On the mean/variance relationship of the firm size distribution: evidence and some theory

In this paper we make use of firm-level data for a sample of European countries to prove the existence of a positive linear relationship between the mean and the variance of firms’ size, an empirical regularity known in mathematical biology as the Taylor power law. A computerized experiment is used to show that the estimated slope of the linear relationship can be fruitfully employed to discriminate among alternative theories of firms’ growth.Taylor power law; Firm size distribution; Stochastic growth

Forget-me-not: History-less Mobile Messaging

Text messaging has long been a popular activity, and today smartphone apps enable users to choose from a plethora of mobile messaging applications. While we know a lot about SMS practices, we know less about practices of messaging applications. In this paper, we take a first step to explore one ubiquitous aspect of mobile messaging – messaging history. We designed, built, and trialled a mobile messaging application without history—named forget-me-not. The two-week trial showed that history-less messaging no longer supports chit-chat as seen in e.g. WhatsApp, but is still considered conversational and more ‘engaging’. Participants expressed being lenient and relaxed about what they wrote. Removing the history allowed us to gain insights into what uses history has in other mobile messaging applications, such as planning events, allowing for distractions, and maintaining multiple conversation threads

Syndepositional cements associated with nannofossils in the Marmolada Massif: Evidences of microbially mediated primary marine cements? (Middle Triassic, Dolomites, Italy)

The Marmolada platform is characterized by striking globose masses (“evinosponges”), arranged in concentric bands, of fibrous calcite cements ranging in size from centimeters to several decimeters. The lithogenetic importance of these peculiar cements has been recognized in many Middle Triassic buildups of the Western Tethys. EDS microanalyses revealed that these fibrous cements contain 1–3 mol% of Mg and detectable amounts of Sr, over 1000 ppm, sometimes exceeding 10,000 ppm. The strontium geochemical signature in neomorphic calcite could reflect the replacement of an aragonitic carbonate precursor. The boundaries between the fibrous calcite bands are marked by alignments of microcrystalline aggregates of fluorapatite and/or dolomite. The presence of fluorapatite may indicate a depositional microenvironment eutrophic or rich in microbial communities. Epifluorescence analyses showed bright bands alternated to dark ones, confirming that organic matter remains occur within the studied cements and could have played a significant role in supporting the widespread syndepositional cementation. High magnification SEM observations on bright epifluorescent bands showed the presence of widespread, more or less spherical bodies ranging in size 100–300 nm. These bodies could represent the relicts of nannobacterial cells

Industrial dynamics, fiscal policy and R&D: evidence from a computational experiment

We present an agent-based computational model in which bounded rational firms and workers trade on fully decentralized markets for final goods and labor by means of random matching protocols. The model replicates several macroeconomic phenomena regularly observed in the data, with aggregate features emerging from the localized interactions of individual entities. The model is then used as a computational laboratory to run an experiment on the role of fiscal policy in increasing macroeconomic performance

Hemodynamic Evaluation of Nonselective \u3b2-Blockers in Patients with Cirrhosis and Refractory Ascites

BACKGROUND:Nonselective \u3b2-blockers (NSBB) have been associated with increased incidence of paracentesis-induced circulatory dysfunction (PICD) and reduced survival in patients with cirrhosis and refractory ascites. AIM:To prospectively evaluate a hemodynamic response to NSBB in cirrhotics listed for liver transplantation with refractory ascites undergoing large volume paracentesis (LVP). METHODS:Patients with cirrhosis and refractory ascites, with an indication to start NSBB in primary prophylaxis for variceal bleeding, were enrolled. During two consecutive LVP, while being, respectively, off and on NSBB, cardiac output (CO), systemic vascular resistances (SVR), peripheral vascular resistances (PVR), and plasma renin activity (PRA) were noninvasively assessed. RESULTS:Seventeen patients were enrolled, and 10 completed the study. Before NSBB introduction, SVR (1896 to 1348\u2009dyn\ub7s\ub7cm-5; p = 0.028) and PVR (47 to 30\u2009mmHg\ub7min\ub7dl\ub7ml-1; p = 0.04) significantly decreased after LVP, while CO showed an increasing trend (3.9 to 4.5\u2009l/m; p = 0.06). After NSBB introduction, LVP was not associated with a significant increase in CO (3.4 to 3.8\u2009l/m; p = 0.13) nor with a significant decrease in SVR (2002 versus 1798\u2009dyn\ub7s\ub7cm-5; p = 0.1). Incidence of PICD was not increased after NSBB introduction. CONCLUSION:The negative inotropic effect of NSBB was counterbalanced by a smaller decrease of vascular resistances after LVP, probably due to splanchnic \u3b22-blockade. This pilot study showed that NSBB introduction may be void of detrimental hemodynamic effects after LVP in cirrhotics with refractory ascites

Positivity to p-ANCA in patients with status epilepticus

BACKGROUND: Status epilepticus (SE) may occur in the setting of several internal or neurologic diseases. Anti-neutrophilic cytoplasmic antibodies (ANCA) are a group of Ig that may be observed in patients with different autoimmune disorders but are particularly associated with systemic vasculitis named ANCA-associated-vasculities (AAV). We herein report 3 patients with SE and positivity to p-ANCA. CASE PRESENTATION: One patient had a catastrophic evolution and died 5 months after disease onset. The other two patients had a good outcome and remained seizure-free at 30 months and 5 years of follow-up respectively. CONCLUSION: This report highlights the importance of considering ANCA dosage in patients with SE of unclear origin

