This paper aims at indicating research perspectives on the mathematical modeling of crowd dynamics, pointing on the one hand to insights into the complexity features of pedestrian flows and on the other hand to a critical overview of the most popular modeling approaches currently adopted in the specialized literature. Particularly, the focus is on scaling problems, namely representation and modeling at microscopic, macroscopic, and mesoscopic scales, which, entangled with the complexity issues of living systems, generate multiscale dynamical effects, such as e.g. self-organization. Mathematical structures suitable to approach such multiscale aspects are proposed, along with a forward look at research developments. © 2012 World Scientific Publishing Company.

alpha-Helices are peculiar atomic arrangements characterizing protein structures. Their occurrence can be used within crystallographic methods as minimal a priori information to drive the phasing process towards solution. Recently, brute-force methods have been developed which search for all possible positions of alpha-helices in the crystal cell by molecular replacement and explore all of them systematically. Knowing the alpha-helix orientations in advance would be a great advantage for this kind of approach. For this purpose, a fully automatic procedure to find alpha-helix orientations within the Patterson map has been developed. The method is based on Fourier techniques specifically addressed to the identification of helical shapes and operating on Patterson maps described in spherical coordinates. It supplies a list of candidate orientations, which are then refined by using a figure of merit based on a rotation function calculated for a template polyalanine helix oriented along the current direction. The orientation search algorithm has been optimized to work at 3 A resolution, while the candidates are refined against all measured reflections. The procedure has been applied to a large number of protein test structures, showing an overall efficiency of 77% in finding alpha-helix orientations, which decreases to 48% on limiting the number of candidate solutions (to 13 on average). The information obtained may be used in many aspects in the framework of molecular-replacement phasing, as well as to constrain the generation of models in computational modelling programs. The procedure will be accessible through the next release of IL MILIONE and could be decisive in the solution of new unknown structures.

Per circa un millennio, l'ambra ha goduto di una particolare fortuna in Puglia e nella vicina Basilicata, tanto da costituire uno dei principali fossili-guida utilizzati per ricostruire la storia archeologica della regione. Particolarmente interessante è la diffusione delle ambre figurate nel Basso Adriatico, presenti esclusivamente nelle ricche sepolture indigene della Puglia centro-settentrionale (Peucezia e Daunia) durante la fase preromana, con la pressochè totale esclusione del distretto meridionale (Messapia) e con qualche sporadica testimonianza a Taranto. Il volume rappresenta un primo importante tentativo verso una classificazione tipologica delle ambre figurate rinvenute nella Puglia preromana, in un arco cronologico che va dal VII al IV secolo a.C.

We present a one space dimensional model with finite speed of propagation for population dynamics, based both on the hyperbolic Cattaneo dynamics and the evolutionary game theory. We prove analytical properties of the model and global estimates for solutions, by using a hyperbolic nonlinear Trotter product formula.