451 research outputs found

    Fire Safety Engineering: evacuation management in emergency conditions

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    The disruptive events that occurred in Italy in 2016 have increased the attention to the evaluation of the evacuation procedures in emergency conditions. The strategies to adopt should be established on the basis of performance-based criteria of design and management, which are the same used in Fire Safety Engineering. In the specific case of the evacuation plan, the latter should be designed according to certain variables that may be successfully used also in other kinds of emergencies related to earthquakes or hydrogeological instability

    A Macroscopic Mathematical Model For Cell Migration Assays Using A Real-Time Cell Analysis

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    Experiments of cell migration and chemotaxis assays have been classically performed in the so-called Boyden Chambers. A recent technology, xCELLigence Real Time Cell Analysis, is now allowing to monitor the cell migration in real time. This technology measures impedance changes caused by the gradual increase of electrode surface occupation by cells during the course of time and provide a Cell Index which is proportional to cellular morphology, spreading, ruffling and adhesion quality as well as cell number. In this paper we propose a macroscopic mathematical model, based on \emph{advection-reaction-diffusion} partial differential equations, describing the cell migration assay using the real-time technology. We carried out numerical simulations to compare simulated model dynamics with data of observed biological experiments on three different cell lines and in two experimental settings: absence of chemotactic signals (basal migration) and presence of a chemoattractant. Overall we conclude that our minimal mathematical model is able to describe the phenomenon in the real time scale and numerical results show a good agreement with the experimental evidences

    Topographical and Thematic Perspectives in the Latin Poetry of the First Anglo-Norman Kings

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    This study deals with Norman poetry: it examines the authors, the texts, and especially the literary genres to which they belonged, in the period between the XIth and XIIth centuries. Following a chronological order, the analysis starts from XIth-century Normandy: the main political and religious centres, Rouen, Caen and Le Bec, were also the most important places of poetic output. Most of these writings are hagiographies or encomia of important figures in the ducal and royal courts. In this regard, Serlo of Bayeux stands out as a clear example: his poems are valuable historical evidence for the Norman relationship with the English and their king in 1105-1106. In England, after the bold enterprise of William the Conqueror, Norman, Flemish, French and Italian learned men had a very important role in cultural life. York and Canterbury were the most prominent centres for versification. The study ends by focusing on the numerous verses contained in the historical works of Orderic Vitalis, William of Malmesbury and Henry of Huntingdon.Cette étude traite de la poésie normande : elle examine les auteurs, les textes et surtout les genres littéraires auxquels ils appartiennent, aux XIe et XIIe siècles. Suivant l’ordre chronologique, l’analyse commence à partir de la Normandie du XIe siècle. Les principaux centres politiques et religieux, Rouen, Caen et Le Bec, sont aussi les chefs-lieux de la production poétique. La plupart de ces écrits sont hagiographiques ou laudatifs de figures importantes dans les cours ducales et royales. À cet égard, Serlon de Bayeux se détache comme un exemple clair : ses poèmes sont une précieuse preuve historique de la relation normande avec les Anglais et leur roi en 1105-1106. En Angleterre, après l’audacieuse entreprise de Guillaume le Conquérant, les savants normands, flamands, français et italiens ont joué un rôle très important dans la vie culturelle. York et Cantorbéry étaient les centres les plus importants pour la versification. L’étude se termine en se concentrant sur les nombreux versets contenus dans les œuvres historiques d’Orderic Vital, Guillaume de Malmesbury et Henri de Huntingdon.Lo studio riguarda la poesia normanna: autori, testi, ma soprattutto i loro generi letterari, nel periodo tra XI e XII secolo. L’analisi procede a un esame in ordine cronologico, a partire dalla Normandia del Mille. I principali centri politici e religiosi, Rouen, Caen, Le Bec, furono allo stesso tempo capoluoghi di produzione poetica. In maggioranza i testi riguardano temi agiografici o encomiastici, rivolti alle più eminenti figure delle corti ducali e regali. A questo proposito, Serlo di Bayeux rappresenta un caso esemplare, con i suoi versi, circa le relazioni con gli Inglesi e il loro sovrano nel periodo tra 1105 e 1106. In Inghilterra, in particolare, dopo l’audace impresa di Guglielmo il Conquistatore, intellettuali normanni, fiamminghi, francesi e italiani ebbero un ruolo molto importante nella vita culturale britannica. York e Canterbury furono gli ambiti preminenti anche sotto il profilo della versificazione. Lo studio termina con un esame specifico dei numerosi carmi presenti nelle cronache di Orderico Vitale, Guglielmo di Malmesbury ed Enrico di Huntingdon

    Can the fatty acids profile of Tuber aestivum - T. uncinatum species complex have chemotaxonomic value?

