Volume II of Classical Recursion Theory describes the universe from a local (bottom-up or synthetical) point of view, and covers the whole spectrum, from the recursive to the arithmetical sets. The first half of the book provides a detailed picture of the computable sets from the perspective of Theoretical Computer Science. Besides giving a detailed description of the theories of abstract Complexity Theory and of Inductive Inference, it contributes a uniform picture of the most basic complexity classes, ranging from small (...) time and space bounds to the elementary functions, with a particular attention to polynomial time and space computability. It also deals with primitive recursive functions and larger classes, which are of interest to the proof theorist. The second half of the book starts with the classical theory of recursively enumerable sets and degrees, which constitutes the core of Recursion or Computability Theory. Unlike other texts, usually confined to the Turing degrees, the book covers a variety of other strong reducibilities, studying both their individual structures and their mutual relationships. The last chapters extend the theory to limit sets and arithmetical sets. The volume ends with the first textbook treatment of the enumeration degrees, which admit a number of applications from algebra to the Lambda Calculus. The book is a valuable source of information for anyone interested in Complexity and Computability Theory. The student will appreciate the detailed but informal account of a wide variety of basic topics, while the specialist will find a wealth of material sketched in exercises and asides. A massive bibliography of more than a thousand titles completes the treatment on the historical side. (shrink)

This multifaceted collection of essays, reminiscences, and professional papers combine to create an exceptional tribute to the unusual, enigmatic, and ultimately fascinating personality of Georg Kreisel. An eminently influential logician and mathematical philosopher, Kreisel is revealed as much more in this entertaining juxtaposition of viewpoints from famous contributors like Verena Huber-Dyson, Sol Feferman, and Francis Crick. Mathematics fans and armchair philosophers will delight in this look at Kreisel as he conveys his unique personal and intellectual influence.

Il campo di esperienza che Galvano della Volpe ha aperto nella filosofia italiana del Novecento non si chiude con la fine di una stagione culturale.

A lesion to the brain is not necessary for a successful neural transplantation. Embryonic Purkinje cells placed on the surface of an uninjured adult cerebellum can develop and migrate into the host molecular layer. Both the Purkinje cells that migrated into the host cerebellum and those that remained in the graft were innervated by collateral sprouting of adult intact climbing fibers.

La reconstruction est encore incomplète et lacunaire, mais l’on devine déjà l’allure complète du projet. Le trait les plus importants en sont les suivants. -/- i) Le premier niveau empirique correspond à ce que Piaget a appelé les tableaux perceptifs, et à leurs copies dans la mémoire, mais sans ordre temporel, sans structure spatiale et ne contenant pas encore des objets. ii) La première construction théorique permet d’obtenir le temps. iii) A partir de l’ordre temporel, une première structure spatiale (bidimensionnelle) (...) est possible, sans introduction de nouveaux niveaux théoriques. Ces niveaux théoriques semblent en revanche être nécessaires pour la construction d’une structure spatiale tri- dimensionnelle. Ce pas n’a pas encore été franchi. Il sera cer- tainement relié à la construction de la notion d’objet. iv) Ici la construction présente un premier grand vide. Un saut est effectué jusqu’à une théorie générale de la substance, appelée système physique. Il s’agit en réalité d’une théorie de la mesure, c’est-à-dire du procédé qui permet à la fois de connaître les propriétés des systèmes physiques, propriétés qui exigent un niveau théorique propre, et de définir un premier critère d’acceptation de l’identification des substances. Il s’agit d’une théorie holiste relative à l’introduction de termes théoriques. v) Cette description générale permet les premiers pas vers une théorie de la mécanique quantique. vi) Il est aussi possible dans le même cadre de recomprendre les notions élémentaires de la mécanique classique, sans présupposer les notions de masse et de force. vii) Dans d’autres travaux, qui ont servi de préparation à celui-ci, les notions de sujet, d’intersubjectivité et de conscience ont également été approchées d’une façon constructiviste. L’esquisse de la construction a même été prolongée jusqu’au domaine de la morale. Ces dernières notions ne font pas l’objet de cette recherche. -/- Ces éléments ont été évoqués ici pour donner une vision d’ensemble du projet, qui peut être visualisé dans le schéma suivant. (shrink)

Background:In the variegated legislative framework on advance directives, the first specific regulation in Italy on this issue came into force only in 2018.Research objective:This qualitative study...

Scanning the corpus and repertoire of anthropological science, insofar as we wish and are able to, we note that ethnological observations and studies on theatre are not lacking, but that they seem to have been isolated opportunities for investigation that have never grown into a research tradition.

Actin is a key protein in numerous cellular functions. One recent study has identified a large set of genes, associated with the actin cytoskeleton, which could be grouped into a wide spectrum of cytoplasmic and nuclear functions, such as protein biosynthesis and gene transcription.1 Deletions of many of the identified genes affected cellular actin organization,1 suggesting a functional link between different actin fractions probably regulated through changes in actin dynamics. The data are very exciting; speculations on the crosstalk between cytoplasmic (...) and nuclear actin fractions in different cellular contexts may help placing the results in perspective to further understand how actin‐mediated signalling affects cellular functions, such as gene expression. BioEssays 29:407–411, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Even before Erving Goffman, in his studies of interaction, develops and makes the most of the metaphor of a daily life entirely composed of representation, or even stage acting, sociology had already stolen from theatre a number of terms and modes particular to it: the concept of “role”, to take the most classic example, but also the term “actor”, which sociology in fact translates as social actor.

The effective reasoning capability of an agent can be defined as its capability to infer, within a given space and time bound, facts that are logical consequences of its knowledge base. In this paper we show how to determine the effective reasoning capability of an agent with limited memory by encoding the agent as a transition system and automatically verifying whether a state where the agent believes a certain conclusion is reachable from the start state. We present experimental results using (...) the Model Based Planner (MBP) which illustrates how the length of the deduction varies for different memory sizes. (shrink)