3,043 research outputs found

    Light and neutron scattering studies of the OH stretching band in liquid and supercritical water

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    The hydrogen projected OH stretching density of states has been determined by an inelastic neutron scattering experiment in liquid and supercritical water, The results, compared with new measurements of the isotropic Raman spectra at the same state conditions, support the interpretation of the Raman spectra in terms of superposition of the allowed nu(1) band with the overtone of the nu(2) band. (C) 1998 American Institute of Physics

    Effects of Prediction Feedback in Multi-Route Intelligent Traffic Systems

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    We first study the influence of an efficient feedback strategy named prediction feedback strategy (PFS) based on a multi-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. In this scenario, our model incorporates the effects of adaptability into the cellular automaton models of traffic flow. Simulation results adopting this optimal information feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux. At the end of this paper, we also discuss in what situation PFS will become invalid in multi-route systems.Comment: 15 pages, 15 figures, Physica A (2010), doi:10.1016/j.physa.2010.02.03

    Prediction feedback in intelligent traffic systems

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    The optimal information feedback has a significant effect on many socioeconomic systems like stock market and traffic systems aiming to make full use of resources. In this paper, we studied dynamics of traffic flow with real-time information provided and the influence of a feedback strategy named prediction feedback strategy is introduced, based on a two-route scenario in which dynamic information can be generated and displayed on the board to guide road users to make a choice. Our model incorporates the effects of adaptability into the cellular automaton models of traffic flow and simulation results adopting this optimal information feedback strategy have demonstrated high efficiency in controlling spatial distribution of traffic patterns compared with the other three information feedback strategies, i.e., vehicle number and flux.Comment: 14 pages, 15 figure

    Establishing comprehensive oral assessments for children with safeguarding concerns.

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    The dental profession is well placed to contribute important information in child protection cases but no previous research has been reported that assesses the volume or impact of this information. Comprehensive oral assessment clinics were introduced and established as an integral part of comprehensive medical assessments for children with welfare concerns in Greater Glasgow and Clyde. An assessment protocol and standardised paperwork for comprehensive oral assessments were developed to enhance information sharing and patient access to appropriate care. Two cases are presented and discussed to demonstrate the value of dental input

    Effect of Erdosteine on COPD Exacerbations in COPD Patients with Moderate Airflow Limitation

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    Background: The RESTORE study, a multi-national randomized, placebo-controlled study, showed that erdosteine - a muco-active antioxidant that modulates bacterial adhesiveness - reduced the rate and duration of exacerbations in moderate and severe COPD with a history of exacerbations. How much benefit patients with less severe disease experience when taking this drug remains unclear. Methods: This post hoc analysis of the 254 RESTORE participants with spirometrically-defined moderate COPD (post-bronchodilator forced expiratory volume in 1 second [FEV1] 50\u201279% predicted) examined exacerbation rate and duration, time to first exacerbation, and exacerbation-free time. Data were analyzed using descriptive statistics and comparisons between treatment groups used Wilcoxon rank-sum tests, Mann-Whitney U-tests, or log rank tests. Results: Patients with moderate COPD received erdosteine 300 mg twice daily (n=126) or placebo (n=128) added to usual COPD therapy for 12 months. During this time, there were 53 exacerbations in the erdosteine group and 74 in the placebo group, with 42.1% and 57.8% of patients, respectively, experiencing an exacerbation. There was a 47% reduction in the mean exacerbation rate with erdosteine compared to placebo (0.27 vs 0.51 exacerbations per-patient per-year, respectively, P=0.003), and a 58.3% reduction in the mild exacerbation rate (0.23 vs 0.53 mild exacerbations per-patient per-year, P=0.001). Mean duration of exacerbations was 26% shorter in erdosteine-treated patients (9.1 vs 12.3 days for placebo, P=0.022), with significant reductions in the duration of mild and moderate-to-severe exacerbations. Mean time to first exacerbation was prolonged by 7.7% (182 days for erdosteine vs 169 days for placebo, P<0.001) and the mean exacerbation-free time was increased by 51 days (279 days for erdosteine vs 228 days for placebo; P<0.001). Conclusion: These results indicate that adding erdosteine to usual COPD maintenance therapy reduces the number of mild, and duration of all, exacerbations in patients with moderate COPD and a history of exacerbations

