Fixed Points and Attractors of Reactantless and Inhibitorless Reaction Systems

Reaction systems are discrete dynamical systems that model biochemical processes in living cells using finite sets of reactants, inhibitors, and products. We investigate the computational complexity of a comprehensive set of problems related to the existence of fixed points and attractors in two constrained classes of reaction systems, in which either reactants or inhibitors are disallowed. These problems have biological relevance and have been extensively studied in the unconstrained case; however, they remain unexplored in the context of reactantless or inhibitorless systems. Interestingly, we demonstrate that although the absence of reactants or inhibitors simplifies the system's dynamics, it does not always lead to a reduction in the complexity of the considered problems.Comment: 29 page

Motivi biblici nell’opera teatrale di Stanisław Wyspiański e Jerzy Grotowski

The paper deals about two plays by the so called “fourth bard” of Polish literature, the modernist playwright Stanislaw Wyspianski (1869-1907). Best known for his drama The Wedding (1901), Wyspiański devoted his first theatrical work, an opera libretto published only after his death, to Daniel (1895). In this early  work, the Biblical theme is developed according to the messianic virtues attributed to poetry by the main Polish romantic poet and playwright, Adam Mickiewicz. While writing about Daniel, Wyspiański was inspired by a Rembrandt’s painting, Belshazzar's Feast (1635) preserved at the National Gallery in London. As a matter of fact, the biblical thread of Daniel’s prophetic dream about the subduing of Three Kings (Daniel 7: 24) was exploited by Wyspiański in order to allude to the political predicament of the Polish nation oppressed by the three parting powers: Prussia, Austria and Russia. The play was therefore edited by Austrian censorship and was staged for the first time only in 1927, once Poland had regained her independence: not on a Polish scene, though, but by the Krokewer Yidish Teater in Dawid Liebl’s yiddish translation.  The second play partly centered on a biblical theme is Akropolis (1904), a monumental drama set in Cracow’s Pantheon, the Wawel cathedral. In the second act of the play, the characters of the tapestries hanging on the walls of the cathedral come to life. One of the tapestries portraits the story of Jacob (Genesis: 25-33). Wyspiański was very likely inspired by  Raffaello’s fresco paintings in Eliodor’s room at the Vatican, and by Gerhard Hauptmann’s fragment Das Hirtenlied. The playwright closely follows the text of the Bible but for a few „apocryphical” insertions, the more relevant of which refer to Jacob’s struggle with the Angel. The Angel defies Jacob, founder of tribes”, claiming that he’ll thread „on the weak ones, in this graveyard of tribes”. Much has been debated on where the action of the drama should take place. Wyspiański himself thought about staging Akropolis in the cathedral on the Wawel hill, but the best known production of the play, performed by Jerzy Grotowski (1962), dispensed from the original setting. For Wyspiański, the cathedral on the Wawel hill, with her tombs, was the most significant achievement in Polish national history  and culture, but for Grotowski the most meaningful event in the history of the whole humankind had taken place in Auschwitz extermination camp. Grotowski sees the setting of the play – using Wyspianski’s words - „in a graveyard of tribes”. This graveyard is not longer the peaceful and magnificent cathedral where the playwright used to stroll in search of inspiration, but a dramatically real one, the graveyard in which millions of human beings belonging to all nations have been buried after having completed the crematorium in which they and their companions will be burned. Grotowski has not altered Wyspiański’s lines, just changed the order of the scenes, so that Jacob’s struggle with the Angel could be at the centre of  a play which could be reintepreted by the light shed on Auschwitz  extermination machine by Tadeusz Borowski’s concentrationary  short stories. The last line of the play comes from a caption imagined by Wyspiański for its monumental drama, but the old words have for the modern audience a tragic and complete new meaning: „they’re gone, spirals of smoke float in the air”. &nbsp

Studio non lineare della convezione naturale in uno strato poroso orizzontale

In questo elaborato si costituisce un modello numerico del problema di Darcy-Bénard con l’obiettivo di definire la sua risoluzione mediante il pacchetto software Mathematica 11.1 (© Wolfram, inc.). La struttura della tesi comprenderà, nel capitolo 2, una descrizione delle equazioni fondamentali che governano il moto di un fluido condotta avvalendosi dell’approssimazione di Oberbeck-Boussinesq, inoltre si descriveranno le condizioni al contorno e le condizioni iniziali applicabili ad un generico sistema di equazioni differenziali. Nel capitolo 3 verrà descritto il problema di Darcy-Bénard riferito ad uno strato poroso orizzontale, nonché le caratteristiche generali dei mezzi porosi stessi. Si porrà particolare attenzione al caso in cui le equazioni che descrivono il problema siano considerate non lineari, stazionarie e descritte utilizzando la funzione di corrente, tale scenario costituirà il modello del problema che si cercherà in seguito di risolvere numericamente. Sarà poi necessario, nel capitolo 4, introdurre il metodo degli elementi finiti il quale verrà utilizzato implicitamente dal software di calcolo per discretizzare il dominio del problema in esame e permettere quindi la risoluzione numerica del problema stesso. Il capitolo 5 riguarderà la descrizione della tecnica di implementazione del problema di Darcy-Bénard sul software utilizzato mostrando sia la procedura utilizzata che i risultati ottenuti. Verranno individuate le varie configurazioni a diverso numero di celle convettive che si formano al variare del numero di Rayleigh, si otterrà una correlazione tra il numero di Rayleigh e il numero di Nusselt medio alla parete e, infine, verrà riportato l’andamento dell’energia cinetica, per le configurazioni a diverso numero di celle ottenute. Nel capitolo 6 sarà condotta una analisi dei risultati visualizzati nel capitolo 5 ed il loro confronto con risultati ottenuti nella letteratura attualmente esistente

