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Selected papers of The ninth Italian Conference on Theoretical Computer Science (ICTCS 2005)
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Modelling an Ammonium Transporter with SCLS
Full text linkThe Stochastic Calculus of Looping Sequences (SCLS) is a recently proposed modelling language for the representation and simulation of biological systems behaviour. It has been designed with the aim of combining the simplicity of notation of rewrite systems with the advantage of compositionality. It also allows a rather simple and accurate description of biological membranes and their interactions with the environment.In this work we apply SCLS to model a newly discovered ammonium transporter. This transporter is believed to play a fundamental role for plant mineral acquisition, which takes place in the arbuscular mycorrhiza, the most wide-spread plant-fungus symbiosis on earth. Due to its potential application in agriculture this kind of symbiosis is one of the main focuses of the BioBITs project. In our experiments the passage of NH3 / NH4+ from the fungus to the plant has been dissected in known and hypothetical mechanisms; with the model so far we have been able to simulate the behaviour of the system under different conditions. Our simulations confirmed some of the latest experimental results about the LjAMT2;2 transporter. The initial simulation results of the modelling of the symbiosis process are promising and indicate new directions for biological investigations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mobility Types in Coq
No full textThe need for formal methods for certifying the good behaviour of computer software is dramatically increasing with the growing complexity of the latter. Moreover, in the global computing framework one must face the additional issues of concurrency and mobility. In the recent years many new process algebras have been introduced in order to reason formally about these problems; the common pattern is to specify a type system which allows one to discriminate between *good" and "bad" processes. In this paper we focus on an incremental type system for a variation of the Ambient Calculus called M 3, i.e., Mobility types for Mobile processes in Mobile ambients and we formally prove its soundness in the proof assistant Coq
“Wave-Style” Geometry of Interaction Models in Rel Are Graph-Like Lambda-Models
No full textWe study the connections between graph models and “wave-style” Geometry of Interaction (GoI) λ-models. The latters arise when Abramsky’s GoI axiomatization, which generalizes Girard’s original GoI, is applied to a traced monoidal category with the categorical product as tensor, using a countable power as the traced strong monoidal functor !. Abramsky hinted that the category Rel of sets and relations is the basic setting for traditional denotational “static semantics”. However, the category Rel together with the cartesian product apparently escapes original Abramsky’s axiomatization. Here we show that, by moving to the category Rel* of pointed sets and relations preserving the distinguished point, and by sligthly relaxing Abramsky’s GoI axiomatization, we can recover a large class of graph-like models as wave models. Furthermore, we show that the class of untyped λ-theories induced by wave-style GoI models is richer than that induced by game models
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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