A quantum computational semantics for epistemic logical operators. Part I: epistemic structures

Some critical open problems of epistemic logics can be investigated in the framework of a quantum computational approach. The basic idea is to interpret sentences like “Alice knows that Bob does not understand that π is irrational” as pieces of quantum information (generally represented by density operators of convenient Hilbert spaces). Logical epistemic operators (to understand, to know. . .) are dealt with as (generally irreversible) quantum operations, which are, in a sense, similar to measurement-procedures. This approach permits us to model some characteristic epistemic processes, that concern both human and artificial intelligence. For instance, the operation of “memorizing and retrieving information” can be formally represented, in this framework, by using a quantum teleportation phenomenon

Ab initio phenomenological simulation of the growth of large tumor cell populations

In a previous paper we have introduced a phenomenological model of cell metabolism and of the cell cycle to simulate the behavior of large tumor cell populations (Chignola R and Milotti E, Phys. Biol. 2 (2005) 8-22). Here we describe a refined and extended version of the model that includes some of the complex interactions between cells and their surrounding environment. The present version takes into consideration several additional energy-consuming biochemical pathways such as protein and DNA synthesis, the tuning of extracellular pH and of the cell membrane potential. The control of the cell cycle - that was previously modeled by means of ad hoc thresholds - has been directly addressed here by considering checkpoints from proteins that act as targets for phosphorylation on multiple sites. As simulated cells grow, they can now modify the chemical composition of the surrounding environment which in turn acts as a feedback mechanism to tune cell metabolism and hence cell proliferation: in this way we obtain growth curves that match quite well those observed in vitro with human leukemia cell lines. The model is strongly constrained and returns results that can be directly compared with actual experiments, because it uses parameter values in narrow ranges estimated from experimental data, and in perspective we hope to utilize it to develop in silico studies of the growth of very large tumor cell populations (10^6 cells or more) and to support experimental research. In particular, the program is used here to make predictions on the behaviour of cells grown in a glucose-poor medium: these predictions are confirmed by experimental observation.Comment: 67 pages, pdf only, submitted to Physical Biolog

Quantum information, cognition, and music

Parallelism represents an essential aspect of human mind/brain activities. One can recognize some common features between psychological parallelism and the characteristic parallel structures that arise in quantum theory and in quantum computation. The article is devoted to a discussion of the following questions: 1. a comparison between classical probabilistic Turing machines and quantum Turing machines. 2. possible applications of the quantum computational semantics to cognitive problems. 3. parallelism in music

Epistemic quantum computational structures in a Hilbert-space environment

Some critical open problems of epistemic logics can be investigated in the framework of a quantum computational approach. The basic idea is to interpret sentences like “Alice knows that Bob does not understand that π is irrational” as pieces of quantum information (generally represented by density operators of convenient Hilbert spaces). Logical epistemic operators (to understand, to know ...) are dealt with as (generally irreversible) quantum operations, which are, in a sense, similar to measurement-procedures. This approach permits us to model some characteristic epistemic processes, that concern both human and artificial intelligence. For instance, the operation of “memorizing and retrieving information” can be formally represented, in this framework, by using a quantum teleportation phenomenon

Lo stereotipo di genere nel servizio sociale. Esiti di una survey nazionale sugli assistenti sociali

L’assistente sociale è un professionista noto per le sue capacità di lavorare con le differenze, le ha studiate a lungo nei corsi di laurea, ha appreso non solo come accettarle e rispettarle, ma anche come valorizzarle e farne una risorsa. Ma sarà in grado di adottare la stessa sensibilità quando l’oggetto di indagine non è una persona che accede ai servizi, una famiglia, un servizio, un progetto, ma proprio se stesso? Il presente contributo si propone di indagare la percezione causata dalla differenza di genere tra gli assistenti sociali (e aspiranti tali), in termini di capacità, caratteristiche e prospettive e come tale differenza rilevi nei vari contesti di lavoro

Narrare la differenza di genere nella pratica professionale. Resoconti e storie di assistenti sociali

La sezione conclusiva della survey sugli stereotipi nel servizio sociale offriva la possibilità di raccontare episodi o situazioni nelle quali il genere dell’assistente sociale poteva aver avuto un impatto ritenuto significativo nella gestione di un “caso”, o in generale di lasciare commenti al questionario. Le domande erano libere, con campi non obbligatori, nei quali si è chiesto agli assistenti sociali di raccontarsi senza alcun vincolo. Lo scopo era quello di lasciare spazio alle memorie di ciascuno e fare emergere sprazzi di pratiche professionali, impresse nella storia lavorativa, che le domande del questionario potevano aver rievocato. Ne è nata una miscellanea di storie che rilevano, da una parte, un bisogno di raccontare e di trasmettere l’esperienza vissuta nel lavoro, dall’altra, le criticità che si incontrano nella pratica e che attivano la riflessività del professionista. Ciò sembra aver dato spazio al desiderio degli assistenti sociali di riflettere in modo critico sul proprio lavoro, senza timore di esporre le difficoltà e le fragilità del lavoro quotidiano in ambiti complessi e incerti, riuscendo a evidenziare un sapere costruito nel tempo, informale e tacito, ma significativamente operativo