    Los restos que no sobran en el bosque : indagando entre troncos y hojarasca

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    Los detritos, aunque a veces imperceptibles, son un componente esencial del bosque. Cumplen funciones ecológicas indispensables, como albergar innumerables especies, proveer protección al suelo, regular procesos de ciclado de nutrientes y ser importantes reservorios de carbono y agua. Si bien sabemos que las actividades humanas los alteran, no conocemos cómo cambian y cuáles son las consecuencias de estos cambios. Es necesario estudiarlos y comenzar a tenerlos en cuenta a la hora de generar políticas y estrategias de manejo sostenibl

    Silicon Mie Resonators for Highly Directional Light Emission from monolayer MoS2

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    Controlling light emission from quantum emitters has important applications ranging from solid-state lighting and displays to nanoscale single-photon sources. Optical antennas have emerged as promising tools to achieve such control right at the location of the emitter, without the need for bulky, external optics. Semiconductor nanoantennas are particularly practical for this purpose because simple geometries, such as wires and spheres, support multiple, degenerate optical resonances. Here, we start by modifying Mie scattering theory developed for plane wave illumination to describe scattering of dipole emission. We then use this theory and experiments to demonstrate several pathways to achieve control over the directionality, polarization state, and spectral emission that rely on a coherent coupling of an emitting dipole to optical resonances of a Si nanowire. A forward-to-backward ratio of 20 was demonstrated for the electric dipole emission at 680 nm from a monolayer MoS2 by optically coupling it to a Si nanowire

    Networked buffering: a basic mechanism for distributed robustness in complex adaptive systems

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    A generic mechanism - networked buffering - is proposed for the generation of robust traits in complex systems. It requires two basic conditions to be satisfied: 1) agents are versatile enough to perform more than one single functional role within a system and 2) agents are degenerate, i.e. there exists partial overlap in the functional capabilities of agents. Given these prerequisites, degenerate systems can readily produce a distributed systemic response to local perturbations. Reciprocally, excess resources related to a single function can indirectly support multiple unrelated functions within a degenerate system. In models of genome:proteome mappings for which localized decision-making and modularity of genetic functions are assumed, we verify that such distributed compensatory effects cause enhanced robustness of system traits. The conditions needed for networked buffering to occur are neither demanding nor rare, supporting the conjecture that degeneracy may fundamentally underpin distributed robustness within several biotic and abiotic systems. For instance, networked buffering offers new insights into systems engineering and planning activities that occur under high uncertainty. It may also help explain recent developments in understanding the origins of resilience within complex ecosystems. \ud \u

    Compact High-Redshift Galaxies Are the Cores of the Most Massive Present-Day Spheroids

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    Observations suggest that effective radii of high-z massive spheroids are as much as a factor ~6 smaller than low-z galaxies of comparable mass. Given the apparent absence of low-z counterparts, this has often been interpreted as indicating that the high density, compact red galaxies must be 'puffed up' by some mechanism. We compare the ensemble of high-z observations with large samples of well-observed low-z ellipticals. At the same physical radii, the stellar surface mass densities of low and high-z systems are comparable. Moreover, the abundance of high surface density material at low redshift is comparable to or larger than that observed at z>1-2, consistent with the continuous buildup of spheroids over this time. The entire population of compact, high-z red galaxies may be the progenitors of the high-density cores of present-day ellipticals, with no need for a decrease in stellar density from z=2 to z=0. The primary difference between low and high-z systems is thus the observed low-density material at large radii in low-z spheroids (rather than the high-density material in high-z spheroids). Such low-density material may either (1) assemble at z2. Mock observations of low-z massive systems show that the high-z observations do not yet probe sufficiently low surface brightness material to detect the low surface density 'wings' (if present). Thus, if the high-z galaxies resemble the most massive systems today, their inferred effective radii could be under-estimated by factors ~2-4. This difference arises because massive systems at low redshift are not well-fit by single Sersic profiles. We discuss implications of our results for physical models of galaxy evolution.Comment: 14 pages, 6 figures, accepted to MNRAS (revised to match published version
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