Asymptotics of LQG fusion coefficients

The fusion coefficients from SO(3) to SO(4) play a key role in the definition of spin foam models for the dynamics in Loop Quantum Gravity. In this paper we give a simple analytic formula of the EPRL fusion coefficients. We study the large spin asymptotics and show that they map SO(3) semiclassical intertwiners into $SU(2)_L\times SU(2)_R$ semiclassical intertwiners. This non-trivial property opens the possibility for an analysis of the semiclassical behavior of the model.Comment: 14 pages, minor change

Pectin-based bioinks for 3D models of neural tissue produced by a pH-controlled kinetics

Introduction: In the view of 3D-bioprinting with cell models representative of neural cells, we produced inks to mimic the basic viscoelastic properties of brain tissue. Moving from the concept that rheology provides useful information to predict ink printability, this study improves and expands the potential of the previously published 3D-reactive printing approach by introducing pH as a key parameter to be controlled, together with printing time. Methods: The viscoelastic properties, printability, and microstructure of pectin gels crosslinked with CaCO3 were investigated and their composition was optimized (i.e., by including cell culture medium, HEPES buffer, and collagen). Different cell models representative of the major brain cell populations (i.e., neurons, astrocytes, microglial cells, and oligodendrocytes) were considered. Results and Discussion: The outcomes of this study propose a highly controllable method to optimize the printability of internally crosslinked polysaccharides, without the need for additives or post-printing treatments. By introducing pH as a further parameter to be controlled, it is possible to have multiple (pH-dependent) crosslinking kinetics, without varying hydrogel composition. In addition, the results indicate that not only cells survive and proliferate following 3D-bioprinting, but they can also interact and reorganize hydrogel microstructure. Taken together, the results suggest that pectin-based hydrogels could be successfully applied for neural cell culture

Prosodiatopia: parametri prosodici per un modello di riconoscimento diatopico

Il contributo intende individuare i parametri prosodici pertinenti per la caratterizzazione diatopica del parlante italiano su base prosodica. Nella convinzione che la prosodia possa essere un potente indice sociofonetico nel territorio italiano, si evidenzino i tratti intonativi di alcune varietà regionali italiane (Roma, Milano e Catanzaro). Gli indici più significativi risultano essere la durata e lo 'scaling' melodico. I risultati, assolutamente originali nel panorama degli studi sull'intonazione in Italia, sembrano confermare che la prosodia è un importante fonte di informazione per lo sviluppo di modelli automatici per la ricognizione geografica dei parlanti italiani

Prosodic Parameters for the Detection of Regional Varieties in Italian

The paper investigates the prosodic parameters which can be considered as relevant for the detection of regional varieties in spoken Italian. On the basis of acoustic analysis of three Italian varieties (Rome, Milan and Catanzaro), a crucial role is recognized in scaling and duration. Besides these features, tonal patterns and local pitch range also came out as being significant in variety discrimination through statistical distances. The same parameters are found relevant in sentence-type discrimination within the same variety. Results allow us to consider prosody as an important source of information for developing an automatic model in the geographical recognition of the speaker