Risk stratification in transthyretin-related cardiac amyloidosis

Transthyretin related cardiac amyloidosis (TTR-CA) is an infiltrative cardiomyopathy that cause heart failure with preserved ejection fraction, mainly in aging people. Due to the introduction of a non invasive diagnostic algorithm, this disease, previously considered to be rare, is increasingly recognized. The natural history of TTR-CA includes two different stages: a presymptomatic and a symptomatic stage. Due to the availability of new disease-modifying therapies, the need to reach a diagnosis in the first stage has become impelling. While in variant TTR-CA an early identification of the disease may be obtained with a genetic screening in proband's relatives, in the wild-type form it represents a challenging issue. Once the diagnosis has been made, in order to identifying patients with a higher risk of cardiovascular events and death it is necessary to focus on risk stratification. Two prognostic scores have been proposed both based on biomarkers and laboratory findings. However, a multiparametric approach combining information from electrocardiogram, echocardiogram, cardiopulmonary exercise test and cardiac magnetic resonance may be warranted for a more comprehensive risk prediction. In this review, we aim at evaluating a step by step risk stratification, providing a clinical diagnostic and prognostic approach for the management of patients with TTR-CA

Esophageal chemical clearance and baseline impedance values in patients with chronic autoimmune atrophic gastritis and gastro-esophageal reflux disease

Background: The factors influencing new markers of gastro-esophageal reflux disease detected by impedance-pH monitoring - mean nocturnal baseline impedance (MNBI) and post-reflux swallow-induced peristaltic wave (PSPW) index - need to be evaluated. Aim: To compare endoscopy-negative heartburn with chronic autoimmune atrophic gastritis (CAAG). Materials and methods: 24 patients with CAAG, 25 with non-erosive reflux disease (NERD) and 25 with functional heartburn (FH) were included. In all patients the main impedance-pH monitoring parameters were calculated. Results: CAAG and NERD patients had a number of reflux events (non-acid ones being more common among the former group) which was higher than that found in FH (p 3000 Ohm), CAAG (> 2000 Ohm) and NERD (<1000 Ohm) patients (p = 0.0046). The PSPW index was similar between CAAG and NERD patients but significantly lower in comparison to FH (p <0.0001). Conclusion: Patients with CAAG have evidence of non-acid reflux based on the high number of reflux events and confirmed by low values of MNBI and PSPW index. MNBI is a strong marker of acid/non-acid reflux-induced mucosal damage, whereas the PSPW index can reliably discriminate patients with reflux from those with FH, independently of the acidity of refluxate. (C) 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.Peer reviewe

Barrett's esophagus in 2016: From pathophysiology to treatment

Esophageal complications caused by gastroesophageal reflux disease (GERD) include reflux esophagitis and Barrett's esophagus (BE). BE is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). The carcinogenic sequence may progress through several steps, from normal esophageal mucosa through BE to EAC. A recent advent of functional esophageal testing (particularly multichannel intraluminal impedance and pH monitoring) has helped to improve our knowledge about GERD pathophysiology, including its complications. Those findings (when properly confirmed) might help to predict BE neoplastic progression. Over the last few decades, the incidence of EAC has continued to rise in Western populations. However, only a minority of BE patients develop EAC, opening the debate regarding the cost-effectiveness of current screening/surveillance strategies. Thus, major efforts in clinical and research practice are focused on new methods for optimal risk assessment that can stratify BE patients at low or high risk of developing EAC, which should improve the cost effectiveness of screening/surveillance programs and consequently significantly affect health-care costs. Furthermore, the area of BE therapeutic management is rapidly evolving. Endoscopic eradication therapies have been shown to be effective, and new therapeutic options for BE and EAC have emerged. The aim of the present review article is to highlight the status of screening/surveillance programs and the current progress of BE therapy. Moreover, we discuss the recent introduction of novel esophageal pathophysiological exams that have improved the knowledge of the mechanisms linking GERD to BE

H-BET Historic Built Environment Typologies. Open spaces and SUOD events in the compact historic town

The relationships between the Built Environment (BE) and SUdden-Onset Disasters (SUOD) are increasingly the focus of hazard mitigation investigation. Specifically, in the Historic Built Environment (HBE), defined as the network of buildings, infrastructure, and open spaces of the compact historic city, recent and past events have shown the need for an elevation of the resilience of the resident community. Previous studies by the author’s research team have objectified the characterisation of HBEs prone to SUODs. What emerged was the primary importance of open spaces in the Built Environment as elements to be characterised with respect to possible emergency phases and BE user behaviour. Specifically, the Historic Built Environment Typologies (H-BETs) can help to evaluate user behaviour during and after the event. Focusing on the role of the classification of the open spaces, the paper presents the H-BETs and their potential role in the multi-risk assessment of the compact historic town. The specific risk conditions of the urban areas (e.g., crowding, the complexity of the overall form of BEs, characteristics of built elements, uses of BEs), and the physical characteristics of historic urban BE (e.g., the height of the built fronts, number, and type of accesses, the slope of the ground) are considered together in order to propose a classification of different type of open spaces, starting from morphological classes towards the definition of a complete typological categorisation, representative of the urban system’s variables that interact with the identified SUOD hazards