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    Fatty acid (FA) profiles are considered as chemotaxonomic markers to define groups of various taxonomic ranks in bacteria, yeasts, and fungi. Tuber aestivum is one of the most common European truffles that has environmental and economic values. While genetic studies suggest that T. aestivum Vittad. and T. uncinatum Chatin are synonymous, there is still debate over whether this is a species complex. In this work, we evaluate the differences in the total and individual FAs content of T. aestivum and T. uncinatum morphotypes, and T. melanosporum n-hexane extracts. The higher amounts of total linoleic acid and total oleic acid are found in T. uncinatum and characterize it from the T. aestivum. The composition of FA profiles of T. uncinatum-T. aestivum were distinguished by the presence of free palmitoleic acid (a chemotaxonomic marker) in T. uncinatum and absent in T. aestivum. Cluster analysis indicated that there were two groups for the FA profiles of the Tuber spp. hexanic extract: T. aestivum extract and T. uncinatum and T. melanosporum extracts. Our results indicate that T. aestivum and T. uncinatum have to be considered as two different taxa within the T. aestivum species complex

    The recent behaviour of financial market volatility

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    A striking feature of financial market behaviour in recent years has been the low level of price volatility over a wide range of financial assets and markets. The issue has attracted the attention of central bankers and financial regulators due to the potential implications for financial stability. This paper makes an effort to shed light on this phenomenon, drawing on literature surveys, reviews of previous analyses by non-academic commentators and institutions, and some new empirical evidence. The paper consists of seven sections. Section 2 documents the current low level of volatility, putting it into a historical perspective. Section 3 briefly reviews the theoretical determinants of volatility, with the aim of helping the reader through the subsequent sections of this Report, which are devoted to the explanations of the phenomenon under study. These explanations have been grouped into four categories: real factors; financial factors; shocks; and monetary policy. Thus, Section 4 looks into the relation between volatility and real factors, from both a macro- and a microeconomic perspective. Section 5 considers how the recent developments in financial innovation and improvements in risk management techniques might have contributed to the decline in volatility. Section 6 considers the relation between real and financial shocks and volatility. Finally, Section 7 explores whether more systematic and transparent monetary policies might have led to lower asset price volatility.financial volatility, risk taking, international financial markets

    Identification of a Widespread Palmitoylethanolamide Contamination in Standard Laboratory Glassware

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    Introduction: Fatty acid ethanolamides (FAEs) are a family of lipid mediators that participate in a host of biological functions. Procedures for the quantitative analysis of FAEs include organic solvent extraction from biological matrices (e.g., blood), followed by purification and subsequent quantitation by liquid chromatography-mass spectrometry (LC/MS) or gas chromatography-mass spectrometry. During the validation process of a new method for LC/MS analysis of FAEs in biological samples, we observed unusually high levels of the FAE, palmitoylethanolamide (PEA), in blank samples that did not contain any biological material. Materials and Methods: We investigated a possible source of this PEA artifact via liquid chromatography coupled to tandem mass spectrometry, as well as accurate mass analysis. Results: We found that high levels of a contaminant indistinguishable from PEA is present in new 5.75″ glass Pasteur pipettes, which are routinely used by laboratories to carry out lipid extractions. This artifact might account for discrepancies found in the literature regarding PEA levels in human blood serum and other tissues. Conclusions: It is recommended to take into account this pitfall by analyzing potential contamination of the disposable glassware during the validation process of any method used for analysis of FAEs

    SPH simulation of periodic wave breaking in the surf zone. A detailed fluid dynamic validation

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    The estimation of wave breaking and run-up on sloped beaches is a relevant issue in different coastal engineering applications. The present study stresses on the capabilities of a Smoothed Particle Hydrodynamics (SPH) solver, with optimal numerical and physical parameters, to accurately simulate the complex flow field in the surf zone and run-up region. Numerical results are compared with high quality experimental measurements of the local flow field in terms of instantaneous and phase averaged values. The selected test case regards the propagation and breaking of regular non-linear waves on a smooth impermeable plane slope. The comparison is based on a complete set of 128 consecutive non-linear regular waves. The level of accuracy of the numerical results and the ability of the model to reproduce the periodic flow in the surf-zone is provided. Current limitations and uncertainty sources are identified and discussed to guide future developments

    The Effects of the COVID-19-induced Lockdown on the Social Capital and Cultural Capital in Italy

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    The present study investigated the effects of the first COVID-19 lockdown on the Cultural and Social Capitals in Italy in a large group of adults (n = 1125). The relationships between the COVID-19 spread and participants’ Cultural Capital, Social Capital, educational level, occupational prestige, and age were studied using structural equation models. For women but not for men, pandemic spread was positively affected by occupational prestige and it had a positive relationship with their Social Capital (women: CFI = 0.949; RMSEA = 0.059 [CI = 0.045-0.075]; men: CFI = 0.959; RMSEA = 0.064 [CI = 0.039–0.087]). Moreover, the participants were divided into three validated clusters based on their Cultural and Social Capitals levels to investigate changes in the Capitals compared with the pre-lockdown period. It was found that the lockdown contributed to improving the gap among individuals increasing high levels and decreasing low levels of both the Capitals. People with high Cultural and Social Capitals seemed to have seized the opportunity given by COVID-19 restrictions to cultivate their cultural interests and become more involved within their networks. In contrast, individuals with low Cultural and Social Capitals paid the highest price for the social isolation. Given that the Capitals encourage healthy behavior and influence well-being and mental health, institutions should develop or improve their policies and practices to foster individual resources, and make fairer opportunities available during the pandemic
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