10,943 research outputs found

    Global and regional importance of the direct dust-climate feedback.

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    Feedbacks between the global dust cycle and the climate system might have amplified past climate changes. Yet, it remains unclear what role the dust-climate feedback will play in future anthropogenic climate change. Here, we estimate the direct dust-climate feedback, arising from changes in the dust direct radiative effect (DRE), using a simple theoretical framework that combines constraints on the dust DRE with a series of climate model results. We find that the direct dust-climate feedback is likely in the range of -0.04 to +0.02 Wm -2 K-1, such that it could account for a substantial fraction of the total aerosol feedbacks in the climate system. On a regional scale, the direct dust-climate feedback is enhanced by approximately an order of magnitude close to major source regions. This suggests that it could play an important role in shaping the future climates of Northern Africa, the Sahel, the Mediterranean region, the Middle East, and Central Asia

    Evaluation of the burden of HPV-related hospitalizations as a useful tool to increase awareness: 2007–2017 data from the sicilian hospital discharge records

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    In light of the implementation of human papillomavirus (HPV) prevention strategies, epidemiological studies in different geographical areas are required in order to assess the impact of HPV-related diseases. The purpose of the present study was to describe the burden of HPV-related hospitalizations in Sicily. A retrospective observational study estimated 43,531 hospitalizations attributable to HPV from 2007 to 2017. During the observed period, there was a decrease for all HPV-related conditions with a higher reduction, among neoplasms, for cervical cancer (annual percent change (APC) = −9.9%, p < 0.001). The median age for cervical cancer was 45 years old, with an increasing value from 43 to 47 years (p < 0.001). The age classes with greater decreases in hospital admissions for invasive cancers were women aged 35 years or more (APC range from −5.5 to −9.86) and 25–34 years old (APC = −11.87, p < 0.001) for women with cervical carcinoma in situ. After ten years for vaccine introduction and sixteen years for cervical cancer screening availability, a relatively large decrease in hospital admissions for cervical cancer and other HPV-related diseases in Sicily was observed. Some clinical characteristics of hospitalization, such as increasing age, are suggestive clues for the impact of preventive strategies, but further research is needed to confirm this relationship

    Magnetic order and the electronic ground state in the pyrochlore iridate Nd2Ir2O7

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    We report a combined muon spin relaxation/rotation, bulk magnetization, neutron scattering, and transport study of the electronic properties of the pyrochlore iridate Nd2Ir2O7. We observe the onset of strongly hysteretic behavior in the temperature dependent magnetization below 120 K, and an abrupt increase in the temperature dependent resistivity below 8 K. Zero field muon spin relaxation measurements show that the hysteretic magnetization is driven by a transition to a magnetically disordered state, and that below 8 K a complex magnetically ordered ground state sets in, as evidenced by the onset of heavily damped spontaneous muon precession. Our measurements point toward the absence of a true metal-to-insulator phase transition in this material and suggest that Nd2Ir2O7 lies either within or on the metallic side of the boundary of the Dirac semimetal regime within its topological phase diagram.Comment: 21 pages, 7 figure

    Cell therapy in patients with critical limb ischemia

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    Critical limb ischemia (CLI) represents the most advanced stage of peripheral arterial obstructive disease (PAOD) with a severe obstruction of the arteries which markedly reduces blood flow to the extremities and has progressed to the point of severe rest pain and/or even tissue loss. Recent therapeutic strategies have focused on restoring this balance in favor of tissue survival using exogenousmolecular and cellular agents to promote regeneration of the vasculature.These are based on stimulation of angiogenesis by extracellular and cellular components. This review article carries out a systematic analysis of the most recent scientific literature on the application of stem cells in patients with CLI. The results obtained from the detailed analysis of the recent literature data have confirmed the beneficial role of cell therapy in reducing the rate of major amputations in patients with CLI and improving their quality of life

    The Effect of Advanced Traveller Information Systems (ATIS) on public transport demand and its uncertainty

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    Advanced Traveller Information Systems (ATISs) include a broad range of advanced computer and communication technologies. These systems are designed to provide transit riders pre-trip and real-time information, to make better informed decisions regarding their mode of travel, planned routes and travel times. ATISs include in-vehicle displays, terminal or wayside based information centres, information by phone or mobile and internet. In this article, a Stated Preference survey has been carried out in order to know the preferences of public transport\u2019s customers related to different ATISs and their willingness to pay in Palermo. An ordered probit demand model has been calibrated to determine the potential additional share of demand attracted by the adoption of ATISs. Finally, Monte Carlo simulation has been carried out to appraise the uncertainty on some parameters of the calibrated demand model. The results show that respondents give more importance to the type of information and its cost, whereas they are less interested in the system that provides the information

    Surface magnetic canting in a ferromagnet

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    The surface magnetic canting (SMC) of a semi-infinite film with ferromagnetic exchange interaction and competing bulk and surface anisotropies is investigated via a nonlinear mapping formulation of mean-field theory previously developed by our group [L. Trallori et al., Int. J. Mod. Phys. B 10, 1935-1988 (1996)], and extended to the case where an external magnetic field is applied to the system. When the field H is parallel to the film plane, the condition for SMC is found to be the same as that recently reported by Popov and Pappas [Phys. Rev. B 64, 184401 (2001)]. The case of a field H applied perpendicularly to the film plane is also investigated. In both cases, the zero-temperature equilibrium configuration is easily determined by our theoretical approach.Comment: 4 pages, 3 figure

    Low-speed impact craters in loose granular media

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    We report on craters formed by balls dropped into dry, non-cohesive, granular media. By explicit variation of ball density ρb\rho_{b}, diameter DbD_{b}, and drop height HH, the crater diameter is confirmed to scale as the 1/4 power of the energy of the ball at impact: Dc(ρbDb3H)1/4D_{c}\sim(\rho_{b}{D_{b}}^{3}H)^{1/4}. Against expectation, a different scaling law is discovered for the crater depth: d(ρb3/2Db2H)1/3d\sim({\rho_{b}}^{3/2}{D_{b}}^{2}H)^{1/3}. The scaling with properties of the medium is also established. The crater depth has significance for granular mechanics in that it relates to the stopping force on the ball.Comment: experiment; 4 pages, 3 figure
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