard model, as derived by Perez-Castillo and Sherrington. Fast convergence towards a fixed point function ρ(E)\rho(E) for infinite steps of RSB is observed. A surprisingly small number of harmonic oscillator wave-functions suffices to represent this fixed point function. This allows to determine an anharmonic potential V(x) with nonanalytic shift, whose first excited state represents ρ(E)\rho(E) and hence P(h). The harmonic potential with unconventional shift V2(x)(xx0)2=(xx0sign(x))2V_2(x)\sim (|x|-x_0)^2=(x-x_0\,sign(x))^2 yields already a very good approximation, since anharmonic couplings of V(x)V2(x)xm,m>2,V(x)-V_2(x)\sim |x|^{m}, m>2, decay rapidly with increasing m. We compare the pseudogap-forming effect of replica symmetry breaking, hosted by the fermionic SK-model, with the analogous effect in the Coulomb glass as designed by Davies-Lee-Rice and described by M\"uller-Pankov.Comment: 11 pages, 3 figures, submitted to Phil. Mag., special edition in honour of David Sherrington's 70th birthda

    External costs of atmospheric Pb emissions: valuation of neurotoxic impacts due to inhalation

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    <p>Abstract</p> <p>Background</p> <p>The Impact Pathway Approach (IPA) is an innovative methodology to establish links between emissions, related impacts and monetary estimates. Only few attempts have so far been presented regarding emissions of metals; in this study the external costs of airborne lead (Pb) emissions are assessed using the IPA. Exposure to Pb is known to provoke impacts especially on children's cognition. As cognitive abilities (measured as IQ, intelligence quotient) are known to have implications for lifetime income, a pathway can be established leading from figures for Pb emissions to the implied loss in earnings, and on this basis damage costs per unit of Pb emission can be assessed.</p> <p>Methods</p> <p>Different types of models are here linked. It is relatively straightforward to establish the relationship between Pb emissions and consequent increase in air-Pb concentration, by means of a Gaussian plume dispersion model (OML). The exposed population can then be modelled by linking the OML-output to population data nested in geo-referenced grid cells. Less straightforward is to establish the relationship between exposure to air-Pb concentrations and the resulting blood-Pb concentration. Here an Age-Dependent Biokinetic Model (ADBM) for Pb is applied. On basis of previous research which established links between increases in blood-Pb concentrations during childhood and resulting IQ-loss we arrive at our results.</p> <p>Results</p> <p>External costs of Pb airborne emissions, even at low doses, in our site are in the range of 41-83 €/kg emitted Pb, depending on the considered meteorological year. This estimate applies only to the initial effects of air-Pb, as our study does not address the effects due to the Pb environmental-accumulation and to the subsequent Pb re-exposure. These are likely to be between one and two orders of magnitude higher.</p> <p>Conclusions</p> <p>Biokinetic modelling is a novel tool not previously included when applying the IPA to explore impacts of Pb emissions and related external costs; it allows for more fine-tuned, age-dependent figures for the external costs from low-dose exposure. Valuation of additional health effects and impacts e.g. due to exposure via ingestion appear to be feasible when extending the insights from the present pilot study.</p
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