2,316 research outputs found
Fulvio Papi lettore di poesia
No full textMy paper analyzes Fulvio Papi’s essays on poetry. First of all, I consider his reflecting and theoretical essays concerning the forms of philosophical questioning of poetry as a writing practice. I then examine his 2009 essay on Antonia Pozzi’s poetic production. Papi shows how the poet’s vital experience is transfigured in the compositional and enunciative rules of the text
Statistically based multiwavelet denoising
No full textAbstractIn this work, we consider a statistically based multiwavelet thresholding method which acts on the empirical wavelet coefficients in groups, rather than individually, in order to obtain an edge-preserving image denoising technique. Our strategy allows us to exploit the dependencies between neighboring coefficients to make a simultaneous thresholding decision, so that estimation accuracy is increased.By interpreting the multiwavelet analysis in a statistical context, we propose a new weighted multiwavelet matrix thresholding rule, based on the statistical modeling of empirical coefficients. This allows the thresholding decision to be adapted to the local structure of the underlying image, hence producing edge-preserving denoising. Extensive numerical results are presented showing the performance of our denoising procedure
‘A Local Habitation and a Name’: The Dublin Mechanics’ Institute and the Evolution of Dublin’s Public Sphere, 1824–1904
No full textThe author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: Research for this article has been partially funded by the University of Oviedo through the Emerging Research Project PAPI-17-PEMERG-18 and a Campus de Excelencia staff mobility grant (2018)
La scienza di Roma
No full textDa sempre Roma è un crocevia della scienza, personaggi del calibro di Galileo Galilei, Niccolò Copernico, Angelo Secchi, Enrico Fermi, Giovanni Battista Grassi, Stanislao Cannizzaro, Guglielmo Marconi, Vito Volterra, per citarne solo alcuni, nel tempo hanno dato vita ad una miriade di vicende storico-scientifiche note e meno note fatte di umanità, di curiosità e di passione per la ricerca. Aerospazio, agronomia, antropologia, astronomia, biologia, chimica, fisica, matematica, medicina, scienze della Terra: non esistono discipline che non abbiano trovato nella città di Roma la sede per il loro sviluppo e spesso il loro momento fondativo basti pensare all’astrofisica o alla fisica nucleare.
Obiettivo e punto di forza dell’esposizione è quello di raccontare la storia delle idee scientifiche e il loro impatto nella società attraverso i grandi scienziati che a Roma hanno lavorato e le grandi scoperte che qui sono state fatte; il tutto attraverso una commistione di linguaggi in cui si fondano il rigore scientifico e la suggestione estetica, la spiegazione e l’emozione. Una narrazione testuale sintetica e suggestiva accompagna il visitatore nelle nove sezioni della mostra, alternandosi alla contemplazione di reperti scientifici originali emozionanti e spesso inediti come, ad esempio, gli acquarelli delle fasi lunari disegnate da Galileo Galilei, il cranio originale dell’uomo di Neanderthal di Saccopastore, gli strumenti originali dei “ragazzi di via Panisperna”, le tavole sciateriche di Athanasius Kircher. Pensare la Roma del nuovo millennio significa rappresentare l’immagine e l’identità di una storia unica. Una storia nella quale la scienza è fondamentale anche per affrontare le sfide drammatiche del mondo contemporaneo.
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Rome has always been a crossroads of science; figures of the calibre of Galileo Galilei, Copernicus, Angelo Secchi, Enrico Fermi, Giovanni Battista Grassi, Stanislao Cannizzaro, Guglielmo Marconi and Vito Volterra, to name but a few, have breathed life over the centuries into a myriad well-known or lesser-known historical and scientific events imbued with humanity, curiosity and a passion for research. Aerospace, agronomy, anthropology, astronomy, biology, chemistry, physics, mathematics, medicine and earth sciences: there is not a single discipline that has not found in the city of Rome the perfect stage for its development and indeed on many occasions even its founding moment - one has but to think of astrophysics and nuclear physics.
The exhibition sets out to illustrate the history of scientific ideas and their impact on society through the great scientists who have worked in Rome and the major discoveries that have been made here, the whole through a combination of different languages merging scientific stringency and aesthetic appeal, explanation and emotion. A pithy and intriguing textual narrative accompanies the visitor through the nine sections of the exhibition, alternating with the contemplation of exciting original scientific exhibits often never shown in public before, for example the watercolours depicting the phases of the moon painted by Galileo Galilei, the original skull of Neanderthal Man from Saccopastore, the original implements used by the “boys from Via Panisperna” or Athanasius Kircher's Sciateric Tables.
