A mechanistic approach to design smart scaffolds for tissue engineering

This thesis describes a library of novel 3D scaffolds designed and optimized for tissue engineering and regenerative medicine applications. Tissue engineering aims at restoring or regenerating a deamaged tissue by combining cells, derived from a patient biopsy, with a 3D porous matrix, functioning as a scaffold. After isolation\ud and eventual in vitro expansion, cells are seeded on the 3D scaffolds and, depending on the strategy, implanted directly or at a later stage in the patient¿s body

Population size bias in Diffusion Monte Carlo

The size of the population of random walkers required to obtain converged estimates in DMC increases dramatically with system size. We illustrate this by comparing ground state energies of small clusters of parahydrogen (up to 48 molecules) computed by Diffusion Monte Carlo (DMC) and Path Integral Ground State (PIGS) techniques. We contend that the bias associated to a finite population of walkers is the most likely cause of quantitative numerical discrepancies between PIGS and DMC energy estimates reported in the literature, for this few-body Bose system. We discuss the viability of DMC as a general-purpose ground state technique, and argue that PIGS, and even finite temperature methods, enjoy more favorable scaling, and are therefore a superior option for systems of large size.Comment: Seven pages, four figure

Contractual Community in the Self-Organising City. Freedom, Creativity, Subsidiarity

In our cities, both "land-use regulation" and "territorial collective services" have traditionally been guaranteed through the efforts of public administrations. In more recent times, greater space has been taken by different forms of private land-use regulation and collective service provision, that is, by "contractual communities". These contractual communities are territory-based organisational forms (prevalently - but not only - residential ones) by which members join on the basis of a contract unanimously accepted, and in light of the benefits it will guarantee them. The contract establishes a set of commitments (e.g., rules of cohabitation) and rights (e.g., the availability of a package of services) for the members. The literature on contractual communities (particularly on that specific form of contractual community that is represented by homeowners associations) so far consists largely of profoundly critical writings that raise numerous concerns about the phenomenon. Some other writers, on the contrary, have taken a wholly positive, acritical approach toward contractual communities. In this book a middle path is explored, one that aims to take a serious look at the phenomenon of contractual communities, and avoids taking an overly alarmist view while steering clear of equally unwarranted apologies. In the case of contractual communities there are both problems and opportunities. There is a genuine need for honest questioning and realistic responses. In this perspective the book propose a revised idea of the state role (and of the law role) that permits ample leeway for all possible forms of contractual community. The idea is that cases in which coercive action by a public agency was deemed indispensable have been unjustly overstated; whereas the potential of voluntary self-organising processes has been seriously understate

Itinerant-electron magnetism: the importance of many-body correlations

Do electrons become ferromagnetic just because of their repulisve Coulomb interaction? Our calculations on the three-dimensional electron gas imply that itinerant ferromagnetim of delocalized electrons without lattice and band structure, the most basic model considered by Stoner, is suppressed due to many-body correlations as speculated already by Wigner, and a possible ferromagnetic transition lowering the density is precluded by the formation of the Wigner crystal.Comment: published version including supplementary materia

The Cournot outcome as the result of price competition

In a homogeneous product duopoly with concave revenue and convex costs we study a two stage game in which, first, firms engage simultaneously in capacity (production) and, after production levels are made public, there is sequential price competition in the second stage. Randomizing the order of play in the price subgame, we can find: (i) that the Cournot outcome can be sustained as a pure strategy subgame perfect Nash equilibrium (SPNE) of the whole game, (ii) a SPNE in which firms produce strictly more than the Cournot outcome.subgame perfect Nash equilibrium ; price ; quantity ; pure strategies ; Cournot