Il personaggio di Ergasilo nei Captivi di Plauto

La figura del parassita Ergasilo, tra i protagonisti dei Captivi di Plauto, viene analizzata da svariati punti di vista: inquadramento del personaggio nell'economia della commedia; definizione della sua controversa funzione drammatica; analisi della sua singolare caratterizzazione come affabulatore e attore; rapporto tra il personaggio plautino e la tradizione comica greca. In due appendici si affrontano la questione relativa al soprannome del parassita e quella della storia del termine stesso

EtherSolve: Computing an Accurate Control-Flow Graph from Ethereum Bytecode

Motivated by the immutable nature of Ethereum smart contracts and of their transactions, quite many approaches have been proposed to detect defects and security problems before smart contracts become persistent in the blockchain and they are granted control on substantial financial value. Because smart contracts source code might not be available, static analysis approaches mostly face the challenge of analysing compiled Ethereum bytecode, that is available directly from the official blockchain. However, due to the intrinsic complexity of Ethereum bytecode (especially in jump resolution), static analysis encounters significant obstacles that reduce the accuracy of exiting automated tools. This paper presents a novel static analysis algorithm based on the symbolic execution of the Ethereum operand stack that allows us to resolve jumps in Ethereum bytecode and to construct an accurate control-flow graph (CFG) of the compiled smart contracts. EtherSolve is a prototype implementation of our approach. Experimental results on a significant set of real world Ethereum smart contracts show that EtherSolve improves the accuracy of the execrated CFGs with respect to the state of the art available approaches. Many static analysis techniques are based on the CFG representation of the code and would therefore benefit from the accurate extraction of the CFG. For example, we implemented a simple extension of EtherSolve that allows to detect instances of the re-entrancy vulnerability

Platelet-activating factor mediates CD40-dependent angiogenesis and endothelial-smooth muscle cell interaction.

The aim of the present study was to investigate whether stimulation of CD40 expressed by endothelial or smooth muscle cells triggers the synthesis of platelet-activating factor (PAF), an inflammatory mediator with angiogenic properties, and whether PAF contributes to CD40-induced neoangiogenesis. The results obtained indicate that the interaction of CD40 with soluble CD154 or with CD154 expressed on the membrane of leukocytes (CD154-transfected J558 cells) or of activated platelets, stimulated the synthesis of PAF by endothelial cells but not by smooth cells. The synthesis of PAF triggered by activated platelets was inhibited by a soluble CD40-murine Ig fusion protein that prevents the interaction between membrane CD40 and CD154. Studies with specific inhibitors and evaluation of protein phosphorylation indicated the involvement in PAF synthesis of two intracellular signaling pathways leading to cytosolic phospholipase A 2 activation: a phospholipase Cγ-protein kinase C-Raf-p42/p44-mitogen-activated protein kinase (MAPK) and a MAPK kinase-3/6-dependent activation of p38 MAPK. PAF synthesized by endothelial cells after CD40 stimulation was instrumental in the in vitro migration and vessel-like organization of endothelial cells, and in the interaction between endothelial cells and smooth muscle cells, as inferred by the inhibitory effect of two different PAF receptor antagonists, WEB2170 and CV3988. In vivo, blockade of PAF receptors prevented the angiogenic effect triggered by CD40 stimulation in a murine model of s.c. Matrigel implantation. In conclusion, these observations indicate that PAF synthesis induced by stimulation of endothelial CD40 contributes to the formation and organization of new vessels. This may be relevant in the vascular remodeling associated with tumor and inflammatory neoangiogenesis

Citrate Anticoagulation for Continuous Renal Replacement Therapy in Critically Ill Patients: Success and Limits