The exhibition layout is enriched with video exhibits and iconographical apparatus in a fascinating and gripping setting designed to integrate players of different kinds (students, citizens, tourists, students,) also through an approach based on science for the people, by the people. Devising the Rome of the new millennium means representing the image and identify of a unique history. A history in which science also plays a crucial role in addressing the dramatic challenges of the contemporary world
Convex orderings in affine root systems II
No full textAbstractThis paper contains several results concerning convex orderings in root systems. These results complete the analysis developed in earlier papers by the author. We obtain, in the finite case, a combinatorial characterization of reflections, longest elements in standard parabolic subgroups of the Weyl group of the root system, and of Coxeter elements. In the affine case, a refinement of the main construction done earlier by the author (J. Algebra172, 1995, 613–623) is described; moreover, infinite periodic compatible sets are classified
Is Pulmonary Artery Pulsatility Index (PAPi) a Predictor of Outcome after Pulmonary Endarterectomy?
No full textBackground: Pulmonary endarterectomy (PEA) is the gold standard therapy for chronic thromboembolic pulmonary hypertension (CTEPH). Traditionally, pulmonary vascular resistance (PVR) represents the main prognostic factor after surgery. The pulmonary artery pulsatility index (PAPi) has been proposed for the assessment of RV in advanced heart failure, but it has never been applied in CTEPH patients. The aim of the present study is to describe PAPi in patients who underwent PEA, before and after surgery, and to define its predictive impact on postoperative outcomes. Methods: We retrospectively reviewed 188 consecutive adult patients who underwent PEA, between December 2003 and December 2021. PAPi was calculated for 186 patients and reported. Patients were partitioned in two groups using median preoperative PAPi as cutoff value: Group 1 with PAPi ≤ 8.6 (n = 94) and Group 2 with PAPi > 8.6 (n = 92). The propensity-score-matched analysis identified 67 pairs: Early outcomes were compared between two groups. Results: Mean preoperative PAPi was 10.3 ± 7.2. Considering matched populations, no differences emerged in terms of postoperative hemodynamics; Group 1 demonstrated higher 90-day mortality significance (10.4% vs. 3.0%, p = 0.082); the need for mechanical circulatory support (MCS) was similar, but successful weaning was unlikely (25% vs. 85.7%, p = 0.032). Conclusions: Mean PAPi in the CTEPH population is higher than in other diseases. Low PAPi (≤8.6) seems to be associated with lower postoperative survival and successful weaning from MCS
Optimal Asset-Liability Management with Constraints: A Dynamic Programming Approach.
No full textThis paper is devoted to the analysis of a discrete-time dynamic programming algorithm for the numerical solution of an optimal asset-liability management model with transaction costs and in presence of constraints. By exploiting the financial properties of the model, we propose an approximation method based on the classical dynamic programming algorithm, which reduces significantly the computational and storage requirements of the algorithm and avoids any artificial boundary condition. The regularity of the value function is used to estimate the global error introduced by the numerical procedure and to prove a convergence result
Franciscans and Mathematics. The Case of Mariotto Guiducci, Friar Minor and Abacus Master (1427- Post 1496
No full textIl contributo intende tracciare un profilo del fiorentino Mariotto Guiducci, frate minore e maestro d’abaco del XV secolo, autore di un trattato matematico conservato alla Biblioteca Nazionale di Firenze. Attraverso risultanze archivistiche e bibliografiche edite e inedite, il caso di studio può offrire ulteriori spunti per una riflessione intorno al tema, recentemente ripreso, dei rapporti tra francescanesimo e scienze matematiche fra medioevo e rinascimento. L’indagine proposta si articola in due parti: la prima parte apre uno squarcio sulla famiglia Guiducci e l’insegnamento della matematica pratica a Firenze e a Prato, accennando alla vita conventuale e all’esperienza di insegnante di fra Mariotto; la seconda è dedicata al codice autografo e al Libro d’arismetricha in esso contenuto, espressione di una cultura matematica tipica della tradizione abacistica.The paper focuses on the figure of Mariotto Guiducci, a Florentine franciscan friar and abacus master from the 15th century, author of a mathematical treatise preserved in the National Library of Florence. By archival and bibliographical records, the case study may offer further insights about the topic, recently revived, on the relationship between Franciscanism and the mathematical sciences between the Middle Ages and the Renaissance. The article is divided in two parts: the first opens a glimpse into the Guiducci family and the teaching of practical mathematics in Florence and Prato, hinting at the convent life and experience of Mariotto; the second part is dedicated to the autograph codex and the Libro d’arismetricha, expression of a mathematical culture typical of the abacus tradition
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