Predictability of extreme events in social media

It is part of our daily social-media experience that seemingly ordinary items (videos, news, publications, etc.) unexpectedly gain an enormous amount of attention. Here we investigate how unexpected these events are. We propose a method that, given some information on the items, quantifies the predictability of events, i.e., the potential of identifying in advance the most successful items defined as the upper bound for the quality of any prediction based on the same information. Applying this method to different data, ranging from views in YouTube videos to posts in Usenet discussion groups, we invariantly find that the predictability increases for the most extreme events. This indicates that, despite the inherently stochastic collective dynamics of users, efficient prediction is possible for the most extreme events.Comment: 13 pages, 3 figure

Stochastic dynamics and the predictability of big hits in online videos

The competition for the attention of users is a central element of the Internet. Crucial issues are the origin and predictability of big hits, the few items that capture a big portion of the total attention. We address these issues analyzing 10 million time series of videos' views from YouTube. We find that the average gain of views is linearly proportional to the number of views a video already has, in agreement with usual rich-get-richer mechanisms and Gibrat's law, but this fails to explain the prevalence of big hits. The reason is that the fluctuations around the average views are themselves heavy tailed. Based on these empirical observations, we propose a stochastic differential equation with L\'evy noise as a model of the dynamics of videos. We show how this model is substantially better in estimating the probability of an ordinary item becoming a big hit, which is considerably underestimated in the traditional proportional-growth models.Comment: Manuscript (8 pages and 5 figures

Extracting information from S-curves of language change

It is well accepted that adoption of innovations are described by S-curves (slow start, accelerating period, and slow end). In this paper, we analyze how much information on the dynamics of innovation spreading can be obtained from a quantitative description of S-curves. We focus on the adoption of linguistic innovations for which detailed databases of written texts from the last 200 years allow for an unprecedented statistical precision. Combining data analysis with simulations of simple models (e.g., the Bass dynamics on complex networks) we identify signatures of endogenous and exogenous factors in the S-curves of adoption. We propose a measure to quantify the strength of these factors and three different methods to estimate it from S-curves. We obtain cases in which the exogenous factors are dominant (in the adoption of German orthographic reforms and of one irregular verb) and cases in which endogenous factors are dominant (in the adoption of conventions for romanization of Russian names and in the regularization of most studied verbs). These results show that the shape of S-curve is not universal and contains information on the adoption mechanism. (published at "J. R. Soc. Interface, vol. 11, no. 101, (2014) 1044"; DOI: http://dx.doi.org/10.1098/rsif.2014.1044)Comment: 9 pages, 5 figures, Supplementary Material is available at http://dx.doi.org/10.6084/m9.figshare.122178

Treatment of atherosclerotic renovascular hypertension: review of observational studies and a meta-analysis of randomized clinical trials.

open9Atherosclerotic renal artery stenosis can cause ischaemic nephropathy and arterial hypertension. We herein review the observational and randomized clinical trials (RCTs) comparing medical and endovascular treatment for control of hypertension and renal function preservation. Using the Population Intervention Comparison Outcome (PICO) strategy, we identified the relevant studies and performed a novel meta-analysis of all RCTs to determine the efficacy and safety of endovascular treatment when compared with medical therapy. The following outcomes were examined: baseline follow-up difference in mean systolic and diastolic blood pressure (BP), serum creatinine, number of drugs at follow-up, incident events (heart failure, stroke, and worsening renal function), mortality, cumulative relative risk of heart failure, stroke, and worsening renal function. Seven studies comprising a total of 2155 patients (1741 available at follow-up) were considered, including the recently reported CORAL Study. Compared with baseline, diastolic BP fell more at follow-up in patients in the endovascular than in the medical treatment arm (standard difference in means -0.21, 95% confidence interval (CI): -0.342 to -0.078, P = 0.002) despite a greater reduction in the mean number of antihypertensive drugs (standard difference in means -0.201, 95% CI: -0.302 to -0.1, P < 0.001). At variance, follow-up changes (from baseline) of systolic BP, serum creatinine, and incident cardiovascular event rates did not differ between treatment arms. Thus, patients with atherosclerotic renal artery stenosis receiving endovascular treatment required less anti-antihypertensive drugs at follow-up than those medically treated. Notwithstanding this, they evidenced a better control of diastolic BP.openopenCaielli P;Frigo AC;Pengo MF;Rossitto G;Maiolino G;Seccia TM;Calò LA;Miotto D;Rossi GPCaielli, P; Frigo, ANNA CHIARA; Pengo, Mf; Rossitto, G; Maiolino, G; Seccia, TERESA MARIA; Calò, La; Miotto, Diego; Rossi, Gianpaol

The Process Manager in the ATLAS DAQ System

The Process Manager is the component responsible for launching and controlling processes in the ATLAS DAQ system. The tasks of the Process Manager can be coarsely grouped into three categories: process creation, control and monitoring. Process creation implies the creation of the actual process on behalf of different users and the preparation of all the resources and data needed to actually start the process. Process control includes mostly process termination and UNIX signal dispatching. Process monitoring implies both giving state information on request and initiating call-backs to notify clients that processes have changed states. This paper describes the design and implementation of the DAQ Process Manager for the ATLAS experiment. Since the Process Manager is at the basis of the DAQ control system it must be extremely robust and tolerate the failure of any other DAQ service. Particular emphasis will be given to the testing and quality assurance procedures carried out to validate this component

