Opinion dynamics with emergent collective memory: the impact of a long and heterogeneous news history

In modern society people are being exposed to numerous information, with some of them being frequently repeated or more disruptive than others. In this paper we use a model of opinion dynamics to study how this news impact the society. In particular, our study aims to explain how the exposure of the society to certain events deeply change people's perception of the present and future. The evolution of opinions which we consider is influenced both by external information and the pressure of the society. The latter includes imitation, differentiation, homophily and its opposite, xenophobia. The combination of these ingredients gives rise to a collective memory effect, which is triggered by external information. In this paper we focus our attention on how this memory arises when the order of appearance of external news is random. We will show which characteristics a piece of news needs to have in order to be embedded in the society's memory. We will also provide an analytical way to measure how many information a society can remember when an extensive number of news items is presented. Finally we will show that, when a certain piece of news is present in the society's history, even a distorted version of it is sufficient to trigger the memory of the originally stored information.Comment: 30 pages, 6 figure

New insights into pathogenesis and treatment of anca-associated vasculitis. autoantibodies and beyond

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of rare systemic diseases affecting small-caliber vessels. The damage caused by AAV mainly involves the lung and kidneys. AAV includes three different types: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Although the different phenotypic forms of AAV share common features, recent studies have shown that there are significant differences in terms of pathogenetic mechanisms involving both the adaptive and innate immune systems. Advances in our understanding of pathogenesis have enabled the development of immuno-targeted therapies. This review illustrates the characteristics of the various forms of AAV and the new therapies available for this disease that can have lethal consequences if left untreated

Duality for a boundary driven asymmetric model of energy transport

We study the Asymmetric Brownian Energy, a model of heat conduction defined on the one-dimensional finite lattice with open boundaries. The system is shown to be dual to the Symmetric inclusion process with absorbing boundaries. The proof relies on a non-local map transformation procedure relating the model to its symmetric version. As an application, we show how the duality relation can be used to analytically compute suitable exponential moments with respect to the stationary measure.Comment: 15 pages, no figur

Natural history of patients with non cirrhotic portal hypertension: Comparison with patients with compensated cirrhosis

Background. The knowledge of natural history of patients with portal hypertension (PH) not due to cirrhosis is less well known than that of cirrhotic patients. Aim. To describe the clinical presentation and the outcomes of 89 patients with non-cirrhotic PH (25 with non-cirrhotic portal hypertension, INCPH, and 64 with chronic portal vein thrombosis, PVT) in comparison with 77 patients with Child A cirrhosis. Methods. The patients were submitted to a standardized clinical, laboratory, ultrasonographic and endoscopic follow-up. Variceal progression, incidence of variceal bleeding, portal vein thrombosis, ascites and survival were recorded. Results. At presentation, the prevalence of varices, variceal bleeding and ascites was similar in the 3 groups. During follow-up, the rate of progression to varices at risk of bleeding (p<0.0001) and the incidence of first variceal bleeding (p=0.02) were significantly higher in non-cirrhotic then in cirrhotic patients. A PVT developed in 32% of INCPH patients and in 18% of cirrhotics (p=0.02). Conclusions. In the patients with non–cirrhotic PH variceal progression is more rapid and bleeding more frequent than in cirrhotics. Patients with INCPH are particularly prompt to develop PVT. This observational study suggests that the management of patients with non-cirrhotic PH should take into consideration the natural history of portal hypertension in these patients and cannot be simply derived by the observation of cirrhotic patients

Calculation of Linear and Non-linear Electric Response Properties of Systems in Aqueous Solution: A Polarizable Quantum/Classical Approach with Quantum Repulsion Effects

We present a computational study of polarizabilities and hyperpolarizabilities of organic molecules in aqueous solutions, focusing on solute-water interactions and the way they affect a molecule's linear and non-linear electric response properties. We employ a polarizable quantum mechanics/molecular mechanics (QM/MM) computational model that treats the solute at the QM level while the solvent is treated classically using a force field that includes polarizable charges and dipoles, which dynamically respond to the solute's quantum-mechanical electron density. Quantum confinement effects are also treated by means of a recently implemented method that endows solvent molecules with a parametric electron density, which exerts Pauli repulsion forces upon the solute. By applying the method to a set of aromatic molecules in solution we show that, for both polarizabilities and first hyperpolarizabilities, observed solution values are the result of a delicate balance between electrostatics, hydrogen-bonding, and non-electrostatic solute solvent interactions

