Metaphor. The good argument in science communication

The relation between metaphor and argumentation in science communication is becoming a crucial tool for critical metaphor studies. In this article, by means of a crossed analysis (epistemological, cognitive and linguistic), I focus especially on a peculiar dynamic of metaphor use in scientific communication showing opposite, paradoxical attitudes towards the use of metaphors, respectively, ubiquity vs. invisibility, inclination vs. resistance, deliberate vs. non-deliberate. In this way, an overall philosophical reflection about the underlying reasons for the ambivalence in the use of metaphor in scientific communication would be proposed and discussed

Recursive Estimation of Camera Motion from Uncalibrated Image Sequences

In This memo we present an extension of the motion estimation scheme presented in a previous CDS technical report [14, 16], in order to deal with image sequences coming from an uncalibrated camera. The scheme is based on some results in epipolar geometry and invariant theory which can be found in [6]. Experiments are performed on noisy synthetic images

Dynamic Estimation of Rigid Motion from Perspective Views via Recursive Identification of Exterior Differential Systems with Parameters on a Topological Manifold

We formulate the problem of estimating the motion of a rigid object viewed under perspective projection as the identification of a dynamic model in Exterior Differential form with parameters on a topological manifold. We first describe a general method for recursive identification of nonlinear implicit systems using prediction error criteria. The parameters are allowed to move slowly on some topological (not necessarily smooth) manifold. The basic recursion is solved in two different ways: one is based on a simple extension of the traditional Kalman Filter to nonlinear and implicit measurement constraints, the other may be regarded as a generalized "Gauss-Newton" iteration, akin to traditional Recursive Prediction Error Method techniques in linear identification. A derivation of the "Implicit Extended Kalman Filter" (IEKF) is reported in the appendix. The ID framework is then applied to solving the visual motion problem: it indeed is possible to characterize it in terms of identification of an Exterior Differential System with parameters living on a C0 topological manifold, called the "essential manifold". We consider two alternative estimation paradigms. The first is in the local coordinates of the essential manifold: we estimate the state of a nonlinear implicit model on a linear space. The second is obtained by a linear update on the (linear) embedding space followed by a projection onto the essential manifold. These schemes proved successful in performing the motion estimation task, as we show in experiments on real and noisy synthetic image sequences

Optimal piezo-electro-mechanical coupling to control plate vibrations

A new way of coupling electrical and mechanical waves, using piezoelectric effect, is presented here. Since the energy exchange between two systems supporting wave propagation is maximum when their evolution is governed by similar equations, hence, an optimal electromechanical coupling is obtained by designing an electric network which is "analog" to the mechanical structure to be controlled. In this paper, we exploit this idea to enhance the coupling, between a Kirchhoff-Love plate and one possible synthesis of its circuital analog, as obtained by means of a set of piezoelectric actuators uniformly distributed upon the plate. It is shown how this approach allows for an optimal energy exchange between the mechanic and the electric forms independent of the modal evolution of the structure. Moreover, we show how an efficient electric dissipation of the mechanical energy can be obtained adding dissipative elements in the electric network.Comment: 9 page

Il cinema «idea» di Eduardo

Eduardo nel cinema è stato attore, sceneggiatore, regista. Il saggio di Frezza ricostruisce la sua poliedrica attività cinematografica dagli anni trenta agli anni sessanta, anche in relazione/ opposizione con l'opera e la statura filmica del fratello Peppino; la particolare maniera di Eduardo di essere attore nel cinema diviene, in una riflessione dedicata proprio al modo d'essere attori sullo schermo da parte di Orson Welles, occasione privilegiata, estremamente illuminante, per chiarire le caratteristiche problematiche di un ruolo chiave della comunicazione filmica.In the cinema Eduardo was an actor, scriptwriter and director. The Frezza paper reconstructs his multifaceted cinematographic activities from the 30s to the 60s also in relation/opposition to the work and film stature of his brother Peppino. It also explores the particular way in which Eduardo is an actor in cinema becomes, in reflecting on what is an actor on the Orson Wells scale, a privileged occasion, extremely enlightening in terms of the problematic characteristics of a key role of film communication

Crossovers between epigenesis and epigenetics. A multicenter approach to the history of epigenetics (1901-1975)

The origin of epigenetics has been traditionally traced back to Conrad Hal Waddington's foundational work in 1940s. The aim of the present paper is to reveal a hidden history of epigenetics, by means of a multicenter approach. Our analysis shows that genetics and embryology in early XX century--far from being non-communicating vessels--shared similar questions, as epitomized by Thomas Hunt Morgan's works. Such questions were rooted in the theory of epigenesis and set the scene for the development of epigenetics. Since the 1950s, the contribution of key scientists (Mary Lyon and Eduardo Scarano), as well as the discussions at the international conference of Gif-sur-Yvette (1957) paved the way for three fundamental shifts of focus: 1. From the whole embryo to the gene; 2. From the gene to the complex extranuclear processes of development; 3. From cytoplasmic inheritance to the epigenetics mechanisms