2D Zernike polynomial expansion: finding the protein-protein binding regions

We present a method for efficiently and effectively assessing whether and where two proteins can interact with each other to form a complex. This is still largely an open problem, even for those relatively few cases where the 3D structure of both proteins is known. In fact, even if much of the information about the interaction is encoded in the chemical and geometric features of the structures, the set of possible contact patches and of their relative orientations are too large to be computationally affordable in a reasonable time, thus preventing the compilation of reliable interactome. Our method is able to rapidly and quantitatively measure the geometrical shape complementarity between interacting proteins, comparing their molecular iso-electron density surfaces expanding the surface patches in term of 2D Zernike polynomials. We first test the method against the real binding region of a large dataset of known protein complexes, reaching a success rate of 0.72. We then apply the method for the blind recognition of binding sites, identifying the real region of interaction in about 60% of the analyzed cases. Finally, we investigate how the efficiency in finding the right binding region depends on the surface roughness as a function of the expansion order

The SDGs in the EU Cultural Policies: an institutional communication perspective

The main goal of this research is to analyze the experts’ opinions on cultural sustainability and the importance of sustainable development in the EU cultural policies. Besides, the research analyses how institutional communication may contribute to the introduction of the sustainable development, and, specifically, of the SDGs in the European Union cultural policies’ definition. In order to achieve these objectives, we share a survey with several experts in EU cultural policies. The experts’ conclusions show that the SDGs need to be explicitly included in the cultural policies, adding a more practical perspective through specific projects and action plans. Institutional communication is a strategic factor for the success of sustainable development in terms of cultural policies and cultural sustainability in the European Union

Diagnostic investigation to support the restoration of the polychrome terracotta relief "Madonna and Child" in Piove di Sacco (Padova, Italy)

Restoration procedures of the polychrome terracotta relief “Madonna and Child” with papier-mâché inserts from a shrine in Piove di Sacco (Padova, orthern Italy) were assisted by analytical investigations, contributing to identify the chemical composition of the pigments, fractures and internal damages, additions and retouchings, which strongly modified the original manufact. In particular, energy dispersive X-ray fluorescence, Raman spectroscopy and FT-IR spectroscopy were employed to determine the chemical composition of pigments on the original layer and on the overpaintings and to understand the artistic techniques. Moreover, X-ray planar radiography and computed tomography were used to understand the structure and its conservative state. Finally, the relief, stylistically dated to the 17th century, turned out to be a Renaissance terracotta artefact. The polychrome blue traces of lapis lazuli highlighted a valuable artwork and the resemblance with the style of Donatello and his apprentices have recently led to further studies, as an initial part of a larger research on polychrome terracotta in Veneto

Relationship between gastric pouch and GERD after laparoscopic sleeve gastrectomy

open9noAims and objectives Laparoscopic Sleeve Gastrectomy (LSG) is considered safe and effective even as conversion procedure after primary bariatric operations. The correlation between gastric pouch volumes and gastro-esophageal reflux disease's (GERD) symptoms (heartburn, reflux, regurgitation) remains unclear (1, 2). With this study we want to assess a correlation between the gastric remnant size and GERD.openPomerri, F.; Romanucci, G.; Barbiero, G.; Zuliani, M.; Ortu, V.; Miotto, D.; Albanese, A.; Prevedello, L.; Foletto, M.Pomerri, Fabio; Romanucci, G.; Barbiero, G.; Zuliani, M.; Ortu, V.; Miotto, Diego; Albanese, A.; Prevedello, L.; Foletto, M

Treatment of Hepatitis C virus genotype 3 infection with direct-acting antiviral agents

Hepatitis C virus (HCV) genotype 3 is responsible for 30.1% of chronic hepatitis C infection cases worldwide. In the era of directacting antivirals, these patients have become one of the most challenging to treat, due to fewer effective drug options, higher risk of developing cirrhosis and hepatocellular carcinoma and lower sustained virological response (SVR) rates. Currently there are 4 recommended drugs for the treatment of HCV genotype 3: pegylated interferon (PegIFN), sofosbuvir (SOF), daclatasvir (DCV) and ribavirin (RBV). Treatment with PegIFN, SOF and RBV for 12 weeks has an overall SVR rate of 83-100%, without significant differences among cirrhotic and non-cirrhotic patients. However, this therapeutic regimen has several contra-indications and can cause significant adverse events, which can reduce adherence and impair SVR rates. SOF plus RBV for 24 weeks is another treatment option, with SVR rates of 82-96% among patients without cirrhosis and 62-92% among those with cirrhosis. Finally, SOF plus DCV provides 94-97% SVR rates in non-cirrhotic patients, but 59-69% in those with cirrhosis. The addition of RBV to the regimen of SOF plus DCV increases the SVR rates in cirrhotic patients above 80%, and extending treatment to 24 weeks raises SVR to 90%. The ideal duration of therapy is still under investigation. For cirrhotic patients, the optimal duration, or even the best regimen, is still uncertain. Further studies are necessary to clarify the best regimen to treat HCV genotype 3 infection491