Archivio Istituzionale della Ricerca- Università del Salento
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Well-posedness of Kolmogorov-Fokker-Planck equations with unbounded drift
No full textWe consider Kolmogorov-Fokker-Planck equations with unbounded drift terms which are only measurable in time and locally Hölder continuous in space. In particular, we extend the parametrix method to this setting and we prove existence and uniqueness of measure solutions to the associated Cauchy problem, as well as the equivalence with the corresponding stochastic formulation
Exploration of billiards with Keplerian potential
No full textWe study a class of elliptic billiards with a Keplerian potential inside, considering two cases: a reflective one, where the particle reflects elastically on the boundary, and a refractive one, where the particle can cross the billiard's boundary entering a region with a harmonic potential. In the latter case the dynamics is given by concatenations of inner and outer arcs, connected by a refraction law. In recent papers (e.g. Barutello et al 2023 Nonlinearity 36 4209; De Blasi and Terracini 2022 Nonlinear Anal. 218 112766; De Blasi and Terracini 2022 Discrete Contin. Dyn. Syst. 43 1269–318; Takeuchi and Zhao 2024 Adv. Math. 436 109411) these billiards have been extensively studied in order to identify which conditions give rise to either regular or chaotic dynamics. In this paper we complete the study by analysing the non focused reflective case, thus complementing the results obtained in Takeuchi and Zhao (2024 Adv. Math. 436 109411) in the focused one. We then analyse the focused and non focused refractive case, where no results on integrability are known except for the centred circular case, by providing an extensive numerical analysis. We present also a theoretical result regarding the linear stability of homothetic equilibrium orbits in the reflective case for general ellipses, highlighting the possible presence of bifurcations already in the integrable framework
Lumen-Apposing Metal Stents for Palliation of Gastrointestinal Tumors
No full text: Interventional endoscopy is gaining ground in the armamentarium of the management of cancer-related complications [...]
Learning English from Videogame Characters: Results from corpus data
No full textStudies have shown that non- anglophone students greatly benefit from watching pop- cultural products such as films and videogames in English, as these support unsupervised language learning, and that scripted dialogue in films and in videogames both resemble spontaneous speech in many ways. But are there any lexico-grammatical features that a person is more likely to encounter, and consequently learn, when playing videogames compared to when watching films? To answer this question this study contrasts scripted dialogue in videogames to film dialogue and spontaneous interactions, at the level of part-of-speech categories. Results highlight a small set of features that are significantly more frequent in videogame scripted dialogue. Such features are mostly connected to the ludic aims of videogames
Study Protocol of Predictive Dynamics of Microbiological Contamination of Groundwater in the Earth Critical Zone and Impact on Human Health (DY.MI.CR.ON Project)
No full textGroundwater is one of the major sources of water supply for human needs. But anthropic activities such as agriculture are causing significant volume depletion and quality deterioration, favoring microbial contamination that has a negative impact on human health. The geological characteristics of the ground can influence the transport of microorganisms, especially if made of permeable rock. Furthermore, irrigation with untreated or partially treated wastewater can represent an additional health risk due to the potential transmission of pathogens to food. The aim of our research is to provide an interdisciplinary perspective on this issue by integrating hygienic, geological, and agronomic skills. Water samplings are scheduled seasonally by four monitoring campaigns in five sampling points placed in two Southern Italy regions, Apulia (one point at the outlet and two wells near the wastewater plant at Carpignano Salentino, Lecce province, Italy) and Sicily (two wells at Scicli and Pozzallo, Ragusa province, Italy) Laboratory experiments of microorganism transport in permeable rocks will be carried out under saturated and unsaturated conditions. A mathematical model of transport through porous media will be implemented and validated with laboratory measurements. The model will be used to develop a monitoring tool to control sites in Apulia and Sicily where periodic cultural and molecular detection of pathogenic bacteria, viruses, and protozoa will also be taken. In addition, an analysis of the microbiological contamination of herbaceous crops due to the use of low-quality water will be conducted to assess the Quantitative Microbial Risk Assessment (QMRA). The project will provide methodological tools to evaluate anthropogenic pressures and their impact on environmental matrices. The results will allow these pressures to be modulated to minimize environmental and agri-food microbiological contamination and protect public health
