The signature of geometrically decomposable aspherical 4-manifolds

We construct examples of geometrically decomposable aspherical 4-manifolds with non-zero signature. We show that all such 4-manifolds satisfy the inequality (of Bogomolov--Miyaoka--Yau type) $\chi\geq 3|\sigma|$. We also construct examples attaining the equality that are non-geometric and have non-zero signature. Finally, we prove that for higher graph 4-manifolds, with complex-hyperbolic vertices, the strict inequality always holds. Moreover, we construct infinitely many examples of higher graph 4-manifolds with non-zero signature and prove that the inequality is strict and sharp in this class.Comment: 17 pages, 1 figure. Comments are welcome

The patient who fell off a skyscraper

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Giuseppe Samonà storico dell’architettura: i rapporti con Gustavo Giovannoni

The essay is intended to highlight the links between Samonà and the "Roman School", in part already analyzed in previous studies. In particular, we contextualize the six letters addressed to Gustavo Giovannoni between late 1929 and mid-1930, preserved in the Giovannoni Archive (Rome, Centro di Studi per la Storia dell’Architettura) and listed in full in the appendix. The letters are mainly related to the studies of Samonà on late Renaissance architecture in Sicily, conducted in 1927 at the suggestion of Ernesto Calandra, which would then be gathered into four essays published between 1932 and 1935, profoundly influenced by the historical-critical ‘giovannoniano’ method. The epistolary contacts with Giovannoni, as well as promoting cultural growth and the rise of the career of teaching, not well structured at the time, show his attempt to get closer to Rome. This is evidenced by repeated references in the letters to Alberto Calza Bini, who was to assist him in obtaining a position at the University of Naples and who, together with Giovannoni and Piacentini, ruled in favor of Samonà in design competitions in the thirties, especially for the Post Office building in the Appio neighborhood in Rome.Il contributo intende puntualizzare i contatti tra Samonà e la “Scuola romana”, in parte già analizzati da precedenti studi. In particolare si contestualizzano le sei lettere indirizzate a Gustavo Giovannoni tra la fine del 1929 e la metà del 1930, conservate nel fondo Giovannoni (Roma, Centro di Studi per la Storia dell’Architettura) e riportate integralmente in appendice. Le lettere sono inerenti principalmente agli studi del Samonà sull’architettura tardo rinascimentale in Sicilia che, intrapresi nel 1927 su suggerimento di Ernesto Calandra, confluiranno in quattro corposi saggi editi tra il 1932 e il 1935, profondamente influenzati dal metodo storico-critico giovannoniano.I contatti epistolari con Giovannoni, oltre a favorire la crescita culturale e l’ascesa della carriera didattica del siciliano, in quegli anni ancora non ben strutturata, testimoniano al contempo il suo tentativo di avvicinarsi all’ambiente romano. Ciò è provato dai ripetuti riferimenti, nelle lettere, alla figura di Alberto Calza Bini, che favorirà la chiamata all’Università di Napoli e che, con Giovannoni e Piacentini, riserverà giudizi favorevoli a Samonà nei concorsi progettuali degli anni Trenta, su tutti quello per il palazzo delle Poste al quartiere Appio a Roma

Schematic Representation of Large Biconnected Graphs

Suppose that a biconnected graph is given, consisting of a large component plus several other smaller components, each separated from the main component by a separation pair. We investigate the existence and the computation time of schematic representations of the structure of such a graph where the main component is drawn as a disk, the vertices that take part in separation pairs are points on the boundary of the disk, and the small components are placed outside the disk and are represented as non-intersecting lunes connecting their separation~pairs. We consider several drawing conventions for such schematic representations, according to different ways to account for the size of the small components. We map the problem of testing for the existence of such representations to the one of testing for the existence of suitably constrained $1$-page book-embeddings and propose several polynomial-time and pseudo-polynomial-time algorithms.Comment: Appears in the Proceedings of the 28th International Symposium on Graph Drawing and Network Visualization (GD 2020

Slow-roll Inflation for Generalized Two-Field Lagrangians

We study the slow-roll regime of two field inflation, in which the two fields are also coupled through their kinetic terms. Such Lagrangians are motivated by particle physics and by scalar-tensor theories studied in the Einstein frame. We compute the power spectra of adiabatic and isocurvature perturbations on large scales to first order in the slow-roll parameters. We discuss the relevance of the extra coupling terms for the amplitude and indexes of the power spectra. Beyond the consistency condition which involves the amplitude of gravitational waves, additional relations may be found in particular models based on such Lagrangians: as an example, we find an additional general consistency condition in implicit form for Brans-Dicke theory in the Einstein frame.Comment: 17 pages, 1 figure, accepted for publication in Phys. Rev.