The rationale for liquid biopsy in colorectal cancer: focus on circulating tumor cells

Capturing circulating tumor cells (CTCs) and/or circulating tumor DNA from blood, which represents a precious source of biological material derived from both primary and metastatic tumors, has been named a 'liquid biopsy'. While the circulating tumor DNA might be more representative of the bulk of the metastatic tumor, CTCs are thought to reflect more of the metastases-initiating cells. Consequently, a liquid biopsy made of tumor cells and tumor DNA that is able to track cancer evolution, as a fingerprint of the patient's individual tumor, and is easy to perform at every stage of the disease course, sounds attractive. This article mainly focuses on the applications of CTCs to track tumor dynamics in real time using colorectal cancer as a model system. The analysis of viable CTCs at DNA, RNA and protein levels, as well as their expansion in vitro, may allow deep investigation of the features of metastases-initiating cells

No effect of albumin infusion on the prevention of hepatic encephalopathy after transjugular intrahepatic portosystemic shunt

Hepatic encephalopathy (HE) is a major problem in patients submitted to TIPS. Previous studies identified low albumin as a factor associated to post-TIPS HE. In cirrhotics with diuretic-induced HE and hypovolemia, albumin infusion reduced plasma ammonia and improved HE. Our aim was to evaluate if the incidence of overt HE (grade II or more according to WH) and the modifications of venous blood ammonia and psychometric tests during the first month after TIPS can be prevented by albumin infusion. Twenty-three patients consecutively submitted to TIPS were enrolled and treated with 1 g/Kg BW of albumin for the first 2 days after TIPS followed by 0,5 g/Kg BW at day 4th and 7th and then once a week for 3 weeks. Forty-five patients included in a previous RCT (Riggio et al. 2010) followed with the same protocol and submitted to no pharmacological treatment for the prevention of HE, were used as historical controls. No differences in the incidence of overt HE were observed between the group of patients treated with albumin and historical controls during the first month (34 vs 31 %) or during the follow-up (39 vs 48 %). Two patients in the albumin group and three in historical controls needed the reduction of the stent diameter for persistent HE. Venous blood ammonia levels and psychometric tests were also similarly modified in the two groups. Survival was also similar. Albumin infusion has not a role in the prevention of post-TIPS HE

Who has the last word? Understanding How to Sample Online Discussions

In online debates individual arguments support or attack each other, leading to some subset of arguments being considered more relevant than others. However, in large discussions readers are often forced to sample a subset of the arguments being put forth. Since such sampling is rarely done in a principled manner, users may not read all the relevant arguments to get a full picture of the debate. This paper is interested in answering the question of how users should sample online conversations to selectively favour the currently justified or accepted positions in the debate. We apply techniques from argumentation theory and complex networks to build a model that predicts the probabilities of the normatively justified arguments given their location in online discussions. Our model shows that the proportion of replies that are supportive, the number of replies that comments receive, and the locations of un-replied comments all determine the probability that a comment is a justified argument. We show that when the degree distribution of the number of replies is homogeneous along the discussion, for acrimonious discussions, the distribution of justified arguments depends on the parity of the graph level. In supportive discussions the probability of having justified comments increases as one moves away from the root. For discussion trees that have a non-homogeneous in-degree distribution, for supportive discussions we observe the same behaviour as before, while for acrimonious discussions we cannot observe the same parity-based distribution. This is verified with data obtained from the online debating platform Kialo. By predicting the locations of the justified arguments in reply trees, we can suggest which arguments readers should sample to grasp the currently accepted opinions in such discussions. Our models have important implications for the design of future online debating platforms

Multilevel Density Functional Theory

We introduce a novel density-based multilevel approach in density functional theory. In this multilevel density functional theory (MLDFT), the system is partitioned in an active and an inactive fragment, and all interactions are retained between the two parts. In MLDFT, the Kohn-Sham equations are solved in the MO basis for the active part only, while keeping the inactive density frozen. This results in a reduction of computational cost. We outline the theory and implementation, and discuss applications to aqueous solutions of methyloxirane and glycidol.Comment: 33 pages and 9 figure