Citrate anticoagulation has risen in interest so it is now a real alternative to heparin in the ICUs practice. Citrate provides a regional anticoagulation virtually restricted to extracorporeal circuit, where it acts by chelating ionized calcium. This issue is particularly true in patients ongoing CRRT, when the “continuous” systemic anticoagulation treatment is per se a relevant risk of bleeding. When compared with heparin most of studies with citrate reported a longer circuit survival, a lower rate of bleeding complications, and transfused packed red cell requirements. As anticoagulant for CRRT, the infusion of citrate is prolonged and it could potentially have some adverse effects. When citrate is metabolized to bicarbonate, metabolic alkalosis may occur, or for impaired metabolism citrate accumulation leads to acidosis. However, large studies with dedicated machines have indeed demonstrated that citrate anticoagulation is well tolerated, safe, and an easy to handle even in septic shock critically ill patients

On the mathematical modelling of tumor-induced angiogenesis

An angiogenic system is taken as an example of extremely complex ones in the field of Life Sciences, from both analytical and computational points of view, due to the strong coupling between the kinetic parameters of the relevant branching-growth-anastomosis stochastic processes of the capillary network, at the microscale, and the family of interacting underlying biochemical fields, at the macroscale. To reduce this complexity, for a conceptual stochastic model we have explored how to take advantage of the system intrinsic multiscale structure: one might describe the stochastic dynamics of the cells at the vessel tip at their natural microscale, whereas the dynamics of the underlying fields is given by a deterministic mean field approximation obtained by an averaging at a suitable mesoscale. But the outcomes of relevant numerical simulations show that the proposed model, in presence of anastomosis, is not self-averaging, so that the "propagation of chaos" assumption cannot be applied to obtain a deterministic mean field approximation. On the other hand we have shown that ensemble averages over many realizations of the stochastic system may better correspond to a deterministic reaction-diffusion system.The authors acknowledge the contribution of the anonymous Referees for a significant improvement of the manuscript. This work has been supported by the Spanish Ministerio de Econom´ıa y Competitividad grant MTM2014- 56948-C2-2-P. VC has been supported by a Chair of Excellence UC3M-Santander at the Universidad Carlos III de Madrid. It is a great pleasure to acknowledge fruitful discussions with Daniela Morale of the Department of Mathematics of the University of Milan

Design science research: scientific research linked to artifact design

Na Educação, desenvolvemos artefatos: aulas, recursos didáticos e práticas educacionais. É possível inter-relacionar o desenvolvimento de um artefato com a produção de conhecimento teórico, sendo Design Science Research (DSR) a abordagem que apresentamos neste texto para a realização de pesquisas científicas atreladas ao desenvolvimento de artefatos. Nessa abordagem, objetiva-se projetar uma realidade diferente, modificada por artefatos projetados para resolver problemas em determinados contextos, sendo o conhecimento científico resultado da investigação do uso do artefato numa determinada situação. A DSR é uma abordagem ainda em discussão; neste artigo apresentamos como temos nos apropriado de DSR. Em particular, apresentamos o Modelo-DSR em que sintetizamos as principais lições aprendidas por nosso grupo. Para exemplificar o uso do Modelo-DSR, apresentamos a pesquisa sobre os Tapetes Musicais Inteligentes. Consideramos que o Modelo-DSR tem ajudado a tornar as pesquisas de nosso grupo mais rigorosas em termos teórico-epistemológico-metodológico e, assim, mais relevantes em termos científicos. Apresentamos esse modelo por considera-lo um instrumento útil para apoiar outros pesquisadores que desejam pensar-fazer DSR.In Education, we develop artifacts: classes, didactic resources and educational practices. It is possible to interrelate the development of an artifact with the production of theoretical knowledge, and Design Science Research (DSR) is the approach we present on this article, used to do scientific research connected to the development of artifacts. Through this approach, the goal is to design a different reality, modified by artifacts designed to solve problems in given contexts, with the scientific knowledge being the result of the investigation of the use of the artifact in a given situation. DSR is an approach that is still under discussion; in this article, we show how our research group has been appropriating DSR. In particular, we present the DSR Model in which we synthesized the main lessons learned by our group. In order to exemplify the use of the DSR Model, we present the research on Smart Musical Mats. We consider that the DSR Model has been helping make our group’s researches more rigorous in theoretical, epistemological and methodological terms and, thus, more relevant in scientific terms. We present this model because we consider it to be a useful instrument to support other researchers that want to consider and use DSR.info:eu-repo/semantics/publishedVersio