Dorsal Prefrontal Cortex Impairment in Methoxetamine-Induced Psychosis: an 18F-FDG PET/CT Case Study

Submitted15 June 2018. Accepted 13 December 2018. Epub ahead of print 13 February 2019Novel psychoactive substances (NPSs) have currently become a major public health concern because of relatively easy accessibility to these compounds and difficulty in identifying them with routine laboratory techniques. Here, we report the 18 F-fluorodeoxyglucose positron emission tomography/computerized tomography ( 18 F-FDG PET/CT) case study of a 23-year-old man who developed a substance-induced psychotic disorder after having intravenously injected himself with an unspecified amount of methoxetamine (MXE), a ketamine derivative hallucinogen. From a clinical perspective, a blunted affective responsiveness with diminished social drive and sense of purpose, along with a profound detachment from the environment, was observed. Psychometric and neuropsychological assessments highlighted severe dissociative symptoms and lack of motivation, along with a mild impairment of verbal fluency, working memory, and attention. Patient’s 18 F-FDG PET/CT scans displayed a significant bilateral deficit of tracer uptake within the dorsolateral prefrontal cortex (DLPFC). DLPFC activity is critical to goal-oriented cognitive functions, including working memory and sustained attention. DLPFC is also involved in both the temporal integration across multiple sensory modes and in the volitional control of actions, leading to the possibility to construct logically coherent temporal configurations of thought, speech, and behavior. This report highlights that a single acute MXE intoxication may produce severe brain impairment.Peer reviewedFinal Accepted Versio

MicroRNAs from saliva of anopheline mosquitoes mimic human endogenous miRNAs and may contribute to vector-host-pathogen interactions

During blood feeding haematophagous arthropods inject into their hosts a cocktail of salivary proteins whose main role is to counteract host haemostasis, inflammation and immunity. However, animal body fluids are known to also carry miRNAs. To get insights into saliva and salivary gland miRNA repertoires of the African malaria vector Anopheles coluzzii we used small RNA-Seq and identified 214 miRNAs, including tissue-enriched, sex-biased and putative novel anopheline miRNAs. Noteworthy, miRNAs were asymmetrically distributed between saliva and salivary glands, suggesting that selected miRNAs may be preferentially directed toward mosquito saliva. The evolutionary conservation of a subset of saliva miRNAs in Anopheles and Aedes mosquitoes, and in the tick Ixodes ricinus, supports the idea of a non-random occurrence pointing to their possible physiological role in blood feeding by arthropods. Strikingly, eleven of the most abundant An. coluzzi saliva miRNAs mimicked human miRNAs. Prediction analysis and search for experimentally validated targets indicated that miRNAs from An. coluzzii saliva may act on host mRNAs involved in immune and inflammatory responses. Overall, this study raises the intriguing hypothesis that miRNAs injected into vertebrates with vector saliva may contribute to host manipulation with possible implication for vector-host interaction and pathogen transmission

Resolving inconsistencies and redundancies in declarative process models

Declarative process models define the behaviour of business processes as a set of constraints. Declarative process discovery aims at inferring such constraints from event logs. Existing discovery techniques verify the satisfaction of candidate constraints over the log, but completely neglect their interactions. As a result, the inferred constraints can be mutually contradicting and their interplay may lead to an inconsistent process model that does not accept any trace. In such a case, the output turns out to be unusable for enactment, simulation or verification purposes. In addition, the discovered model contains, in general, redundancies that are due to complex interactions of several constraints and that cannot be cured using existing pruning approaches. We address these problems by proposing a technique that automatically resolves conflicts within the discovered models and is more powerful than existing pruning techniques to eliminate redundancies. First, we formally define the problems of constraint redundancy and conflict resolution. Second, we introduce techniques based on the notion of automata-product monoid, which guarantees the consistency of the discovered models and, at the same time, keeps the most interesting constraints in the pruned set. The level of interestingness is dictated by user-specified prioritisation criteria. We evaluate the devised techniques on a set of real-world event logs

Semantical Vacuity Detection in Declarative Process Mining

A large share of the literature on process mining based on declarative process modeling languages, like declare, relies on the notion of constraint activation to distinguish between the case in which a process execution recorded in event data “vacuously” satisfies a constraint, or satisfies the constraint in an “interesting way”. This finegrained indicator is then used to decide whether a candidate constraint supported by the analyzed event log is indeed relevant or not. Unfortunately, this notion of relevance has never been formally defined, and all the proposals existing in the literature use ad-hoc definitions that are only applicable to a pre-defined set of constraint patterns. This makes existing declarative process mining technique inapplicable when the target constraint language is extensible and may contain formulae that go beyond pre-defined patterns. In this paper, we tackle this hot, open challenge and show how the notion of constraint activation and vacuous satisfaction can be captured semantically, in the case of constraints expressed in arbitrary temporal logics over finite traces. We then extend the standard automata-based approach so as to incorporate relevance-related information. We finally report on an implementation and experimentation of the approach that confirms the advantages and feasibility of our solution