438 research outputs found

    Cloud-based Content Distribution on a Budget

    Full text link
    To leverage the elastic nature of cloud computing, a solution provider must be able to accurately gauge demand for its offering. For applications that involve swarm-to-cloud interactions, gauging such demand is not straightforward. In this paper, we propose a general framework, analyze a mathematical model, and present a prototype implementation of a canonical swarm-to-cloud application, namely peer-assisted content delivery. Our system – called Cyclops – dynamically adjusts the off-cloud bandwidth consumed by content servers (which represents the bulk of the provider's cost) to feed a set of swarming clients, based on a feedback signal that gauges the real-time health of the swarm. Our extensive evaluation of Cyclops in a variety of settings – including controlled PlanetLab and live Internet experiments involving thousands of users – show significant reduction in content distribution costs (by as much as two orders of magnitude) when compared to non-feedback-based swarming solutions, with minor impact on content delivery times

    Oxidative stress: new insights on the association of nonalcoholic fatty liver disease and atherosclerosis

    Get PDF
    Non-alcoholic fatty liver disease (NAFLD) represents the most common and emerging chronic liver disease worldwide. It includes a wide spectrum of liver diseases ranging from simple fatty liver to non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and more severe liver complications such as cirrhosis, hepatocellular carcinoma and liver mortality. NAFLD is strongly associated with obesity, insulin resistance, hypertension, and dyslipidaemia, and is now regarded as the liver manifestation of the metabolic syndrome. The increased mortality of patients with NAFLD is primarily a result of cardiovascular disease and, to a lesser extent, to liver related diseases. Increased oxidative stress has been reported in both patients with NAFLD and patient with cardiovascular risk factors. Thus, oxidative stress represents a shared pathophysiological disorder between the two conditions. Several therapeutic strategies targeting oxidative stress reduction in patients with NAFLD have been proposed, with conflicting results. In particular, vitamin E supplementation has been suggested for the treatment of non-diabetic, non-cirrhotic adults with active NASH, although this recommendation is based only on the results of a single randomized controlled trial. Other antioxidant treatments suggested are resveratrol, silybin, L-carnitine and pentoxiphylline. No trial so far, has evaluated the cardiovascular effects of antioxidant treatment in patients with NAFLD. New, large-scale studies including as end-point also the assessment of the atherosclerosis markers are needed

    Phytosanitary Certification

    Get PDF

    THE IMPACT OF MONETARY POLICY SHOCK ON PUBLIC DEBT: A DSGE APPROACH

    Get PDF
    The impact of monetary policy shock on public debt: a DSGE approach Nowadays, the increase in public debt and inflation are key concerns of the political debate among policymakers. In this regard, some economists have argued that the reason why inflation is higher lies in a transitory rise of commodity prices; others, instead, have asserted that permanent changes in the labor market caused by the Covid-19 pandemic, may also contribute to keeping inflation high for a long time. This paper aims to investigate the effects of a positive monetary policy shock on the public debt-to-GDP ratio. Moreover, it assesses its different impacts on households. For these purposes, the paper employs an extended version of the New Keynesian Dynamic Stochastic General Equilibrium (DSGE) model Ă  la Leeper et al., (2017) considering an economy populated by savers and hand-to-mouth households, with distortionary taxation. Our analysis confirms that an increase in inflation contributes to public debt-to-GDP ratio reduction, thanks to the positive impact on output in the short term. Moreover, results highlight a trade-off between agents: savers as forward-looking agents invest their savings in the short term by increasing their income; on the opposite, hand-to-mouth households suffer a loss of income. This paper contributes to the literature on monetary and fiscal policy, which focuses on the relationship between public debt and inflation

    Implementing post-orthodontic compliance among adolescents wearing removable retainers through Whatsapp: a pilot study

    Get PDF
    Purpose: To determine whether the use of social media is useful in improving compliance and follow-up attendance among patients wearing retainers after orthodontic treatment. Patients and methods: Sixty post-orthodontic patients (aged 16-19 years), randomized in two groups: follow-up supported by participation in WhatsApp chat group (SG), and Control Group (CG). All patients were scheduled for quarterly check-ups for monitoring of orthodontic stability by measurement of intercanine width at the beginning of the study (t(0)) and every 4 months t(1), t(2), t(3)) for 1 year of observation. Patients in the SG additionally participated in a WhatsApp chat group, where they would send, on a weekly basis, snapshots showing his/her occlusion. Every month, the orthodontist acting as the moderator awarded the best five snapshots by publishing a ranking in the chat. Results: Participants in the SG featured smaller changes from the intercanine widths at baseline (at debonding) compared to the CG patients at all times during 1 year of follow-up. Follow-up attendance was regular in both groups in the first 8 months of follow-up. After that, patient compliance decreased in the CG, with eight patients missing check-up appointments. Conclusion: Engaging adolescent patients directly through WhatsApp activity seems to increase regularity in wearing removable retainers, attendance to follow-up schedule, and yield better long-term outcome in terms of orthodontic stability and compliance

    Apps for oral hygiene in children 4 to 7 years : fun and effectiveness

    Get PDF
    Nowadays apps in preschool age are largely used in learning improvement. The aim of this work was to test effectiveness of apps in improving oral hygiene in children patients aged from 4 to 7 years and evaluating correlation between parents educational attainment and children oral hygiene. 100 patients aged from 4 to 7 years were randomly assigned by an external office in the study group (SG: 32 females, 18 males) and in the control group (CG: 28 females and 22 males). Plaque index (PI) and carious lesions localisation were detected. At baseline all patients and one of the parents were instructed at chair-side about the proper oral hygiene techniques. SG patients were also given app as an aid in oral hygiene practice. Follow-up was 12 months. Measurements were made every three months at chair-side visits. Information about children compliance in oral hygiene and educational level of parents were obtained by questionnaires at t0 and after 12 months. SG patients showed stronger oral hygiene and PI lower than those in CG. Questionnaire showed higher compliance of SG patients and parents educational level seemed to affect children oral hygiene. Apps in children allowed achieving encouraging results with improvement of oral hygiene and health

    Charge Recombination Kinetics of Bacterial Photosynthetic Reaction Centres Reconstituted in Liposomes: Deterministic Versus Stochastic Approach

    Get PDF
    In this theoretical work, we analyse the kinetics of charge recombination reaction after a light excitation of the Reaction Centres extracted from the photosynthetic bacterium Rhodobacter sphaeroides and reconstituted in small unilamellar phospholipid vesicles. Due to the compartmentalized nature of liposomes, vesicles may exhibit a random distribution of both ubiquinone molecules and the Reaction Centre protein complexes that can produce significant differences on the local concentrations from the average expected values. Moreover, since the amount of reacting species is very low in compartmentalized lipid systems the stochastic approach is more suitable to unveil deviations of the average time behaviour of vesicles from the deterministic time evolution
    • …
    corecore