UNA LOTTA (IMPARI) CONTRO LA RAGIONE? PER UNA RILETTURA DI CARLO ANTONI

This paper deals with Carlo Antoni’s 1942 book «La lotta contro la ragione» (The Fight Against Reason). This book was in line with an anti-Enlightenment re-appraisal of the eighteenth century as it was brought forward, for instance, by Antonello Gerbi. The young Gerbi, back in 1932, in his book «La politica del Romanticismo», Politics of Romanticism, deals with some of the authors (Hamann, Herder, Möser), later on dealt with by Antoni. In the USA, there was a similar «critical» appraisal of the Enlightenment (C.L. Becker). Antoni was a classical-liberal, follower of Croce. This kind of classical-liberal thought re-evaluated quite modern concept as those of «little homeland», religion and nation, private property, and was opposed to the cosmopolitan, universalist liberalism of the men of the Enlightenment. It was especially opposed to that, in as much as this kind of «Enlightened liberalism», in the French spirit of radical rationalism, endorsed absolutism, and centralization, from Louis XIV to Napoleon

Aortic stenting in the growing sheep causes aortic endothelial dysfunction but not hypertension: Clinical implications for coarctation repair

Stent implantation is the treatment of choice for adolescents and adults with aortic coarctation (CoAo). Despite excellent short-term results, 20%-40% of the patients develop arterial hypertension later in life, which was attributed to inappropriate response of the aortic baroreceptors to increased stiffness of the ascending aorta (ASAO), either congenital or induced by CoAo repair. In particular, it has been hypothesized that stent itself may cause or sustain hypertension. Therefore, we aimed to study the hemodynamic and structural impact following stent implantation in the normal aorta of a growing animal

Reverse-engineering of architectural buildings based on an hybrid modeling approach

We thank MENSI and REALVIZ companies for their helpful comments and the following people for providing us images from their works: Francesca De Domenico (Fig. 1), Kyung-Tae Kim (Fig. 9). The CMN (French national center of patrimony buildings) is also acknowledged for the opportunity given to demonstrate our approach on the Hotel de Sully in Paris. We thank Tudor Driscu for his help on the English translation.This article presents a set of theoretical reflections and technical demonstrations that constitute a new methodological base for the architectural surveying and representation using computer graphics techniques. The problem we treated relates to three distinct concerns: the surveying of architectural objects, the construction and the semantic enrichment of their geometrical models, and their handling for the extraction of dimensional information. A hybrid approach to 3D reconstruction is described. This new approach combines range-based modeling and image-based modeling techniques; it integrates the concept of architectural feature-based modeling. To develop this concept set up a first process of extraction and formalization of architectural knowledge based on the analysis of architectural treaties is carried on. Then, the identified features are used to produce a template shape library. Finally the problem of the overall model structure and organization is addressed

iga anticardiolipin in patients with gastroenteric tumor

Recently the presence of antiphospholipid antibodies in patients with cancer has been demonstrated, suggesting an involvement of autoimmune response in neoplastic conditions. The presence of antiphospholipid antibodies in tumor disease is highly correlated with the risk of developing thrombotic complications, which represents a significant cause of morbidity and mortality in cancer patients. Interestingly, it has been highlighted that high levels of IgM and IgG anticardiolipin antibodies are more often produced in patients with gastroenteric tumor than in patients with either ovarian or breast tumor. Thus far, there are no data looking into the role or measurements of IgA in patients with solid cancer. Our preliminary results, in this study, demonstrate that testing only for IgG and IgM anticardiolipin antibodies may increase the incidence of false positive because 44% who were IgA positive and IgG and IgM negative had high titres of CA19.9 and CEA. We suggest that taking into account the role of IgA could substantially improve the detection of antiphospholipids antibodies in subjects with solid cancer, and this detection may allow us for better prevention and management of thrombotic complications in these patients

A New Approach to Land-Use Structure. Patch Perimeter Metrics as a Spatial Analysis Tool

This work introduces a new class of landscape metrics characterizing basic features of patch perimeters. Specific computation on patch perimeters was carried out on fine-grained land-use maps with the aim to characterize spatial patterns of neighbor patches, evidencing contact points and perimeter length between two (or more) land-use types. A detailed set of class and landscape metrics were derived from such analysis. This approach is complementary to classical landscape metrics and proved to be particularly useful to characterize complex, fragmented landscapes profiling metropolitan regions based on integrated evaluations of their structural (landscape) and functional (land-use) organization. A multivariate analysis was run to characterize distinctive spatial patterns of the selected metrics in four metropolitan regions of southern Europe reflecting different morphological configurations (Barcelona: compact, polycentric; Lisbon: dispersed, mono-centric; Rome: dispersed, polycentric; and Athens: compact, mono-centric). Perimeter metrics assumed different values for each investigated land-use type, with peculiar characteristics associated to each city. Land-use types assessing residential, discontinuous urban patches were associated to particularly high values of perimeter metrics, possibly indicating patch fragmentation, spatially-associated distribution of land-use types and landscape complexity. Multivariate analysis indicates substantial differences among cities, reflecting the range of morphological configurations described above (from compact mono-centric to dispersed polycentric) and suggesting that urban expansion is accompanied with multiple modifications in the use of the surrounding non-urban land. The computational approach proposed in this study and based on spatially-explicit metrics of landscape configuration and proximity may reflect latent changes in local socio-spatial structures. Our results demonstrate that scattered urban expansion determines a polarization in suburban areas with highly fragmented and more homogeneous landscapes, respectively, associated with mixed cropland and forest systems