1,721,022 research outputs found
Pheromone signalling in Euplotes raikovi: expression and ligand-stimulated internalization of the membrane-bound pheromone isoforms
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Performance and Dependability Analysis of Fault-Tolerant Memory Mechanisms Using Stochastic Well-Formed Nets
No full textThis paper presents a performance and dependability study of a software fault-tolerant memory mechanism, namely the Distributed Memory (DM), which has been developed within a R&D European project. Relying on the UML specification (produced within the project), Stochastic Well-Formed Nets models of the DM are developed and analysed. Combinatorial methods are used in conjunction with state space based methods to study the impact of the mechanism configuration on its reliability and performance
Taming the complexity of biological pathways through parallel computing
No full textBiological systems are characterised by a large number of interacting entities whose dynamics is described by a number of reaction equations. Mathematical methods for modelling biological systems are mostly based on a centralised solution approach: the modelled system is described as a whole and the solution technique, normally the integration of a system of ordinary differential equations (ODEs) or the simulation of a stochastic model, is commonly computed in a centralised fashion. In recent times, research efforts moved towards the definition of parallel/distributed algorithms as a means to tackle the complexity of biological models analysis. In this article, we present a survey on the progresses of such parallelisation efforts describing the most promising results so far obtained
Addenda et corrigenda (in tutta l’Edizione)
No full textL'appendice registra i corrigenda emersi successivamente alla pubblicazione dell'Edizione Nazionale delle Opere di Giuseppe Parin
An in-silico comparative study of lipases from the antarctic psychrophilic ciliate euplotes focardii and the mesophilic congeneric species euplotes crassus: Insight into molecular cold-adaptation
Full text linkCold-adapted enzymes produced by psychrophilic organisms have elevated catalytic activities at low temperatures compared to their mesophilic counterparts. This is largely due to amino acids changes in the protein sequence that often confer increased molecular flexibility in the cold. Comparison of structural changes between psychrophilic and mesophilic enzymes often reveal molecular cold adaptation. In the present study, we performed an in-silico comparative analysis of 104 hydrolytic enzymes belonging to the family of lipases from two evolutionary close marine ciliate species: The Antarctic psychrophilic Euplotes focardii and the mesophilic Euplotes crassus. By applying bioinformatics approaches, we compared amino acid composition and predicted secondary and tertiary structures of these lipases to extract relevant information relative to cold adaptation. Our results not only confirm the importance of several previous recognized amino acid substitutions for cold adaptation, as the preference for small amino acid, but also identify some new factors correlated with the secondary structure possibly responsible for enhanced enzyme activity at low temperatures. This study emphasizes the subtle sequence and structural modifications that may help to transform mesophilic into psychrophilic enzymes for industrial applications by protein engineering
Parametric Stochastic Well-Formed Nets and Compositional Modelling
No full textColored nets have been recognized as a powerful modelling paradigm for the validation and evaluation of systems, both in terms of compact representation and aggregate state space generation. In this paper we discuss the issue of adding compositionality to a class of stochastic colored nets named Stochastic Well-formed Nets, in order to increase modularity and reuse of the modelling efforts. This requires the notion of Parametric Stochastic Well-formed net: nets in which a certain amount of information is left unspecified, and is instantiated only upon model composition. The choice of the compositional rule has been based on previous work on layered models for integrated hardware and software systems (the processes, services and resources methodology), and an example of layered modelling with Parametric Stochastic Well-formed net is presented to show the efficacy of the proposed formalism
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
Beccaria, Cesare, e altri illuministi lombardi
No full textAnalisi della posizione degli illuministi italiani (Beccaria e la cerchia milanese del "Caffè" in particolare) rispetto alle problematiche religiose e al rapporto tra religione e autorità politica
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