Lessico e grammatiche del greco antico. un tentativo di bilancio quantitativo
No full textLe Indicazioni Nazionali del 2010 affermano che, nella competenza linguistica del greco antico, rientra la “conoscenza articolata del lessico (per famiglie semantiche e per ambiti lessicali)” e aggiungono che occorre mettere lo studente in condizioni di “comprendere il testo greco...anche senza l’ausilio del vocabolario”. Il contributo proposto vuole verificare se, come e in che misura alcune delle grammatiche oggi più in uso nei Licei classici abbiano dato risposta a questa richiesta. Nello specifico, si ricorre a una metodologia che si viene costruendo con gli studenti del corso di "Didattica del greco" per “smontare” e “rimontare” le unità didattiche delle grammatiche, che – per un verso - tiene conto (ove presenti) delle dichiarazioni programmatiche e – per l’altro – cerca di individuare le scelte da esse compiute per proporre elenchi di parole, creare esercizi, aggiungere schede lessicali o integrare schede di civiltà fornite di lessico specifico. A tal fine è stato realizzato e si mette a frutto un database di tutte le parole usate dalle dette grammatiche, modulo e unità ed esercizio per esercizio, incrociandole con il lessico frequenziale di Cauquil- Villeneuve
A Pontryagin maximum principle for agent-based models with convex state space
No full textWe derive a first order optimality condition for a class of agent-based systems, as well as for their mean-field counterpart. A relevant difficulty of our analysis is that the state equation is formulated on possibly infinite-dimensional convex subsets of Banach spaces. This is a typical feature of many problems in multi-population dynamics, where a convex set of probability measures may account for the population, the degree of influence or the strategy attached to each agent. Due to the lack of a linear structure and of local compactness, the usual tools of needle variations and linearisation procedures used to derive Pontryagin type conditions have to be generalised to the setting at hand. This is done by considering suitable notions of differentials and by a careful inspection of the underlying functional structures
Il diritto comune delle situazioni patrimoniali nell'opera "Il diritto civile nella legalità costituzionale secondo il sistema italo-europeo delle fonti"
Get PDFLo scritto prende in esame la genesi della nota teoria del “Diritto comune delle situazioni patrimoniali”, elaborata dal prof. Pietro Perlingieri sulla scia della crisi della distinzione fra diritti reali e diritti di credito. L’ordinamento giuridico accomuna le situazioni giuridiche patrimoniali entro una cornice omogenea di principi e regole, mentre tiene nettamente distinte le situazioni patrimoniali da quelle esistenziali: queste ultime sono portatrici di logiche proprie, legate alla persona umana ed impermeabili alle categorie del patrimonio
Endoscopic ultrasound guided liver biopsy and portal pressure gradient: when, why and how? Can it become the standard of care in endo-hepatology?
No full textIntroduction: The armamentarium of 'Endo-hepatology' is proliferating with the advancements in techniques and availability of new devices in the field of endoscopic ultrasound (EUS). This has resulted in the merger of multitude of diagnostic and therapeutic interventions, such as EUS-liver biopsy (LB), EUS-angioembolization of gastric varices, EUS-portal pressure gradient (PPG) measurement, and others into a 'one-stop-shop' for efficient patient management. Lack of standardization of these techniques form a major hinderance in their widespread adoption. Areas covered: A comprehensive literature search was undertaken across various databases on EUS-LB and EUS-PPG till November 2024 for reviews, observational studies, and randomized trials on EUS-LB and EUS-PPG, describing its indications, technique, and data of safety and efficacy, detailing its role in day-to-day clinical practice. Expert opinion: EUS-LB and EUS-PPG have shown promise in the ever-growing field of endo-hepatology. EUS-LB has exhibited excellent safety profile and comparable tissue yield compared to its percutaneous counterpart. On the other hand, EUS-PPG seems to be a viable alternative although it needs to be standardized further. From a patient and hospital perspective, they might prove to be convenient and cost effective. Nevertheless, more evidence is warranted before they can be labeled as the new standard of care